A review of molecular mechanisms linked to potential renal injury agents in tropical rural farming communities

MicroRNA-204 may predict the renal function in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease significantly affects human health by loss of excretory kidney function. MicroRNAs have potential predictive and therapeutic significance for chronic kidney disease and fibrosis-related kidney diseases. This study aimed to investigate expression profiling and clinical significance of microRNA-204 (miR-204) expression in patients with chronic kidney disease.

METHODS

A total of 126 patients with chronic kidney disease and age-matched 126 healthy controls were enrolled in this study. Blood samples were collected from participants and expression levels of miR-204 were detected using reverse transcription quantitative polymerase chain reaction. Expression of inflammatory cytokines in glomerular cells was measured using reverse transcription quantitative polymerase chain reaction. Inflammatory cytokines in serum were analyzed using enzyme-linked immunosorbent assay in all participants. Multivariate Cox-regression analysis was used to analyze the association between serum level of miR-204 and inflammation, renal fibrosis, and degree of chronic kidney disease.

RESULTS

Chronic kidney disease patients had higher inflammatory cytokines including IL-1β, IL-6, TNF-α, IL-10, and IL-17 than healthy volunteers. Expression levels of inflammatory cytokines (IL-1β, IL-6, TNF-α, IL-10, and IL-17) were upregulated in patients with chronic kidney disease compared to healthy volunteers. Serum level of miR-204 was lower in chronic kidney disease patients than healthy patients. Expression of miR-204 was higher in healthy volunteers than patients with chronic kidney disease. In addition, expression of miR-204 was lower in glomerular cells in chronic kidney disease patients than those in the healthy volunteers. Furthermore, higher serum level of miR-204 was associated with better renal function in chronic kidney disease patients than patients who had lower serum level of miR-204. High serum levels of miR-204 were associated with degree of renal fibrosis and injury of chronic kidney disease patients. Multivariate Cox-regression analysis identified expression of miR-204 was positively correlated with inflammation in patients with chronic kidney disease.

CONCLUSION

Outcomes indicate that serum levels of miR-204 are downregulated in serum in patients with chronic kidney disease. Data suggest that serum levels of miR-204 can be used to evaluate the renal function in patients with chronic kidney disease.

Intraoperative hyperthermia is associated with increased acute kidney injury following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: a retrospective cohort study

BACKGROUND

Acute kidney injury (AKI) is common after cytoreduction surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for peritoneal surface malignancies. Herein we analyzed the association between intraoperative hyperthermia and AKI following CRS-HIPEC.

METHODS

In this retrospective cohort study, we collected baseline and perioperative data from patients who underwent CRS-HIPEC mainly for pseudomyxoma peritonei between 2014 and 2020. Nasopharyngeal temperature was recorded at 5-min intervals. The area above the threshold was calculated for intraoperative hyperthermia (>37.0 °C). AKI was diagnosed and classified according to the KDIGO creatinine criteria. A multivariable logistic regression model was established to assess the association between hyperthermia and AKI.

RESULTS

A total of 480 patients were included in the analysis. Of these, 10.6% (51/480) developed AKI within 7 postoperative days. After correction for confounding factors, a larger area above the threshold of hyperthermia was significantly associated with an increased risk of AKI (odds ratio [OR] 1.36, 95% CI 1.14-1.63, p = 0.001). Among other factors, older age (OR 1.05, 95% CI 1.02-1.09, p = 0.002), postoperative hypotension requiring vasopressors (OR 2.09, 95% CI 1.02-4.27, p = 0.042), and intraperitoneal chemotherapy containing cisplatin (OR 2.75, 95% CI 1.20-6.33, p = 0.017) were also associated with an increased risk of AKI. Patients with AKI required longer mechanical ventilation, stayed longer in the intensive care unit and hospital, developed more complications, and required more intensive care unit readmission.

CONCLUSIONS

Among patients undergoing CRS-HIPEC, intraoperative hyperthermia was independently associated with a higher risk of AKI; this effect was additive to other risk factors including cisplatin-containing chemotherapy.

Transcriptomic and behavioral analyses reveal unique target tissues and molecular pathways associated with embryonic exposure to low level glyphosate and metal mixtures in zebrafish

Investigation of developmental molecular events following exposure to environmentally relevant agrochemical mixtures is critical to predicting their potential long-term ecological and human health risks. Here, we sought to uncover transcriptomic changes during zebrafish (Danio rerio) embryonic development following exposure to glyphosate and co-exposure to metals. Glyphosate is widely used globally with an allowable drinking water limit of 700 ppb. We examined effects of glyphosate (10 ppb) alone and when co-exposed to a metal mixture containing low levels of arsenic (4 ppb), lead (5 ppb), cadmium (2 ppb), and vanadium (15 ppb). This mixture was derived based on behavioral and morphological toxicity findings and environmentally relevant concentrations found in agricultural regions where glyphosate and metals are ubiquitously present. Gene expression patterns coupled to a single-cell transcriptomic dataset revealed that developmental exposure (28-72 h post fertilization) to glyphosate dysregulates expression of developmental genes specific to the central nervous system. Subsequent studies indicated significant suppression of larval zebrafish movement with 10 ppb glyphosate exposure. Studies with glyphosate + metals mixture and metals mixture alone showed unique developmental transcriptomic patterns and behavioral changes compared to glyphosate exposure alone. However, some outcomes (e.g., changes in expression of genes involved in epigenetic regulation and extracellular matrix patterning) were common across all three exposures compared to the control. Notably, glyphosate + metals co-exposure distinctly suppresses lysosomal transcripts and targets renal developmental genes. While further studies are required to uncover the precise nature of the interactions between glyphosate and metals, our study shows that glyphosate at very low levels is a behavioral and neurotoxicant that changes when metals are present. Given this herbicide affects distinctive physiological processes, including renal development and lysosomal dysregulation when co-exposed with metals, we conclude that environmental cation levels should be considered in glyphosate toxicity and risk assessment.

Chronic kidney disease with unknown cause across the global spectrum

PURPOSE OF REVIEW

In the 1990s, a type of chronic kidney disease with unknown cause (CKDu) was identified in Central America and Sri Lanka. Patients lacked hypertension, diabetes, glomerulonephritis, or other usual causes of kidney failure. Affected patients are predominantly male agricultural workers aged 20-60 years, living in economically disadvantaged areas with poor access to medical care. Patients typically present late and progress to end-stage kidney disease within 5 years, resulting in social and economic hardship for families, regions, and countries. This review covers the current state of knowledge for this disease.

RECENT FINDINGS

The prevalence of CKDu is increasing in known endemic regions and across the globe, reaching epidemic proportions. There is primary tubulointerstitial injury with secondary glomerular and vascular sclerosis. No definitive etiologic factors have been identified, and these may vary or overlap in different geographic locations. The leading hypotheses include exposure to agrochemicals, heavy metals and trace elements, and kidney injury from dehydration/heat stress. Infections and lifestyle factors may play a role, but are likely not key. Genetic and epigenetic factors are beginning to be explored.

SUMMARY

CKDu is a leading cause of premature death in young-to-middle-aged adults in endemic regions and has become a public health crisis. Studies are underway to investigate clinical, exposome, and omics factors, and hopefully will provide insights into pathogenetic mechanisms resulting in biomarker discovery, preventive measures, and therapeutics.