Single-Cell Transcriptomics Reveals Early Emergence of Liver Parenchymal and Non-parenchymal Cell Lineages

Probably not a substantial claim: may not pass S3 (load-bearing).

Inducible lineage tracing of early hemogenic sites with Cdh5-cre does not account for all hematopoietic cells within the embryo.

“Inducible lineage tracing of early hemogenic sites with Cdh5-cre, however, does not account for all hematopoietic cells within the embryo”

• cites Hirschi, 2012 sourcePartly supported

  The “Hemogenic endothelial cells” section describes inducible VE-cadherin lineage tracing of cells labeled in the embryonic AGM. The “Postnatal hemogenic endothelium?” section says embryonically labeled HSCs do not account for all hematopoietic cells generated postnatally, not all hematopoietic cells within the embryo. The claim changes the population to which that finding applies. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites Zovein et al., 2008 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

HSECs present in the early liver are derived from the hemangioblast, from which vascular endothelial cells and early hematopoietic cells are also derived.

“HSECs present in the early liver are derived from the hemangioblast, from which vascular endothelial cells and early hematopoietic cells are also derived”

• cites Bollerot et al., 2005 sourcePartly supported

  The “Hemangioblast or hemogenic endothelium?” section describes the hemangioblast as a proposed common progenitor of endothelial and hematopoietic cells. The Concluding Remarks say that hemangioblasts in fetal liver have been reported but need confirmation; they do not establish that early-liver HSECs derive from hemangioblasts. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites Zovein et al., 2008 sourcePartly supported

  The Results section, “Fetal liver VE-cadherin population is migratory and does not originate in situ” (page unavailable), says the fetal-liver hematopoietic population likely migrated from the AGM. The paper traces hematopoietic cells to endothelium, but does not establish that the early-liver cells, vascular endothelial cells, and early hematopoietic cells all derive from a hemangioblast. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The fetal liver is the main site of hematopoiesis during development, harboring hematopoietic stem cells from E10.5 until E16.5, when they migrate to the bone marrow.

“The fetal liver is also the main site of hematopoiesis during development, harboring hematopoietic stem cells from E10.5 until E16.5, when they migrate to the bone marrow”

• cites Gordillo et al., 2015 sourcePartly supported

  In “Hepatoblast proliferation and expansion” (page unavailable), the paper calls the fetal liver a major transitional site for mammalian hematopoiesis and says hematopoietic progenitor cells develop there from about E10 in mice. It does not establish that the liver is the main site, specify hematopoietic stem cells from E10.5 to E16.5, or say that they then migrate to the bone marrow. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

A proportion of HSECs may be derived from the endocardium and endoderm.

“though a proportion may be derived from the endocardium and endoderm”

• cites Goldman et al., 2014 sourcePartly supported

  The Discussion (page unavailable) reports that endoderm-derived progenitors contribute to a subpopulation of hepatic endothelial cells and suggests these may be fetal liver sinusoidal endothelial cells. Our copy does not identify the endocardium as a source of those cells, so only the endoderm part is supported. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites Zhang et al., 2016 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Signals from the overlying cardiac mesoderm and septum transversum mesenchyme (STM) induce hepatoblast transition into a pseudostratified columnar epithelium and their invasion of the STM by E9.5.

“Signals from the overlying cardiac mesoderm and septum transversum mesenchyme (STM) induce their transition into a pseudostratified columnar epithelium and their invasion of the STM by E9.5”

• cites Houssaint, 1980 sourceNot checked — no full text of the source
• cites Tremblay and Zaret, 2005 sourcePartly supported

  The section ‘Liver progenitors within the ventral midline of the endoderm lip’ reports liver-bud descendants invading mesenchyme, and the Fig. 2 caption likewise describes liver-bud cells invading local mesenchyme. Our copy does not establish that cardiac mesoderm and STM signals induce this invasion or a transition to pseudostratified columnar epithelium by E9.5. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The STM gives rise to the liver mesenchyme, which in the adult liver encompasses the mesothelium and hepatic stellate cells (HSCs).

“The STM gives rise to the liver mesenchyme, which in the adult liver encompasses the mesothelium, the external cellular lining of the liver, and hepatic stellate cells (HSCs), the sinusoidal pericytes”

• cites Asahina et al., 2009 sourcePartly supported

  The introductory passage (page unavailable) describes septum transversum mesenchyme (STM) as a proposed source of HSCs, but says its contribution had not been definitively established. The Results, “Cell Lineage Analysis of Liver Mesenchymal Cells” (page unavailable), traces fetal HSCs and submesothelial cells to mesoderm and finds that some liver mesothelial cells share that lineage; it does not establish that STM gives rise to all these cells or demonstrate the claimed lineage in adults. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Hepatoblasts, the bipotent progenitor for hepatocytes and cholangiocytes, develop from the definitive endoderm by embryonic day E8.75.

“Hepatoblasts, the bipotent progenitor for hepatocytes and cholangiocytes, develop from the definitive endoderm by embryonic day (E)8.75”

• cites Gordillo et al., 2015 sourcePartly supported

  The Introduction (Fig. 2; page unavailable) traces hepatoblasts to foregut definitive endoderm and identifies them as bipotential progenitors of hepatocytes and cholangiocytes. But the liver-budding section (Fig. 3; page unavailable) describes hepatic endoderm at E8.75 and identifies its cells as hepatoblasts at E10, so it does not support the claim that hepatoblasts have developed by E8.75. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites Tremblay and Zaret, 2005 sourcePartly supported

  The section ‘Identifying progenitors for the liver and other ventral tissues in the lateral endoderm’ (page not provided) traces mouse endoderm cells to the liver bud and reports liver progenitors at the 7–10-somite stage. The Fig. 2 caption identifies HNF4α as a hepatoblast marker. Our copy does not establish the specific E8.75 timing or state that these hepatoblasts are bipotent progenitors of hepatocytes and cholangiocytes. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Hand1 and Foxf1 are required for mesoderm development.

“both of which are required for mesoderm development”

• cites Mahlapuu et al., 2001 sourceNot checked — no full text of the source
• cites Maska et al., 2010 sourcePartly supported

  The paper’s main text (indexed under Abstract; page unavailable) reports essential roles for Hand1 in extraembryonic and lateral mesoderm, including enteric smooth muscle organization. It does not address Foxf1, and its Hand1 findings concern specific mesodermal tissues rather than mesoderm development generally (searched: Foxf1 and Foxf1 required for mesoderm development). (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

By E10.5, hepatoblasts, endothelia, and HSCs begin to organize into primitive sinusoidal capillaries.

“By E10.5, hepatoblasts, endothelia, and HSCs begin to organize into primitive sinusoidal capillaries”

• cites Gordillo et al., 2015 sourcePartly supported

  The Introduction (Fig. 1; page unavailable) describes sinusoids as endothelial vessels beside hepatocyte cords, with hepatic stellate cells nearby. The liver-lineages section says stellate cells associate with sinusoidal endothelium and regulate vascular development. Neither passage says that these three cell types begin organizing into primitive sinusoidal capillaries by E10.5; the paper’s E10.5 passage instead concerns mesothelial cells lining the developing liver lobes. (LLM, conf=0.82)

  Experimental — accuracy not yet measured

May combine two claims.

Cells fated for the endothelial terminal state diverge at E10.5 activating regulators of angiogenesis, such as Tbx1 and Foxc2, as well as genes associated with blood flow-associated shear stress, including Klf2 and Klf4.

“Cells fated for the endothelial terminal state diverge at E10.5 activating regulators of angiogenesis, such as Tbx1 and Foxc2, as well as genes associated with blood flow-associated shear stress, including Klf2 and Klf4”

• cites Sangwung et al., 2017 sourcePartly supported

  The Introduction (page unavailable) says KLF2 and KLF4 are enriched in endothelium and regulated by flow, supporting their association with blood-flow responses. It does not establish that endothelial-fated cells diverge at E10.5 or activate Klf2 and Klf4 at that stage, and it does not address Tbx1 or Foxc2. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

May combine two claims.

These factors are not enriched within the HSEC trajectory where instead, beginning as early as E8.75, HSEC-specific transcription factors are activated, including Tfec, Nr5a2, Sox17, and Oit3, as well as genes associated with HSEC identity, including Stab2, Lyve1, and Fcgrt.

“These factors are not enriched within the HSEC trajectory where instead, beginning as early as E8.75, HSEC-specific transcription factors are activated, including Tfec, Nr5a2, Sox17, and Oit3, as well as genes associated with HSEC identity, including Stab2, Lyve1, and Fcgrt”

• cites Géraud et al., 2010 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

FGF and BMP signaling have previously been shown to coordinate the specification of anterior and posterior hepatic endodermal populations, respectively.

“while FGF and BMP signaling have previously been shown to coordinate the specification of anterior and posterior hepatic endodermal populations, respectively”

• cites Palaria et al., 2018 sourceSupported
• cites Tremblay and Zaret, 2005 sourceCould not verify

  The Discussion describes fate mapping of liver progenitors before hepatic specification, and the movement section tracks their positions during foregut closure. Searches for FGF, BMP, and bone morphogenetic protein found no passage in our copy assigning FGF to anterior and BMP to posterior hepatic endoderm specification. (LLM, conf=0.74)

  Experimental — accuracy not yet measured
• cites Wang et al., 2015 sourcePartly supported

  The Discussion reports that reduced FGF signaling has severe effects on specification of the anterior liver bud but little effect on the posterior bud. It proposes BMP as a candidate signal for posterior induction and says studies are ongoing; it does not say BMP’s posterior role had previously been shown. The indexed passages provide no page numbers. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The embryonic liver is formed from the posterior ventral foregut endoderm, which invades the STM in response to migratory cues.

“The embryonic liver is formed from the posterior ventral foregut endoderm, which invades the STM in response to migratory cues”

• cites Gordillo et al., 2015 sourcePartly supported

  In “Liver diverticulum formation and budding” (page unavailable), the review says the ventral foregut forms the liver diverticulum and that hepatoblasts invade the septum transversum to form the liver bud. Its signaling-pathways figure identifies posterior foregut precursors with hepato-pancreatic potential. The cited passages do not say that migratory cues drive the invasion; the review also describes zebrafish liver budding as occurring without migratory invasion. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites Tremblay and Zaret, 2005 sourcePartly supported

  The fate-mapping results and Fig. 2 caption show that ventral endoderm progenitors contribute to the mouse liver bud and that labeled liver-bud cells invade local mesenchyme. But the paper describes two distinct progenitor populations, not a solely posterior ventral-foregut origin, and the passages do not identify the mesenchyme as STM or establish migratory cues as the cause of invasion. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

TGFβR3 may act as a reservoir for TGFβ ligand, establishing a signaling environment for later in development.

“here TGFβR3 may act as a reservoir for TGFβ ligand, establishing a signaling environment for later in development”

• cites Andres et al., 1989 sourcePartly supported

  The paper proposes that betaglycan might help retain and deliver activated TGFβ locally (opening summary, p. 3137; discussion). That supports the hedged reservoir idea, but the paper does not connect this role to establishing a signaling environment for later in development. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Pyy is specifically expressed within the posterior foregut endoderm.

“with Pyy being specifically expressed within the posterior foregut endoderm”

• cites Hou et al., 2007 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The temporal emergence of hepatoblasts is in line with previous studies, with specification from the endoderm in early organogenesis (E8.75), migration at E9.5, and the beginnings of hepatoblast function at E10.5.

“The temporal emergence of hepatoblasts is in line with previous studies, with specification from the endoderm in early organogenesis (E8.75), migration at E9.5, and the beginnings of hepatoblast function at E10.5”

• cites Gordillo et al., 2015 sourcePartly supported

  The figure caption in ‘Liver diverticulum formation and budding’ (page unavailable) places hepatic specification at E8.75, but places hepatoblast migration into the septum transversum at E10 rather than E9.5. The ‘Hepatoblast proliferation and expansion’ section describes liver-bud growth at E10.5, not the onset of hepatoblast function, so that part of the timeline is unsupported. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites Si-Tayeb et al., 2010 sourceNot checked — no full text of the source
• cites Tremblay and Zaret, 2005 sourcePartly supported

  The Discussion (page not available in our copy) traces liver progenitors from early endoderm, describes their movement, and shows labeled descendants invading the mesenchyme of the liver bud. It does not establish specification at E8.75, migration specifically at E9.5, or the onset of hepatoblast function at E10.5. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

May combine two claims.

Hepatoblasts remain pseudo-epithelial; they maintain cell polarity, stable epithelial contacts, and a regular, cobblestone-like morphology.

“Hepatoblasts remain pseudo-epithelial; they maintain cell polarity, stable epithelial contacts, and a regular, cobblestone-like morphology”

• cites Gordillo et al., 2015 sourcePartly supported

  The liver-budding section describes hepatoblasts as pseudostratified cells that delaminate, and the bile-duct-development figure calls them epithelial progenitor cells. The hepatoblast-proliferation section reports that oncostatin M can induce E-cadherin-based junctions in vitro. These passages do not establish that hepatoblasts retain polarity and stable epithelial contacts or have a regular, cobblestone-like morphology. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Epithelial-mesenchymal plasticity has been previously identified within hepatic tissues and cell lines.

“epithelial-mesenchymal plasticity has been previously identified within hepatic tissues and cell lines”

• cites Dong et al., 2018 sourcePartly supported

  The Results section on the epithelial/mesenchymal hybrid state reports co-expression of epithelial and mesenchymal markers in developing mouse liver epithelial cells, supporting the hepatic-tissue portion. The paper does not identify this state in hepatic cell lines, and its Discussion says adult liver epithelial cells did not show the same hybrid state. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites Goldman et al., 2016 sourceSupported
• cites Li et al., 2011Not matched

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

May combine two claims.

In zebrafish, emergence and positioning of hepatoblasts is accomplished by CCM, with ephrin signaling and hepatoblast filopodia mediating contacts between gut tube and mesodermal lineages.

“In zebrafish, emergence and positioning of hepatoblasts is accomplished by CCM, with ephrin signaling and hepatoblast filopodia mediating contacts between gut tube and mesodermal lineages”

• cites Cayuso et al., 2016 sourcePartly supported

  The Results section, “Hepatoblasts Actively Migrate during Liver Budding” (page unavailable), describes coordinated hepatoblast movement into the liver bud, suggesting collective cell migration. The Discussion describes EphrinB1/EphB3b signaling and protrusions facilitating contacts between hepatoblasts and lateral plate mesoderm. However, the Introduction says hepatoblasts are specified by signals from the mesoderm; the paper does not establish that collective cell migration accomplishes their initial emergence. (LLM, conf=0.82)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In models of liver fibrosis, DLL4 promotes capillarization and liver scarring, whereas KLF2 maintains endothelial integrity.

“Interestingly, in models of liver fibrosis, DLL4 promotes capillarization and liver scarring, whereas KLF2 maintains endothelial integrity”

• cites Chen et al., 2019 sourcePartly supported

  The Conclusions (section 5; page unavailable) state that DLL4 overexpression promotes LSEC capillarization and that DLL4 knockdown alleviates both capillarization and liver fibrosis in CCl4-treated mice. The cited paper does not support the separate assertion that KLF2 maintains endothelial integrity; searches for KLF2 and Krüppel-like factor 2 found no relevant passage. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites Marrone et al., 2015 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

In vitro studies have shown evidence of collective migration of hepatic cell lines.

“in vitro studies have further shown evidence of collective migration of hepatic cell lines”

• cites Cheng et al., 2018 sourceSupported
• cites Han et al., 2019 sourceNot checked — no full text of the source
• cites Suárez-Causado et al., 2015 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

DLK1 may contribute to the lateral inhibition of Notch in HSEC progenitors.

“DLK1 may contribute to the lateral inhibition of Notch in HSEC progenitors, comparable to its role in the differentiation of type I from type II alveolar cells in lung repair”

• cites Finn et al., 2019 sourceSupported

May combine two claims.

The study characterizes two distinct mesothelial cell types as well as early hepatic stellate cells.

“We characterize two distinct mesothelial cell types as well as early hepatic stellate cells”

May combine two claims.

The data detail divergence of vascular and sinusoidal endothelia, including a distinct transcriptional profile for sinusoidal endothelial specification by E8.75.

“Our data detail divergence of vascular and sinusoidal endothelia, including a distinct transcriptional profile for sinusoidal endothelial specification by E8.75”

The quote only partly states this claim.

Using Harmony and Palantir, the study revealed uncharacterized diversity within endothelial, mesenchymal, and hepatic cell lineages during liver development.

“Using these methods, we have revealed uncharacterized diversity within endothelial, mesenchymal, and hepatic cell lineages during liver development”

May combine two claims.

By E10.5, SOX9 is widespread among mesothelial cells in both caudal and rostral lobes, whereas ISL1 is limited to the rostral liver mesothelium.

“By E10.5, SOX9 is widespread among mesothelial cells in both caudal and rostral lobes, whereas ISL1 is limited to the rostral liver mesothelium”

May combine two claims.

Mesothelium I expresses Sox9 and Tbx18.

“including Sox9 and Tbx18 within the mesothelium I cluster”

May combine two claims.

STM I cluster is composed predominantly of cells from E8.75 and is enriched for Hand1 and Foxf1.

“One cluster, which represents early STM (STM I), is composed predominantly of cells from E8.75 and is enriched for Hand1 and Foxf1”

May combine two claims.

The study sees 378 Foxa2-Kdr co-expressing cells, which may represent a population of endothelial-fated endodermal cells.

“We do, however, see 378 Foxa2-Kdr co-expressing cells, which may represent a population of endothelial-fated endodermal cells”

May combine two claims.

ALCAM immunostaining identifies all STM-derived populations at E9.5 and E10.5, including mesothelial progenitors and unspecified STM progenitors that lack expression of mesothelial factors.

“ALCAM immunostaining identifies all STM-derived populations at E9.5 and E10.5, including mesothelial progenitors and unspecified STM progenitors that lack expression of mesothelial factors”

May combine two claims.

At E9.5, SOX9+ and ISL1+ mesothelial populations occupy the ventral and anterior portions of the tissue, respectively.

“Immunostaining identifies emergent mesothelial populations expressing SOX9 or ISL1, which at E9.5 occupy the ventral and anterior portions of the tissue, respectively”

May combine two claims.

HSC cluster is composed of cells from E9.5 and E10.5 and expresses markers of the HSC lineage, including Lhx2 and Des.

“The HSC cluster, composed of cells from E9.5 and E10.5, expresses various markers of the HSC lineage, including Lhx2 and Des”

May combine two claims.

The authors computationally segregated 3,691 liver mesenchymal cells from E8.75, E9.5, and E10.5 libraries and identified five distinct populations based on clustering and differential gene expression analyses.

“we computationally segregated 3,691 liver mesenchymal cells from our E8.75, E9.5, and E10.5 libraries and identified five distinct populations based on clustering and differential gene expression analyses (Figures 3A and S3A; Table S2).”

• AssumptionRests on an assumption: Little is known about the complete diversity and timing of emergent mesenchymal populations within the early liver.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Surface ectoderm is not captured in the study's libraries, but the study found overlap between surface ectoderm and its gut tube endoderm cluster.

“While surface ectoderm is not captured in our libraries, due to expression of genes associated with epithelial identity like Epcam and Cdh1, we found overlap between it and our gut tube endoderm cluster”

May combine two claims.

The study identified four distinct populations based on clustering and differential gene expression analyses, representing hemangioblasts, hematopoietic progenitors, endothelium, and HSECs.

“We identified four distinct populations based on clustering and differential gene expression analyses, representing hemangioblasts, hematopoietic progenitors, endothelium, and HSECs”

May combine two claims.

Within the data, there are two distinct primitive streak clusters composed of cells from E7.5, which appear primed to either an endodermal or mesodermal cell fate, likely corresponding to the proximal and distal primitive streak.

“Within our data, we further note two distinct primitive streak clusters composed of cells from E7.5, which appear primed to either an endodermal or mesodermal cell fate, likely corresponding to the proximal and distal primitive streak”

May combine two claims.

Unspecified STM progenitors are found proximal to the hepatic bud at E9.5 and at the distal tip of the caudal lobe at E10.5, and ALCAM-expressing unspecified STM populations persist at the distal tip of the caudal liver lobe at E10.5.

“These unspecified progenitors are found proximal to the hepatic bud at E9.5 and at the distal tip of the caudal lobe at E10.5”

• Also stated in: § Results · boosted

  “our gene expression and immunostaining data reveal the persistence of ALCAM-expressing unspecified STM populations at the distal tip of the caudal liver lobe at E10.5”

May combine two claims.

The three remaining clusters represent emerging mesothelia and HSCs, including two distinct mesothelial populations.

“the three remaining clusters represent emerging mesothelia and HSCs, including two distinct mesothelial populations.”

May combine two claims.

Both the endothelial and HSEC lineages emerge initially through an unspecified endothelial progenitor, activating and maintaining expression of genes such as Cdh5, Pecam1, and Cd34, while downregulating factors associated with hemangioblast identity.

“Both the endothelial and HSEC lineages emerge initially through an unspecified endothelial progenitor, activating and maintaining expression of genes such as Cdh5, Pecam1, and Cd34, while downregulating factors associated with hemangioblast identity”

May combine two claims.

HSECs are composed predominantly of cells from E10.5, though cells from E8.75 and E9.5 are also present.

“HSECs are composed predominantly of cells from E10.5, though cells from E8.75 and E9.5 are also present”

May combine two claims.

Mesothelium II expresses Foxf1 and Isl1.

“and Foxf1 and Isl1 in the mesothelium II cluster”

May combine two claims.

The authors computationally segregated 2,332 hepatic progenitors sequenced from E7.5 to E10.5 and identified four distinct cell states.

“we computationally segregated 2,332 hepatic progenitors sequenced from E7.5 to E10.5 and used clustering and differential expression analyses to identify four distinct cell states”

May combine two claims.

VIM immunostaining of Afp-GFP livers shows presence of double-positive cells within hepatic cords at E9.75 and within the liver parenchyma at E10.5.

“VIM immunostaining of Afp-GFP livers shows presence of double-positive cells within hepatic cords at E9.75 and within the liver parenchyma at E10.5”

May combine two claims.

Pronounced VEGF signaling toward liver endothelia and PDGF signaling between hepatoblasts and HSCs are seen.

“we see pronounced VEGF signaling toward liver endothelia, as well as PDGF signaling between hepatoblasts and HSCs”

Probably not a substantial claim: may not pass S3 (load-bearing).

TGFβ1 from endothelia and TGFβ2 from HSCs and the hepatomesenchyme are predicted to signal via TGFβR3 toward all populations.

“TGFβ1 from endothelia and TGFβ2 from HSCs and the hepatomesenchyme are predicted to signal via TGFβR3 toward all populations”

May combine two claims.

Canonical RELN signaling via VLDLR is predicted autocrinally and toward HSCs, while non-canonical RELN interactions via EPHA4 are predicted to influence HSCs and hepatomesenchymal cells.

“Our analysis predicts canonical RELN signaling via VLDLR autocrinally as well as toward HSCs, while non-canonical RELN interactions via EPHA4 are predicted to influence HSCs and hepatomesenchymal cells.”

May combine two claims.

The hepatomesenchymal population maintains diminished expression of genes associated with hepatic identity, such as Afp and Dlk1, and activates genes required for mesenchymal development, such as Vim, Pdgfra, Hand2, and Gata4.

“This population maintains diminished expression of genes associated with hepatic identity, such as Afp and Dlk1, and activates genes required for mesenchymal development, such as Vim, Pdgfra, Hand2, and Gata4”

May combine two claims.

DLL4 active in the endothelia, and enriched within HSECs, signals autocrinally via NOTCH1, and further signals to other sinusoidal populations via NOTCH2.

“DLL4 active in the endothelia, and enriched within HSECs, signals autocrinally via NOTCH1, whereas it further signals to other sinusoidal populations via NOTCH2”

May combine two claims.

Both hepatic and epithelial gene profiles are low within the hepatomesenchymal cluster, where a mesenchymal gene program is activated.

“Both of these gene profiles are low within the hepatomesenchymal cluster, where in lieu we observe the activation of a mesenchymal gene program”

May combine two claims.

BMPs and TGFβs are predicted to promote genes associated with mesenchymal cell fate, including Col1a1, Des, and Mmp2, whereas IGF1 is predicted to specifically activate Pdgfra.

“BMPs and TGFβs are predicted to promote a variety of genes associated with mesenchymal cell fate, including Col1a1, Des, and Mmp2, whereas IGF1 is predicted to specifically activate Pdgfra”

May combine two claims.

A cluster representing hepatoblasts migrating into the STM is composed predominantly of cells from E9.5 and has activated expression of genes associated with hepatic cell fate, including Hnf4a and Foxa3.

“A cluster representing hepatoblasts migrating into the STM is composed predominantly of cells from E9.5 and has activated expression of genes associated with hepatic cell fate, including Hnf4a and Foxa3”

May combine two claims.

Immunostaining of E10.5 Afp-GFP livers shows robust expression of PDGFRα in HSCs and in a portion of GFP+ cells, likely representing the hepatomesenchyme.

“Immunostaining of E10.5 Afp-GFP livers shows robust expression of PDGFRα in HSCs as well as in a portion of GFP+ cells, likely representing the hepatomesenchyme”

May combine two claims.

The authors observe unexpected heterogeneity within mesenchymal populations, including emergent HSCs and two distinct mesothelial populations, which occupy distinct niches within the early liver.

“We further observe unexpected heterogeneity within mesenchymal populations, including emergent HSCs and two distinct mesothelial populations, which occupy distinct niches within the early liver.”

May combine two claims.

Reln is among the first genes expressed by hepatoblasts during hepatic endoderm specification at E8.75, and RELN is specifically expressed at E9.5 and E10.5 in AFP-GFP+ hepatoblasts.

“Reln is among the first genes expressed by hepatoblasts during hepatic endoderm specification at E8.75, and immunostaining demonstrates specific expression of RELN at E9.5 and E10.5 in AFP-GFP+ hepatoblasts”

May combine two claims.

More than 40 significant ephrin-Eph interactions are identified, including interactions between all sinusoidal cell populations.

“We identify more than 40 significant ephrin-Eph interactions in our analysis, which include interactions between all sinusoidal cell populations”

May combine two claims.

Differentiation potential is highest within the endoderm and migrating hepatoblasts and low in hepatoblasts and hepatomesenchyme.

“Differentiation potential is highest within the endoderm and migrating hepatoblasts and low in hepatoblasts and hepatomesenchyme”

May combine two claims.

The epithelial gene profile is highest among the endoderm and decreases during hepatoblast migration, whereas the hepatic profile is inversely related.

“The epithelial profile is highest among the endoderm and decreases during hepatoblast migration, whereas the inverse is true for the hepatic profile”

May combine two claims.

Within cells fated for the hepatoblast terminal state, Foxa1 is reactivated along with maintenance of hepatic identity genes; within the hepatomesenchymal trajectory, these genes are not sustained.

“within cells fated for the hepatoblast terminal state, we see the reactivation of Foxa1 along with the maintenance of genes associated with hepatic identity; however, within the hepatomesenchymal trajectory, we do not see their sustained expression”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Median reads per cell ranged from 53,200 to 384,336, with median UMI counts of 9572 to 40,995 per cell.

“Median reads per cell ranged from 53,200 to 384,336 with median UMI of 9572 to 40,995 per cell.”

May combine two claims.

Within hepatoblasts, trajectory analyses reveal a gradual shift from an epithelial to a hepatic transcriptional profile alongside activation of genes canonically associated with hepatic migration, including Hhex and Tbx3, starting at E8.75.

“Within hepatoblasts, trajectory analyses reveal a gradual shift from an epithelial to a hepatic transcriptional profile alongside the activation of genes canonically associated with hepatic migration, including Hhex and Tbx3, starting at E8.75.”

May combine two claims.

Distinct hepatic parenchymal populations exist in the liver bud, including a hepatomesenchymal cell type.

“We delineate distinct hepatic parenchymal populations in the liver bud, including a hepatomesenchymal cell type”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Across 15 samples, 45,547 single cells were collected, with 1413 to 7983 cells collected per sample.

“From 15 samples, 45,547 single cells were collected, ranging from 1413 to 7983 cells collected per sample.”

May combine two claims.

Exceptional diversity exists within spatially distinct liver mesenchymal progenitors, including distinct mesothelial populations and the earliest evidence of HSCs.

“We characterize exceptional diversity within spatially distinct liver mesenchymal progenitors, including distinct mesothelial populations and the earliest evidence of HSCs.”

May combine two claims.

HSEC progenitors are present by E8.75 and express genes associated with sinusoidal function.

“We further show evidence of HSEC progenitors by E8.75, which express genes associated with sinusoidal function”

May combine two claims.

In total, 45,334 single-cell transcriptomes from 15 scRNA-seq libraries passed quality control, with a median of 4,190 genes with expression detected per cell.

“In total, 45,334 single-cell transcriptomes from 15 scRNA-seq libraries passed quality control, with a median of 4,190 genes with expression detected per cell”

Probably not a substantial claim: may not pass S3 (load-bearing).

Sinusoidal dysfunction, including defenestration and HSC activation, precedes scar formation and liver fibrosis.

“Sinusoidal dysfunction, including defenestration and HSC activation, precedes scar formation and liver fibrosis”

• cites Poisson et al., 2017 sourceNot checked — no full text of the source
• cites Puche et al., 2013 sourceNot checked — no full text of the source

May combine two claims.

A local maximum exists at the interface between the endothelial and HSEC clusters, suggesting the presence of a second cell fate decision in HSEC specification.

“a local maximum exists at the interface between the endothelial and HSEC clusters, suggesting the presence of a second cell fate decision in HSEC specification”

May combine two claims.

While it is likely that endothelium of cardiac origin is included in this analysis, the study could not deconvolute endocardial and vascular endothelial contribution to liver endothelial lineages based on transcription alone.

“Of note, while it is likely that endothelium of cardiac origin is included in this analysis, we could not deconvolute endocardial and vascular endothelial contribution to liver endothelial lineages based on transcription alone”

May combine two claims.

Hepatomesenchymal cells represent a subpopulation of hepatoblasts that exhibits epithelial-to-mesenchymal plasticity, adopting a hybrid epithelial-mesenchymal phenotype.

“Together, these data suggest that hepatomesenchymal cells represent a subpopulation of hepatoblasts that exhibits epithelial-to-mesenchymal plasticity, adopting a hybrid epithelial-mesenchymal phenotype.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The failure of trajectory analysis to delineate lineage relationships is likely due to incomplete capture of liver mesenchymal progenitors or complex lineage relationships between these populations.

“likely due to incomplete capture of liver mesenchymal progenitors or complex lineage relationships between these populations”

May combine two claims. The quote only partly states this claim.

Blood flow plays a role in HSEC specification and in the divergence of HSEC progenitors from the vascular endothelium.

“Taken together, this suggests roles for blood flow as well as competition for NOTCH receptor occupancy by Delta-like ligands during HSEC specification.”

• Also stated in: § Discussion · hedged

  “we propose a role for blood flow in their divergence from the vascular endothelium”

• AssumptionRests on an assumption: Vascular endothelia express mechanosensitive ion channels along with their downstream flow-responsive genes, including Klf2 and Klf4.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The divergence of hepatoblast and hepatomesenchymal lineages is reminiscent of the polarization that takes place during collective cell migration (CCM).

“The divergence of hepatoblast and hepatomesenchymal lineages is reminiscent of the polarization that takes place during collective cell migration (CCM).”

May combine two claims.

Complete sinusoidal perfusion and fenestration occur at E12.5 and E15.5, respectively.

“complete sinusoidal perfusion and fenestration, which occur at E12.5 and E15.5, respectively”

• cites Enzan et al., 1997 sourceNot checked — no full text of the source
• cites Lorenz et al., 2018 sourceNot checked — no full text of the source

May combine two claims.

Hepatoblast migration is accomplished through CCM in mouse, where parenchymal progenitors are polarized into follower and leader cells: hepatoblasts and hepatomesenchyme, respectively.

“Our data suggest that hepatoblast migration is accomplished through CCM in mouse, where parenchymal progenitors are polarized into follower and leader cells: hepatoblasts and hepatomesenchyme, respectively.”

Classified as probably not a substantial claim.

Batch correction was performed to correct for non-biological confounders between replicates and time points.

“batch correction were performed to correct for non-biological confounders between replicates and time points”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In this study, randomization, stratification, blinding, and sample-size estimation were not performed.

“Randomization, stratification, blinding, or sample-size estimation were not performed.”

May combine two claims.

Hepatomesenchymal cells undergo a partial EMT, activating expression of a suite of genes involved in cell migration.

“Hepatomesenchymal cells undergo a partial EMT, activating the expression of a suite of genes involved in cell migration.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The authors' signaling analysis suggests potential roles for PDGF, TGFβ, or IGF pathways in polarization of hepatoblast and hepatomesenchymal cells.

“our signaling analysis suggests potential roles for PDGF, TGFβ, or IGF pathways.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Cells were filtered based on unique features (>1000 genes) and mitochondrial RNA content (<20%).

“cells were subsequently filtered based on unique features (> 1000 genes) and mitochondrial RNA content (< 20%)”

May combine two claims.

Hepatomesenchymal cells are specified at two temporally distinct points during the epithelial-to-hepatic transition and migrate into the STM via a partial EMT, with activation of Snai1, Snai2, and Zeb2.

“these analyses suggest that hepatomesenchymal cells are specified at two temporally distinct points during the epithelial-to-hepatic transition and migrate into the STM via a partial EMT, with the activation of Snai1, Snai2, and Zeb2.”