Podocyte-Parietal Epithelial Cell Interdependence in Glomerular Development and Disease
PECs are thought to contribute to disease progression and severity, and the interdependence between these two cell-types during development and in various manifestations of kidney pathology is the primary focus of this review.
KEY FINDINGS: PECs are thought to contribute to disease progression and severity, and the interdependence between these two cell-types during development and in various manifestations of kidney pathology is the primary focus of this review.
BACKGROUND: Podocytes and parietal epithelial cells (PECs) are among the few principal cell types within the kidney glomerulus, the former serving as a crucial constituent of the kidney filtration barrier and the latter representing a supporting epithelial layer that adorns the inner wall of Bowman's capsule.
DETAILS: Podocytes and PECs share a circumscript developmental lineage that only begins to diverge during the S-shaped body stage of nephron formation - occurring immediately before the emergence of the fully mature nephron. These two cell-types therefore share a highly conserved gene expression program, evidenced by recently discovered intermediate cell types occupying a distinct spatio-temporal gene expression zone between podocytes and PECs. In addition to their homeostatic functions, podocytes and PECs also have roles in kidney pathogenesis. Rapid podocyte loss in diseases such as Rapidly Progressive Glomerulonephritis (RPGN) and collapsing and cellular subtypes of Focal Segmental Glomerulosclerosis (FSGS) is closely allied with PEC proliferation and migration towards the capillary tuft - resulting in the formation of crescents and pseudo-crescents.
Our Most Popular Resources
Copyright © American Society of Nephrology. All rights reserved.
Source: Bronstein, R., Pace, J., Gowthaman, Y., et al. (2023). Podocyte-Parietal Epithelial Cell Interdependence in Glomerular Development and Disease. Journal of the American Society of Nephrology . 2023; 10.1681/ASN.104. Published: February 16, 2023. DOI: 10.1681/ASN.0000000000000104.
Kidney Juxtaglomerular Cells' Renin Shutdown Mechanism in Blood Pressure Regulation
Juxtaglomerular cells monitor calcium levels to toggle renin release. Studying live tissue outperforms isolated cell models for understanding renin regulation. Targeting renin suppression could yield novel hypertension therapies and reduce related complications.
KEY FINDINGS: The findings demonstrate that juxtaglomerular cells shut down renin production through calcium-mediated mechanisms observed directly in kidney tissue. This approach highlights the brakes on hormone systems, differing from traditional focus on activation pathways.
BACKGROUND: Juxtaglomerular cells in the kidney serve as key sensors for blood pressure homeostasis. These cells release renin, a hormone that elevates blood pressure when levels drop too low. They rely on intracellular calcium as an on-off switch to control renin production, preventing hypotension.
DETAILS: Juxtaglomerular cells function as the body's primary baroreceptors, constantly assessing systemic blood pressure through mechanosensory mechanisms in the afferent arterioles. When pressure falls, these cells detect reduced stretch and rising intracellular calcium, triggering renin release to activate the renin-angiotensin-aldosterone system (RAAS). This study shifts focus to the inhibitory phase: how elevated calcium levels or other signals in intact kidney tissue suppress renin synthesis, acting as a regulatory "brake" to prevent overactivation. Traditional research emphasized renin induction using isolated cell cultures, which overlooked tissue-specific interactions like interstitial signaling and vascular coupling. By contrast, this work analyzed living kidney slices, revealing precise calcium-dependent shutdown pathways that halt transcription and secretion in real-time. This tissue-level insight explains why excessive renin persists in hypertension, potentially due to faulty off-switches, and opens avenues for therapies targeting suppression rather than blockade alone—such as modulating calcium channels or downstream inhibitors.
Our Most Popular Resources
Telomere Dysfunction in Renal Tubular Epithelial Cells Leads to Kidney Fibrosis
Trf1 deletion in renal tubular epithelial cells led to renal tubulointerstitial fibrosis, contributing to CKD pathogenesis and progression. Loss of Trf1 induced cellular senescence, DNA damage, and telomere shortening and activated regenerative repair. Trf1 deletion triggered kirsten rat sarcoma viral oncogene homolog and TNF-alpha signaling through NF-KB pathway in renal tubules, suggesting a key molecular mechanism in CKD progression.
KEY FINDINGS: The study underlies a role of renal tubular epithelial cells in the development and progression of kidney fibrosis and CKD induced by telomere dysfunction.
BACKGROUND: Renal tubular epithelial cells are the critical mediators of kidney fibrogenesis. Telomere dysfunction has been associated with kidney injury and fibrosis. However, the role of telomere dysfunction specifically in renal tubular epithelial cells in the onset and progression of kidney fibrosis remains poorly understood. TRF1 is a critical component of the telomeric protective complex known as shelterin, and its deficiency results in telomere dysfunction.
DETAILS: To investigate the impact of telomere dysfunction on kidney injury and fibrosis, authors generated mice depleted for the shelterin component TRF1 specifically in renal tubular epithelial cells.vGenetic ablation of Trf1 caused decline in kidney function accompanied by increased tubular injury and tubulointerstitial fibrosis 8 weeks after TRF1 depletion, concomitant with excessive accumulation of extracellular matrix, cell cycle arrest at G2/M phase, and telomeric damage. Trf1Δ/Δ mice activated regenerative repair mechanisms, supporting proliferation-mediated telomere shortening in renal tubular epithelial cells. At humane end point, Trf1Δ/Δ mice displayed elevated urinary albumin-to-creatinine ratio (UACR), associated with augmented interstitial fibrosis and tubular atrophy eventually leading to CKD. At the mechanistic level, authors reported the unprecedented finding that Trf1 deletion upregulates the Ras–Raf–Mek–Erk, PI3k/Akt/mammalian target of rapamycin, and p38 pathways.
Our Most Popular Resources
Copyright © American Society of Nephrology. All rights reserved.
Source: Saraswati, S., Martínez, P., Serrano, R., et al. Telomere Dysfunction in Renal Tubular Epithelial Cells Leads to Kidney Fibrosis. Journal of the American Society of Nephrology. 2025; 36(12): 2348-2363. Published: December, 2025. DOI: 10.1681/ASN.0000000771.
Effects of Sodium Glucose Cotransporter 2 Inhibitors by Diabetes Status and Level of Albuminuria
Within the studied participants, there were clear absolute benefits of SGLT2 inhibitors on kidney, hospitalization, and mortality outcomes irrespective of diabetes status and level of UACR.
KEY FINDINGS: Within the studied participants, there were clear absolute benefits of SGLT2 inhibitors on kidney, hospitalization, and mortality outcomes irrespective of diabetes status and level of UACR.
BACKGROUND: There is uncertainty about the effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors in participants with chronic kidney disease, with guidelines offering different strengths of recommendation based on diabetes status and urine albumin to creatinine ratio (UACR). Study was conducted to assess the relative and absolute effects of SGLT2 inhibitor use across efficacy and serious safety outcomes in participants stratified by diabetes status and UACR (>=200 mg/g or <200 mg/g). Included 8 randomized clinical trials that studied an SGLT2 inhibitor with a label indication for use in kidney disease and recorded longitudinal kidney outcomes and baseline data on albuminuria. Assessed the effects of SGLT2 inhibitor use on clinical efficacy and safety outcomes. Heterogeneity by baseline level of UACR was assessed separately by diabetes status.
DETAILS: A total of 58,816 participants (mean age, 64 [SD, 10] years; 35% were female; 48,946 with diabetes and 9870 without diabetes) were included from trials comparing an SGLT2 inhibitor vs placebo. Allocation to an SGLT2 inhibitor produced a lower rate of kidney disease progression (33 vs 48 for placebo per 1000 patient-years; hazard ratio [HR], 0.65 [95% CI, 0.60-0.70] in those with diabetes and 32 vs 46 per 1000; HR, 0.74 [95% CI, 0.63-0.85] in those without diabetes), a lower rate of acute kidney injury (14 vs 18 per 1000 [HR, 0.77; 95% CI, 0.69-0.87] with diabetes and 13 vs 18 per 1000 [HR, 0.72; 95% CI, 0.56-0.92] without diabetes), a lower rate of any hospitalization (202 vs 231 per 1000 [HR, 0.90; 95% CI, 0.87-0.92] with diabetes and 203 vs 237 per 1000 [HR, 0.89; 95% CI, 0.83-0.95] without diabetes), and a lower rate of any death (42 vs 47 per 1000 [HR, 0.86; 95% CI, 0.80-0.91] with diabetes and 42 vs 48 per 1000 [HR, 0.91; 95% CI, 0.78-1.05] without diabetes). Diabetes-specific HRs were similar in participants (with a UACR >=200 mg/g vs with a UACR <200 mg/g) considered separately. Higher absolute risk at a UACR of 200 mg/g or greater meant larger estimated absolute benefits on kidney disease progression were evident in this subgroup. Clear absolute benefits were evident for other efficacy outcomes, and particularly hospitalization, in participants with a UACR less than 200 mg/g. Net absolute benefits remained in the analyses of non–heart failure populations and when estimated glomerular filtration rate was less than 60 mL/min/1.73 m2.
Our Most Popular Resources
Copyright © American Medical Association. All Rights Reserved.
Source: Staplin, N., Roddick, A. J., Neuen, B. L., et al. Effects of Sodium Glucose Cotransporter 2 Inhibitors by Diabetes Status and Level of Albuminuria: A Meta-Analysis. JAMA. . 2025; Published online: November 7, 2025. DOI: 10.1001/jama.2025.20835.
Fish-Oil Supplementation and Cardiovascular Events in Patients Receiving Hemodialysis
In this trial involving participants receiving hemodialysis, fish oil (n-3 fatty acids) was compared with corn-oil placebo. The rate of serious cardiovascular events was lower with daily fish-oil supplementation.
KEY FINDINGS: The rate of serious cardiovascular events among participants receiving maintenance hemodialysis was lower with daily supplementation with n-3 fatty acids than with placebo.
BACKGROUND: Cardiovascular disease is the leading cause of death in patients receiving hemodialysis, yet effective preventive therapies remain limited. Supplementation with n-3 polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may have cardiovascular benefits in the general population, but efficacy among patients receiving hemodialysis is uncertain.
DETAILS: In a double-blind, randomized, placebo-controlled trial conducted at 26 sites in Canada and Australia, we assigned adult patients receiving maintenance hemodialysis to daily supplementation with fish oil (4 g of n-3 polyunsaturated fatty acids [1.6 g of EPA and 0.8 g of DHA]) or corn-oil placebo. The primary end point was a composite of all serious cardiovascular events including sudden and nonsudden cardiac death, fatal and nonfatal myocardial infarction, peripheral vascular disease leading to amputation, and fatal and nonfatal stroke. Secondary end points included extension of the primary end point to include noncardiac causes of death, the individual components of the primary end point, and a first cardiovascular event or death from any cause. In a double-blind, randomized, placebo-controlled trial conducted at 26 sites in Canada and Australia, we assigned adult patients receiving maintenance hemodialysis to daily supplementation with fish oil (4 g of n-3 polyunsaturated fatty acids [1.6 g of EPA and 0.8 g of DHA]) or corn-oil placebo. The primary end point was a composite of all serious cardiovascular events including sudden and nonsudden cardiac death, fatal and nonfatal myocardial infarction, peripheral vascular disease leading to amputation, and fatal and nonfatal stroke. Secondary end points included extension of the primary end point to include noncardiac causes of death, the individual components of the primary end point, and a first cardiovascular event or death from any cause.
Our Most Popular Resources
Copyright © Massachusetts Medical Society. All rights reserved.
Source: Lok, C. E., Farkouh, M., Hemmelgam, B. R., et al. Fish-Oil Supplementation and Cardiovascular Events in Patients Receiving Hemodialysis. NEJM. 2025; Published: November 7, 2025. DOI: 10.1056/NEJMoa2513032.
UNC Researchers Discover Method to Combat Antibiotic Treatment Failure
In animal models, the selected molecule substantially improved pathogen clearance for S. aureus, M. tuberculosis, and S. enterica when used in combination with existing antibiotics. This finding supports a new therapeutic concept: targeting the host cell environment can potentiate antibiotic activity and overcome intracellular bacterial persistence. The discovery presents an innovative direction for combating infections that evade standard therapy.
KEY FINDINGS: Enhanced antibiotic performance observed in preclinical mouse models. Potential to improve treatment outcomes for multiple intracellular bacterial infections. Ongoing efforts include mechanism elucidation and patent development.
BACKGROUND: Antibiotic resistance has severely limited the effectiveness of conventional treatments against persistent bacterial infections. Some pathogens, such as Staphylococcus aureus, Mycobacterium tuberculosis, and Salmonella enterica, can survive inside immune cells, remaining dormant and shielded from antibiotic action. The increasing prevalence of such infections underscores an urgent need for alternative approaches that do not rely solely on developing stronger antibiotics.
DETAILS: Researchers at the University of North Carolina (UNC) School of Medicine, led by Dr. Brian Conlon and Dr. Kuan-Yi Lu, identified a novel small molecule that modifies immune cell behavior to enhance antibiotic performance. Instead of directly targeting bacteria, the molecule reprograms the host's immune cells to activate dormant pathogens, rendering them more susceptible to antibiotic killing.
Our Most Popular Resources
The team screened approximately 5,000 small molecules through the UNC Small Molecule Screening Core. They used luminescent reporter strains of S. aureus to identify compounds that triggered bacterial activation. The most promising compound was subsequently tested in mouse models, where it significantly improved antibiotic efficacy when administered alongside standard treatments.
In animal models, the selected molecule substantially improved pathogen clearance for S. aureus, M. tuberculosis, and S. enterica when used in combination with existing antibiotics. This finding supports a new therapeutic concept: targeting the host cell environment can potentiate antibiotic activity and overcome intracellular bacterial persistence. The discovery presents an innovative direction for combating infections that evade standard therapy.
Copyright © UNC School of Medicine. All rights reserved.
Source: Conlon, B. and Kuan-Yi, L. UNC Researchers Discover Method to Combat Antibiotic Treatment Failure. UNC Health Newsroom. 2025; Published: October 14, 2025.
Specialty: