Guidelines for minimal information on cellular senescence experimentation in vivo

In the paper

“Indeed, p16Ink4a is often used as a prognostic marker in some cancers, such as breast, colon, or head and neck cancer; however, in cancers, p16 rarely induces cell cycle arrest151.”

What the sources say

• Disputed

  The Results state that p16INK4a acts to promote cell-cycle arrest, and the Discussion reports that disrupting INK4a disabled drug-induced arrest in the lymphoma model. That conflicts with the claim that p16 rarely induces arrest in cancers. The paper links INK4a status to treatment outcome, but the passages do not establish its use as a prognostic marker in breast, colon, or head and neck cancer; no page numbers are available in our copy. (LLM, conf=0.84)

  Checked by a reasoning model — may be wrong.

  cites [151] sourceExperimental — accuracy not yet measured

In the paper

“Additional CDKIs, such as p15Ink4b, p19Ink4d, and p27Kip1, could be potentially involved in the induction of cellular senescence5, but there is currently little evidence to support the use of their expression as markers of senescence in situ or in vivo.”

What the sources say

• Partly supported

  The citation follows the sentence’s claim that p15Ink4b, p19Ink4d, and p27Kip1 may help induce senescence; the subsequent statement about their suitability as markers is not attached to it. In Results (“Perforin deficiency accelerates senescence with age”; page unavailable), the paper reports p15 expression among markers examined in senescent tissues, but does not establish a role in induction or address p19Ink4d or p27Kip1. (LLM, conf=0.78)

  cites [5] sourceExperimental — accuracy not yet measured

In the paper

“γ-H2A.X is formed by post-translational modifications triggered by DSBs, while 53BP1 is recruited to DSBs in response to damage undergoing RNA-mediated condensation21.”

What the sources say

• ?Could not verify

  The Results section on p16-expressing FAPs describes γH2A.X-positive nuclei as a mark of DNA damage, and the Methods section describes staining for γH2A.X. Neither passage explains how γH2A.X forms. Searches for double-strand-break-triggered modification and RNA-mediated recruitment of 53BP1 found no passage addressing either mechanism. (LLM, conf=0.76)

  cites [21] sourceExperimental — accuracy not yet measured

In the paper

“One consideration for measuring p16Ink4a mRNA is that the CDKN2A locus encodes another mRNA coding for p19Arf (mouse)/p14ARF (human), which shares the second exon of CDKN2A, generating a region of sequence similarity between these two transcripts5.”

What the sources say

• ?Could not verify

  The Results section, ‘Perforin deficiency accelerates senescence with age’ (page unavailable), identifies p16 with Cdkn2a and measures p16 expression. It does not address an ARF transcript, a shared second exon, or sequence similarity. Searches for p19Arf/p14ARF and CDKN2A alternative transcripts found no passage establishing the claim. (LLM, conf=0.73)

  cites [5] sourceExperimental — accuracy not yet measured

In the paper

“The release of HMGB1 from the nucleus is an early sign of senescence induction13 and can be detected in situ (Fig. 1 D).”

What the sources say

• ?Could not verify

  The Results section discusses telomeric DNA-damage foci during senescence, while the Methods > Immunofluorescence section lists antibodies for Ki67, γH2A.X and 53BP1. Searches for HMGB1 and nuclear release found no passage addressing whether HMGB1 release is an early sign of senescence. The in situ detection statement points to the citing paper’s own Fig. 1 D, not explicitly to this source. (LLM, conf=0.76)

  cites [13] sourceExperimental — accuracy not yet measured

In the paper

“Specifically, the levels of PCNA and KI67 provide an estimation of which cell cycle phase a cell is in, with PCNA being at the highest level in the S phase and KI67 in the M phase9,10 (Fig. 1 B).”

What the sources say

• ?Could not verify

  The Results section on senescent stellate cells calls Ki-67 a proliferation-associated marker, and Experimental procedures lists a Ki67 antibody. Neither passage addresses whether its level identifies a cell-cycle phase. Searches for PCNA and for the claimed S- and M-phase peaks found no supporting passage in our copy; page numbers were not provided. (LLM, conf=0.72)

  cites [9] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Methods section ('Antibodies for IHC/IF'; page unavailable) lists antibodies for PCNA and Ki-67, and the Results use PCNA-negative cells as a senescence marker. Searches for cell-cycle phases and peak expression found no passage saying that their levels estimate a cell’s phase, that PCNA peaks in S phase, or that Ki-67 peaks in M phase. (LLM, conf=0.76)

  cites [10] sourceExperimental — accuracy not yet measured

In the paper

“Thus, certain generic probes and primers designed to detect transcripts from the CDKN2A locus can simultaneously measure Arf and Ink4a mRNAs, making the validation of detection strategies essential.”

What the sources say

• ?Could not verify

  The Methods (Quantitative PCR; page unavailable) describe measuring mRNA and refer primer sequences to supplementary methods. The Results (Perforin deficiency accelerates senescence with age; page unavailable) report p16 expression, but neither passage addresses whether CDKN2A probes or primers detect both Arf and Ink4a, or whether detection strategies require validation. Searches for those terms and for primer specificity found no decisive passage in our copy. (LLM, conf=0.76)

  cites [5] sourceExperimental — accuracy not yet measured

In the paper

“In addition, HMGB1 loss/release is triggered under various stress conditions, including necrosis and apoptosis14, making its use as a sole marker of senescence unfeasible.”

What the sources say

• ?Could not verify

  The Results section on dietary restriction discusses TAF, SADS and karyomegaly as senescence markers, but does not discuss HMGB1. Searches for HMGB1 loss or release, necrosis, apoptosis, and its suitability as a sole marker found no passage in our copy addressing the claim. (LLM, conf=0.74)

  cites [14] sourceExperimental — accuracy not yet measured

In the paper

“Telomeric DNA damage is more senescence-specific and can be quantified by combining fluorescence in situ hybridization (FISH) for telomeric sequences and immunostaining (immunoFISH) for DSB-associated proteins22.”

What the sources say

• ?Could not verify

  The Methods section on immunofluorescence and quantification describes staining and counting DNA-damage markers, but not telomeric FISH or immunoFISH. Searches for telomeric DNA damage and telomere-associated damage foci found no passage in our copy establishing that the measure is more senescence-specific or describing the claimed combined assay. Page numbers were not available. (LLM, conf=0.76)

  cites [22] sourceExperimental — accuracy not yet measured

In the paper

“Lipofuscin, comprising heavily oxidized proteins/lipoproteins and metals, is resistant to hydrolysis by lysosomal enzymes and forms intra-lysosomal aggregates, eventually generating dysfunctional lysosomes and impaired autophagic flux33.”

What the sources say

• Partly supported

  In “Importance of protein and lipid damage in senescent cells” (page unavailable), the paper describes lipofuscin as a nondegradable product of protein and lipid oxidation that resides primarily in lysosomes. The same section reports impaired autophagic flux in senescent cells, but does not establish that lipofuscin causes it through intra-lysosomal aggregation and lysosomal dysfunction; it also does not identify metals as a component. (LLM, conf=0.88)

  cites [33] sourceExperimental — accuracy not yet measured

In the paper

“Moreover, while decondensation occurs in essentially all centromeric satellites in vitro24, only a fraction of centromeric satellites undergo unwinding in vivo25,26 (Fig. 1 F).”

What the sources say

• ?Not checked — no full text of the sourcecites [24] source
• ?Could not verify

  The Introduction and Results discuss senescent cells in the murine skeleton, not centromeric satellites. Searches for centromeric-satellite unwinding and decondensation found no passage addressing the claimed in vitro–in vivo difference. (LLM, conf=0.76)

  cites [25] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The STAR METHODS passages describe telomere staining and other assays in adipose tissue, not centromeric satellites. Searches for centromeric-satellite unwinding in vivo and decondensation in vitro found no passage addressing the claim; page numbers were not supplied. (LLM, conf=0.78)

  cites [26] sourceExperimental — accuracy not yet measured

In the paper

“The origin of SASP factors can be traced using histological methods; however, secreted factors are normally small proteins poorly retained within cells, which makes their detection using IHC/IHF highly challenging, although there has been some success, for example, with IHC against IL-1α29 and IL-1β30.”

What the sources say

• ?Could not verify

  Section 3 discusses p21 regulation during the cell cycle, and Section 2 discusses p21 binding to PCNA; neither addresses detection of secreted SASP factors. Searches for SASP, IHC/IHF, and IL-1α found no passage reporting successful IL-1α immunohistochemistry, the specific point to which this citation is attached. (LLM, conf=0.78)

  cites [29] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Introduction describes the SASP as secretion of cytokines, growth factors, and proteases. The Immunofluorescence methods describe staining for lamins, not IL-1α or IL-1β. Searches for IL-1 staining and poor cellular retention found no passage addressing the claimed difficulty of IHC/IHF detection or the reported successes with either interleukin. (LLM, conf=0.76)

  cites [30] sourceExperimental — accuracy not yet measured

In the paper

“SASP inducers are diverse; however, in most cases, they rely on the involvement of NF-κB, CEBPβ, and/or STAT signaling28.”

What the sources say

• ?Could not verify

  The Introduction and section 3 discuss Ki-67 in cell-cycle regulation and mention senescent cells, but neither addresses SASP induction. Searches for SASP and for NF-κB, CEBPβ, and STAT signaling found no passage in our copy supporting the attributed claim. (LLM, conf=0.76)

  cites [28] sourceExperimental — accuracy not yet measured

In the paper

“Increased production and secretion of cytokines, growth factors, matrix-remodeling enzymes, lipids, extracellular vesicles, and miRNAs, generally defined as the senescence-associated secretory phenotype (SASP)17,27, is a core feature of cellular senescence and a major mediator of the pathophysiological functions of senescent cells.”

What the sources say

• Partly supported

  The Introduction (page unavailable) describes a pro-inflammatory secretion pattern as a major change in senescent cells, supporting the claim that a secretory phenotype is a core feature. The Discussion (page unavailable) says inflammatory stimuli from senescent cells might contribute to bystander effects and age-related loss of organ function, but it does not establish SASP as a major mediator of senescent cells’ pathophysiological functions generally. (LLM, conf=0.84)

  cites [17] sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [27] source

In the paper

“With aging, there was a marked increase in CDKN2A mRNA levels in the osteocyte-enriched bone samples (Fig. 2 D), with a modest increase in CDKN1A mRNA levels73.”

What the sources say

• ?Could not verify

  The Results passage on Fig. 2D compares gene-expression profiles of young and aged skin stem cells, not osteocyte-enriched bone samples. Searches for CDKN2A, CDKN1A, and osteocytes found no passage reporting the claimed mRNA changes. (LLM, conf=0.76)

  cites [73] sourceExperimental — accuracy not yet measured

In the paper

“There is considerable evidence that senescent cells accumulate with aging and skeletal injury in the bone microenvironment25,73–76.”

What the sources say

• Partly supported

  The Introduction states that senescent cells accumulate in the bone microenvironment with age, and the Results report increased percentages of senescent skeletal cells in aged mice. The Discussion links injury to a possible role for p21-positive senescent cells and reports p21 upregulation after bone fracture, but does not establish that senescent cells accumulate in the bone microenvironment following skeletal injury. (LLM, conf=0.84)

  cites [25] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Abstract and Discussion describe aging hair-follicle stem cells, the skin microenvironment, and impaired hair regeneration after skin injury. Searches for senescent cells, bone, and skeletal injury found no passage in our copy addressing accumulation of senescent cells in the bone microenvironment. (LLM, conf=0.78)

  cites [73] sourceExperimental — accuracy not yet measured
• Partly supported

  The paper states that cells bearing senescence markers accumulate in tissues with age (opening background passage, indexed under Abstract; page unavailable). Its study concerns lung aging and COPD, not the bone microenvironment or skeletal injury, so those parts of the cited claim are not supported. (LLM, conf=0.88)

  cites [74] sourceExperimental — accuracy not yet measured
• Partly supported

  The Article section says cellular senescence occurs in ageing and wound healing. It does not say that senescent cells accumulate after skeletal injury or locate that accumulation in the bone microenvironment; searches for skeletal injury, bone, and fracture found no supporting passage. Page numbers were not available in our copy. (LLM, conf=0.78)

  cites [75] sourceExperimental — accuracy not yet measured
• Partly supported

  The Results section (“Bleomycin injury induces cell senescence”; page unavailable) reports a senescent signature after lung injury, and the paper discusses senescence in the context of ageing. It does not establish that senescent cells accumulate with ageing or skeletal injury in the bone microenvironment; those are different conditions and tissue. (LLM, conf=0.83)

  cites [76] sourceExperimental — accuracy not yet measured

In the paper

“For example, p16+ cells may predominate in aged adipose tissue, whereas p21 predominates in obesity84,85.”

What the sources say

• ?Could not verify

  The Introduction discusses p16 and p21 in aging bone marrow, not aged adipose tissue. Searches for aged adipose tissue and obesity with p21 found no passage comparing which marker predominates in those conditions; the obesity-related material appears only in the References. (LLM, conf=0.75)

  cites [84] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Discussion (page unavailable) contrasts p16-positive cells in age-related bone loss with p21-positive cells in radiation-induced bone loss and marrow adiposity. Searches for aged adipose tissue and obesity found no passage comparing which cell population predominates in those conditions. (LLM, conf=0.74)

  cites [85] sourceExperimental — accuracy not yet measured

In the paper

“In aged vs. young mouse bones, there is an increase in p16+, KI67−, BCL2+, and SASP+ cells (and an analogous increase in the p21+ population) in late osteoblast/osteocytic and bone mesenchymal cells6.”

What the sources say

• ?Could not verify

  The sections “The zone encompasses healing processes” and “P-rpS6 deficiency accelerates wound closure” discuss p21-positive keratinocytes in wounded skin, not aged versus young mouse bones. Searches for osteoblasts, osteocytes, bone mesenchymal cells, and the specified marker combination found no passage addressing the claimed age-related increases. Page numbers were not available in our copy. (LLM, conf=0.78)

  cites [6] sourceExperimental — accuracy not yet measured

In the paper

“The outer layer of the animal body is readily accessible for sample collection and is suitable as an index organ for aging and age-related pathologies of internal organs, such as the cardiovascular system, bones, and brain51–53, among others.”

What the sources say

• ?Could not verify

  The Introduction discusses senescence markers in aging tissues, and Experimental procedures describes fibroblasts obtained from skin biopsies. Neither section says skin is readily accessible for sampling or can serve as an index of aging and disease in internal organs. Searches for those concepts returned no supporting passage; page numbers were not available in our copy. (LLM, conf=0.76)

  cites [51] sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [52] source
• ?Could not verify

  The Introduction links cellular senescence to age-related disorders, and the Histology section describes tissue staining, but neither identifies skin as an accessible sampling site or an index of aging and disease in internal organs. Searches for skin, skin biopsy, and an index organ found no passage addressing that claim. (LLM, conf=0.75)

  cites [53] sourceExperimental — accuracy not yet measured

In the paper

“certain senescence markers, such as SA-β-gal, despite being more intense in senescence-high conditions, such as aging, are also detectable in the neurons of young and healthy mice46,50”

What the sources say

• Partly supported

  The Deregulated Metabolic Profile section describes SA-β-gal as prominent in senescent cells, and Murine Models of Accelerated Senescence and Aging reports SA-β-gal-positive cells in mice with accelerated aging. The copy does not establish that staining is more intense with ordinary aging or that SA-β-gal is detectable in neurons of young, healthy mice. (LLM, conf=0.83)

  cites [46] sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [50] source

In the paper

“In animal models of idiopathic pulmonary fibrosis (IPF), bleomycin-induced injury66 and telomere deficiency72 drive fibroblasts and epithelial cells towards increased levels of senescence, a feature also observed in the lung tissue of patients with IPF.”

What the sources say

• ?Not checked — no full text of the sourcecites [66] source
• ?Could not verify

  The Results section on aged keratinocytes addresses wound repair in mouse skin, not senescence in pulmonary fibrosis. Searches for bleomycin, telomere deficiency, and lung fibrosis found no passage in our copy supporting the claim attributed to citation 72. (LLM, conf=0.77)

  cites [72] sourceExperimental — accuracy not yet measured

In the paper

“The lung can be driven into pathological conditions by a variety of external stimuli, including smoke exposure64 and viral infections65,71.”

What the sources say

• ?Not checked — no full text of the sourcecites [64] source
• ?Could not verify

  The Introduction mentions chronic lung disease among pathologies associated with senescent cells, and Results > The p16-3MR Mouse Model reports a response to irradiation in mouse lungs. Neither passage links lung pathology to smoke exposure or viral infection; searches for those stimuli found no supporting passage in our copy. Page numbers were not available. (LLM, conf=0.74)

  cites [65] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Introduction discusses fluorescence imaging, and Methodology discusses imaging mice; neither addresses lung pathology. Searches for smoke exposure and viral infection found no passage linking either to pathological lung conditions. In the citing sentence, this source appears to be cited for viral infections, but our copy does not address that point. (LLM, conf=0.76)

  cites [71] sourceExperimental — accuracy not yet measured

In the paper

“fibroblasts present not only papillary and reticular phenotypes, but also heterogeneous populations if studied at the single-cell level58,59.”

What the sources say

• ?Could not verify

  The cited paper’s Materials and Methods passages describe rat hippocampal tissue, dendritic spines, and serum assays, not fibroblast phenotypes. Searches for papillary and reticular fibroblasts and for single-cell fibroblast heterogeneity found no passage addressing the claim. No page numbers were provided for these passages. (LLM, conf=0.76)

  cites [58] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Methods (‘Single cell preparation and FACS’) and Extended Data Figures 4–5 describe sorting and identifying brain cell populations, not fibroblast populations. Searches for papillary and reticular fibroblasts and single-cell fibroblast heterogeneity found no passage addressing either part of the claim. (LLM, conf=0.78)

  cites [59] sourceExperimental — accuracy not yet measured

In the paper

“Like many other tissues, there are numerous distinct cell types within the lung required for creating functional substructures; thus, there is also heterogeneity of senescence phenotypes across lung cell types64–70 (Fig. 2 C).”

What the sources say

• ?Not checked — no full text of the sourcecites [64] source
• Partly supported

  The Results section on senescent endothelial and mesenchymal cells reports that fibroblasts and endothelial cells, but not epidermal cells, predominated among senescent cells after skin injury. This supports cell-type differences in senescence in skin, but the paper does not establish the claimed heterogeneity across lung cell types or discuss their functional substructures. (LLM, conf=0.83)

  cites [65] sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [66] source
• Partly supported

  The Results and Discussion describe distinct cell populations and stem-cell niches in skin, with senescent fibroblasts disrupting those niches. This supports skin as an example of tissue complexity, but the paper does not establish heterogeneity of senescence phenotypes across lung cell types; searches for lung cell types and lung senescence returned only skin-focused passages. (LLM, conf=0.78)

  cites [67] sourceExperimental — accuracy not yet measured
• Partly supported

  The Results sections on fibroblast subpopulations and aging describe functionally distinct cell populations in human skin and differences among aging dermal fibroblast subpopulations (pages not specified). They do not establish that lung cell types have heterogeneous senescence phenotypes or describe their roles in lung substructures. The paper supports the skin-tissue analogy, not its extension to the lung. (LLM, conf=0.78)

  cites [68] sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [69] source
• ?Not checked — no full text of the sourcecites [70] source

In the paper

“Age-related changes in murine liver cells include increased SA-β-gal activity78, DNA damage, TAFs19,20,78, karyomegaly, SADS26, ALISE26, LINE-1 elements79, and SASP factors40, some of them specified to occur in hepatocytes19,26.”

What the sources say

• Partly supported

  The aged-mouse-lung analysis reports SASP factors in age-associated macrophages, supporting the SASP portion attached to this citation. It does not establish increased SASP factors in murine liver cells or hepatocytes; the other listed changes have separate citations and are not attributed to this source. (LLM, conf=0.86)

  cites [78] sourceExperimental — accuracy not yet measured
• Partly supported

  The Abstract (page unavailable) says senescent cells secrete bioactive molecules, including interleukins and growth factors, and reports senescence-marker-positive hepatocytes in mouse livers. It does not show that SASP factors increase with age in murine liver cells. The other listed markers have separate citations in the citing sentence and are not attributed to this paper. (LLM, conf=0.85)

  cites [19] sourceExperimental — accuracy not yet measured
• Partly supported

  The passage on plaque-rich aortic arches (section labeled Abstract; page unavailable) reports elevated SASP components in mice, supporting the SASP-factors portion attached to this citation. It concerns atherosclerotic tissue, not age-related changes in murine liver cells or hepatocytes; the other listed markers are attached to different citations. (LLM, conf=0.87)

  cites [20] sourceExperimental — accuracy not yet measured

In the paper

“For example, while the elimination of senescent cells alleviates age-related pathologies in BubR1 and Ercc1 mutant mice, it does not restore their lifespan to that of wild-type animals86,102.”

What the sources say

• ?Not checked — no full text of the sourcecites [86] source
• Partly supported

  The Introduction (page unavailable) reports that inactivating p16 partially rescues several age-related phenotypes in a progeroid mouse strain. It does not say that senescent cells were eliminated, address Ercc1 mutant mice, or compare the mutants’ lifespan with that of wild-type animals. (LLM, conf=0.83)

  cites [102] sourceExperimental — accuracy not yet measured

In the paper

“Historically, some of the first transgenic animals used for senescence research were knockout models of the major cell cycle inhibitors, p16-KO and p21-KO mice97,98.”

What the sources say

• ?Could not verify

  The 'Senescence in T Cells' section (page unavailable) discusses p16INK4a expression and senescence markers in mice, but not p16- or p21-knockout models. Searches for those knockout models and their historical use found no passage establishing that they were among the first transgenic animals used in senescence research. (LLM, conf=0.76)

  cites [97] sourceExperimental — accuracy not yet measured
• Partly supported

  The ‘Cellular senescence and immune cell fate decision’ section (page unavailable) describes knockout mice for the CDKN2A locus, which encodes p16INK4a and p14/p19ARF, and their use in studying senescence. It mentions p21 in the cell-cycle-arrest pathway, but does not identify p21-knockout mice as a research model or say these models were among the first transgenic animals used in senescence research. (LLM, conf=0.86)

  cites [98] sourceExperimental — accuracy not yet measured

In the paper

“Moreover, as mentioned above, the promoter activity of p16 is generally weak, and if the neomycin cassette is not removed, its strong promoter may affect the p16 promoter, which could be related to the differences observed between studies109,110.”

What the sources say

• ?Could not verify

  Section 3 discusses p16-based mouse models, and Section 2 discusses p16 as a senescence marker; neither addresses the strength of the p16 promoter or differences between studies caused by a neomycin cassette. Searches for “neomycin cassette,” “p16 promoter,” and weak promoter activity found no passage supporting the claimed mechanism. Page numbers were not available in our copy. (LLM, conf=0.76)

  cites [109] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Materials and Methods and Discussion passages describe a p21 promoter–luciferase reporter, not a p16 promoter. Searches for p16 promoter activity and neomycin-cassette interference found no passage addressing either point or linking them to differences between studies; page numbers were unavailable in our copy. (LLM, conf=0.76)

  cites [110] sourceExperimental — accuracy not yet measured

In the paper

“To detect the senescence-like state in immune cell populations, an assay based on analysis of CDKN2A mRNA in PBMCs or selected subsets such as CD3+ T cells was developed and shown to correlate with biological age and exposure to stress such as smoking or diet96.”

What the sources say

• ?Could not verify

  The Results section reports p16 qPCR in old mouse muscle and senescence markers in mouse hepatocytes, not a CDKN2A mRNA assay in PBMCs or CD3+ T cells. Searches for that assay and for correlations with biological age, smoking, or diet found no passage addressing the claim. (LLM, conf=0.76)

  cites [96] sourceExperimental — accuracy not yet measured

In the paper

“These age-related changes are characterized by altered ratios of naïve and memory T cells, lymphoid to myeloid cells, CD4+ to CD8+ cells, and thymic atrophy.”

What the sources say

• ?Could not verify

  The Results section on p16-high and p21-high cells describes immune cell types in aged mouse tissues, but not age-related changes in their ratios. Searches for naïve and memory T cells, CD4/CD8 ratios, lymphoid-to-myeloid ratios, and thymic atrophy found no passage addressing the claimed pattern; the References mention memory-like T cells only in another paper’s title. (LLM, conf=0.76)

  cites [91] sourceExperimental — accuracy not yet measured

In the paper

“With aging, the immune system loses its ability to mount an effective immune response against invading pathogens and cancer cells, a phenomenon termed immunosenescence91.”

What the sources say

• ?Could not verify

  The Introduction (page unavailable) discusses cellular senescence and its increase with aging, not an age-related loss of immune responses to pathogens or cancer cells. Searches for “immunosenescence,” immune responses, pathogens, and cancer found no passage defining or substantiating the claimed phenomenon; a reference to impaired immune surveillance concerns senescent-cell accumulation instead. (LLM, conf=0.76)

  cites [91] sourceExperimental — accuracy not yet measured

In the paper

“Interestingly, p21 increased with age in a subset of terminally differentiated myofibers, which also displayed other senescence-associated markers such as TAF, SADS, nuclear loss of LMNB1, HMGB1, and a unique SASP88,89.”

What the sources say

• ?Could not verify

  The Discussion (page unavailable) discusses longer-lasting p21 expression in older mouse hepatocytes, not an age-related increase in terminally differentiated myofibers. Searches for myofibers and the specified markers found no passage addressing TAF, SADS, nuclear loss of LMNB1 or HMGB1, or a unique myofiber SASP. (LLM, conf=0.76)

  cites [88] sourceExperimental — accuracy not yet measured
• Partly supported

  The section ‘IL-33 from senescent HSCs promotes obesity-associated HCC development’ reports more p21-positive hepatic stellate cells in high-fat-diet mouse livers, alongside SASP factors. It does not report an age-related increase in p21 in terminally differentiated myofibers or the listed markers in those cells (searched: myofibers, skeletal muscle, TAF, SADS, and HMGB1). (LLM, conf=0.78)

  cites [89] sourceExperimental — accuracy not yet measured

In the paper

“However, FAPs also exhibit pro-inflammatory SASP, TAFs, and SADS.”

What the sources say

• Partly supported

  The Introduction (page unavailable) says that SASP generally includes pro-inflammatory chemokines and cytokines, supporting the pro-inflammatory SASP component. The paper studies hepatic stellate cells; the passages do not establish that FAPs exhibit this phenotype or address the claimed TAFs and SADS. (LLM, conf=0.78)

  cites [88] sourceExperimental — accuracy not yet measured

In the paper

“Interestingly, adaptive immune function can be improved by short-term treatment with rapamycin95, which reduces the markers of senescence and SASP in PBMCs93.”

What the sources say

• ?Could not verify

  The Results section reports increased circulating SASP proteins in p21-overexpressing mice, and Materials and Methods describes measuring those proteins in mouse plasma. Neither passage addresses rapamycin treatment or reduced senescence and SASP markers in PBMCs; searches for rapamycin and PBMCs found no supporting passage in our copy. The adaptive-immune-function clause is attached to a different citation. (LLM, conf=0.75)

  cites [95] sourceExperimental — accuracy not yet measured
• Partly supported

  The main text (Fig. 3a–d) reports reduced senescence markers in the adipose tissue, skeletal muscle and eye of AP20187-treated transgenic mice. It does not show that rapamycin reduces senescence or SASP markers in PBMCs. The adaptive-immune-function statement is attached to a different citation (95), so it is not assessed here. (LLM, conf=0.84)

  cites [93] sourceExperimental — accuracy not yet measured

In the paper

“Notably, senescent cell identification by scRNAseq has been successful in multiple in vivo studies, providing valuable insights into proper study design68,129,137,138.”

What the sources say

• Partly supported

  The Results section (‘scRNA-seq analysis of sun-protected human skin’; page unavailable) describes an in vivo human-skin scRNA-seq study and explains a design choice intended to limit photoaging as a confounder. The passages retrieved for ‘senescent’ and ‘senescence’ discuss age-related fibroblast changes, but do not report identifying senescent cells. The cited paper therefore supports the study-design aspect, not the attributed success in senescent-cell identification. (LLM, conf=0.82)

  cites [68] sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [129] source
• Partly supported

  In “Cellular Senescence and Cellular Aging in Vivo” (page unavailable), the paper reports an in vivo single-cell transcriptomics study that measured p16-positive cells in old mice. It also discusses challenges in designing in vivo senescence assessments, but says scRNA-seq might refine assessment in the future; it does not establish successful senescent-cell identification across multiple in vivo studies or say those studies yielded study-design guidance. (LLM, conf=0.82)

  cites [137] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Results section on single-cell heterogeneity describes imaging and mass-spectrometry proteomics, not identification of senescent cells by scRNA-seq. Searches for “senescent,” “senescence,” and “scRNA-seq” found no passage in our copy reporting multiple in vivo senescence studies or lessons for their design; the scRNA-seq mention is a reference to a pancreatic-cancer study. (LLM, conf=0.74)

  cites [138] sourceExperimental — accuracy not yet measured

In the paper

“Induction of senescence is a tumor suppressor mechanism143–145 and a side effect of several chemotherapeutic drugs that induce a phenotype that might be considered an acquired premature progeroid syndrome in both normal and cancer cells146.”

What the sources say

• ?Could not verify

  The cited paper’s Abstract discusses senescent cells in aging and their possible physiological roles, but does not address senescence as a tumor-suppressor mechanism or a side effect of chemotherapy. Searches for chemotherapy, tumor suppression, and progeroid effects found no passage supporting the attributed claim. (LLM, conf=0.76)

  cites [143] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Introduction describes cellular stress as a trigger of senescence, and the Results discuss senolytic treatment, but neither passage says that senescence is a tumor-suppressor mechanism or a side effect of chemotherapy. Searches for tumor suppression, chemotherapy-induced senescence, and progeroid syndrome found no passage in our copy addressing those claims. (LLM, conf=0.72)

  cites [144] sourceExperimental — accuracy not yet measured
• Partly supported

  The Introduction says senescence is an important physiological defense against malignant transformation, supporting the tumor-suppression part. The paper describes inducing senescence by irradiation in kidney epithelial cells (Results), but does not say that senescence is a side effect of chemotherapeutic drugs or describe a premature progeroid syndrome in normal and cancer cells. (LLM, conf=0.86)

  cites [145] sourceExperimental — accuracy not yet measured
• Partly supported

  The Results and Discussion (page unavailable) describe doxorubicin as a chemotherapeutic agent known to cause senescence and report using it to induce senescence in primary fibroblasts. The paper does not establish the claim about several chemotherapeutic drugs or a premature progeroid phenotype in both normal and cancer cells. Its abstract also links senescence to tumor suppression, although that clause has separate citations in the citing sentence. (LLM, conf=0.88)

  cites [146] sourceExperimental — accuracy not yet measured

In the paper

“The development of reporter transgenic models has enabled researchers to use FACS to enrich p16high and p21high cells and combine this with downstream omics analysis and single-cell omics transcriptomics (for example,109).”

What the sources say

• Partly supported

  Section 3 describes transgenic mouse models that permit visualization of p16-expressing cells, and Section 2 identifies p16 and p21 as senescence markers (page numbers unavailable). Neither passage says the models enable FACS enrichment of both p16-high and p21-high cells or links that enrichment to downstream omics analysis. (LLM, conf=0.83)

  cites [109] sourceExperimental — accuracy not yet measured

In the paper

“Spatial omics has not yet been used extensively for senescence research but is in development132–136.”

What the sources say

• ?Could not verify

  The Discussion (page unavailable) proposes developing reagents to study p15 INK4b and ARF in chicken cell senescence, but does not discuss spatial omics. Searches for spatial omics and spatial transcriptomics in senescence research found no passage addressing whether these methods are in development or how extensively they have been used. (LLM, conf=0.76)

  cites [132] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Data availability section describes bulk and single-cell RNA-seq and microscopy, while the Short article reports transcriptomic profiling of senescent cells. Searches for spatial omics and spatially resolved transcriptomics found no passage assessing how extensively spatial omics has been used in senescence research or saying it is in development. (LLM, conf=0.73)

  cites [133] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Discussion describes imaging senescent tissue regions, and Materials and Methods describes RNA sequencing of flow-sorted lung cells. Neither passage addresses spatial omics or whether its use in senescence research is limited or in development; searches for spatial omics and spatial transcriptomics found no relevant passage. The passages provide no page numbers. (LLM, conf=0.76)

  cites [134] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Introduction discusses senescent cells and drug development, while the Discussion describes imaging and transcriptional comparisons in a zebrafish model (page numbers unavailable). Searches for spatial omics and spatial transcriptomics found no passage addressing how extensively spatial omics has been used in senescence research or whether it is in development. (LLM, conf=0.72)

  cites [135] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Introduction section on distinct senescence transcriptomes describes single-cell RNA sequencing, and the STAR Methods list imaging separately. Searches for spatial omics, spatial transcriptomics, and spatial methods found no passage assessing how extensively spatial omics has been used in senescence research or saying it is in development. The available passages therefore do not establish the attributed claim. (LLM, conf=0.75)

  cites [136] sourceExperimental — accuracy not yet measured

In the paper

“In contrast, p21 is elevated in salamander cells in regenerating limbs126 and in the regenerating fins of zebrafish118.”

What the sources say

• ?Could not verify

  The Results report elevated p21 in the aged killifish telencephalon, not in regenerating salamander limbs or zebrafish fins. The Discussion mentions injury-induced senescent cells in salamanders and zebrafish but does not say p21 is elevated in those tissues; searches for p21 with both regeneration contexts found no supporting passage. (LLM, conf=0.77)

  cites [126] sourceExperimental — accuracy not yet measured
• ?Could not verify

  Citation 126 is attached to the salamander-limb claim, not the zebrafish-fin claim. The Methods and Results and Discussion describe human WI-38 fibroblasts and report elevated p21 in those cells, but no passage addresses p21 in regenerating salamander limbs (searched: salamander cells, regenerating limbs). (LLM, conf=0.76)

  cites [118] sourceExperimental — accuracy not yet measured

In the paper

“Based primarily on the frequency of p16+ cells in situ, most conditions driving senescence, including age, yield a relatively small number of senescent cells, often estimated to be <10%130.”

What the sources say

• ?Could not verify

  The Experimental Procedures describe counting γ-H2AX-positive kidney cells, and the Discussion describes SA-β-gal staining in zebrafish skin. Neither passage estimates senescent-cell frequency across conditions from p16+ cells in situ. Searches for p16, senescent-cell proportions, and the <10% estimate found no passage addressing the claim. (LLM, conf=0.76)

  cites [130] sourceExperimental — accuracy not yet measured

In the paper

“such as the recent generation of the p21-GFP transgenic reporter zebrafish128.”

What the sources say

• ?Could not verify

  The Methods describe GFP-labelled fly clones in larval imaginal discs, not a zebrafish reporter. Searches for “p21-GFP transgenic reporter zebrafish” and “zebrafish p21 senescence reporter model” found no passage in our copy addressing the claimed model. (LLM, conf=0.76)

  cites [128] sourceExperimental — accuracy not yet measured

In the paper

“It is currently limited to unbiased transcriptomics and targeted proteomics on commercial platforms, although other omics modalities are in development (e.g., single-cell proteomics131).”

What the sources say

• ?Could not verify

  The Methods sections on RNA isolation and RT-qPCR and on Western blotting describe measurements in the killifish visual system, not the availability or limitations of senescence omics approaches. Searches for unbiased transcriptomics, targeted proteomics, commercial platforms, and single-cell proteomics found no passage addressing the claim. Page numbers were not available in our copy. (LLM, conf=0.76)

  cites [131] sourceExperimental — accuracy not yet measured

In the paper

“Among potential biomarkers, the relevance of pro-survival proteins is that they enable cancer cells to avoid cell death upon acute stress (e.g., during chemotherapy or radiotherapy) and are targetable for cancer senolysis148,149.”

What the sources say

• Partly supported

  The Results section (‘Predictors can assist in the characterization and discovery of senotherapies’; page unavailable) identifies BCL-2 family inhibitors as senolytics and reports that they selectively reduced senescent A549 cancer cells. It does not establish that pro-survival proteins enable cancer cells to avoid death during acute stress from chemotherapy or radiotherapy. (LLM, conf=0.85)

  cites [148] sourceExperimental — accuracy not yet measured
• ?Could not verify

  The Discussion (page unavailable) addresses senescence and cancer, while the Results section describes drug-induced senescence and its detection. Neither states that pro-survival proteins help cancer cells survive acute stress or can be targeted for cancer senolysis; searches for those terms found no supporting passage in our copy. (LLM, conf=0.76)

  cites [149] sourceExperimental — accuracy not yet measured

In the paper

“Except in some mouse models of senescence reactivation, such as through p53 restoration153, cells within a tumor are heterogeneous, with only a fraction becoming positive for cellular senescence markers.”

What the sources say

• ?Could not verify

  The paper’s References section lists work on tumor senescence, but that listing does not establish how senescence markers are distributed among cells within a tumor. Searches of our copy for tumor heterogeneity, the fraction positive for senescence markers, and p53-restoration mouse models found no passage addressing the claim. (LLM, conf=0.76)

  cites [153] sourceExperimental — accuracy not yet measured

In the paper

“For example, p16 overexpression serves as a marker for highly proliferative HPV-16 positive cervical cancer cells, driven by RB1 (pRB) inhibition of the viral protein E7151.”

What the sources say

• ?Could not verify

  The Results report high p16INK4a levels in proliferating p53-null lymphomas and increased p16INK4a after chemotherapy, but do not address cervical cancer. Searches for HPV-16, E7, and RB1/pRB inhibition found no passage establishing the claimed marker or mechanism; page numbers were unavailable in our copy. (LLM, conf=0.75)

  cites [151] sourceExperimental — accuracy not yet measured

In the paper

“The senescent phenotype is heterogeneous and no single marker is adequate to confirm the state of senescence.”

In the paper

“Finally, similar to other forms of damage, oxidative damage is not specific to senescence, and is therefore recommended only as an auxiliary marker.”

In the paper

“In contrast, the majority of cells divide in vivo once every few weeks or months, and many cells are in a post-mitotic state.”

In the paper

“Even in cell culture, SA-β-gal staining results in false-positive staining of starved or confluent cells, whereas for in vivo and in situ conditions, the range of specificity of SA-β-gal is unknown.”

In the paper

“Finally, although the stability of cell cycle arrest has been canonically associated with cultured senescent cells, this feature has not yet been verified as being associated with senescence in situ or in vivo.”

In the paper

“Different cell types may be intrinsically resistant or susceptible to senescence (depending on the stimuli); and Different cell types may exhibit different senescence phenotypes (expressing different senescence-associated markers).”

In the paper

“However, DSBs are not specific to senescence, and it is currently unclear whether the number of DNA lesions can be used as a discriminant of senescence in situ.”

In the paper

“The first is the presence of p21 and/or p16Ink4a, two markers that have guided research on senescence in vivo in the last two decades.”

In the paper

“However, as 4-HNE provides a relatively small epitope, the specificity of the antibody should be thoroughly established and verified using a series of suitable controls (for example, see Table 1).”

In the paper

“The available methodology for in situ and in vivo measurements offers only a snapshot of cell physiology and, apart from transgenic “tracker” animals, it is not yet possible to validate the persistence of p16Ink4a or p21Cip1/Waf expression in situ or in vivo.”

In the paper

“One feature of senescence-associated changes in chromatin with an established methodology for in situ detection is senescence-associated decondensation of satellites24 (SADS; Fig. 1 F).”

What the sources say

• ?Not checked — no full text of the sourcecites [24] source

In the paper

“Different cell types may exhibit different senescence phenotypes (expressing different senescence-associated markers).”

In the paper

“However, as with all approaches of RNA measurements, the extent to which the transcript level reflects the protein level is not well established; thus, caution is advised when drawing conclusions from these quantitative analyses.”

In the paper

“Thus, the lack of PCNA or KI67 staining or thymidine analog incorporation can be a strong indicator for senescence induction in most cell culture experiments, but the lack of proliferation in vivo is not sufficient to indicate stable cell cycle arrest and cellular senescence.”

In the paper

“Auxiliary markers pertain to the core features of senescence, including erosion of the nuclear envelope, a decline in proliferation markers, activation of alarmins, DNA damage, chromatin abnormalities, pro-secretory phenotypes, metabolic alterations, oxidative damage, and lysosomal alterations (Fig. 1).”

In the paper

“In summary, the cell cycle inhibitors p21Cip1/Waf and/or p16Ink4a are integral to senescence, both in situ and in vivo, and we recommend that every rodent study utilize at least one of these.”

In the paper

“Based on published evidence and agreement of the research community working on this article, we categorized these markers as primary and auxiliary.”

In the paper

“Numerous liver cell types, including hepatocytes, endothelial cells, hepatic stellate cells, and cholangiocytes, display markers associated with senescence during aging, injury and regeneration, obesity, and age-related diseases, with different cell types displaying different senescence markers (Fig. 2 E).”

In the paper

“While working with these models, it is important to be aware that they affect only a single component of the senescence machinery and thus might not reflect the whole biology of cellular senescence.”

In the paper

“Furthermore, many models for senescence reporting utilize transgenes driven by different parts of the native promoter of the senescence regulatory gene (Table 2), making it challenging to compare the results between models.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Table 2

In the paper

“Reporters using eGFP or tdTomato fluorescence enable the detection of p21+ or p16+ cells in situ, whereas models with luciferase enable the approximation of senescent cells in live animals by measuring the amount of light emitted after the administration of an enzymatic substrate for the luciferase reporter.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Table 2

In the paper

“While these models are suitable for estimating the quantity of a particular type of senescent cell, the results must be validated with additional senescence markers since single molecular endpoints are not specific for senescence.”

In the paper

“Similar to other transgenic models used in senescence research, the activity of the transgene is dependent on a single gene, which is inadequate for fully defining the senescent cell burden in vivo.”

In the paper

“Therefore, it is possible that the elimination of senescence in other tissues contributed to the observed phenotype.”

In the paper

“By definition, the models underestimate the senescent cell burden in vivo because they only look at a single senescent cell type (e.g., p16-expressing) and many senescence markers exhibit low expression levels, leading to low signal-to-noise ratios.”

In the paper

“Hence, although the transcriptional profile of cells or tissue regions of interest can be used to approximate the burden of senescence, the conclusions are not definitive in the absence of orthogonal validation, ideally measuring non-mRNA endpoints.”

In the paper

“Applying omics to assess the macromolecular composition of tissues, in principle, permits the unambiguous identification of senescent cells and their detailed characterization.”

In the paper

“Understanding the methods by which a signature is developed is also critical for identifying potential biases or limitations; for example, a SASP-heavy signature may not be accurate for some subsets of immune cells.”

In the paper

“Features such as reduced proliferation, pro-inflammatory and angiogenic factors, and resistance to apoptosis provide promising markers of senescence in cancer, but will remain context-dependent for each cancer, or even for each patient within a cohort, as very few cancers present with a homogenous mutational background.”

In the paper

“However, the detection of these markers in human cancers can be challenging because of the universal limitations of human sample analysis.”

In the paper

“Human samples provide the best source of information about how cellular senescence contributes to human physiology and pathology, relative to inbred and specified pathogen-free mice.”

In the paper

“Evidence of the expression of at least three senescence markers representing different properties of cellular senescence in a given tissue strongly supports that the observed phenomena are indeed related to cellular senescence.”

In the paper

“As of 2024, the scientific community does not have definitive recommendations for assessing cellular senescence in human tissues, except for the suggestion of using a large sample size and investigating several markers with a preference for those that are highly stable.”

In the paper

“However, our knowledge of the functional impact of the burden of senescent cells in human samples is significantly less well established than that in mice.”

In the paper

“Often, human samples, especially those collected from live subjects, are small and low in number, and this, combined with the high interindividual variability, poses problems in reaching statistical significance.”

In the paper

“Genetic heterogeneity between individuals in the human population will likely influence the distribution of senescence biomarkers from person to person.”

In the paper

“While the impact of tumor cell senescence on tumor progression is currently not well defined, it is clearly context dependent.”

In the paper

“The sheer diversity of cancer types (Fig. 3) and the lack of multiple established senescence markers related to cell cycle control to define cancer cell senescence in these diverse tumor types remain challenging.”

In the paper

“Finally, the present version of the MISCE is based on current knowledge and will need to be updated as our understanding of senescence in vivo increases.”

In the paper

“Importantly, the majority of our specific recommendations are applicable to mouse models, as studies in human samples, non-mammalian animals, and tumors require further research before we feel confident in providing clear recommendations without being too restrictive for research progress.”

In the paper

“Thus, in general, senescent cells in tumors present the same challenges as those in normal tissues; they need to be properly identified, and the impact of their modulation or elimination must be functionally evaluated in tumor tissues.”