Daily Endocrinology Research Analysis
Analyzed 82 papers and selected 3 impactful papers.
Summary
Analyzed 82 papers and selected 3 impactful articles.
Selected Articles
1. Metabolic dysfunction-associated steatohepatitis exacerbated by Clostridium perfringens-derived ammonia is attenuated by tripeptide DT-109.
Across human cohorts and primate/mouse models, C. perfringens overgrowth increased intestinal ammonia, disrupted barrier integrity, and activated CD8+ T cells via FosB–CCL5 to drive MASH. The tripeptide DT-109 reduced C. perfringens and ammonia, restored barrier function, normalized CD8+ T cell activity, and ameliorated MASH features.
Impact: This work reveals a novel, targetable microbiome–ammonia–immune axis in MASH and demonstrates cross-species therapeutic efficacy of DT-109, opening translational paths for a disease with limited treatments.
Clinical Implications: Suggests microbiome-directed and ammonia-lowering interventions (e.g., DT-109) as potential therapies. Biomarkers such as intestinal ammonia, C. perfringens abundance, and CD8+ T cell CCL5 signaling could aid stratification.
Key Findings
- C. perfringens expansion increased intestinal ammonia and disrupted barrier integrity in MASH.
- Ammonia triggered FosB-mediated CCL5 upregulation in CD8+ T cells, driving hepatic cytotoxicity.
- DT-109 reduced C. perfringens and ammonia, restored barrier integrity, normalized CD8+ T cells, and improved MASH across species.
- Causality supported by microbiota transplantation and NirA-knockout mutant experiments.
Methodological Strengths
- Multi-omics across human cohorts and primate/mouse models with in vitro/in vivo validation
- Causal inference via microbiota transplantation and bacterial gene knockout (NirA) approaches
Limitations
- Predominantly preclinical; absence of randomized human intervention trials with DT-109
- Safety, dosing, and durability of DT-109 effects in humans remain to be established
Future Directions: Early-phase clinical trials to evaluate DT-109 safety/efficacy; validation of ammonia and C. perfringens as biomarkers/targets; dissecting FosB–CCL5 signaling for adjunctive immunomodulation.
The global prevalence of metabolic dysfunction-associated steatohepatitis (MASH) is rising, driven by a complex interplay of metabolic disturbances, inflammation, and fibrosis, yet effective treatment options remain limited. This study examined the relationships among intestinal microbial dysbiosis, ammonia production, and hepatic CD8+ T cell activity in MASH, and assessed the therapeutic potential of DT-109, a glycine-based tripeptide. We investigated the gut-liver axis across human cohorts and both non-human primate and mouse MASH models. Multi-omics approaches were used to characterize ileal microbiota, ammonia levels, and hepatic immune and metabolic pathways. Causality was verified through microbiota transplantation, C. perfringens NirA-knockout mutants, and functional validation in vitro and in vivo. The efficacy of DT-109 was evaluated in non-human primates and mice. Our results revealed a significant increase in the ammonia-producing gut bacterium C. perfringens, which led to elevated intestinal ammonia and disruption of the intestinal barrier in MASH. Elevated ammonia levels triggered FosB-mediated upregulation of chemokine C-C motif ligand 5 (CCL5) in CD8+ T cells, which in turn drove T cell cytotoxicity in the liver. Notably, DT-109 effectively lowered C. perfringens abundance, reduced intestinal ammonia, restored intestinal barrier integrity, and alleviated CD8+ T cell dysregulation in MASH. These results identify a distinct mechanism in which gut-derived ammonia drives CD8+ T cell-mediated MASH and demonstrate that DT-109 effectively targets this axis by inhibiting C. perfringens and reducing ammonia, ultimately ameliorating MASH.
2. A comparison of the effects of tirzepatide and dulaglutide on major kidney events in people with type 2 diabetes: pre-specified exploratory analyses of the SURPASS-CVOT trial.
In a large, double-blind RCT (SURPASS-CVOT), tirzepatide reduced major kidney events versus dulaglutide among adults with type 2 diabetes and ASCVD. Benefits were mainly due to reduced new-onset macroalbuminuria in low-to-moderate CKD and slower eGFR decline in high-risk CKD.
Impact: Head-to-head randomized evidence indicates renal advantages of a dual-incretin agonist over a GLP-1 RA, informing therapeutic selection in high-risk type 2 diabetes.
Clinical Implications: For patients with ASCVD and CKD risk, tirzepatide may offer enhanced renal protection relative to dulaglutide. Findings support considering kidney outcomes when personalizing incretin-based therapy.
Key Findings
- Tirzepatide reduced major kidney events compared with dulaglutide in SURPASS-CVOT.
- Reduction in new-onset macroalbuminuria drove benefit in low-to-moderate CKD.
- Slower eGFR decline observed in participants with high-risk CKD on tirzepatide.
- Results derived from a large, randomized, double-blind, active-comparator global trial.
Methodological Strengths
- Randomized, double-blind, global active-comparator design with large sample size
- Pre-specified exploratory kidney outcomes across CKD risk strata
Limitations
- Exploratory analysis; kidney outcomes were not the primary endpoint
- Effect largely driven by albuminuria changes; long-term hard renal endpoints not established
Future Directions: Confirmatory renal outcome trials and mechanistic studies to delineate tirzepatide’s kidney protective pathways versus GLP-1 RAs.
BACKGROUND: In the SURPASS-CVOT trial, tirzepatide, a dual incretin agonist that targets the glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors, was shown to be non-inferior to dulaglutide for the primary composite cardiovascular outcome in people with type 2 diabetes and atherosclerotic cardiovascular disease. Here, we report the results of a pre-specified exploratory analysis of SURPASS-CVOT that aimed to assess major kidney events in the overall population, low-to-moderate-risk chronic kidney disease population, and high-risk chronic kidney disease population. METHODS: SURPASS-CVOT was a randomised, active comparator-controlled, double-blind trial that enrolled people with type 2 diabetes and atherosclerotic cardiovascular disease at 640 sites in 30 countries. Participants aged 40 years or older with type 2 diabetes and atherosclerotic cardiovascular disease, HbA FINDINGS: Between May 29, 2020, and June 27, 2022, 16 979 participants were screened and 13 299 (2948 with high-risk chronic kidney disease) were randomly assigned. After excluding 134 participants randomly assigned in error, 6586 were assigned to tirzepatide and 6579 were assigned to dulaglutide. At baseline, 4142 (32·0%) of 12 954 participants had microalbuminuria and 1491 (11·5%) of 12 954 had macroalbuminuria, and 2928 (22·5%) of 13 004 had an eGFR less than 60 mL/min per 1·73 m INTERPRETATION: Among people with type 2 diabetes and atherosclerotic cardiovascular disease, tirzepatide was associated with a reduced risk of major kidney events compared with dulaglutide, primarily driven by a reduction in new-onset macroalbuminuria in people with low-to-moderate-risk chronic kidney disease, and slowed decline in kidney function in people with high-risk chronic kidney disease. FUNDING: Eli Lilly and Company.
3. Intratrabecular bone remodeling - a previously overlooked mode of remodeling hyperactivated by parathyroid hormone.
Using iliac crest biopsies from a randomized hypoparathyroidism trial and a 24-month extension, the study identifies intratrabecular remodeling as a physiological mode hyperactivated by PTH(1-84), markedly increasing intratrabecular porosity and shifting pore activity states. Withdrawal normalizes remodeling; active vitamin D suppresses it. Time-lapse synchrotron μCT and micro-FE analyses corroborate dynamics and biomechanical context.
Impact: Redefines cancellous bone remodeling by uncovering a robust intratrabecular mode under PTH therapy, with direct implications for interpreting anabolic treatment effects and optimizing vitamin D co-therapy.
Clinical Implications: Highlights a PTH-driven internal remodeling process that may remove old/damaged bone yet increase intratrabecular porosity; suggests monitoring microarchitectural effects and considering active vitamin D dosing to modulate remodeling.
Key Findings
- PTH(1-84) induced an 18-fold and 36-fold increase in intratrabecular porosity at 6 and 30 months, respectively.
- Remodeling state shifted toward eroded and eroded-formative pores under PTH, reversing to quiescent states after withdrawal.
- Active vitamin D supplementation correlated negatively with intratrabecular remodeling metrics.
- Time-lapse synchrotron μCT in rabbits and micro-FE analysis confirmed remodeling dynamics and strain complexity.
Methodological Strengths
- Randomized clinical biopsies with longitudinal open-label extension and quantitative histomorphometry
- Multimodal validation including synchrotron μCT and micro-finite-element analysis
Limitations
- Iliac crest biopsy site may not capture skeletal heterogeneity; clinical fracture outcomes not assessed
- Sample sizes per subgroup/timepoint not detailed in abstract; generalizability requires caution
Future Directions: Quantify links between intratrabecular remodeling and fracture risk; define optimal PTH and active vitamin D regimens to balance anabolic gains and porosity.
Currently, no consensus exists on either terminology, definition, or the biological significance of the phenomena intratrabecular tunneling. Despite this, observations of intratrabecular tunneling are frequently reported in literature covering diseases or treatments involving parathyroid hormone or kidneys. A few attempts to quantify this phenomena have been made mainly based on bone resorption, despite the concurrent presence of bone formation. This study demonstrates that intratrabecular tunneling is a previously unrecognized physiological mode of intratrabecular bone remodeling occurring across conditions and ages. Similar to intracortical remodeling, it is induced by PTH-treatment and creates an extensive interconnected tunnel-network that hollows out the trabeculae. This study primarily utilizes iliac crest bone biopsies collected from a clinical trial where patients with hypoparathyroidism were randomized to receive daily injections with either 100μg rhPTH(1-84) or placebo as add-on to conventional therapy for 6 months. In addition, further bone biopsies were collected from a 24-month open-label extension study, including patients receiving either only conventional treatment, continued rhPTH-treatment or discontinued rhPTH-treatment. Histomorphometry demonstrated that PTH-treatment induced an 18-fold and 36-fold increase in intratrabecular porosity after 6 and 30 months of treatment, respectively. After 6-months of PTH- versus conventional treatment, a median 7.7% versus 0.0% were eroded pores, 69.1% versus 0.0% were eroded-formative pores, 12.9% versus 0.0% were formative pores and 0.9% versus 81.2% were quiescent pores. PTH-treatment withdrawal normalized the intratrabecular remodeling to levels similar to conventional therapy. The intratrabecular remodeling mainly occurred in plates and junctions of trabeculae, and not in trabecular rods. Intratrabecular remodeling parameters showed a positive correlation with PTH-induced trabecular mineralization and a negative correlation with active vitamin D-supplementary doses. Dynamics of the PTH-induced intratrabecular remodeling could be tracked using time-lapsed synchrotron radiation μCT in a rabbit model and the complexity of the trabecular strain environment was confirmed with micro-finite-element analysis. This study describes a previously overlooked physiological mode of bone remodeling – intratrabecular remodeling – which is highly activated by PTH-treatment while inhibited by supplementary active Vitamin D treatment. Low levels of intratrabecular bone remodeling can be observed across conditions, skeletal sites, and aging. Intratrabecular remodeling has the potential to change the bone microarchitecture from inside the structures, and remove the oldest and most damaged bone, not reached by surface-based remodeling. Finally, the study shows that a preclinical 4D-rabbit model has the potential to elucidate the dynamics and biomechanical drivers of intratrabecular remodeling.