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Cited by 39Cholesterol and Lipid MetabolismLipid metabolism and disordersCancer, Lipids, and Metabolism

The DOI matches its Crossref record; 66 of the 67 references it cites were found in a registry or an index; 12 of the 83 sources its claims cite were checked for support.

Hepatic SREBP signaling requires SPRING to govern systemic lipid metabolism in mice and humans

Open access
Hendrix, Sebastian, Kingma, Jenina, Ottenhoff, Roelof, Valiloo, Masoud, Svecla, Monika, Zijlstra, Lobke F., Sachdev, Vinay, Kovac, Kristina, Levels, Johannes H. M., Jongejan, Aldo, de Boer, Jan F., Kuipers, Folkert, Rimbert, Antoine, Norata, Giuseppe D., Loregger, Anke, Zelcer, Noam·2023·Nature Communications
DOI 10.1038/s41467-023-40943-1PMC PMC10457316
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Abstract

The sterol regulatory element binding proteins (SREBPs) are transcription factors that govern cholesterol and fatty acid metabolism. We recently identified SPRING as a post-transcriptional regulator of SREBP activation. Constitutive or inducible global ablation of Spring in mice is not tolerated, and we therefore develop liver-specific Spring knockout mice (LKO). Transcriptomics and proteomics analysis reveal attenuated SREBP signaling in livers and hepatocytes of LKO mice. Total plasma cholesterol is reduced in male and female LKO mice in both the low-density lipoprotein and high-density lipoprotein fractions, while triglycerides are unaffected. Loss of Spring decreases hepatic cholesterol and triglyceride content due to diminished biosynthesis, which coincides with reduced very-low-density lipoprotein secretion. Accordingly, LKO mice are protected from fructose diet-induced hepatosteatosis. In humans, we find common genetic SPRING variants that associate with circulating high-density lipoprotein cholesterol and ApoA1 levels. This study positions SPRING as a core component of hepatic SREBP signaling and systemic lipid metabolism in mice and humans.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

Liver-specific loss of Spring in mice attenuates hepatic SREBP1/2 signaling, lowers plasma and hepatic lipids, reduces de novo lipogenesis and VLDL secretion, and protects against fructose-induced hepatosteatosis. In humans, common SPRING variants associate with HDL cholesterol and ApoA1 levels, positioning SPRING as a core hepatic SREBP regulator and systemic lipid determinant.

Key findings

  • Hepatic Spring deletion attenuated SREBP signaling: RNAseq showed downregulation of cholesterol biosynthesis and the SREBP1/2 gene programs; proteomics quantified 1,893 proteins, with 253 down- and 187 up-regulated in LKO livers, including reduced cholesterol and fatty acid synthesis proteins.
  • LKO mice had lower plasma total cholesterol in males and females (p < 0.0001) in both LDL and HDL fractions, while triglycerides were unaffected; hepatic cholesterol and triglycerides were also lower (male cholesterol p = 0.0035, TG p = 0.037; female cholesterol p = 0.0012, TG p = 0.0002).
  • Loss of Spring reduced de novo lipogenesis and VLDL secretion: newly synthesized C16:0 p = 0.006, C16:1 p = 0.029, C18:0 p = 0.002, C18:1 p = 0.019; hepatocyte cholesterol synthesis p = 0.0004; poloxamer-407 plasma TG accumulation p = 0.0023, AUC p = 0.034. LKO mice were protected from fructose-induced hepatosteatosis, with largely absent neutral-lipid staining and no fructose-induced hepatic cholesterol increase.
  • In humans, 17 SPRING SNPs associated with HDL-c (p < 5.0E-08) in GLGC (~1.6 million individuals); top SNP rs10507274-C (~6% frequency) associated with higher HDL-c (p = 8.6E-11, Beta = +0.0183) and in UK Biobank (~500,000) with higher HDL-c (p = 5.3E-09) and ApoA1 (p = 8.3E-16).

Methods

  • Generated liver-specific Spring knockout mice (Alb-Cre+ Spring fl/fl) and control littermates; also tested tamoxifen-inducible global deletion. Phenotyping included chow, fasting/refeeding, high-fructose diet, glucose/insulin tolerance tests, and poloxamer 407 VLDL secretion assay.
  • Used RNAseq, unbiased label-free proteomics, qPCR, immunoblot, primary hepatocytes, [13C]acetate DNL and [14C]acetate cholesterol synthesis, and FPLC plasma lipoprotein fractionation.
  • Human analyses used GLGC GWAS summary statistics (~1,654,960 individuals) and UK Biobank (~500,000) for SPRING locus associations, plus variant effect prediction and AlphaFold2 modeling.

Limitations

  • The paper states the mechanism linking SPRING p.Gln55Arg to increased HDL in humans is unclear; the proposed structural effect is speculative, and the atomic structure of SPRING alone or with S1P has not been reported.
  • The paper states the relative roles of S1P and other S1P substrates in hepatic SPRING-dependent SREBP regulation were not extensively evaluated; future studies are warranted. It also notes the primary cause of lethargy after global Spring deletion was not identified.
  • Evident from the text: human evidence is genetic association only, without functional validation of rs10507274; many dietary/metabolic challenge experiments used male mice, and the mouse LKO model cannot establish causality for human lipoprotein traits.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1038/s41467-023-40943-1

Cites

66 of 66 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

12 of 83 cited sources checked · 4 supported · 1 flagged · accuracy not yet measured

  • Premisecitation

    The proteolytic activation of S1P into its mature Golgi-associated form is attenuated in SPRING-deficient cells.

    “Additionally, the proteolytic activation of S1P into its mature Golgi-associated form is attenuated13,14.”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [13] Xiao, J. et al. POST1/C12ORF49 regulates the SREBP pathway by promoting site-1 protease maturation. Protein Cell 12, 279–296 (2021). source
    • cites [14] Hendrix, S. et al. Intermolecular proteolytic processing of SPRING and Site-1-protease regulate SREBP signaling. bioRxiv https://doi.org/10.1101/2023.03.28.534447 (2023). source
  • Premiseown data

    Ablation of Scap, Mbtps1, and Spring results in decreased cholesterol synthesis in isolated primary hepatocytes.

    “Moreover, (iv) ablation of all 3 genes results in decreased cholesterol synthesis in isolated primary hepatocytes”
    Quote in the paperSubstantial claim3 of 4 sources checked
    • cites [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source

      The Results (‘SPRING is a determinant of the SREBP pathway in cells’; page unavailable) report that loss of Spring attenuated SREBP activity in primary mouse hepatocytes. But the cholesterol-synthesis assay was performed in Hap1 cells (Methods, ‘Cholesterol synthesis assay’; page unavailable), and the copy does not report decreased cholesterol synthesis after ablation of Scap, Mbtps1, and Spring in isolated primary hepatocytes. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [21] Yang, J. et al. Decreased lipid synthesis in livers of mice with disrupted Site-1 protease gene. Proc. Natl Acad. Sci. USA 98, 13607–13612 (2001). source
    • cites [31] Matsuda, M. et al. SREBP cleavage-activating protein (SCAP) is required for increased lipid synthesis in liver induced by cholesterol deprivation and insulin elevation. Genes Dev. 15, 1206–1216 (2001). source

      The Results (page unavailable in our copy) report that cholesterol synthesis fell by 84% in fresh primary hepatocytes from SCAP-disrupted mice. The paper does not report corresponding ablation experiments for Mbtps1 or Spring, so it supports only the Scap portion of the claim. (LLM, conf=0.90)

      Experimental — accuracy not yet measured
    • cites [32] Moon, Y. A. et al. The Scap/SREBP pathway is essential for developing diabetic fatty liver and carbohydrate-induced hypertriglyceridemia in animals. Cell Metab. 15, 240–246 (2012). source

      The Results section on sucrose-fed hamsters reports that Scap silencing reduced liver mRNAs for two cholesterol-synthesizing enzymes. It describes primary hepatocytes only as a screen for Scap siRNA, not as a measurement of cholesterol synthesis. Our copy does not report ablation of Mbtps1 or Spring, so it does not support the claim for all three genes. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Restoration of SREBP function in Hap1-SpringKO cells occurs when SCAP is introduced.

    “This contrasts with the restoration of SREBP function in these cells when SCAP is introduced10.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source
  • Findingown data

    Total plasma cholesterol is reduced in male and female LKO mice, in both the LDL and HDL fractions.

    “Total plasma cholesterol is reduced in male and female LKO mice in both the low-density lipoprotein and high-density lipoprotein fractions”
    • Also stated in: § Lipid metabolism is dysregulated in LKO mice · plain
      “Both male and female LKO mice showed a dramatic reduction in circulating cholesterol levels”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The SREBP pathway governs hepatic lipid and lipoprotein metabolism, and perturbations in this pathway have profound metabolic effects.
  • Findingown data

    Transcriptomics and proteomics analysis reveal attenuated SREBP signaling in livers and hepatocytes of LKO mice.

    “Transcriptomics and proteomics analysis reveal attenuated SREBP signaling in livers and hepatocytes of LKO mice.”
    • Also stated in: § SREBP signaling is attenuated in livers of LKO mice · boosted
      “revealed a dramatic attenuation of the complete SREBP1- and SREBP2-regulated gene programs”
    Quote in the paperSubstantial claim
  • It may state two separate claims as one. 22
  • Probably not a substantial claim. 22

  • It may state two separate claims as one.

    Premiseown data

    In plasma, total cholesterol and triglycerides are lower in all mice with the exception that triglycerides are largely unchanged in Spring LKO.

    “In plasma, (iii) total cholesterol and triglycerides are lower in all mice with the only exception being that the latter is largely unchanged in Spring LKO.”
    Quote in the paperSubstantial claim3 of 4 sources checked
    • cites [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source

      The Results section (‘Spring attenuates hepatic SREBP signaling in vivo’; page unavailable) reports no differences in plasma lipids after hepatic Spring silencing, contrary to the claimed reductions. It also says constitutive Spring-knockout mice could not be studied because of early embryonic lethality. (LLM, conf=0.90)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites [21] Yang, J. et al. Decreased lipid synthesis in livers of mice with disrupted Site-1 protease gene. Proc. Natl Acad. Sci. USA 98, 13607–13612 (2001). source
    • cites [31] Matsuda, M. et al. SREBP cleavage-activating protein (SCAP) is required for increased lipid synthesis in liver induced by cholesterol deprivation and insulin elevation. Genes Dev. 15, 1206–1216 (2001). source

      The Results and Tables 1–2 report lower plasma cholesterol and triglycerides in SCAP-deficient mice, although the triglyceride difference narrows with fasting. The paper studies SCAP-deficient mice, not Spring LKO mice, so it does not support the claim about unchanged triglycerides in Spring LKO or the generalization to all the mice mentioned. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [32] Moon, Y. A. et al. The Scap/SREBP pathway is essential for developing diabetic fatty liver and carbohydrate-induced hypertriglyceridemia in animals. Cell Metab. 15, 240–246 (2012). source

      The Results section on liver-specific Scap deletion reports lower liver triglycerides in mice, not lower plasma cholesterol and triglycerides. The plasma-triglyceride reduction reported in the Results concerns sucrose-fed hamsters. Searches for Spring LKO and mouse plasma lipid measurements found no passage addressing the claimed exception or the stated pattern across mice; page numbers were unavailable in our copy. (LLM, conf=0.76)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim.

    Premisecitation

    A decrease in ER-membrane cholesterol content results in dissociation of INSIG from SCAP and COPII-dependent anterograde transport of the SCAP/SREBP complex to the Golgi.

    “A decrease in ER-membrane cholesterol content results in the dissociation of INSIG from SCAP, and COPII-dependent anterograde transport of the SCAP/SREBP complex to the Golgi4,5”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [4] Radhakrishnan, A., Goldstein, J. L., McDonald, J. G. & Brown, M. S. Switch-like control of SREBP-2 transport triggered by small changes in ER cholesterol: a delicate balance. Cell Metab. 8, 512–521 (2008). source
    • cites [5] Espenshade, P. J., Li, W. P. & Yabe, D. Sterols block binding of COPII proteins to SCAP, thereby controlling SCAP sorting in ER. Proc. Natl Acad. Sci. USA 99, 11694–11699 (2002). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Released N-terminal SREBP-1 and SREBP-2 transcriptional domains translocate to the nucleus to activate transcriptional programs that promote fatty acid and cholesterol biosynthesis.

    “The released N-terminal SREBP-1 and −2 transcriptional domains translocate to the nucleus to activate transcriptional programs that promote fatty acid and cholesterol biosynthesis, respectively8.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [8] Horton, J. D., Goldstein, J. L. & Brown, M. S. SREBPs: activators of the complete program of cholesterol and fatty acid synthesis in the liver. J. Clin. Investig. 109, 1125–1131 (2002). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation

    SCAP and the remnant C-terminal domain of SREBP undergo retrograde transport to the ER, where remnant SREBP is degraded and SCAP can enter a new cycle of SREBP activation.

    “At the same time, SCAP and the remnant C-terminal domain of SREBP undergo retrograde transport to the ER, where remnant SREBP is degraded and SCAP can enter a new cycle of SREBP activation1,9.”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [1] Goldstein, J. L., DeBose-Boyd, R. A. & Brown, M. S. Protein sensors for membrane sterols. Cell 124, 35–46 (2006). source

      The passage describing Scap/SREBP transport (indexed as Abstract; page unavailable) says the complex moves from the ER to the Golgi, where SREBP is processed. Searches for retrograde transport, the SREBP remnant, and Scap recycling found no passage saying that Scap and the remnant return to the ER or that the remnant is degraded there. (LLM, conf=0.72)

      Experimental — accuracy not yet measured
    • cites [9] Kober, D. L. et al. Identification of a degradation signal at the carboxy terminus of SREBP2: A new role for this domain in cholesterol homeostasis. Proc. Natl Acad. Sci. USA 117, 28080–28091 (2020). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Pharmacological or antisense-mediated inhibition of hepatic SCAP function in rodents and non-human primates is emerging as a potential lipid-lowering and hepato/cardio-protective strategy.

    “pharmacological or antisense-mediated inhibition of hepatic SCAP function in rodents and non-human primates is emerging as a potential lipid-lowering and hepato/cardio-protective strategy32,42,43”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [32] Moon, Y. A. et al. The Scap/SREBP pathway is essential for developing diabetic fatty liver and carbohydrate-induced hypertriglyceridemia in animals. Cell Metab. 15, 240–246 (2012). source

      The Results section reports that hepatic Scap silencing with siRNA lowered plasma and liver triglycerides in sucrose-fed hamsters; the Discussion identifies Scap as a potential target for treating fatty liver and hypertriglyceridemia. The paper does not report SCAP inhibition in non-human primates, pharmacological or antisense-oligonucleotide SCAP inhibition, or cardiovascular protection. Page numbers are unavailable in our copy. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [42] Jensen, K. K. et al. Dose-dependent effects of siRNA-mediated inhibition of SCAP on PCSK9, LDLR, and plasma lipids in mouse and rhesus monkey. J. Lipid Res. 57, 2150–2162 (2016). source
    • cites [43] Tang, J. J. et al. Inhibition of SREBP by a small molecule, betulin, improves hyperlipidemia and insulin resistance and reduces atherosclerotic plaques. Cell Metab. 13, 44–56 (2011). source

  • It may state two separate claims as one.

    Findingown data

    No differences in weight gain or in the liver/body-weight ratio were observed between control and LKO mice during the fructose dietary challenge.

    “No differences in weight gain or in the liver/body-weight ratio were observed between control and LKO mice during the dietary challenge”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    Glucose and insulin tolerance tests were comparable between LKO and control mice.

    “In both assays LKO and their control counterpart mice were comparable”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingnone given

    The rs10507274-C variant results in a p.Gln55Arg change in SPRING, which is associated with elevated circulating HDL and ApoA1 levels in humans.

    “The identified SNP (rs10507274-C) results in a p.Gln55Arg change in SPRING (SPRINGQ55R), which is associated with elevated circulating HDL and ApoA1 levels in humans.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data

    Dietary fructose did not induce changes in circulating plasma cholesterol and triglyceride levels; these were comparable to those measured in chow-fed mice.

    “Similarly, dietary fructose did not induce changes in circulating plasma cholesterol and triglyceride levels, and these were comparable to those measured in chow-fed mice”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data

    LKO mice were born with normal mendelian distribution and showed no overt hepatic phenotype when fed normal chow.

    “LKO mice were born with normal mendelian distribution and showed no overt hepatic phenotype when fed normal chow (Fig. 1b–d).”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    None of the 17 SPRING SNPs that significantly associated with plasma HDL-c associated with hepatic Spring expression, nor were they reported in the GTEx dataset as eQTLs.

    “None of the 17 SPRING SNPs that significantly associated with plasma HDL-c associated with hepatic Spring expression, nor were they reported in the GTEx dataset as eQTLs.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    Proteomics quantified 1893 proteins, of which 253 were down-regulated and 187 up-regulated in livers of LKO mice.

    “A total of 1893 proteins were quantified, of which 253 and 187 were down- and up-regulated, respectively, in livers of LKO mice.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data

    Impaired VLDL-triglyceride secretion did not result in increased hepatic cholesterol or triglyceride levels; these were lower in both male and female LKO mice.

    “Importantly, impaired VLDL-triglyceride secretion did not result in increased hepatic cholesterol or triglyceride levels, as these were lower in both male and female LKO mice”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data

    rs10507274 was associated with a reduction in plasma LDL cholesterol and triglyceride levels, but this did not reach genome-wide statistical significance.

    “Of note, rs10507274 was associated with a reduction in plasma low-density lipoprotein cholesterol and triglyceride levels, but this did not reach genome-wide statistical significance”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    LKO mice appeared refractory to fructose and hepatic cholesterol content remained comparable to that in chow-fed LKO mice.

    “In contrast to control mice, LKO mice appeared to be refractory to fructose and hepatic cholesterol content remained comparable to that in chow-fed LKO mice.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Findingown data

    Plasma glucose levels in 4 h fasted mice were slightly lower in LKO mice.

    “Unexpectedly, plasma glucose levels in 4 h fasted mice were slightly lower in LKO mice”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Findingown data

    By 2 weeks after the last tamoxifen injection, Spring(fl/fl) CreERT2+ mice reached humane endpoint criteria requiring their killing, precluding detailed analysis of this inducible global deletion model.

    “By 2 weeks post the last injection Spring(fl/fl) CreERT2+ mice reached humane endpoint criteria requiring their killing thereby precluding detailed analysis of this model.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Findingown data

    No steric clashes were found in this region in all wild type models of SPRING.

    “No steric clashes were found in this region in all wild type models of SPRING”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Association of SREBPs with SCAP and INSIG couples their ER retention and proteolytic activation to sensing of ER membrane cholesterol by SCAP.

    “Their association in a complex with SCAP and INSIG couples their retention in the ER and subsequent proteolytic activation to the sensing of cholesterol content in the ER membrane by SCAP1–3.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [1] Goldstein, J. L., DeBose-Boyd, R. A. & Brown, M. S. Protein sensors for membrane sterols. Cell 124, 35–46 (2006). source
    • cites [2] Jeon, T. I. & Osborne, T. F. SREBPs: metabolic integrators in physiology and metabolism. Trends Endocrinol. Metab. 23, 65–72 (2012). source
    • cites [3] Brown, M. S., Radhakrishnan, A. & Goldstein, J. L. Retrospective on cholesterol homeostasis: the central role of scap. Annu. Rev. Biochem. 87, 783–807 (2018). source

  • It may state two separate claims as one.

    Interpretationown data

    This study positions SPRING as a core component of hepatic SREBP signaling and systemic lipid metabolism in mice and humans.

    “This study positions SPRING as a core component of hepatic SREBP signaling and systemic lipid metabolism in mice and humans.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Premisecitation

    In the liver, cholesterol levels are lower in Scap and Spring mice, but unchanged in Mbtps1 mice.

    “In the liver (i) cholesterol levels are lower in Scap and Spring mice, but unchanged in Mbtps1 mice”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source
    • cites [21] Yang, J. et al. Decreased lipid synthesis in livers of mice with disrupted Site-1 protease gene. Proc. Natl Acad. Sci. USA 98, 13607–13612 (2001). source
    • cites [31] Matsuda, M. et al. SREBP cleavage-activating protein (SCAP) is required for increased lipid synthesis in liver induced by cholesterol deprivation and insulin elevation. Genes Dev. 15, 1206–1216 (2001). source
    • cites [32] Moon, Y. A. et al. The Scap/SREBP pathway is essential for developing diabetic fatty liver and carbohydrate-induced hypertriglyceridemia in animals. Cell Metab. 15, 240–246 (2012). source

  • It may state two separate claims as one.

    Study design and conductown data

    Ablation of hepatic Spring in LKO mice was highly effective and tissue specific.

    “Ablation of hepatic Spring was highly effective and tissue specific (Fig. 1a)”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    SREBPs are proteolytically cleaved by the sequential activity of S1P and S2P in the Golgi.

    “where SREBPs are proteolytically cleaved by the sequential activity of S1P and S2P (encoded by MBTPS1 and MBTPS2, respectively)6,7”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [6] Sakai, J. et al. Sterol-regulated release of SREBP-2 from cell membranes requires two sequential cleavages, one within a transmembrane segment. Cell 85, 1037–1046 (1996). source
    • cites [7] Seidah, N. G. & Prat, A. The biology and therapeutic targeting of the proprotein convertases. Nat. Rev. Drug Discov. 11, 367–383 (2012). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Global deletion of Srebf1 results in 50-85% embryonic lethality.

    “In mice, global deletion of Srebf1 (encoding SREBP1) results in 50–85% embryonic lethality29”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [29] Shimano, H. et al. Elevated levels of SREBP-2 and cholesterol synthesis in livers of mice homozygous for a targeted disruption of the SREBP-1 gene. J. Clin. Invest. 100, 2115–2124 (1997). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Global ablation of Spring and Mbtps1 in mice is embryonically lethal.

    “Additionally, while global ablation of Spring and Mbtps1 in mice is embryonically lethal10,21”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source
    • cites [21] Yang, J. et al. Decreased lipid synthesis in livers of mice with disrupted Site-1 protease gene. Proc. Natl Acad. Sci. USA 98, 13607–13612 (2001). source

  • It may state two separate claims as one.

    Interpretationown data

    Hepatic loss of Scap, Mbtps1, and Spring has largely overlapping consequences, consistent with SPRING's proposed mechanism of action.

    “This comparison illustrates the largely overlapping consequence of hepatic loss of Scap, Mbtps1, and Spring, consistent with the latter’s proposed mechanism of action.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Interpretationreasoning

    A different process likely underlies the reduced glucose levels in LKO mice.

    “indicating that a different process likely underlies the reduced glucose levels in LKO”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Functional prediction algorithms (8 of 10), including SIFT and PolyPhen, considered p.Gln55Arg benign and tolerated, with only Mutation taster and LRT scoring this change as deleterious.

    “Functional prediction algorithms (8 of 10), including SIFT33 and PolyPhen34, considered this change to be benign and tolerated, with only Mutation taster35 and LRT36 scoring this change as deleterious.”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [33] Ng, P. C. & Henikoff, S. Predicting deleterious amino acid substitutions. Genome Res. 11, 863–874 (2001). source
    • cites [34] Adzhubei, I. A. et al. A method and server for predicting damaging missense mutations. Nat. Methods 7, 248–249 (2010). source
    • cites [35] Schwarz, J. M., Cooper, D. N., Schuelke, M. & Seelow, D. MutationTaster2: mutation prediction for the deep-sequencing age. Nat. Methods 11, 361–362 (2014). source
    • cites [36] Chun, S. & Fay, J. C. Identification of deleterious mutations within three human genomes. Genome Res. 19, 1553–1561 (2009). source

  • It may state two separate claims as one.

    Interpretationown data

    Loss of hepatic Spring bears semblance to reduced SCAP activity: it improves the plasma lipid profile, reduces hepatic lipid content, decreases fasting glucose, and protects mice from fructose-induced hepatosteatosis, with no measurable or overt signs of hepatic damage.

    “Namely, this improves the plasma lipid profile, reduces hepatic lipid content, decreases fasting glucose, and protects mice from fructose-induced hepatosteatosis; all with no measurable or overt signs of hepatic damage.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductnone given

    p values were corrected for multiple testing using the Benjamini-Hochberg false discovery rate.

    “The p values were corrected for multiple testing using the Benjamini-Hochberg false discovery rate.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Premisecitation

    The SPRING cysteine-rich domain is necessary and sufficient for interacting with S1P and SCAP, and for promoting S1P proteolytic maturation and restoration of SREBP signaling in SPRINGKO cells.

    “which is both necessary and sufficient for interacting with S1P12–14 and SCAP10, and for promoting S1P proteolytic maturation and restoration of SREBP signaling in SPRINGKO cells14”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source
    • cites [12] Bayraktar, E. C. et al. Metabolic coessentiality mapping identifies C12orf49 as a regulator of SREBP processing and cholesterol metabolism. Nat. Metab. 2, 487–498 (2020). source
    • cites [13] Xiao, J. et al. POST1/C12ORF49 regulates the SREBP pathway by promoting site-1 protease maturation. Protein Cell 12, 279–296 (2021). source
    • cites [14] Hendrix, S. et al. Intermolecular proteolytic processing of SPRING and Site-1-protease regulate SREBP signaling. bioRxiv https://doi.org/10.1101/2023.03.28.534447 (2023). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductnone given

    Unless indicated, immunoblots are representative of at least three independent experiments with similar results.

    “Unless indicated, immunoblots are representative of at least three independent experiments with similar results.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim.

    Study design and conductnone given

    In all experiments, Alb-Cre-Spring(fl/fl) littermates were used as controls.

    “and in all experiments Alb-Cre–Spring(fl/fl) littermates were used as controls.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    The Global Lipids Genetics Consortium aggregated GWAS results from 1,654,960 individuals from 201 primary studies representing five genetic ancestry groups.

    “The Global Lipids Genetics Consortium aggregated GWAS results from 1,654,960 individuals from 201 primary studies representing five genetic ancestry groups28.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [28] Graham, S. E. et al. The power of genetic diversity in genome-wide association studies of lipids. Nature 600, 675–679 (2021). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductown data

    No violation of normal distribution was found using the Shapiro-Wilk and Kolmogorov-Smirnov tests.

    “No violation of normal distribution was found using the Shapiro-Wilk and Kolmogorov-Smirnov tests.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim.

    Premisecitation

    Expression of Cre-recombinase in the Spring(fl/fl) model results in excision of exons 2-5.

    “Expression of Cre-recombinase results in excision of exons 2-5.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Loregger et al. [10] Loregger, A. et al. Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism. Nat. Commun. 11, 1128 (2020). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductnone given

    The mouse ID was included as a random effect in the linear model to estimate the consensus correlation, using duplicateCorrelation from the limma package.

    “The mouse ID was included as a random effect in the linear model to estimate the consensus correlation, using duplicateCorrelation from the limma package.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    The Genebass dataset encompasses 4529 phenotypes with gene-based and single-variant testing across 394,841 individuals with exome sequence data from the UK Biobank.

    “The dataset encompasses 4529 phenotypes with gene-based and single-variant testing across 394,841 individuals with exome sequence data from the UK Biobank.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [64] Karczewski, K. J. et al. Systematic single-variant and gene-based association testing of thousands of phenotypes in 394,841 UK Biobank exomes. Cell Genom. 2, 100168 (2022). source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation

    The UK Biobank is a population-based prospective cohort in the United Kingdom in which more than 500,000 individuals aged between 40 and 69 years were included from 2006 to 2010.

    “The UK Biobank study, described in detail previously58, is a population-based prospective cohort in the United Kingdom in which >500,000 individuals aged between 40 and 69 years were included from 2006 to 2010.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [58] Sudlow, C. et al. UK biobank: an open access resource for identifying the causes of a wide range of complex diseases of middle and old age. PLoS Med. 12, e1001779 (2015). source

  • It may state two separate claims as one.

    Interpretationcitation

    The variant amino acid is located distal to the S1P cleavage site in SPRING and is not expected to preclude the cleavage event or their interaction.

    “The variant amino acid is located distal to the S1P cleavage site in SPRING we identified (R45NLL48), and is not expected to preclude the cleavage event or their interaction”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14] Hendrix, S. et al. Intermolecular proteolytic processing of SPRING and Site-1-protease regulate SREBP signaling. bioRxiv https://doi.org/10.1101/2023.03.28.534447 (2023). source

  • It may state two separate claims as one.

    Premisecitation

    These individuals present with skeletal dysplasia and elevated levels of mistargeted lysosomal enzymes in their circulation.

    “Clinically, these individuals present with skeletal dysplasia and elevated levels of mistargeted lysosomal enzymes in their circulation.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [39] Kondo, Y. et al. Site-1 protease deficiency causes human skeletal dysplasia due to defective inter-organelle protein trafficking. JCI Insight 3, e121596 (2018). source
    • cites [40] Meyer, R., Elbracht, M., Opladen, T. & Eggermann, T. Patient with an autosomal-recessive MBTPS1-linked phenotype and clinical features of Silver-Russell syndrome. Am. J. Med. Genet. A 182, 2727–2730 (2020). source
    • cites [41] Carvalho, D. R., Speck-Martins, C. E., Brum, J. M., Ferreira, C. R. & Sobreira, N. L. M. Spondyloepimetaphyseal dysplasia with elevated plasma lysosomal enzymes caused by homozygous variant in MBTPS1. Am. J. Med. Genet. A 182, 1796–1800 (2020). source

  • It may state two separate claims as one.

    Premisecitation

    Despite having only about 1% functional MBTPS1 transcripts, plasma lipid levels were largely unchanged in the patient compared to the unaffected mother and sister, with the notable difference being a reduction in plasma HDL levels.

    “Remarkably, despite having only ~1% functional MBTPS1 transcripts, plasma lipid levels were largely unchanged in the patient as compared to the unaffected mother and sister39, the only notable difference being a reduction in plasma HDL levels.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [39] Kondo, Y. et al. Site-1 protease deficiency causes human skeletal dysplasia due to defective inter-organelle protein trafficking. JCI Insight 3, e121596 (2018). source
42 of 42

  • The authors state this as an assumption.

    A fructose-enriched diet stresses hepatic de novo lipogenesis and promotes development of hepatosteatosis.

    “reasoning that this carbohydrate-rich diet stresses hepatic DNL and development of hepatosteatosis”

  • The paper relies on this without support.

    The SREBP pathway governs hepatic lipid and lipoprotein metabolism, and perturbations in this pathway have profound metabolic effects.

    “The SREBP pathway governs hepatic lipid and lipoprotein metabolism, and lesions or perturbations in this pathway have profound metabolic effects.”

  • The paper relies on this without support.

    The insulin-driven transcriptional program is required to prime hepatocytes to increase de novo lipogenesis in the face of enhanced substrate availability.

    “This insulin-driven transcriptional program is required, amongst others, to prime hepatocytes to increase de novo lipogenesis (DNL) in face of enhanced substrate availability.”
3 of 3

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Fasting-refeeding groups account for 17, not 18, LKO mice

    Minor

    The two reported LKO subgroups contain 9 and 8 mice, totaling 17, but the stated LKO total is 18.

    Reported 18 · recomputed 17

  • Transaminase results cite panels measuring other outcomes

    Minor

    The text points to Fig. 4e and f for plasma transaminases, but those panels concern fatty acids and cholesterol synthesis. The figure caption places AST and ALT in Fig. 5e and f.

  • Proteomics sample counts differ between figure and methods

    Minor

    Figure 2 says five mice per group were collected for proteomics, whereas the methods say liver tissue from six mice per group was prepared for that analysis. The text does not account for the difference.

3 of 3

Citations

Cites

Flagged first, then by citations

1 of the 67 references couldn’t be matched to a known paper.

Cited by

Sorted by citations

Related

Metadata

Authors
Hendrix, S., Kingma, J., Ottenhoff, R., Valiloo, M., Svecla, M., Zijlstra, L. F., Sachdev, V., Kovac, K., Levels, J. H. M., Jongejan, A., de Boer, J. F., Kuipers, F., Rimbert, A., Norata, G. D., Loregger, A., & Zelcer, N.
Affiliations
  • Amsterdam University Medical Centers (NL)
  • University of Milan (IT)
  • Amsterdam UMC Location University of Amsterdam (NL)
  • University Medical Center Groningen (NL)
  • Centre National de la Recherche Scientifique (FR)
Corresponding author
Zelcer, Noam
ORCID
Venue
Nature Communications
Publisher
Springer Science and Business Media LLC
Published
2023-08-25
Volume
14
Issue
1
Pages
5181-5181
ISSN
2041-1723 (ISSN-L)
DOI
10.1038/s41467-023-40943-1
PMC
PMC10457316
OpenAlex
W4386164985
Cited by
34
References
67
Citations by year
2026: 8 · 2025: 16 · 2024: 9 · 2023: 1
FWCI
4.14
Type
journal article
Language
en
Open access
Licence
Locations
  • Nature Communications (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • HAL (submittedVersion, cc-by)
  • Archivio Istituzionale della Ricerca (Universita Degli Studi Di Milano) (submittedVersion, cc-by)
  • Pure Amsterdam UMC (submittedVersion, cc-by)
  • RePEc: Research Papers in Economics (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Amsterdam UMC (VU Amsterdam) - Institutional Repository (submittedVersion, other-oa)
  • University of Groningen research database (University of Groningen / Centre for Information Technology) (submittedVersion, cc-by)
Funders
  • Università degli Studi di Milano
  • Institut Français de Bioinformatique (ANR-11-INBS-0013)
  • Agence Nationale de la Recherche (ANR-21-CE14-0051, ANR-11-INBS, ANR-11-INBS-0013)
  • Rijksuniversiteit Groningen
  • Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO; 016.176.643, 016.176.643)
  • H2020 European Research Council (862537)
  • FP7 Ideas: European Research Council (617376)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biochemistry › Cholesterol and Lipid Metabolism
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Lipid metabolism and disorders
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Cancer, Lipids, and Metabolism
Keywords
springs, SREBP signaling, SREBP, hepatic lipid metabolism, liver-specific knockout mice, serum cholesterol, very low density lipoprotein secretion, hepatic steatosis, fructose diet, HDL cholesterol, apolipoprotein A-I, post-transcriptional regulation, genetic variants
MeSH terms
Animals, Female, Humans, Lipoproteins, HDL, Liver, Male, Hepatocytes, Lipid Metabolism, Mice, Sterol Regulatory Element Binding Protein 1

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-11-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-11-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Cited sources are checked with a language model’s help (gpt-6-sol).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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