RNAi therapy to the wall of arteries and veins: anatomical, physiologic, and pharmacological considerations

Emerging RNAi Therapies to Treat Hypertension

Hypertension (HTN), often dubbed the "silent killer," poses a significant global health challenge, affecting over 1.3 billion individuals. Despite advances in treatment, effective long-term blood pressure (BP) control remains elusive, necessitating novel therapeutic approaches. Poor control of BP remains a leading cause of cardiovascular morbidity and mortality worldwide and is becoming an even larger global health problem due to the aging population, rising rates of obesity, poorer dietary patterns and overall cardiometabolic health, and suboptimal rates of patient adherence and optimal BP control. Ribonucleic acid interference (RNAi) technology, which leverages the body's natural gene-silencing mechanism, has emerged as a promising strategy for several diseases and has recently been tested for its antihypertensive effects. We systematically reviewed peer-reviewed articles from databases including PubMed, EMBASE, and Scopus for studies examining RNAi's role in managing HTN, focusing on mechanisms, clinical utility, and safety profile. Key early-phase trials of some RNAi-leading candidate drugs are detailed. Also highlighted are challenges such as target specificity, delivery mechanisms, durability of effect, and immunogenicity. We conclude by summarizing how RNAi has a significant potential role in HTN therapy due to their unique benefits, such as long-term duration of action, infrequent dosing, and lack of major side effects.

BRG1 is involved in vascular calcification in chronic renal disease via autophagy of vascular smooth muscle cells

We aimed to investigate the mechanisms of Brahma related gene 1 (BRG1) in promoting vascular calcification in chronic kidney disease (CKD). The expression of BRG1 was examined in high phosphorus stimulated rat aortic smooth muscle cells (RASMCs) and calcified artery tissues from rat models and hemodialysis patients. Autophagosome formation was measured in high phosphorus stimulated RASMCs with and without BRG1 knock-down. We also detected the coexistence of BGR1 and exosomes, and measured the circulatory levels of BRG1 in the hemodialysis patients. BRG1 promoted the osteogenic transdifferentiation of RASMCs. Silencing BRG1 prevented autophagy from being induced by high phosphorus stimulation in RASMCs. Increased expression of BRG1 was observed in calcified blood vessels. Serum BRG1 level increased in the hemodialysis patients. BRG1 was involved in the development of high phosphorus induced osteogenic phenotype in vitro and in vivo, and its underlying mechanism might be facilitating autophagy.

The Potential Role of Creatine in Vascular Health

Creatine is an organic compound, consumed exogenously in the diet and synthesized endogenously via an intricate inter-organ process. Functioning in conjunction with creatine kinase, creatine has long been known for its pivotal role in cellular energy provision and energy shuttling. In addition to the abundance of evidence supporting the ergogenic benefits of creatine supplementation, recent evidence suggests a far broader application for creatine within various myopathies, neurodegenerative diseases, and other pathologies. Furthermore, creatine has been found to exhibit non-energy related properties, contributing as a possible direct and in-direct antioxidant and eliciting anti-inflammatory effects. In spite of the new clinical success of supplemental creatine, there is little scientific insight into the potential effects of creatine on cardiovascular disease (CVD), the leading cause of mortality. Taking into consideration the non-energy related actions of creatine, highlighted in this review, it can be speculated that creatine supplementation may serve as an adjuvant therapy for the management of vascular health in at-risk populations. This review, therefore, not only aims to summarize the current literature surrounding creatine and vascular health, but to also shed light onto the potential mechanisms in which creatine may be able to serve as a beneficial supplement capable of imparting vascular-protective properties and promoting vascular health.

Bromodomain and BET family proteins as epigenetic targets in cancer therapy: their degradation, present drugs, and possible PROTACs

Alteration in the pattern of epigenetic marking leads to cancer, neurological disorders, inflammatory problems etc. These changes are due to aberration in histone modification enzymes that function as readers, writers and erasers. Bromodomains (BDs) and BET proteins that recognize acetylation of chromatin regulate gene expression. To block the function of any of these BrDs and/or BET protein can be a controlling agent in disorders such as cancer. BrDs and BET proteins are now emerging as targets for new therapeutic development. Traditional drugs like enzyme inhibitors and protein–protein inhibitors have many limitations. Recently Proteolysis-Targeting Chimeras (PROTACs) have become an advanced tool in therapeutic intervention as they remove disease causing proteins. This review provides an overview of the development and mechanisms of PROTACs for BRD and BET protein regulation in cancer and advanced possibilities of genetic technologies in therapeutics.

Alteration in the pattern of epigenetic marking leads to cancer, neurological disorders, inflammatory problems etc.

In vivo modulation of a dominant-negative variant in mouse models of von Willebrand disease type 2A

Essentials Treatment options for von Willebrand disease (VWD) patients are limited. The p.P1127_C1948delinsR deletion/variant is a useful model to study VWD in vitro and in vivo. Counteracting dominant-negative effects restores von Willebrand factor multimerization in mice. This is the first siRNA-based treatment applied to a mouse model of VWD-type 2A. ABSTRACT: Background Treatment options for patients suffering from von Willebrand disease (VWD) are limited. Von Willebrand factor (VWF) is a polymeric protein that undergoes regulated dimerization and subsequent multimerization during its biosynthesis. Numerous heterozygous variants within the VWF gene display a dominant-negative effect and result in severe VWD. Previous studies have suggested that preventing the assembly of wild-type and mutant heteropolymers using siRNAs may have beneficial effects on VWF phenotypes in vitro. Objectives To study heterozygous dominant-negative variants in vivo, we developed a mouse model of VWD-type 2A and tested two independent strategies to modulate its detrimental effect. Methods The p.P1127_C1948delinsR deletion/variant, causing defective VWF multimerization, was expressed in mice as a model of VWD-type 2A variant. Two corrective strategies were applied. For the first time in a mouse model of VWD, we applied siRNAs selectively inhibiting translation of the mutant transcripts and we combined the VWD-type 2A deletion with the Cys to Arg substitution at position 2773, which is known to prevent dimerization. Results The RNA silencing approach induced a modest but consistent improvement of the VWF multimer profile. However, due to incomplete efficiency, the dominant-negative effect of the original variant could not be completely prevented. In contrast, the DNA approach resulted in increased antigen levels and restoration of a normal multimer profile. Conclusions Our data showed that preventing the detrimental impact of dominant-negative VWF variants by independent molecular mechanisms has beneficial consequences in vivo, in mouse models of dominant VWD.

miR-183-96-182 clusters alleviated ox-LDL-induced vascular endothelial cell apoptosis in vitro by targeting FOXO1

OBJECTIVE

To investigate the role of FOXO1 and miR-183-96-182 clusters in ox-LDL induced endothelial cell apoptosis.

METHODS

FOXO1 overexpression (OE) and knockdown (KD) as well as AKT1 OE in human umbilical vein endothelial cells (HUVECs) and human aortic endothelial cells (HAECs) were achieved by lentiviral transduction. Upregulation of miR-183-5p, miR-182-5p or miR-96-5p was mimicked by agomir treatment. FOXO1 gene transcription was monitored by FOXO1 promotor reporter assay. Cell apoptosis in culture was monitored by TiterTACS in situ detection. Regulation of FOXO1 gene expression by an miRNA targeting mechanism was monitored by AGO2-RNA immunoprecipitation assay.

RESULTS

FOXO1 mRNA and protein expression levels in ox-LDL treated HUVECs or HAECs were significantly upregulated due to transcriptional and miRNA targeting mechanisms. MiR-183-5p, miR-182-5p and miR-96-5p expression levels in HUVECs or HAECs were significantly reduced by ox-LDL treatment, the overexpression of which by agomir treatment partially reduced the FOXO1 mRNA/protein expression levels and cell apoptosis which was upregulated by ox-LDL treatment. FOXO1 overexpression antagonized the effect of the agomir treatment indicated above. MiR-183-5p, miR-182-5p and miR-96-5p agomir treatment partially rescued the FOXO1 pSer256/total FOXO1 protein ratio and the AKT1 pSer473 level that were reduced by ox-LDL treatment in the HUVECs or HAECs. AKT1 overexpression significantly reduced FOXO1 protein expression, increased miR-182-5p and miR-183-5p expression, and partially alleviated ox-LDL induced HUVEC or HAEC apoptosis in an miR-183-5p and miR-182-5p-dependent manner.

CONCLUSION

miR-183-96-182 clusters could partially alleviate ox-LDL-induced apoptosis in HUVECs or HAECs by targeting FOXO1.

An Emerging Role for Circular RNAs in Osteoarthritis

Circular RNAs (circRNAs) are currently classed as non-coding RNAs that, unlike the better known canonical linear RNAs, form a covalently closed continuous loop without 5' or 3' polarities. With the development of high throughput sequencing technology, a large number of circRNAs have been discovered in many species. More importantly, growing evidence suggests that circRNAs are abundant, evolutionally conserved, and relatively stable in cells and tissues. Strikingly, recent studies have discovered that circRNAs can serve as microRNA sponges, interact with RNA-binding protein, and regulate gene transcription, as well as protein translation. Osteoarthritis (OA) is the most common chronic degenerative joint disease. CircRNAs are differentially expressed in OA cartilage. Moreover, some circRNAs are involved in multiple pathological processes during OA, mainly extracellular matrix degradation, inflammation, and apoptosis. In this review, we briefly delineate the biogenesis, characteristics, and biofunctions of circRNAs, and then, focus on the role of circRNAs in the occurrence and progression OA.

Vascular smooth muscle cell proliferation as a therapeutic target. Part 1: molecular targets and pathways

Cardiovascular diseases are a major cause of human death worldwide. Excessive proliferation of vascular smooth muscle cells contributes to the etiology of such diseases, including atherosclerosis, restenosis, and pulmonary hypertension. The control of vascular cell proliferation is complex and encompasses interactions of many regulatory molecules and signaling pathways. Herein, we recapitulated the importance of signaling cascades relevant for the regulation of vascular cell proliferation. Detailed understanding of the mechanism underlying this process is essential for the identification of new lead compounds (e.g., natural products) for vascular therapies.

Antiphospholipid antibodies induce thrombosis by PP2A activation via apoER2-Dab2-SHC1 complex formation in endothelium

In the antiphospholipid syndrome (APS), antiphospholipid antibody (aPL) recognition of β2 glycoprotein I promotes thrombosis, and preclinical studies indicate that this is due to endothelial nitric oxide synthase (eNOS) antagonism via apolipoprotein E receptor 2 (apoER2)-dependent processes. How apoER2 molecularly links these events is unknown. Here, we show that, in endothelial cells, the apoER2 cytoplasmic tail serves as a scaffold for aPL-induced assembly and activation of the heterotrimeric protein phosphatase 2A (PP2A). Disabled-2 (Dab2) recruitment to the apoER2 NPXY motif promotes the activating L309 methylation of the PP2A catalytic subunit by leucine methyl transferase-1. Concurrently, Src homology domain-containing transforming protein 1 (SHC1) recruits the PP2A scaffolding subunit to the proline-rich apoER2 C terminus along with 2 distinct regulatory PP2A subunits that mediate inhibitory dephosphorylation of Akt and eNOS. In mice, the coupling of these processes in endothelium is demonstrated to underlie aPL-invoked thrombosis. By elucidating these intricacies in the pathogenesis of APS-related thrombosis, numerous potential new therapeutic targets have been identified.