Maintaining glucose and lipid homeostasis is crucial for health, with dysregulation leading to metabolic diseases such as type 2 diabetes mellitus (T2DM) and metabolic dysfunction–associated fatty liver disease (MAFLD). This study identifies alkylation repair homolog protein 5 (ALKBH5), an RNA N ⁶ -methyladenosine (m ⁶ A) demethylase, as a major regulator in metabolic disease. ALKBH5 is up-regulated in the liver during obesity and also phosphorylated by protein kinase A, causing its translocation to the cytosol. Hepatocyte-specific deletion of Alkbh5 reduces glucose and lipids by inhibiting the glucagon receptor (GCGR) and mammalian target of rapamycin complex 1 (mTORC1) signaling pathways. Targeted knockdown of hepatic Alkbh5 reverses T2DM and MAFLD in diabetic mice, highlighting its therapeutic potential. This study unveils a regulatory mechanism wherein ALKBH5 orchestrates glucose and lipid homeostasis by integrating the GCGR and mTORC1 pathways, providing insight into the regulation of metabolic diseases.

Dongpu Shao, Lei Shi, and Honglei Ji. Mol. Cells 2023;46:414-6. https://doi.org/10.14348/molcells.2023.0060

FGR proto-oncogene (Fgr), a member of the Src family kinases, has garnered attention for its potential involvement in apoptotic signaling, yet its role in cardiovascular diseases, particularly acute myocardial infarction (AMI), remains unexplored. This study sought to investigate whether elevated left ventricular Fgr expression alleviates myocardial injury in the infarcted area and whether this protective mechanism is mediated by modulating phosphoinositide 3-kinase (PI3K)/Akt phosphorylation. The transcriptome-wide association study was initially utilized to screen for susceptibility genes in the left ventricle, with findings validated using bulk-RNA sequencing data from a rat model of left anterior descending coronary artery (LAD) ligation; subsequently, human spatial transcriptomics combined with single-nucleus RNA sequencing data confirmed differential expression of Fgr and PI3K/Akt in the infarcted region. Fgr knockdown via siRNA in H9C2 cells and pharmacological inhibition with TL02-59 in rats were conducted to assess cellular survival and cardiac function, respectively. Fgr emerged as a common candidate gene identified through multi-omics data analysis, with its up-regulation confirmed both in vivo and in vitro. Fgr silencing in an in vitro oxygenglucose deprivation model significantly reduced cell survival and suppressed PI3K/Akt phosphorylation, whereas TL02-59 administration in rats subjected to LAD ligation impaired post-infarction cardiac function while concurrently inhibiting PI3K/Akt phosphorylation levels. This study demonstrates that Fgr is markedly up-regulated in AMI and exerts cardioprotective effects, possibly through modulation of PI3K/Akt signaling phosphorylation, thereby underscoring its potential as a therapeutic target.