Daily Endocrinology Research Analysis
Three studies advance endocrinology across translational and clinical domains: (1) NCOA7-mediated granulophagy clears stress granules to mitigate ovarian aging with therapeutic rescue via LNP-mRNA or rapamycin; (2) gut commensal-derived polypeptides (RORDEPs) improve rodent metabolism and enhance incretin responses, pointing to microbiome-based therapeutics; (3) a randomized, placebo-controlled cross-over trial shows exenatide can rapidly provoke diagnostic hypoglycemia in endogenous hyperinsuli
Summary
Three studies advance endocrinology across translational and clinical domains: (1) NCOA7-mediated granulophagy clears stress granules to mitigate ovarian aging with therapeutic rescue via LNP-mRNA or rapamycin; (2) gut commensal-derived polypeptides (RORDEPs) improve rodent metabolism and enhance incretin responses, pointing to microbiome-based therapeutics; (3) a randomized, placebo-controlled cross-over trial shows exenatide can rapidly provoke diagnostic hypoglycemia in endogenous hyperinsulinemic hypoglycemia, offering a faster alternative to the 72-hour fast.
Research Themes
- Stress granule clearance and ovarian aging (granulophagy) as a therapeutic target
- Microbiome-derived peptides modulating host metabolic and incretin pathways
- GLP-1 receptor agonist challenge as a rapid diagnostic tool for hyperinsulinemic hypoglycemia
Selected Articles
1. Stress granule clearance mediated by V-ATPase-interacting protein NCOA7 mitigates ovarian aging.
This mechanistic study shows that NCOA7 enables autophagic clearance of stress granules (granulophagy) in granulosa cells via interaction with the G3BP1–V-ATPase complex, mitigating oxidative stress–driven ovarian aging. Genetic loss of NCOA7 accelerates ovarian senescence and fecundity decline, whereas rapamycin or LNP-mRNA delivery of NCOA7 rescues granulophagy and delays ovarian aging.
Impact: Identifies granulophagy as a modifiable node in ovarian aging and validates NCOA7 as a therapeutic target with rescue via LNP-mRNA or pharmacologic mTOR modulation. This reframes ovarian aging as a stress granule clearance disorder with tractable interventions.
Clinical Implications: While preclinical, strategies that enhance granulophagy (e.g., mTOR modulation or NCOA7 restoration) could form the basis of future trials to preserve ovarian function, extend reproductive longevity, or optimize ART outcomes in women with accelerated ovarian aging.
Key Findings
- NCOA7 expression is decreased and deleterious variants are identified in ovarian aging contexts; NCOA7 deletion accelerates ovarian senescence and fecundity decline in mice.
- NCOA7 partitions into G3BP1–V-ATPase-containing stress granules and promotes autophagic degradation (granulophagy).
- Rapamycin or LNP-mRNA delivery of NCOA7 enhances stress granule clearance, alleviates granulosa cell senescence, and delays ovarian aging in vivo.
- Defines stress granule clearance as a therapeutic axis for ovarian resilience to stress.
Methodological Strengths
- Multi-system validation including human granulosa cells, mouse genetics, and pharmacologic/mRNA rescue.
- Mechanistic dissection of NCOA7 localization and function in granulophagy (G3BP1–V-ATPase axis).
Limitations
- Preclinical models; translational efficacy and safety in humans remain unproven.
- Exact dosing, timing, and long-term effects of granulophagy modulation require clinical evaluation.
Future Directions: First-in-human biomarker-driven trials of granulophagy enhancers (e.g., mTOR modulators) or NCOA7-based therapeutics in women at risk of accelerated ovarian aging; development of imaging and molecular biomarkers of granulosa cell stress granules.
Reproductive longevity is essential for female fertility and healthy aging; however, the role of stress response, especially stress granule accumulation, in ovarian aging remains elusive and interventions are lacking. Here, we identified deleterious mutations and decreased expression of NCOA7, a stress-response protein related to granulosa cell senescence in women with physiological and pathological ovarian aging. NCOA7 deletion accelerates oxidative stress-related cellular senescence, ovarian aging and fecundity decline in mice. Mechanistically, NCOA7 partitions into the stress granule containing G3BP1-V-ATPase and facilitates autophagic degradation of stress granules to relieve stress. Boosting granulophagy with rapamycin or lipid nanoparticle-based mRNA delivery of NCOA7 accelerates stress granule clearance, alleviating cellular senescence in human granulosa cells and delaying ovarian aging in mice. This study depicts a mechanism for ovarian resilience to stress and provides potential targets for therapeutic strategies to alleviate ovarian aging.
2. Polypeptides synthesized by common bacteria in the human gut improve rodent metabolism.
Two circulating peptides (RORDEP1/2) produced by Ruminococcus torques inversely associate with human adiposity and causally improve rodent metabolism. In mice, RORDEP-expressing strains improved glucose tolerance, increased bone density, and reduced fat mass; recombinant RORDEP1 enhanced incretin responses and insulin action while suppressing hepatic gluconeogenesis and glycogenolysis.
Impact: Demonstrates microbiome-origin peptides as systemically active hormones that modulate incretin and hepatic pathways, opening a translational avenue for peptide/probiotic therapies in obesity and diabetes.
Clinical Implications: Though preclinical, RORDEPs or RORDEP-expressing probiotics could be developed to enhance GLP-1/PYY signaling, reduce adiposity, and improve hepatic insulin sensitivity; safety, immunogenicity, and durability require clinical testing.
Key Findings
- Identified two circulating human peptides (RORDEP1/2) produced by gut commensal Ruminococcus torques that inversely correlate with adiposity.
- RORDEP-expressing strains improved glucose tolerance, increased bone density, and reduced fat mass in both HFD-fed lean and DIO mice, with thermogenesis/lipolysis gene upregulation.
- Recombinant RORDEP1 decreased GIP and increased GLP-1, PYY, and insulin in rats.
- Intestinal delivery of RORDEP1 potentiated insulin-mediated suppression of hepatic glucose production and reprogrammed hepatic gene expression toward glycogenesis/glycolysis.
Methodological Strengths
- Integrated human association, gnotobiotic-style colonization with producing strains, and recombinant peptide pharmacology.
- Multi-organ readouts including bone density, adiposity, incretin hormones, and hepatic transcriptomics/proteomics.
Limitations
- Preclinical rodent data; human efficacy and safety are unknown.
- Potential variability among R. torques strains and peptide bioavailability/stability in humans.
Future Directions: Phase 1 studies of RORDEP1 pharmacokinetics, safety, and incretin responses in humans; standardized RORDEP-producing probiotic development; biomarker-guided trials in obesity/NAFLD/T2D.
The human gut microbiota has the potential to synthesize proteins that may influence host metabolism. Here we report two polypeptides, RUMTOR-derived peptide (RORDEP) 1 and RORDEP2, circulating in human blood and synthesized by specific strains of gut commensal Ruminococcus torques that correlate inversely with adiposity in humans. Oral gavage with RORDEP-expressing strains improved glucose tolerance, increased bone density and reduced fat mass with an enhanced expression of genes and proteins involved in thermogenesis and lipolysis in lean mice on a high-fat diet and diet-induced obese mice. Recombinant RORDEP1 given to rats intraperitoneally decreased plasma gastric inhibitory polypeptide but increased glucagon-like peptide 1, peptide YY and insulin. Intestinal delivery of recombinant RORDEP1 to rats potentiated insulin-mediated inhibition of hepatic glucose production by downregulating genes and proteins controlling liver gluconeogenesis, glycogenolysis and lipogenesis but upregulating those involved in insulin signalling, glycogenesis and glycolysis. These preclinical findings warrant the exploration of RORDEPs for the prevention and treatment of human metabolic disorders.
3. Exenatide for diagnosing endogenous hyperinsulinemic hypoglycemia: a randomized placebo-controlled, double-blind, cross-over proof-of-principle study.
In a double-blind cross-over trial in 14 EHH patients, 10 μg IV exenatide induced diagnostic hypoglycemia in 42% (vs 0% with placebo), with earlier nadirs and lower glucose levels. Exenatide reduced time to hypoglycemia versus the 72-hour fast (median ~1.4 h vs 12 h) and was well tolerated, with elevated proinsulin distinguishing EHH from controls.
Impact: Proposes a practical, rapid diagnostic challenge for EHH that could reduce inpatient time and costs while improving patient experience compared with the 72-hour fast.
Clinical Implications: Exenatide challenge could be incorporated as a stepwise diagnostic test for suspected EHH to shorten diagnostic timelines and triage patients for imaging/surgery; larger validation studies are needed to define sensitivity/specificity and protocols.
Key Findings
- Diagnostic hypoglycemia occurred in 42% of EHH patients with exenatide vs 0% with placebo (P = .005).
- Exenatide led to earlier (median 67 min) and deeper glucose nadirs compared with placebo.
- Proinsulin at 120 min post-exenatide was markedly higher in EHH vs controls (69 vs 9 pmol/L; P = .0001).
- Time to hypoglycemia was significantly shorter with exenatide (~1.4 h) than with the 72-hour fasting test (~12 h).
Methodological Strengths
- Randomized, placebo-controlled, double-blind, cross-over design in confirmed EHH.
- Objective biochemical endpoints (glucose nadir, insulin/C-peptide/proinsulin) and control group comparisons.
Limitations
- Small sample size and proof-of-principle scope limit precision of diagnostic performance estimates.
- Controls received exenatide unblinded; optimal dose/route and standardized diagnostic thresholds require confirmation.
Future Directions: Multicenter trials to establish sensitivity/specificity, optimal dosing and protocols, and comparative effectiveness vs gold-standard fasting in diverse EHH etiologies (e.g., insulinoma, nesidioblastosis).
OBJECTIVE: The 72 h fasting test, gold standard for diagnosing endogenous hyperinsulinemic hypoglycemia (EHH), is cumbersome and costly. We evaluated exenatide, a GLP-1 receptor agonist, as a faster, less burdensome alternative diagnostic tool. DESIGN AND METHODS: In this prospective, placebo-controlled, double-blind, randomized cross-over, proof-of-principle study, 10 μg intravenous exenatide was compared to placebo in 14 patients with confirmed EHH in a fasting test. Fourteen matched controls received 10 μg exenatide unblinded. Clinical monitoring and measurements of glucose, insulin, C-peptide, and proinsulin were performed for 4 h. Follow-up for EHH patients included imaging and histology. RESULTS: Exenatide induced diagnostic hypoglycemia in 6 of 14 EHH patients (42%) compared to none with placebo (P = .005). In patients with EHH, glucose nadir occurred earlier after exenatide (67 min [95% CI 50-142] vs 210 min [95% CI 174-219], P < .0001) and at lower glucose levels (2.68 mmol/L [95% CI 2.26-3.02] vs 3.2 mmol/L [95% CI 2.92-3.77], P < .0001) compared to placebo. Proinsulin levels 120 min post-exenatide were higher in patients with EHH [69 pmol/L (95% CI 3.8-232)] compared to controls [9 pmol/L (95% CI 4.5-16.9), P = .0001]. Compared to the fasting test, exenatide significantly shortened time to hypoglycemia (1.38 h [95% CI .67-2.99] vs 12 h [95% CI 1.44-36.1], P = .032). Exenatide was well tolerated and preferred by patients over the fasting test. CONCLUSIONS: Exenatide is a promising, faster, less cumbersome, and less expensive diagnostic tool for EHH compared to the fasting test. Larger trials are warranted to confirm its diagnostic utility. Trial Registration ClinicalTrials.gov (NCT04909333).