Transcriptionally regulated miR-26a-5p may act as BRCAness in Triple-Negative Breast Cancer

Mechanistic insights into the ameliorative effects of Xianglianhuazhuo formula on chronic atrophic gastritis through ferroptosis mediated by YY1/miR-320a/TFRC signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Xianglianhuazhuo formula (XLHZ) has a potential therapeutic effect on chronic atrophic gastritis (CAG). However, the specific molecular mechanism remains unclear.

AIM OF THE STUDY

To evaluate the effect of XLHZ on CAG in vitro and in vivo and its potential mechanisms.

METHODS

A rat model of CAG was established using a composite modeling method, and the pathological changes and ultrastructure of gastric mucosa were observed. YY1/miR-320a/TFRC and ferroptosis-related molecules were detected. An MNNG-induced gastric epithelial cell model was established in vitro to evaluate the inhibitory effect of XLHZ on cell ferroptosis by observing cell proliferation, migration, invasion, apoptosis, and molecules related to ferroptosis. The specific mechanism of action of XLHZ in treating CAG was elucidated by silencing or overexpression of targets.

RESULTS

In vivo experiments showed that XLHZ could improve the pathological status and ultrastructure of gastric mucosa and inhibit ferroptosis by regulating the YY1/miR-320a/TFRC signaling pathway. The results in vitro demonstrated that transfection of miR-320a mimics inhibited cell proliferation, migration, and invasion while promoting cell apoptosis. MiR-320a targeted TFRC and inhibited ferroptosis. Overexpression of TFRC reversed the inhibitory effect of miR-320a overexpression on cell proliferation. The effect of XLHZ was consistent with that of miR-320a. YY1 targeted miR-320a, and its overexpression promoted ferroptosis.

CONCLUSION

XLHZ inhibited ferroptosis by regulating the YY1/miR-320a/TFRC signaling pathway, ultimately impeding the progression of CAG.

miR-26a Improves Microglial Activation and Neuronal Apoptosis in a Rat Model of Cerebral Infarction by Regulating the TREM1-TLR4/MyD88/NF-κB Axis

Emerging studies have indicated that abnormally expressed microRNAs (miRNAs) are related to the pathogenesis of cerebral ischemia. Nevertheless, the function of miR-26a in neuronal damage and microglial activation during cerebral infarction remains elusive. It was revealed that miR-26a was downregulated in oxygen-glucose deprivation (OGD)-treated microglia and neurons. Overexpressing miR-26a reduced the inflammatory reaction in BV2 cells and decreased neuronal apoptosis following OGD stimulation. miR-26a upregulation inactivated the TLR4/MyD88/NF-κB pathway and inhibited TREM1 expression. Repressing NF-κB phosphorylation inhibited the miR-26a level. As supported by the dual-luciferase reporter assay, TREM1 was directly targeted by miR-26a. Furthermore, a rat model of middle cerebral artery occlusion (MCAO) was built. We discovered that miR-26a improved cognitive, learning, and motor functions and reduced cerebral edema in MCAO rats. Mechanistically, upregulating miR-26a reduced inflammation and neuronal apoptosis by mitigating the TREM1-TLR4/MyD88/NF-κB pathway in the MCAO rat model. Collectively, this study verified that the miR-26a-TREM1-TLR4/MyD88/NF-κB axis contributes to modulating OGD-mediated microglial activation and neuronal injury.