Daily Endocrinology Research Analysis
Three impactful endocrinology papers stand out today: (1) a translational study shows that inulin reshapes gut microbiota to improve metabolic and ovarian function in PCOS; (2) a single-cell atlas elucidates tumorigenic programs and immune microenvironments across adrenal incidentalomas; and (3) a prospective mechanistic study reveals how estradiol and testosterone differentially modulate measured GFR, perfusion, and kidney injury biomarkers during sex hormone therapy.
Summary
Three impactful endocrinology papers stand out today: (1) a translational study shows that inulin reshapes gut microbiota to improve metabolic and ovarian function in PCOS; (2) a single-cell atlas elucidates tumorigenic programs and immune microenvironments across adrenal incidentalomas; and (3) a prospective mechanistic study reveals how estradiol and testosterone differentially modulate measured GFR, perfusion, and kidney injury biomarkers during sex hormone therapy.
Research Themes
- Microbiome–endocrine axis in PCOS therapeutics
- Single-cell profiling of endocrine neoplasia
- Sex hormones and kidney physiology in precision medicine
Selected Articles
1. Gut Microbiota Modulation by Inulin Improves Metabolism and Ovarian Function in Polycystic Ovary Syndrome.
Inulin improved hyperandrogenism and glucose-lipid metabolism in a PCOS cohort and in mice, enriching SCFA-producing taxa and increasing fecal SCFAs. It lowered LBP and ovarian inflammation, effects that were abrogated by LPS, and benefits transferred via FMT from inulin-treated patients to mice.
Impact: This study provides translational evidence that prebiotic modulation of the gut microbiome can ameliorate both metabolic and ovarian dysfunction in PCOS, highlighting a non-pharmacologic therapeutic avenue.
Clinical Implications: Prebiotic inulin may serve as an adjunct therapy in PCOS to improve insulin sensitivity, reduce hyperandrogenism, and attenuate ovarian inflammation, pending confirmation in randomized controlled trials and dose–response studies.
Key Findings
- Inulin improved hyperandrogenism and glucose–lipid metabolism in both a PCOS patient cohort and mouse models.
- Inulin increased SCFA-producing taxa (e.g., Bifidobacterium; CAG12), enhanced SCFA biosynthesis capacity, and raised fecal SCFAs.
- Inulin reduced LBP and ovarian inflammation in PCOS mice; intraperitoneal LPS reversed these benefits.
- FMT from inulin-treated PCOS patients transferred improved insulin sensitivity, lipid handling/thermogenesis, and reduced hyperandrogenism/inflammation to recipient mice.
Methodological Strengths
- Human cohort corroborated with mechanistic mouse experiments and FMT, supporting causality via microbiota.
- Multi-layer evidence including microbial taxa shifts, SCFA measurements, and inflammatory markers (LBP).
Limitations
- Non-randomized design with unspecified patient sample size and potential confounding in human cohort.
- Generalizability and durability of effects are unknown; dosing and formulation of inulin require optimization.
Future Directions: Conduct RCTs to define efficacy, dose–response, and responder phenotypes; integrate metabolomics and immune profiling to validate SCFA–LPS–ovarian inflammation pathways in humans.
The management of metabolic disorder associated with polycystic ovary syndrome (PCOS) has been suggested as an effective approach to improve PCOS which is highly involved with gut microbiota, while the underlying mechanism is unclear. Here, we investigated the role of inulin, a gut microbiota regulator, in the alleviation of PCOS. Our findings showed that inulin treatment significantly improved hyperandrogenism and glucolipid metabolism in both PCOS cohort and mice. Consistent with the cohort, inulin increased the abundance of microbial co-abundance group (CAG) 12 in PCOS mice, including Bifidobacterium species and other short-chain fatty acids (SCFAs)-producers. We further verified the enhancement of SCFAs biosynthesis capacity and fecal SCFAs content by inulin. Moreover, inulin decreased lipopolysaccharide-binding protein (LBP) and ameliorated ovarian inflammation in PCOS mice, whereas intraperitoneal lipopolysaccharide (LPS) administration reversed the protective effects of inulin. Furthermore, fecal microbiota transplantation (FMT) from inulin-treated patients with PCOS enhanced insulin sensitivity, improved lipid accumulation and thermogenesis, reduced hyperandrogenism and ovarian inflammatory response in antibiotic-treated mice. Collectively, these findings revealed that gut microbiota mediates the beneficial effects of inulin on metabolic disorder and ovarian dysfunction in PCOS. Therefore, modulating gut microbiota represents a promising therapeutic strategy for PCOS.
2. Single-Cell Atlas Reveals Tumorigenic Profiles and Immune Dynamics of Adrenal Incidentalomas.
Integrating 302,696 single cells across adrenal incidentaloma subtypes, the study delineates tumorigenic programs, highlights clusterin as a candidate biomarker for adrenocortical adenomas, and identifies MYCN-positive pheochromocytoma clusters linked to poorer survival. Distinct immune ecosystems suggest myeloid regulation in benign tumors and CD8+ T cell–driven activation/infiltration in malignant lesions.
Impact: Provides a foundational single-cell resource with candidate biomarkers and immune context that can refine diagnosis, risk stratification, and therapeutic targeting in adrenal tumors.
Clinical Implications: Clusterin and SF1 signatures may aid in differentiating adrenocortical from medullary tumors and identifying high-risk pheochromocytomas (MYCN-positive); immune profiles could inform selection of immunomodulatory strategies.
Key Findings
- Integrated single-cell RNA-seq of 302,696 cells across nonfunctional adrenocortical adenomas, Conn’s syndrome, and pheochromocytomas.
- Identified clusterin as a candidate biomarker for adrenocortical adenomas and marked SF1 upregulation distinguishing cortical from medullary tumors.
- MYCN-positive pheochromocytoma clusters associated with poorer survival.
- Immune microenvironment differed by lesion type: myeloid-regulated benign tumors versus CD8+ T cell–driven activation/infiltration in malignant lesions.
Methodological Strengths
- Large-scale single-cell integration across multiple adrenal tumor entities.
- Multidimensional analysis linking transcriptional programs, biomarkers, and immune cell ecology.
Limitations
- Primarily cross-sectional profiling without interventional validation or longitudinal outcomes.
- Biomarker utility requires prospective clinical validation and standardized assays.
Future Directions: Prospective validation of clusterin/SF1 signatures and MYCN risk stratification; functional studies to test immune-ecosystem–guided therapies in adrenal tumors.
Adrenal incidentalomas (AIs) are commonly detected endocrine lesions, identified during imaging for unrelated conditions. These lesions exhibit considerable heterogeneity and diverse clinical outcomes. This study employed single-cell RNA sequencing to investigate tumorigenic characteristics of AIs, including non-functional adrenocortical adenomas, Conn's syndrome, and pheochromocytomas. Through integrating public datasets, 302 696 cells are analyzed. Three adrenocortical cell subtypes exhibit gene expression patterns linked to tumorigenesis. Clusterin emerges as a potential biomarker for adrenocortical adenomas. Adrenocortical tumor cells show dysregulated hormone secretion and transcription factor steroidogenic factor 1 (SF1) is significantly upregulated, distinguishing cortical from medullary tumors. In pheochromocytomas, a MYCN proto-oncogene (MYCN)-positive cluster correlates with poorer survival. Immune microenvironment analysis reveals specific immune subtypes and roles in tumor progression. Specifically, myeloid cells may regulate benign tumors, while lymphoid cells, such as CD8-positive (CD8+) T cells, appear to promote immune activation and infiltration in malignant tumors. Overall, this study enhances the understanding of adrenal adenoma heterogeneity, revealing crucial transcriptional profiles, immune interactions, and clinically relevant candidate biomarkers.
3. Unveiling mechanisms underlying kidney function changes during sex hormone therapy.
Feminizing therapy increased mGFR and renal perfusion while reducing tubular injury markers without raising glomerular pressure. Masculinizing therapy was associated with elevations in urine YKL-40 and plasma TNFR-1. Proteomics highlighted estradiol-associated kidney-protective proteins and testosterone-associated opposing profiles, supporting sex-specific renal physiology.
Impact: Direct measurement of GFR and comprehensive biomarker/proteomic profiling reveal mechanistic, sex hormone–driven renal effects, informing kidney risk assessment during gender-affirming therapy and sex-specific precision medicine.
Clinical Implications: Monitor renal function and tubular injury biomarkers during sex hormone therapy; estradiol appears renoprotective whereas testosterone may increase injury-related signals, suggesting tailored monitoring and risk mitigation strategies.
Key Findings
- Feminizing therapy increased mGFR by +3.6% and renal perfusion by +9.1% (P < 0.05) without increasing glomerular pressure.
- Tubular injury biomarkers (urine NGAL, EGF, MCP-1, YKL-40) decreased by 42–58% during feminizing therapy.
- Masculinizing therapy showed stable mGFR/perfusion but increased urine YKL-40 (+134%) and plasma TNFR-1 (+8%).
- Proteomics identified 49 vs 356 differentially expressed proteins in feminizing vs masculinizing therapy, with estradiol positively associated with kidney-protective proteins (e.g., SFRP4, SOD3, TSG-6, agrin).
Methodological Strengths
- Measured GFR via iohexol clearance and renal perfusion via PAH clearance; prospective design.
- Comprehensive tubular injury biomarker panel and plasma proteomics; registered studies (Dutch Trial Register; ClinicalTrials.gov).
Limitations
- Small sample size (n=44) and short follow-up (3 months) limit long-term inference.
- Observational design with potential residual confounding (e.g., antiandrogen types, dosing heterogeneity).
Future Directions: Longer-term, larger cohorts to assess renal outcomes and dose–response; interventional studies testing hormone modulation or adjunct renoprotective strategies.
BACKGROUNDMen with chronic kidney disease (CKD) experience faster kidney function decline than women. Studies in individuals undergoing sex hormone therapy suggest a role for sex hormones, as estimated glomerular filtration rate (eGFR) increases with feminizing therapy and decreases with masculinizing therapy. However, effects on measured GFR (mGFR), glomerular and tubular function, and involved molecular mechanisms remain unexplored.METHODSThis prospective, observational study included individuals initiating feminizing (estradiol and antiandrogens; n = 23) or masculinizing (testosterone; n = 21) therapy. Baseline and 3-month assessments included mGFR (iohexol clearance), kidney perfusion (para-aminohippuric acid clearance), tubular injury biomarkers, and plasma proteomics.RESULTSDuring feminizing therapy, mGFR and kidney perfusion increased (+3.6% and +9.1%, respectively; P < 0.05) without increased glomerular pressure. Tubular injury biomarkers, including urine neutrophil gelatinase-associated lipocalin, epidermal growth factor (EGF), monocyte chemoattractant protein-1, and chitinase 3-like protein 1 (YKL-40), decreased significantly (-53%, -42%, -45%, and -58%, respectively). During masculinizing therapy, mGFR and kidney perfusion remained unchanged, but urine YKL-40 and plasma tumor necrosis factor receptor 1 (TNFR-1) increased (+134% and +8%, respectively; P < 0.05). Proteomic analysis revealed differential expression of 49 proteins during feminizing and 356 proteins during masculinizing therapy. Many kidney-protective proteins were positively associated with estradiol and negatively associated with testosterone, including proteins involved in endothelial function (SFRP4, SOD3), inflammation reduction (TSG-6), and maintaining kidney tissue structure (agrin).CONCLUSIONSex hormones influence kidney physiology, with estradiol showing protective effects on glomerular and tubular function, while testosterone predominantly exerts opposing effects. These findings emphasize the role of sex hormones in sexual dimorphism observed in kidney function and physiology and suggest new approaches for sex-specific precision medicine.TRIAL REGISTRATIONDutch Trial Register (ID: NL9517); ClinicalTrials.gov (ID: NCT04482920).