Psoralen alleviates high glucose-induced HK-2 cell injury by inhibition of Smad 2 signaling via upregulation of microRNA 874

Coumarins as versatile therapeutic phytomolecules: A systematic review

BACKGROUND

Coumarins, abundantly distributed in a plethora of biologically active compounds, serve as a fundamental motif in numerous natural products, drugs, and therapeutic leads. Despite their small size, they exhibit a diverse range of biological activities, intriguing researchers with their immense pharmacological potential.

PURPOSE

This study consolidates the evidence regarding the essential role of coumarins in modern drug discovery, exploring their broad-spectrum pharmaceutical effects, structural versatility, and mechanisms of action across various domains.

METHODS

For literature search, we utilized PubMed, Google scholar, and SciFinder databases. Keyword and keyword combinations such as "coumarins", "natural coumarins", "specific natural coumarins for particular diseases", and "therapeutic effects" were employed to retrieve relevant studies. The search encompassed articles published between 2005 and 2023. Selection criteria included studies reporting on the pharmacological activities of natural coumarins against various diseases.

RESULTS

The results highlight the therapeutic potential of natural coumarins against various diseases, demonstrating anti-cancer, anti-oxidant, and anti-inflammatory activities. They also act as monoamine oxidase inhibitors and phosphodiesterase inhibitors, and as anti-thrombotic, anti-diabetic, and hepatoprotective agents. They also show efficacy against diabetic nephropathy, neurodegenerative diseases, microbial infections and many other diseases.

CONCLUSION

This review underscores the significant role of natural coumarins in medicinal chemistry and drug discovery. Their diverse biological activities and structural versatility make them promising therapeutic agents. This study serves as a catalyst for further research in the field, aiming to address emerging challenges and opportunities in drug development.

DeSUMOylation of RBMX regulates exosomal sorting of cargo to promote renal tubulointerstitial fibrosis in diabetic kidney disease

INTRODUCTION

Diabetic kidney disease (DKD) has become the primary cause of chronic renal failure in China, and renal tubulointerstitial fibrosis plays a central role in DKD progression. Urinary exosomes, which reflect kidney changes, are largely influenced by RNA-binding proteins (RBPs) in their miRNA content.

OBJECTIVES

Our research aimed to determine the effect of the RNA-binding protein RBMX on exosomal miRNA in DKD.

METHODS

We introduced a higher level of Rbmx into diabetic mice using an adenoassociated virus and isolated exosomes from their kidney tissue through advanced centrifugation techniques and specialized kits. We then conducted a series of tests, including qRT-PCR, Western blot, MitoSOX, ATP luminescence, coimmunoprecipitation, SUMOylation assays, RNA immunoprecipitation, and confocal microscopy.

RESULTS

RBMX is found in higher levels in DKD and contributes to worsening kidney fibrosis, mitochondrial damage, and miRNA mismanagement in exosomes. It specifically binds with miR-26a, miR-23c, and miR-874 within the exosomes. This dysfunction may be linked to changes in RBMX SUMOylation. These miRNAs seem to protect against mitochondrial damage in kidney cells by targeting CERS6.

CONCLUSION

DeSUMOylation of RBMX plays a crucial role in determining the makeup of miRNAs in kidney cell exosomes, impacting the protective miRNAs which regulate mitochondrial damage through their interaction with CERS6 mRNA, ultimately affecting mitochondrial health in DKD.

DACH1 attenuated PA-induced renal tubular injury through TLR4/MyD88/NF-κB and TGF-β/Smad signalling pathway

BACKGROUND

Palmitic acid (PA), the major saturated fatty acid in the blood, often induces the initiation and progression of diabetic kidney disease (DKD). However, the underlying mechanism remains unclear. DACH1 is an important regulator of kidney functions. Herein, we investigated the roles of DACH1 in PA-induced kidney injury.

METHODS

Clinical data from the NHANES database were subjected to analyse the association between serum PA (sPA), blood glucose and kidney function. Molecular docking of PA was performed with DACH1. Immunohistochemistry, cell viability, annexin V/7-AAD double staining, TUNEL assay, immunofluorescent staining, autophagic flux analysis, qRT-PCR and western blot were performed.

RESULTS

Clinical data confirmed that sPA was increased significantly in the pathoglycemia individuals compared with controls and correlated negatively with renal function. Our findings suggested that PA could dock with DACH1. DACH1 enhances cell viability by inhibiting apoptosis and attenuating autophagy blockage induced by PA. Furthermore, the results demonstrated that DACH1 ameliorated inflammation and fibrosis through TLR4/MyD88/NF-κB and TGF-β/Smad signalling pathway in PA-treated renal tubular epithelial cell line (HK-2).

CONCLUSIONS

This study proved that sPA presents a risk factor for kidney injuries and DACH1 might serve as a protective target against renal function deterioration in diabetic patients.

A natural products solution to diabetic nephropathy therapy

Diabetic nephropathy is one of the most common complications in diabetes. It has been shown to be the leading cause of end-stage renal disease. However, due to their complex pathological mechanisms, effective therapeutic drugs other than angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), which have been used for 20 years, have not been developed so far. Recent studies have shown that diabetic nephropathy is characterized by multiple signalling pathways and multiple targets, including inflammation, apoptosis, pyroptosis, autophagy, oxidative stress, endoplasmic reticulum stress and their interactions. It definitely exacerbates the difficulty of therapy, but at the same time it also brings out the chance for natural products treatment. In the most recent two decades, a large number of natural products have displayed their potential in preclinical studies and a few compounds are under invetigation in clinical trials. Hence, many compounds targeting these singals have been emerged as a comprehensive blueprint for treating strategy of diabetic nephropathy. This review focuses on the cellular and molecular mechanisms of natural prouducts that alleviate this condition, including preclinical studies and clinical trials, which will provide new insights into the treatment of diabetic nephropathy and suggest novel ideas for new drug development.

Anti-Hyperglycemic Effect of Magnesium-Enhanced Alkaline-Reduced Water on High Glucose-Induced Oxidative Stress in Renal Tubular Epithelial Cells

Diabetes is coupled with hyperglycemia, a state in which elevated glucose levels trigger oxidative stress (OS) in various body functions. One of the organs most afflicted by diabetes is the kidney. Despite this, specific treatments to mitigate the harmful effects of hyperglycemia-induced OS in the kidney have not been extensively explored. This study evaluates the anti-hyperglycemic efficacy of magnesium-enhanced alkaline-reduced water (MARW) in human kidney-2 (HK-2) cells. OS, mitogen-activated protein kinase (MAPK) signaling and fibrosis markers were assessed in high glucose (HG)-induced HK-2 cells, followed by treatment with experimental water for 24 h. Surprisingly, MARW rescued the vitality of HG-induced HK-2 cells, in contrast to that seen with other experimental waters. Additionally, MARW maintained reactive oxygen species, nitric oxide, catalase, glutathione peroxidase, hepatocyte growth factor and glucose uptake in HG-induced HK-2 cells but not in tap water and mineral water. Similarly, MARW downregulated the expression of MAPK and fibrosis-linked signaling proteins such as p-p38, phospho-c-Jun N-terminal kinase, α-smooth muscle actin, matrix metalloproteinase-3 and cleaved caspase 3 in HG-induced HK-2 cells. In conclusion, MARW protects HK-2 cells from the deleterious effects of HG by stabilizing antioxidant defenses and by signaling cascades related to metabolism, apoptosis and fibrosis.

Circulating miRNAs in Type 2 Diabetic Patients with and without Albuminuria in Malaysia

INTRODUCTION

Diabetic kidney disease (DKD) remains the leading cause of chronic kidney disease. Dysregulation of circulating miRNAs has been reported, suggesting their pathological roles in DKD. This study aimed to investigate differentially expressed miRNAs in the sera of type 2 diabetes mellitus (T2DM) patients with and without albuminuria in a selected Malaysian population.

METHOD

Forty-one T2DM patients on follow-up at a community clinic were divided into normo-(NA), micro-(MIC), and macroalbuminuria (MAC) groups. Differential levels of miRNAs in 12 samples were determined using the pathway-focused (human fibrosis) miScript miRNA qPCR array and was validated in 33 samples, using the miScript custom qPCR array (CMIHS02742) (Qiagen GmbH, Hilden, Germany).

RESULTS

Trends of upregulation of 3 miRNAs in the serum, namely, miR-874-3p, miR-101-3p, and miR-145-5p of T2DM patients with MAC compared to those with NA. Statistically significant upregulation of miR-874-3p (p = 0.04) and miR-101-3p (p = 0.01) was seen in validation cohort. Significant negative correlations between the estimated glomerular filtration rate (eGFR) and miR-874-3p (p = 0.05), miR-101-3p (p = 0.03), and miR-145-5p (p = 0.05) as well as positive correlation between miR-874-3p and age (p = 0.03) were shown by Pearson's correlation coefficient analysis.

CONCLUSION

Upregulation of previously known miRNA, namely, miR-145-5p, and possibly novel ones, namely, miR-874-3p and miR-101-3p in the serum of T2DM patients, was found in this study. There was a significant correlation between the eGFR and these miRNAs. The findings of this study have provided encouraging evidence to further investigate the putative roles of these differentially expressed miRNAs in DKD.

MIR210HG Aggravates Sepsis-Induced Inflammatory Response of Proximal Tubular Epithelial Cell via the NF-κB Signaling Pathway

PURPOSE

Acute kidney injury (AKI) is a serious complication of sepsis and is characterized by inflammatory response. MicroRNA-210 host gene (MIR210HG) is upregulated in human proximal tubular epithelial cells under treatment of inflammatory cytokines. This study aimed to explore the role of MIR210HG in sepsis-induced AKI.

MATERIALS AND METHODS

Cell viability was detected by a cell counting kit 8 assay. The levels of proinflammatory cytokines were detected by enzyme-linked immunosorbent assay kits. The protein levels of p65, IκBα, and p-IκBα were examined by western blot analysis. The nuclear translocation of nuclear factor kappa B (NF-κB) was detected by immunofluorescence assay. The histological changes of kidneys were analyzed by hematoxylin and eosin staining assay.

RESULTS

Lipopolysaccharide (LPS) treatment significantly inhibited cell viability and increased productions of proinflammatory cytokines in proximal tubular epithelial cells (HKC-8). Additionally, MIR210HG levels in HKC-8 cells were increased by LPS treatment. MIR210HG silencing inhibited the LPS-induced cell inflammatory response. MIR210HG activated the NF-κB signaling pathway by promoting the phosphorylation of IκBα and nuclear translocation of p65. Rescue assays revealed that the MIR210HG-induced increase of cytokines levels and decline of cell viability were rescued by QNZ treatment. Knockdown of MIR210HG decreased blood urea nitrogen, serum creatinine, and proinflammatory cytokine levels in AKI rats. Moreover, the knockdown of MIR210HG protected against AKI-induced histological changes of kidneys in rats.

CONCLUSION

MIR210HG promotes sepsis-induced inflammatory response of HKC-8 cells by activating the NF-κB signaling pathway. This novel discovery may be helpful for the improvement of sepsis-induced AKI.