Interference of periostin attenuates pathological changes, proinflammatory markers and renal fibrosis in diabetic kidney injury

Melittin induces autophagy to alleviate chronic renal failure in 5/6-nephrectomized rats and angiotensin II-induced damage in podocytes

BACKGROUND/OBJECTIVES

Chronic renal failure (CRF) is a complex pathological condition that lacks a cure. Certain Chinese medicines, such as melittin, a major component in bee venom, have shown efficacy in treating CRF patients. On the other hand, the mechanisms underlying the therapeutic effects of melittin are unclear.

MATERIALS/METHODS

A 5/6 nephrectomy model (5/6 Nx) of renal failure was established on rats for in vivo assays, and mouse podocyte clone 5 (MPC5) mouse podocyte cells were treated with angiotensin II (AngII) to establish an in vitro podocyte damage model. The 24-h urine protein, serum creatinine, and blood urea nitrogen levels were evaluated after one, 2, and 4 weeks. Hematoxylin and eosin staining, Masson staining, and periodic acid-Schiff staining were used to examine the pathological changes in kidney tissues. A cell counting kit 8 assay was used to assess the cell viability. Reverse transcription polymerase chain reaction and Western blot were used to assess the mRNA and protein levels in the cells, respectively.

RESULTS

In the rat 5/6 Nx, melittin reduced the 24-h urinary protein excretion and the serum creatinine and blood urea nitrogen levels. Furthermore, the renal pathology was improved in the melittin-treated 5/6 Nx rats. Melittin promoted podocin, nephrin, Beclin 1, and the LC3II/LC3I ratio and inhibited phosphorylated mammalian target of rapamycin (mTOR)/mTOR in 5/6 Nx-induced rats and AngII-induced MPC5 mouse podocyte cells. Moreover, inhibiting autophagy with 3-MA weakened the effects of melittin on podocin, nephrin, and the LC3II/LC3I ratio in podocytes.

CONCLUSION

Melittin may offer protection against kidney injury, probably by regulating podocyte autophagy. These results provide the theoretical basis for applying melittin in CRF therapy.

Genome-wide screening of m6A profiling of cutaneous wound healing in diabetic mice

OBJECTIVE

Impaired wound healing in diabetes mellitus (DM) is a major health burden on patients, their families, and society. The present study aimed to systematically profile the m6A modification landscape in cutaneous wounds in a diabetic mouse model.

APPROACH

Diabetes was induced in mice through a single intraperitoneal injection of streptozotocin (STZ); a single intraperitoneal injection of PBS was made in control mice for comparisons. Both groups then received an 8-mm diameter, full-thickness dorsal body wound with a biopsy punch. Five days after wound surgery, western blot analysis of harvested wound tissues from both groups was used to assess the expression of m6A-related enzymes. Genome-wide profiling of m6A-tagged transcripts was performed through MeRIP-seq and RNA-seq.

RESULTS

ALKBH5, an m6A eraser, was significantly upregulated, while METTL3, METTL14, and WTAP, m6A writers, were markedly downregulated in the diabetic wounds. Additionally, a total of 1335 m6A peaks were differentially expressed in MeRIP-seq and RNA-seq analyses, with 558 upregulated and 777 downregulated peaks. Finally, there was hypomethylated and hypermethylated differentiation at the gene and transcript levels.

INNOVATION

The present study was the first to reveal the m6A landscape in diabetic wounds in an animal model.

CONCLUSION

This study, by deeply analyzing the role of m6A modifications in diabetic wound healing, provides new insights and understanding into the molecular mechanisms of diabetic wound healing. Future research could further explore how m6A modifications regulate the wound healing process, thereby offering new potential targets for the treatment of diabetic wounds.