Diabetes induces dysregulation of microRNAs associated with survival, proliferation and self-renewal in cardiac progenitor cells

Transcriptome sequencing analysis reveals miR-30c-5p promotes ferroptosis in cervical cancer and inhibits growth and metastasis of cervical cancer xenografts by targeting the METTL3/KRAS axis

Cervical cancer is the most common malignant tumor in the female reproductive system worldwide, and its molecular mechanisms remain complex and poorly understood. Various techniques, including transcriptome sequencing, RT-qPCR, ELISA, immunofluorescence, Western blot, CCK-8 assay, Transwell assay, and xenograft models, were employed to investigate gene/miRNA expression, cellular proliferation, migration, and the interactions between miR-30c-5p, METTL3, and KRAS. Our transcriptome sequencing results demonstrated a significant downregulation of miR-30c-5p in cervical cancer cells. Further investigations using RNA pull-down, dual-luciferase reporter assay, Me-RIP, and PAR-CLIP confirmed METTL3 as one of the downstream targets of miR-30c-5p, while KRAS was identified as an iron-death suppressor gene susceptible to m6A modification. Notably, our Me-RIP analysis demonstrated the involvement of METTL3 in m6A modification of KRAS. In vitro experiments revealed that miR-30c-5p facilitated ferroptosis in cervical cancer cells by inhibiting the METTL3/KRAS axis, thus suppressing proliferation and migration. Additionally, in vivo studies demonstrated that miR-30c-5p repressed the growth and metastasis of cervical cancer xenografts through the inhibition of the METTL3/KRAS axis. Overall, this study highlights the critical role of miR-30c-5p in modulating cervical cancer progression by targeting the METTL3/KRAS axis, providing new insights into the molecular mechanisms underlying cervical cancer growth and metastasis.

Zishen Pill alleviates diabetes in Db/db mice via activation of PI3K/AKT pathway in the liver

Background

The rising global incidence of type 2 diabetes mellitus (T2DM) highlights a need for new therapies. The Zishen Pill (ZSP) is a traditional Chinese herbal decoction that has previously shown hypoglycemic effects in C57BL/KsJ-db/db mice, although the therapeutic mechanism remains unknown. This study aims to explore the underlying mechanisms of ZSP’s hypoglycemic effects using db/db mice.

Methods

Db/db mice were divided into two groups: model group and ZSP group, while wt/wt mice were used as a normal control. ZSP was given to mice by gavage for 40 days. During treatment, blood glucose level and body weight were monitored continuously. Oral glucose tolerance test (OGTT) was performed at day 35. Blood and tissue samples were collected at the end of treatment for further analyses. Mice liver samples were analyzed with mRNA transcriptomics using functional annotation and pathway enrichment to identify potential mechanisms that were then explored with qPCR and Western Blot techniques.

Results

ZSP treatment significantly reduced weight gain and glycemic severity in db/db mice. ZSP also partially restored the glucose homeostasis in db/db mice and increased the hepatic glycogen content. Transcriptomic analyses showed ZSP increased expression of genes involved in glycolysis including Hk2, Hk3, Gck and Pfkb1, and decreased expression of G6pase. Additionally, the gene and protein expression of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway, and Csf1 and Flt3 mRNA expression were significantly upregulated in ZSP group.

Conclusion

ZSP treatment reduced the severity of diabetic symptoms in db/db mice. ZSP increased expression of genes associated with glycogen synthesis and glycolysis, and decreased gluconeogenesis via the enhancement of the PI3K/AKT signaling in the liver.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00683-8.

Therapeutic knockdown of miR-320 improves deteriorated cardiac function in a pre-clinical model of non-ischemic diabetic heart disease

Non-ischemic diabetic heart disease (NiDHD) is characterized by diastolic dysfunction and decreased or preserved systolic function, eventually resulting in heart failure. Accelerated apoptotic cell death because of alteration of molecular signaling pathways due to dysregulation in microRNAs (miRNAs) plays a significant role in the development of NiDHD. Here, we aimed to determine the pathological role of cardiomyocyte-enriched pro-apoptotic miR-320 in the development of NiDHD. We identified a marked upregulation of miR-320 that was associated with downregulation of its target protein insulin growth factor-1 (IGF-1) in human right atrial appendage tissue in the late stages of cardiomyopathy in type 2 diabetic db/db mice and high-glucose-cultured human ventricular cardiomyocytes (AC-16 cells). In vitro knockdown of miR-320 in high-glucose-exposed AC-16 cells using locked nucleic acid (LNA) anti-miR-320 markedly reduced high-glucose-induced apoptosis by restoring IGF-1 and Bcl-2. Finally, in vivo knockdown of miR-320 in 24-week-old type 2 diabetic db/db mice reduced cardiomyocyte apoptosis and interstitial fibrosis while restoring vascular density. This resulted in partial recovery of the impaired diastolic and systolic function. Our study provides evidence that miR-320 is a late-responding miRNA that aggravates apoptosis and cardiac dysfunction in the diabetic heart, and that therapeutic knockdown of miR-320 is beneficial in partially restoring the deteriorated cardiac function.