Sexual Dimorphism of Corticosteroid Signaling during Kidney Development

Sex-Dependent Variations in Gene Expression in Corneal Endothelial Cells Among Healthy Individuals and Patients With Fuchs Endothelial Corneal Dystrophy

PURPOSE

Fuchs endothelial corneal dystrophy (FECD) displays a higher incidence in females than in males, yet the underlying mechanism remains unclear. This study aimed to elucidate sex-dependent differential gene expressions in corneal endothelial cells (CECs) from healthy non-FECD individuals and from patients with FECD.

METHODS

RNA-Seq data from CECs of non-FECD subjects (3 males, 4 females) and FECD subjects (5 males, 5 females) were analyzed to identify differentially expressed genes (DEGs) between the sexes. We used heatmaps and principal component analysis for expression pattern visualization and Gene Ontology analysis for functional categorization of DEGs.

RESULTS

Among the non-FECD subjects, we identified 341 DEGs-143 upregulated and 198 downregulated-in females relative to males. For FECD subjects, 309 DEGs were discovered, with 215 upregulated and 94 downregulated in females compared with males. Heatmaps exhibited hierarchical clustering by sex, whereas principal component analysis delineated distinct male and female clusters in both non-FECD and FECD cohorts. Gene Ontology enrichment analysis linked the upregulated genes in non-FECD females to steroid hormone response, and downregulated ones to cyclin-dependent protein kinase activity. In females with FECD, upregulated genes were associated with immune responses and downregulated genes with peptide hormone binding.

CONCLUSIONS

To our knowledge, these findings are the first to reveal distinct gene expression patterns in CECs between sexes. The observed variations suggest a potential genetic basis for the observed sex disparity in FECD prevalence. Further investigation is warranted to explore these associations and their implications for the pathogenesis of FECD.

Based on Serum Pharmacochemistry and Metabolomics Studied the Pharmacodynamic Material Basis and Mechanism of Rubi Fructus (Fupenzi) in Improving the Symptom of Kidney-Yang Deficiency

Rubi fructus (Fupenzi) is the immature fruit of East China Rubi fructus, which is widely used in medicine, food, health food and other fields. Since ancient times, Fupenzi has been considered to be an important medicine for tonifying the kidney in terms of nourishing the liver and kidney, fixing essence and reducing urine, but its effective components and mechanism are not clear. In this paper, the effective components of Rubi fructus were analyzed by detecting the components of Fupenzi in vivo and in vitro. Adenine was used to replicate the model of kidney yang deficiency, and organ index, biochemical index and histopathology were used to evaluate the effect of different doses of Fupenzi on tonifying kidney yang. Metabonomics technique was used to analyze the metabolic regulation mechanism of Fupenzi in improving kidney yang deficiency syndrome. The results showed that 61 chemical constituents of Fupenzi were identified in vitro, including 18 flavonoids, 19 organic acids, 5 coumarins, 8 terpenoids, 7 amino acids and 4 other components. A total of 51 chemical components were identified, including 30 prototype components and 21 metabolic components, which may be the effective components of Fupenzi. The results of pharmacodynamics showed that compared with the model group, the renal index, testicular index and epididymal index of rats in each Fupenzi group were significantly improved (p<0.01), cAMP significantly increased (p<0.05), cGMP decreased (p<0.05) and cAMP/cGMP ratio increased significantly (p<0.05). The content of ACTH in low dose group increased significantly (p<0.05), while the content of ACTH in middle and high dose groups increased, but there was no significant difference. The results of HE staining showed that compared with the model group, the kidney, testis and epididymis of rats in each treatment group were significantly improved. In general, these changes may be mainly through primary bile acid biosynthesis, linoleic acid metabolism, steroid hormone biosynthesis, β-alanine metabolism, glutathione metabolism, porphyrin and chlorophyll metabolism, unsaturated fatty acid biosynthesis, arachidonic acid metabolism, arginine and proline metabolism and other metabolic pathways to improve adenine-induced metabolic disorders in rats with kidney-yang deficiency syndrome.

Sex dimorphism in kidney health and disease: mechanistic insights and clinical implication

Sex is a key variable in the regulation of human physiology and pathology. Many diseases disproportionately affect one sex: autoimmune diseases, such as systemic lupus erythematosus, are more common in women but more severe in men, whereas the incidence of other disorders such as gouty arthritis and malignant cancers is higher in men. Besides the pathophysiology, sex may also influence the efficacy of therapeutics; participants in clinical trials are still predominately men, and the side effects of drugs are more common in women than in men. Sex dimorphism is a prominent feature of kidney physiology and function, and consequently affects the predisposition to many adult kidney diseases. These differences subsequently influence the response to immune stimuli, hormones, and therapies. It is highly likely that these responses differ between the sexes. Therefore, it becomes imperative to consider sex differences in translational science from basic science to preclinical research to clinical research and trials. Under-representation of one sex in preclinical animal studies or clinical trials remains an issue and key reported outcomes of such studies ought to be presented separately. Without this, it remains difficult to tailor the management of kidney disease appropriately and effectively. In this review, we provide mechanistic insights into sex differences in rodents and humans, both in kidney health and disease, highlight the importance of considering sex differences in the design of any preclinical animal or clinical study, and propose guidance on how to optimal design and conduct preclinical animal studies in future research.

Exploring the pharmacological mechanism of fermented Eucommia ulmoides leaf extract in the treatment of cisplatin-induced kidney injury in mice: Integrated traditional pharmacology, metabolomics and network pharmacology

Cisplatin (CP) is a widely utilized anticancer drug, which also produces significant side effects, notably acute kidney injury (AKI). Fermented Eucommia ulmoides leaf (FEUL), a medicinal and edible Chinese herbal remedy, is known for its renoprotective properties. However, the effect and underlying mechanism of FEUL extract in AKI therapy have remained largely unexplored. This research aimed to elucidate the protective roles of FEUL extract in an AKI mouse model through biochemical assays, histopathological examinations, and investigating the underlying mechanisms based on metabolomics and network pharmacology. The findings demonstrated that pretreatment with orally administered FEUL extract significantly reduced blood urea nitrogen (BUN), and serum creatinine (SCr) levels, and ameliorated CP-induced kidney histopathological injuries. Moreover, FEUL extract attenuated CP-induced endoplasmic reticulum (ER) stress by reducing the protein expressions of PERK, IRE 1α, GRP78, ATF6, ATF4, and CHOP. The metabolomics results indicated that a total of 31 metabolites, involved in taurine and hypotaurine metabolism, lysine degradation, and steroid hormone biosynthesis, were altered after FEUL extract administration. Furthermore, metabolomics integrated with network pharmacology revealed that 8 targets, 4 metabolites, and 3 key pathways including steroid hormone biosynthesis, purine metabolism, and tryptophan metabolism were the main mechanisms of FEUL extract in treating CP-induced AKI. These findings suggested that FEUL extract could offer valuable insights for potential CP-induced AKI treatment strategies.

Sex Differences in Kidney Health and Disease

BACKGROUND

Sex differences exist in kidney physiology and disease which are underpinned by the biological actions of the sex hormones estrogen, progesterone and testosterone. In this review, we present an up-to-date discussion of the hormonal and molecular signalling pathways implicated in sex differences in kidney health and disease.

SUMMARY

Estrogen and progesterone have protective effects on renal blood flow, glomerular filtration rate and nephron ion and water reabsorptive processes, whereas testosterone tends to compromise these functions. The biological effects of estrogen appear to be the most important in reinforcing kidney function and protecting against kidney diseases in females. The actions of estrogen are myriad but all tend to bolster kidney physiology to maintain a steady-state and adaptable extracellular fluid volume (ECFV) and blood pressure. Estrogen safeguards ECFV homeostasis by stimulating renal epithelial sodium channel (ENaC) and water channel (AQP2) expression and transport function. Renal maintenance of ECFV within narrow physiological limits is a first-line of defense against hypertension and lowers the risk of cardiovascular disease in women. The estrogenic and XX chromosome basis for a female advantage are evident in a wide range of kidney diseases including acute kidney injury, chronic kidney disease, end-stage kidney disease, diabetic kidney disease, and polycystic kidney disease. The molecular mechanisms involve estrogen regulation of nephron ion and water transport, genetic immunogenic responses, activation of the protective arm of the renin angiotensin-aldosterone system and XX chromosome reinforcement of immune responses. Kidney disease can also predispose patients to cancer and women are protected in renal cancer with lower incidence, morbidity, and mortality than age-matched men with the disease.

KEY MESSAGES

This review underscores the importance of incorporating sex-specific considerations into clinical practice and basic research to bridge the gap in understanding and addressing biological sex disparities in kidney disease and renal cancer.

Effects of the environment on the evolution of the vertebrate urinary tract

Evolution of the vertebrate urinary system occurs in response to numerous selective pressures, which have been incompletely characterized. Developing research into urinary evolution led to the occurrence of clinical applications and insights in paediatric urology, reproductive medicine, urolithiasis and other domains. Each nephron segment and urinary organ has functions that can be contextualized within an evolutionary framework. For example, the structure and function of the glomerulus and proximal tubule are highly conserved, enabling blood cells and proteins to be retained, and facilitating the elimination of oceanic Ca+ and Mg+. Urea emerged as an osmotic mediator during evolution, as cells of large organisms required increased precision in the internal regulation of salinity and solutes. As the first vertebrates moved from water to land, acid-base regulation was shifted from gills to skin and kidneys in amphibians. In reptiles and birds, solute regulation no longer occurred through the skin but through nasal salt glands and post-renally, within the cloaca and the rectum. In placental mammals, nasal salt glands are absent and the rectum and urinary tracts became separate, which limited post-renal urine concentration and led to the necessity of a kidney capable of high urine concentration. Considering the evolutionary and environmental selective pressures that have contributed to renal evolution can help to gain an increased understanding of renal physiology.

Estrogen-induced signalling and the renal contribution to salt and water homeostasis

The kidney is considered to be one of the most estrogen-responsive, not reproductive organs in the body. Different estrogen receptors (ERs) show sex-specific differences in expression along the nephron and the expression of different ERs also changes with the estrous cycle of the female. The kidney becomes more estrogen-sensitive when estradiol levels are at their highest, just prior to ovulation. This review discusses the different mechanisms by which estradiol can modify the salt and water conservation processes of the kidney through transporter regulation to support the fluid and electrolyte homeostasis changes required in mammalian reproduction. The kidney plays a critical role in regulating blood pressure by controlling fluid homeostasis, and so protects the female cardiovascular system from dramatic changes in whole body fluid volume that occur at critical points in the human menstrual cycle and in pregnancy. This is augmented by the direct actions of estradiol on the cardiovascular system, for example through the direct stimulation of endothelial nitric oxide (NO) synthase, which releases NO to promote vasodilation. This and other mechanisms are less evident in the male and give women a degree of cardiovascular protection up until menopause, when the risks of cardiovascular disease and chronic kidney disease begin to match the risks experienced by males.

The invention of aldosterone, how the past resurfaces in pediatric endocrinology

Sodium and water homeostasis are drastically modified at birth, in mammals, by the transition from aquatic life to terrestrial life. Accumulating evidence during the past ten years underscores the central role for the mineralocorticoid signaling pathway, in the fine regulation of this equilibrium, at this critical period of development. Interestingly, regarding evolution, while the mineralocorticoid receptor is expressed in fish, the appearance of its related ligand, aldosterone, coincides with terrestrial life, as it is first detected in lungfish and amphibian. Thus, aldosterone is likely one of the main hormones regulating the transition from an aquatic environment to an air environment. This review will focus on the different actors of the mineralocorticoid signaling pathway from aldosterone secretion in the adrenal gland, to mineralocorticoid receptor expression in the kidney, summarizing their regulation and roles throughout fetal and neonatal development, in the light of evolution.