Daily Endocrinology Research Analysis
Analyzed 90 papers and selected 3 impactful papers.
Summary
Three impactful endocrinology/metabolism papers stood out today: a mechanistic study identifies RNF8 as the E3 ligase driving stress-induced degradation of hepatic ChREBPα and modulating MASH pathogenesis; a large target-trial emulation links GLP-1 receptor agonists to increased psoriasis but reduced autoimmune blistering disease risk versus DPP-4 inhibitors; and an integrative epidemiology-mechanistic study implicates fried-food–derived acrylamide in MAFLD via an arachidonic acid–PGE2–PPARα axis.
Research Themes
- Mechanistic targets in metabolic liver disease (RNF8–ChREBPα–JNK2 axis)
- Drug safety signals in incretin-based therapies (GLP-1 RAs vs DPP-4is and dermatologic outcomes)
- Dietary exposures and metabolic liver disease risk (acrylamide–PGE2–PPARα pathway)
Selected Articles
1. The E3 Ligase RNF8 Promotes Ubiquitination and Degradation of ChREBPα During Liver Stress Response.
This mechanistic study identifies RNF8 as the stress-induced E3 ligase that ubiquitinates and degrades hepatic ChREBPα via a JNK2-dependent pathway. Acute JNK2 or RNF8 depletion stabilizes ChREBPα in vivo and ameliorates diet-induced steatosis, inflammation, and fibrosis, nominating RNF8-mediated ChREBPα proteolysis as a therapeutic target in MASH.
Impact: It uncovers a previously uncharacterized stress-responsive proteolytic control of a central metabolic transcription factor (ChREBPα) and connects it to steatohepatitis severity, providing a druggable node (RNF8–JNK2).
Clinical Implications: Targeting RNF8 or its JNK2-dependent interaction with ChREBPα could preserve beneficial ChREBPα activity and mitigate steatohepatitis; hepatoselective, context-specific modulation will be essential given ChREBP’s pleiotropic roles.
Key Findings
- Combined palmitate and TNFα stress promotes ubiquitination and proteasome-dependent degradation of ChREBPα in hepatocytes.
- RNF8 is identified as a stress-induced E3 ligase that ubiquitinates ChREBPα in a JNK2-dependent manner.
- Acute in vivo depletion of JNK2 or RNF8 stabilizes hepatic ChREBPα, increases selected ChREBPα targets, and reduces diet-induced steatosis, inflammation, and fibrosis.
Methodological Strengths
- Integrates in vitro stress paradigms with in vivo genetic depletion to establish causality.
- Biochemical mapping of protein–protein interaction and ubiquitination, with pathway (JNK2) dependence.
Limitations
- Preclinical mouse/hepatocyte models; human validation is lacking.
- Not all ChREBPα targets increased upon stabilization, indicating context-dependent effects and potential off-target consequences of RNF8 modulation.
Future Directions: Develop hepatoselective RNF8 or JNK2 modulators; define structural interfaces for RNF8–ChREBPα binding; validate pathway activity and biomarkers in human MASH; assess metabolic safety of chronic RNF8 inhibition.
As the most common chronic liver disease, MASLD can progress to metabolic dysfunction-associated steatohepatitis (MASH) driven by accumulated metabolic and inflammatory stresses. We previously reported that liver ChREBPα protein is markedly downregulated in mouse models of diet-induced MASH and hepatotoxin-induced liver injury. Yet the impact of stress pathways on hepatocyte ChREBPα proteolysis has not been examined. Here, we show that a combined metabolic (palmitate, PA) and inflammatory (TNFα) stress signal promotes ubiquitination and proteasome-mediated degradation of ChREBPα in hepatocytes. More importantly, we identify the stress-induced E3 ligase RNF8 as interacting with and promoting ChREBPα ubiquitination and degradation in a JNK2-dependent manner. In vivo, acute depletion of JNK2 or RNF8 stabilizes ChREBPα in mouse liver, increases some but not all ChREBPα transcriptional targets, and reduces diet-induced liver steatosis, inflammation, and fibrosis. Overall, our findings reveal the biochemical machinery underlying stress-induced ChREBPα proteolysis and suggest that targeting RNF8-mediated ChREBPα ubiquitination could be a new strategy for treating MASH.
2. Frequent fried food intake fuels incidence of metabolic associated fatty liver disease attributed to acrylamide-induced hepatic lipid disorders through arachidonic acid-PGE2-PPARα axis.
In UK Biobank, frequent fried-food intake (notably fried potatoes) was associated with a 15% higher risk of incident MAFLD, partly mediated by BMI, triglycerides, CRP, and HDL-C. Mechanistically, chronic acrylamide exposure in mice induced hepatic lipid accumulation, suppressed adipose browning, and activated an arachidonic acid–PGE2 cascade that inhibited hepatic PPARα, impairing lipid oxidation.
Impact: It links a common dietary behavior to MAFLD using both large-scale human data and mechanistic validation, pinpointing a druggable inflammatory–nuclear receptor axis (PGE2–PPARα).
Clinical Implications: Advise MAFLD risk reduction via minimizing fried-food intake; therapeutically, targeting COX-2/mPGES–PGE2 signaling or restoring PPARα activity may counter acrylamide-driven hepatic lipid dysregulation.
Key Findings
- Frequent fried-food intake was associated with a 15% higher incident MAFLD risk in UK Biobank, mediated by BMI, triglycerides, CRP, and HDL-C.
- Dietary acrylamide exposure in mice increased hepatic lipid deposition, impaired liver function, and induced oxidative stress while suppressing adipose browning (UCP1, PRDM16, PGC1α, C/EBPβ, PPARγ downregulation).
- Acrylamide upregulated COX-2 and mPGES, elevating PGE2 that acted via PTGER3/4 to inhibit hepatic PPARα, thereby reducing lipid oxidation and promoting MAFLD pathogenesis.
Methodological Strengths
- Triangulation of evidence: large prospective cohort with mechanistic validation in vivo plus transcriptomics/lipidomics.
- Use of Cox models and mediation by metabolic/inflammatory markers; receptor-level insights supported by docking.
Limitations
- Dietary intake self-reported; residual confounding cannot be excluded.
- Translational gap in acrylamide dosing between mouse models and typical human exposure.
Future Directions: Quantify acrylamide exposure biomarkers in human MAFLD cohorts; test COX-2/mPGES inhibitors or PPARα agonists in preclinical models of acrylamide-driven steatosis; evaluate dietary interventions reducing fried-food intake.
INTRODUCTION: Fried food and hazard factors, particularly acrylamide, have been implicated in adverse health outcomes. However, how fried food consumption fuels the development of metabolic associated fatty liver disease (MAFLD) remains poorly understood. OBJECTIVES: We investigated fried food consumption in relation to MAFLD risk, which may be driven by acrylamide-induced hepatic lipid metabolism disorders. METHODS: UK Biobank data (n = 208,673) were analyzed to assess the association between fried food consumption and incident MAFLD using Cox proportional hazards models. In vivo, mice were exposed to dietary acrylamide for 14 weeks, followed by measurement of serum and hepatic lipid parameters. Transcriptomics and untargeted lipidomics were performed to elucidate the mechanisms underlying acrylamide-induced lipid dysregulation. The role of PGE2 was further validated via molecular docking analysis. RESULTS: Frequent consumption of fried foods, particularly fried potatoes, was linked with a 15% higher MAFLD risk, which was predominantly mediated by body mass index, serum triglycerides, C-reactive protein, and high-density lipoprotein cholesterol. Furthermore, long-term dietary exposure to acrylamide, a characteristic hazardous compound in fried food, significantly deteriorates lipid deposition, ultimately leading to impaired liver function and oxidative stress in liver of mice. Exposure to acrylamide inhibits the browning of white adipose and disturbs energy metabolism via downregulating uncoupling protein 1 and transcriptional regulators Prdm16, Pgc1α, Cebpβ, and Pparγ. Notably, acrylamide disrupts arachidonic acid metabolism and promotes the production of prostaglandin E2 (PGE2) driven by the upregulation of cyclooxygenase-2 and microsomal prostaglandin E synthase, which subsequently triggers hepatic inflammatory responses. Moreover, PGE2 interacts with PGE receptor Ptger3 or Ptger4 to inhibit PPARα activity, thus disrupting lipid oxidation and contributing to hepatic lipid dysfunction following long-term exposure to acrylamide. CONCLUSION: Both epidemiological and molecular evidence link acrylamide exposure to a higher MAFLD risk through the arachidonic acid-PGE2-PPARα axis, underscoring the importance of minimizing fried food consumption to preserve liver health.
3. Dermatologic outcomes associated with glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes: a large-scale target trial emulation.
In a 1:1 propensity-matched, target trial emulation (n=169,630 per arm), GLP-1 RA initiation was associated with higher incident psoriasis risk but lower risks of pemphigus and bullous pemphigoid versus DPP-4is over up to 4 years. Results were robust to sensitivity and subgroup analyses after accounting for protopathic bias.
Impact: Delivers high-powered, real-world comparative safety data on widely used incretin therapies, revealing divergent dermatologic risks that may influence drug selection and monitoring.
Clinical Implications: For patients at high psoriasis risk, clinicians may weigh alternatives or monitor closely when initiating GLP-1 RAs; conversely, reduced autoimmune blistering risk may favor GLP-1 RAs in susceptible individuals.
Key Findings
- After propensity matching (n=169,630 per arm) and excluding outcomes within 3 months, GLP-1 RAs increased incident psoriasis risk (HR 1.19, 95% CI 1.11–1.28) vs DPP-4is.
- GLP-1 RAs were associated with lower risks of pemphigus (HR 0.32, 95% CI 0.16–0.63) and bullous pemphigoid (HR 0.61, 95% CI 0.43–0.87).
- No significant differences for other autoimmune/inflammatory skin outcomes after multiple-testing correction; findings persisted across sensitivity and subgroup analyses.
Methodological Strengths
- Target trial emulation with active comparator and 1:1 propensity score matching in a very large dataset.
- Mitigation of protopathic bias by excluding early events; robust sensitivity and subgroup analyses.
Limitations
- Observational design cannot eliminate residual confounding or misclassification of diagnoses.
- Class-level analysis; heterogeneity among individual GLP-1 RAs or DPP-4is was not detailed.
Future Directions: Drug-specific analyses, mechanistic studies of GLP-1 signaling in skin immunity, and prospective surveillance to refine dermatologic risk stratification during incretin therapy.
BACKGROUND: While dipeptidyl peptidase-4 inhibitors (DPP-4is) are linked to autoimmune skin diseases, comparative data on glucagon-like peptide-1 receptor agonists (GLP-1 RAs) remain limited. METHODS: We emulated a randomized active-comparator trial using the TriNetX US Collaborative Network. Adults with type 2 diabetes (T2DM) initiating GLP-1 RAs or DPP-4is between January 1, 2018, and December 31, 2022, were identified, excluding prior users of either class. Balanced cohorts (n=169,630 each) were created using 1:1 propensity score matching. To address protopathic bias, outcomes occurring within 3 months after drug initiation were not considered. Patients were followed for up to 4 years for newly diagnosed autoimmune or inflammatory skin diseases. Cox regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Compared with DPP-4i initiation, GLP-1 RA initiation was associated with a higher risk of incident psoriasis (HR 1.19, 95% CI 1.11-1.28) and lower risks of pemphigus (HR 0.32, 95% CI 0.16-0.63) and bullous pemphigoid (HR 0.61, 95% CI 0.43-0.87). No significant differences were observed for other inflammatory or autoimmune skin outcomes after multiple-testing correction. Findings persisted across subgroup and sensitivity analyses. CONCLUSION: In a large, real-world study designed to emulate a clinical trial, GLP-1 RAs were linked to increased psoriasis and decreased autoimmune blistering diseases compared with DPP-4is over up to 4 years' follow-up. These results provide a dermatologic safety context to guide incretin therapy selection and highlight the importance of ongoing skin monitoring.