👤 Rumamol Chandran

Atherosclerosis is a chronic inflammatory condition that remains a major global cause of cardiovascular morbidity and death. Circular RNAs (circRNAs), emerging as key regulators of biological processes, have been linked to atherosclerosis because of their functions in inflammation, lipid metabolism, and plaque stability. This review explores the biogenesis and cellular functions of circRNAs, highlighting specific circRNAs, such as circANRIL, circHIPK, and circRSF1, which influence atherosclerosis progressions and development. CRISPR-Cas technology, specifically Cas9 and Cas13, has transformed the way atherosclerosis is studied and potentially treated. Targeting PCSK9, LDLR, and APOB to modify lipid metabolism, including lowering LDL cholesterol and repairing mutations in familial hypercholesterolemia, has been made possible using CRISPR-Cas9 in atherosclerosis models. In parallel, CRISPR-Cas13 offers a novel approach for RNA-level intervention by selectively editing circRNAs, providing a dynamic approach to regulate atherosclerosis-related pathways. In order to convert these findings into therapeutic treatments, future research should focus on elucidating the mechanics of circRNA, which in turn determines CRISPR-Cas13, and designing specific delivery systems. This review paper demonstrates the revolutionary promise of circRNA research and CRISPR innovation in the treatment of atherosclerosis and underscores the need for extensive preclinical validation to bridge the gap towards clinical use. Show less

Declining mitochondrial function is an established feature of aging and contributes to most aging-related diseases through its impact on various pathologies such as chronic inflammation, fibrosis and cellular senescence. Our recent work suggests that benign prostatic hyperplasia, which is an aging-related disease frequently associated with inflammation, fibrosis and senescence, is characterized by a decline in mitochondrial function. Here, we utilize glycolytic restriction and pharmacologic inhibition of the mitochondrial electron transfer chain complex I to promote mitochondrial dysfunction and identify the cellular processes impacted by declining mitochondrial function in benign prostate stromal cells. Using this model, we show that mitochondrial dysfunction induced alterations in cell-cell and cell-matrix adhesion, elevated fibronectin expression, resistance to anoikis and stress-induced premature senescence (SIPS). We also showed that ablation of ZC3H4, a transcription termination factor implicated in anoikis-resistance and reduced in BPH relative to normal prostates, phenocopied various phenotypes in the human BHPrS1 prostate stromal cell line that resulted from inhibition of complex I. Furthermore, ZC3H4 ablation resulted in the elevation of mitochondrial superoxide (mtROS) and mitochondrial membrane potential, altered mitochondrial morphology and NAD Show less

Lysosomes and related precursor organelles robustly build up in swollen axons that surround amyloid plaques and disrupted axonal lysosome transport has been implicated in worsening Alzheimer's pathology. Our prior studies have revealed that loss of Adaptor protein-4 (AP-4) complex function, linked primarily to Spastic Paraplegia (HSP), leads to a similar build of lysosomes in structures we term "AP-4 dystrophies". Surprisingly, these AP-4 dystrophies were also characterized by enrichment of components of APP processing machinery, β-site cleaving enzyme 1 (BACE1) and Presenilin 2. Our studies examining whether the abnormal axonal lysosome build up resulting from AP-4 loss could lead to amyloidogenesis revealed that the loss of AP-4 complex function in an Alzheimer's disease model resulted in a strong increase in size and abundance of amyloid plaques in the hippocampus and corpus callosum as well as increased microglial association with the plaques. Interestingly, we found a further increase in enrichment of the secretase, BACE1, in the axonal swellings of the plaques of Alzheimer model mice lacking AP-4 complex compared to those having normal AP-4 complex function, suggestive of increased amyloidogenic processing under this condition. Additionally, the exacerbation of plaque pathology was region-specific as it did not increase in the cortex. The burden of the AP-4 linked axonal dystrophies/AP-4 dystrophies was higher in the corpus callosum and hippocampus compared to the cortex, establishing the critical role of AP-4 -dependent axonal lysosome transport and maturation in regulating amyloidogenic amyloid precursor protein processing. Show less

Lysosomes and related precursor organelles robustly build up in swollen axons that surround amyloid plaques and disrupted axonal lysosome transport has been implicated in worsening Alzheimer's pathology. Our prior studies have revealed that loss of Adaptor protein-4 (AP-4) complex function, linked primarily to Spastic Paraplegia (HSP), leads to a similar build of lysosomes in structures we term "AP-4 dystrophies". Surprisingly, these AP-4 dystrophies were also characterized by enrichment of components of APP processing machinery, β-site cleaving enzyme 1 (BACE1) and Presenilin 2. Our studies examining whether the abnormal axonal lysosome build up resulting from AP-4 loss could lead to amyloidogenesis revealed that the loss of AP-4 complex function in an Alzheimer's disease model resulted in a strong increase in size and abundance of amyloid plaques in the hippocampus and corpus callosum as well as increased microglial association with the plaques. Interestingly, we found a further increase in enrichment of the secretase, BACE1, in the axonal swellings of the plaques of Alzheimer model mice lacking AP-4 complex compared to those having normal AP-4 complex function, suggestive of increased amyloidogenic processing under this condition. Additionally, the exacerbation of plaque pathology was region-specific as it did not increase in the cortex. The burden of the AP-4 linked axonal dystrophies/AP-4 dystrophies was higher in the corpus callosum and hippocampus compared to the cortex, establishing the critical role of AP-4 -dependent axonal lysosome transport and maturation in regulating amyloidogenic amyloid precursor protein processing. Show less

Kaposi's sarcoma-associated herpesvirus (KSHV) and its murine homolog, murine gammaherpesvirus 68 (MHV68), are lymphotropic viruses that establish latent infection in their host. Surprisingly, while B cells are the main viral reservoir in vivo, B-cell lines are poorly permissive to infection by either MHV68 or KSHV. Here, we report that most B-cell lines express very little to no cell surface heparan sulfate (HS), a glycosaminoglycan that is essential for infection by these viruses. We found that Ext1, a key enzyme in the biosynthesis of HS, was expressed at a low level in these cells. Transfection of B-cell lines with Ext1 restored high HS expression at the cell surface. Overexpression of Ext1 in murine A20 and M12 B-cell lines increased MHV68 surface binding and enhanced the efficiency of infection. Finally, although it was not sufficient to allow efficient infection, the expression of HS on BJAB cells promoted KSHV binding at the cell surface. Thus, our results indicate that MHV68 and KSHV cycles are blocked in B-cell lines at the binding step due to a lack of surface HS. Show less