miR-26a inhibits atherosclerosis progression by targeting TRPC3

The Multifaceted Nature of Macrophages in Cardiovascular Disease

As the leading cause of mortality worldwide, cardiovascular disease (CVD) represents a variety of heart diseases and vascular disorders, including atherosclerosis, aneurysm, ischemic injury in the heart and brain, arrythmias, and heart failure. Macrophages, a diverse population of immune cells that can promote or suppress inflammation, have been increasingly recognized as a key regulator in various processes in both healthy and disease states. In healthy conditions, these cells promote the proper clearance of cellular debris, dead and dying cells, and provide a strong innate immune barrier to foreign pathogens. However, macrophages can play a detrimental role in the progression of disease as well, particularly those inflammatory in nature. This review will focus on the current knowledge regarding the role of macrophages in cardiovascular diseases.

Protective effect of SERCA2a-SUMOylation by SUMO-1 on diabetes-induced atherosclerosis and aortic vascular injury

Diabetes is a major risk factor for cardiovascular disease. However, the exact mechanism by which diabetes contributes to vascular damage is not fully understood. The aim of this study was to investigate the role of SUMO-1 mediated SERCA2a SUMOylation in the development of atherosclerotic vascular injury associated with diabetes mellitus. ApoE-/- mice were treated with streptozotocin (STZ) injection combined with high-fat feeding to simulate diabetic atherosclerosis and vascular injury. Human aortic vascular smooth muscle cells (HAVSMCs) were treated with high glucose (HG, 33.3 mM) and palmitic acid (PA, 200 µM) for 24 h to mimic a model of diabetes-induced vascular injury in vitro. Aortic vascular function, phenotypic conversion, migration, proliferation, intracellular Ca2+ concentration, the levels of small ubiquitin-like modifier type 1 (SUMO1), SERCA2a and SUMOylated SERCA2a were detected. Diabetes-induced atherosclerotic mice presented obvious atherosclerotic plaques and vascular injury, companied by significantly lower levels of SUMO1 and SERCA2a in aorta. HG and PA treatment in HAVSMCs reduced the expressions of SUMO1, SERCA2a and SUMOylated SERCA2a, facilitated the HAVSMCs phenotypic transformation, proliferation and migration, attenuated the Ca2+ transport, and increased the resting intracellular Ca2+ concentration. We also confirmed that SUMO1 directly bound to SERCA2a in HAVSMCs. Overexpression of SUMO1 restored the function and phenotypic contractile ability of HAVSMCs by upregulating SERCA2a SUMOylation, thereby alleviating HG and PA-induced vascular injury. These observations suggest an essential role of SUMO1 to protect diabetes-induced atherosclerosis and aortic vascular injury by the regulation of SERCA2a-SUMOylation and calcium homeostasis.

Two sides of the same coin: Non-alcoholic fatty liver disease and atherosclerosis

The prevalence of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis remain high, which is primarily due to widespread adoption of a western diet and sedentary lifestyle. NAFLD, together with advanced forms of this disease such as non-alcoholic steatohepatitis (NASH) and cirrhosis, are closely associated with atherosclerotic-cardiovascular disease (ASCVD). In this review, we discussed the association between NAFLD and atherosclerosis and expounded on the common molecular biomarkers underpinning the pathogenesis of both NAFLD and atherosclerosis. Furthermore, we have summarized the mode of function and potential clinical utility of existing drugs in the context of these diseases.

The translational potential of miR-26 in atherosclerosis and development of agents for its target genes ACC1/2, COL1A1, CPT1A, FBP1, DGAT2, and SMAD7

Atherosclerosis is one of the leading causes of death worldwide. miR-26 is a potential biomarker of atherosclerosis. Standardized diagnostic tests for miR-26 (MIR26-DX) have been developed, but the fastest progress has been in predicting the efficacy of IFN-α therapy for hepatocellular carcinoma (HCC, phase 3). MiR-26 slows atherosclerosis development by suppressing ACC1/2, ACLY, ACSL3/4, ALDH3A2, ALPL, BMP2, CD36, COL1A1, CPT1A, CTGF, DGAT2, EHHADH, FAS, FBP1, GATA4, GSK3β, G6PC, Gys2, HMGA1, HMGB1, LDLR, LIPC, IL-1β, IL-6, JAG2, KCNJ2, MALT1, β-MHC, NF-κB, PCK1, PLCβ1, PYGL, RUNX2, SCD1, SMAD1/4/5/7, SREBF1, TAB3, TAK1, TCF7L2, and TNF-α expression. Many agents targeting these genes, such as the ACC1/2 inhibitors GS-0976, PF-05221304, and MK-4074; the DGAT2 inhibitors IONIS-DGAT2Rx, PF-06427878, PF-0685571, and PF-07202954; the COL1A1 inhibitor HT-100; the stimulants 68Ga-CBP8 and RCT-01; the CPT1A inhibitors etomoxir, perhexiline, and teglicar; the FBP1 inhibitors CS-917 and MB07803; and the SMAD7 inhibitor mongersen, have been investigated in clinical trials. Interestingly, miR-26 better reduced intima-media thickness (IMT) than PCSK9 or CT-1 knockout. Many PCSK9 inhibitors, including alirocumab, evolocumab, inclisiran, AZD8233, Civi-007, MK-0616, and LIB003, have been investigated in clinical trials. Recombinant CT-1 was also investigated in clinical trials. Therefore, miR-26 is a promising target for agent development. miR-26 promotes foam cell formation by reducing ABCA1 and ARL4C expression. Multiple materials can be used to deliver miR-26, but it is unclear which material is most suitable for mass production and clinical applications. This review focuses on the potential use of miR-26 in treating atherosclerosis to support the development of agents targeting it.

MiRNA-26a-5p inhibits preterm labor initiation by targeting and regulating TRPC3 ion channel protein expression

The incidence of preterm birth (PTB) is increasing annually worldwide, leading to various health problems or even fetal deaths. Our previous work demonstrated the activation of transient receptor potential cation channel subfamily C 3 (TRPC3) in mice with PTB, and its activation could promote inward flow of calcium ions and uterine smooth muscle (USM) contraction via regulation of Cav3.2, Cav3.1, and Cav1.2. However, the upstream regulators of TRPC3 and its mechanisms remain unknown. In the present study, the binding of miR-26a-5p to the 3' untranslated region of TRPC3 was predicted by bioinformatics databases (TargetScanHuman and starBase v3.0) and confirmed by a dual-luciferase assay. MiR-26a-5p was downregulated, while TRPC3 was upregulated in the USM tissues of patients with PTB compared to people without PTB. The results showed that miR-26a-5p mimic transfection markedly reduced TRPC3 expression in LPS-stimulated USM cells. Additionally, miR-26a-5p regulated intracellular Ca2+ levels in USM cells by targeting TRPC3. Furthermore, miR-26a-5p inhibited the CPI17/PKC/PLCγ signaling pathway and reduced the expression of Cav3.2, Cav3.1, and Cav1.2. In conclusion, miR-26a-5p regulated the initiation of PTB by targeting TRPC3 and regulating intracellular Ca2+ levels. This study provides a promising diagnostic biomarker and therapeutic target for PTB.

The effective constituent puerarin, from Pueraria lobata, inhibits the proliferation and inflammation of vascular smooth muscle in atherosclerosis through the miR-29b-3p/IGF1 pathway

CONTEXT

Atherosclerosis (AS) is the main cause of cardiovascular and cerebrovascular diseases. Pueraria lobata (Willd.) Ohwi (Fabaceae) has a positive effect on improving these diseases.

OBJECTIVE

The P. lobata effect on the proliferation and inflammation of vascular smooth muscle in AS and the potential mechanism were investigated.

MATERIALS AND METHODS

By feeding a high-fat diet to 8-week-old apolipoprotein E knockout mice, an atherosclerosis model was created. H&E and IHC staining were used to analyse the histopathology of mice. CCK-8, TUNEL, and scratch tests were used to detect cell proliferation, apoptosis, and migration after 24 h treatment, respectively. ELISA was performed to evaluate the level of IL-6 and IL-8. The target miRNA and its downstream target gene were screened by the bioinformatics method; RT-qPCR has conducted to analyse the expression of these genes.

RESULTS

In the aortic tissue and serum of AS mice, puerarin can lower the expression of α-SMA and the inflammatory proteins IL-6 and IL-8. Puerarin (200 M) decreased hVSMC proliferation, migration, and IL-6 and IL-8 secretion by more than half. The inhibitory impact of puerarin on hVSMC was decreased by overexpression of miR-29b-3p. IGF1 was miR-29b-3p's downstream target gene. IGF1 expression increased almost 3-fold in AS mice and hVSMC, but miR-29b-3p mimic inhibited it. The effect of miR-29b-3p on hVSMC was reversed when IGF1 was overexpressed.

DISCUSSION AND CONCLUSIONS

Puerarin inhibits the proliferation and inflammation of vascular smooth muscle in AS through the miR-29b-3p/IGF1 pathway. Puerarin may have a beneficial effect in the treatment of atherosclerosis and offer a novel therapy option.

lncRNA TUG1 as potential novel biomarker for prognosis of cardiovascular diseases

Globally, cardiovascular diseases (CVDs) are among the leading causes of death. In light of the high prevalence and mortality of CVDs, it is imperative to understand the molecules involved in CVD pathogenesis and the signaling pathways that they initiate. This may facilitate the development of more precise and expedient diagnostic techniques, the identification of more effective prognostic molecules and the identification of potential therapeutic targets. Numerous studies have examined the role of lncRNAs, such as TUG1, in CVD pathogenesis in recent years. According to this review article, TUG1 can be considered a biomarker for predicting the prognosis of CVD.

The role of macrophage ion channels in the progression of atherosclerosis

Atherosclerosis is a complex inflammatory disease that affects the arteries and can lead to severe complications such as heart attack and stroke. Macrophages, a type of immune cell, play a crucial role in atherosclerosis initiation and progression. Emerging studies revealed that ion channels regulate macrophage activation, polarization, phagocytosis, and cytokine secretion. Moreover, macrophage ion channel dysfunction is implicated in macrophage-derived foam cell formation and atherogenesis. In this context, exploring the regulatory role of ion channels in macrophage function and their impacts on the progression of atherosclerosis emerges as a promising avenue for research. Studies in the field will provide insights into novel therapeutic targets for the treatment of atherosclerosis.

Epigenetic modifications as therapeutic targets in atherosclerosis: a focus on DNA methylation and non-coding RNAs

Significant progress in the diagnosis and treatment of cardiovascular disease (CVD) has been made in the past decade, yet it remains a leading cause of morbidity and mortality globally, claiming an estimated 17.9 million deaths per year. Although encompassing any condition that affects the circulatory system, including thrombotic blockage, stenosis, aneurysms, blood clots and arteriosclerosis (general hardening of the arteries), the most prevalent underlying hallmark of CVD is atherosclerosis; the plaque-associated arterial thickening. Further, distinct CVD conditions have overlapping dysregulated molecular and cellular characteristics which underlie their development and progression, suggesting some common aetiology. The identification of heritable genetic mutations associated with the development of atherosclerotic vascular disease (AVD), in particular resulting from Genome Wide Association Studies (GWAS) studies has significantly improved the ability to identify individuals at risk. However, it is increasingly recognised that environmentally-acquired, epigenetic changes are key factors associated with atherosclerosis development. Increasing evidence suggests that these epigenetic changes, most notably DNA methylation and the misexpression of non-coding, microRNAs (miRNAs) are potentially both predictive and causal in AVD development. This, together with their reversible nature, makes them both useful biomarkers for disease and attractive therapeutic targets potentially to reverse AVD progression. We consider here the association of aberrant DNA methylation and dysregulated miRNA expression with the aetiology and progression of atherosclerosis, and the potential development of novel cell-based strategies to target these epigenetic changes therapeutically.

Circulating microRNAs as putative mediators in the association between short-term exposure to ambient air pollution and cardiovascular biomarkers

BACKGROUND

Exposure to ambient air pollution is associated with increased cardiovascular morbidity and mortality. Circulating microRNAs (miRNAs) may mediate cardiovascular effects of exposure to air pollution. This study aims to investigate whether circulating miRNAs mediate the associations between short-term human exposure to ambient air pollution and cardiovascular biomarkers.

METHODS

Twenty-four healthy adults residing in the Research Triangle area of North Carolina, USA were enrolled between December 2016 and July 2019. Circulating miRNAs, protein, and lipid biomarkers were assessed repeatedly for 3 sessions separated by at least 7 days. Linear mixed-effects models were used to assess the associations between air pollutant concentrations obtained from nearby air quality monitoring stations and miRNAs controlling for covariates including omega-3 index, relative humidity, and temperature. miRNAs that were significantly altered were then matched with protein or blood lipid biomarkers using either Ingenuity Pathway Analysis or a literature search. A mediation analysis was performed to test the statistical significance of miRNA's mediating effects between exposure to air pollution and cardiovascular biomarkers.

RESULTS

Short-term exposure to ambient fine particulate matter (PM_2.5), ozone (O₃), and nitrogen dioxide (NO₂) was associated with changes in 11, 9, and 24 circulating miRNAs, respectively. Pathway analysis showed that several miRNAs including miR-125b-5p, miR-144-5p, miR-26a-5p, and miR-34a-5p may mediate the effects of air pollutant exposure on the changes of downstream protein / lipid biomarkers including serum amyloid A (SAA), C-reactive protein (CRP), soluble vascular adhesive molecules 1 (sICAM1), total cholesterol, and high-density lipoproteins (HDL). Mediation analysis showed that only miR-26a-5p significantly mediated air pollutant (PM_2.5 and NO₂)-induced effects on blood CRP and total cholesterol levels. For example, 34.1% of PM_2.5-associated changes in CRP were significantly mediated by miR-26a-5p at lag4 [indirect effects, 0.06 (0.02, 0.10), P = 0.005]. Similarly, the proportions of indirect effects of miR-26a-5p on the association between NO₂ exposure and CRP were 46.8% at lag2 [0.06 (0.02, 0.11), P = 0.003], 61.2% at lag3 [0.05 (0.00, 0.09), P = 0.04], and 30.8% at 5-day moving average [0.06 (0.02, 0.10), P = 0.01]. In addition, omega-3 index may be a significant modifying factor of the mediated effects of miRNAs.

CONCLUSIONS

This study demonstrates that short-term exposure to ambient PM_2.5, O₃, and NO₂ was associated with specific circulating miRNAs, and some of which may mediate their effects on the downstream inflammation and blood lipid markers.

Decoding microRNA drivers in Atherosclerosis

An estimated 97% of the human genome consists of non-protein-coding sequences. As our understanding of genome regulation improves, this has led to the characterization of a diverse array of non-coding RNAs (ncRNA). Among these, micro-RNAs (miRNAs) belong to the short ncRNA class (22–25 nucleotides in length), with approximately 2500 miRNA genes encoded within the human genome. From a therapeutic perspective, there is interest in exploiting miRNA as biomarkers of disease progression and response to treatments, as well as miRNA mimics/repressors as novel medicines. miRNA have emerged as an important class of RNA master regulators with important roles identified in the pathogenesis of atherosclerotic cardiovascular disease. Atherosclerosis is characterized by a chronic inflammatory build-up, driven largely by low-density lipoprotein cholesterol accumulation within the artery wall and vascular injury, including endothelial dysfunction, leukocyte recruitment and vascular remodelling. Conventional therapy focuses on lifestyle interventions, blood pressure-lowering medications, high-intensity statin therapy and antiplatelet agents. However, a significant proportion of patients remain at increased risk of cardiovascular disease. This continued cardiovascular risk is referred to as residual risk. Hence, a new drug class targeting atherosclerosis could synergise with existing therapies to optimise outcomes. Here, we review our current understanding of the role of ncRNA, with a focus on miRNA, in the development and progression of atherosclerosis, highlighting novel biological mechanisms and therapeutic avenues.

Circulating miRNA Correlates with Lipid Profile and Disease Activity in Psoriatic Arthritis, Rheumatoid Arthritis, and Ankylosing Spondylitis Patients

This study aimed to investigate the associations of microRNA (miRs) signatures with cytokines, serum lipids, and disease activity in patients with psoriatic arthritis (PsA), ankylosing spondylitis (AS), and rheumatoid arthritis (RA). In total, 65 patients (PsA n = 25, AS n = 25, RA n = 15) and 25 healthy controls (HC) were enrolled into the study. The expression of miR-223-5p, miR-92b-3p, miR-485-3p, miR-10b-5p, let-7d-5p, miR-26a-2-3p, miR-146b-3p, and cytokines levels were measured in sera. DIANA-mirPath analysis was used to predict pathways targeted by the dysregulated miRs. Disease activity scores were calculated. Lipid profile, uric acid, glucose level, and C-reactive protein (CRP) concentrations were determined in the blood. Based on lipid profiles, the PsA group had hypertriglyceridaemia, and RA patients revealed mixed dyslipidaemia, while in AS, no specific changes were found. miR expression analysis revealed upregulation of miR-26a-2-3p and miR-10b-5p in PsA, miR-485-3p in AS, and let-7d-5p in RA. Several correlations between disease activity indexes, metabolites levels, and expression of miRs were observed in PsA, RA, and AS patients. Finally, in ROC analysis, miR-26a-2-3p/miR-485-3p, and let-7d-5p/miR-146b-3p tandems revealed high sensitivity and specificity in distinguishing between PsA, AS, and RA. Our study illustrates the superiority of miR expressions in distinguishing between RA, PsA, and AS. In PsA, a unique regulatory pathway exists through miR-26a-2-3p, miR-223-5p, miR-10b-5p, and miR-92b-3p that converges proatherogenic metabolism and disease activity.

A microRNA checkpoint for Ca2+ signaling and overload in acute pancreatitis

Acute pancreatitis (AP) is a common digestive disease without specific treatment, and its pathogenesis features multiple deleterious amplification loops dependent on translation, triggered by cytosolic Ca2+ ([Ca2+]i) overload; however, the underlying mechanisms in Ca2+ overload of AP remains incompletely understood. Here we show that microRNA-26a (miR-26a) inhibits pancreatic acinar cell (PAC) store-operated Ca2+ entry (SOCE) channel expression, Ca2+ overload, and AP. We find that major SOCE channels are post-transcriptionally induced in PACs during AP, whereas miR-26a expression is reduced in experimental and human AP and correlated with AP severity. Mechanistically, miR-26a simultaneously targets Trpc3 and Trpc6 SOCE channels and attenuates physiological oscillations and pathological elevations of [Ca2+]i in PACs. MiR-26a deficiency increases SOCE channel expression and [Ca2+]i overload, and significantly exacerbates AP. Conversely, global or PAC-specific overexpression of miR-26a in mice ameliorates pancreatic edema, neutrophil infiltration, acinar necrosis, and systemic inflammation, accompanied with remarkable improvements on pathological determinants related with [Ca2+]i overload. Moreover, pancreatic or systemic administration of an miR-26a mimic to mice significantly alleviates experimental AP. These findings reveal a previously unknown mechanism underlying AP pathogenesis, establish a critical role for miR-26a in Ca2+ signaling in the exocrine pancreas, and identify a potential target for the treatment of AP.

Recent advance in treatment of atherosclerosis: Key targets and plaque-positioned delivery strategies

Atherosclerosis, a chronic inflammatory disease of vascular wall, is a progressive pathophysiological process with lipids oxidation/depositing initiation and innate/adaptive immune responses. The coordination of multi systems covering oxidative stress, dysfunctional endothelium, diseased lipid uptake, cell apoptosis, thrombotic and pro-inflammatory responding as well as switched SMCs contributes to plaque growth. In this circumstance, inevitably, targeting these processes is considered to be effective for treating atherosclerosis. Arriving, retention and working of payload candidates mediated by targets in lesion direct ultimate therapeutic outcomes. Accumulating a series of scientific studies and clinical practice in the past decades, lesion homing delivery strategies including stent/balloon/nanoparticle-based transportation worked as the potent promotor to ensure a therapeutic effect. The objective of this review is to achieve a very brief summary about the effective therapeutic methods cooperating specifical targets and positioning-delivery strategies in atherosclerosis for better outcomes.

microRNA-26a shuttled by extracellular vesicles secreted from adipose-derived mesenchymal stem cells reduce neuronal damage through KLF9-mediated regulation of TRAF2/KLF2 axis

Extracellular vesicles (EVs) are nano-sized vesicles secreted actively by numeorus cells and have fundamental roles in intercellular communication through shuttling functional RNAs. This study sets out to elucidate the role of microRNA-26a (miR-26a) shuttled by EVs derived from adipose-derived mesenchymal stem cells (ASCs) in neuronal damage. After extraction and identification of ASC-derived EVs (ASC-EVs), mouse cortical neuronal cells were selected to establish an in vivo cerebral ischemia/reperfusion mouse model and an in vitro oxygen glucose deprivation/reperfusion (OGD/RP) cell model. The downstream genes of miR-26a were analyzed. The gain- and loss-of function of miR-26a and KLF9 was performed in mouse and cell models. Neuronal cells were subjected to co-culture with ASC-EVs and biological behaviors were detected by flow cytometry, Motic Images Plus, TTC, TUNEL staining, qRT-PCR and western blot analysis. ASC-EVs protected neuronal cells against neuronal damage following cerebral ischemia/reperfusion, which was related to transfer of miR-26a into neuronal cells. In neuronal cells, miR-26a targeted KLF9. KLF9 could suppress the expression of TRAF2 and KLF2 to facilitate neuronal damage. In vitro and in vivo results showed that miR-26a delivered by ASC-EVs inhibited neuronal damage. In summary, ASC-EVs-derived miR-26a can arrest neuronal damage by disrupting the KLF9-meidated suppression on TRAF2/KLF2 axis.

Long noncoding RNA GAS5 in age-related diseases

Aging refers to a natural process and a universal phenomenon in all cells, tissues, organs and the whole organism. Long non-coding RNAs (lncRNAs) are non-coding RNAs with the length of 200 nucleotides. LncRNA growth arrest-specific 5 (lncRNA GAS5) is often down-regulated in cancer. The accumulation of lncRNA GAS5 has been found to be able to inhibit cancer growth, invasion and metastasis, while enhancing the sensitivity of cells to chemotherapy drugs. LncRNA GAS5 can be a signaling protein, which is specifically transcribed under different triggering conditions. Subsequently, it is involved in signal transmission in numerous pathways as a signal node. LncRNA GAS5, with a close relationship to multiple miRNAs, was suggested to be involved in the signaling pathway under three action modes (i.e., signal, bait and guidance). LncRNA GAS5 was found to be involved in different age-related diseases (e.g., rheumatoid arthritis, type 2 diabetes, atherosclerosis, osteoarthritis, osteoporosis, multiple sclerosis, cancer etc.). This study mainly summarized the regulatory effect exerted by lncRNA GAS5 on age-related diseases.

A Review of miRNAs as Biomarkers and Effect of Dietary Modulation in Obesity Associated Cognitive Decline and Neurodegenerative Disorders

There has been a progressive increase in the prevalence of obesity and its comorbidities such as type 2 diabetes and cardiovascular diseases worldwide. Recent studies have suggested that the crosstalk between adipose tissue and central nervous system (CNS), through cellular mediators and signaling pathways, may causally link obesity with cognitive decline and give rise to neurodegenerative disorders. Several mechanisms have been proposed in obesity, including inflammation, oxidative stress, insulin resistance, altered lipid and cholesterol homeostasis, which may result in neuroinflammation, altered brain insulin signaling, amyloid-beta (Aβ) deposition and neuronal cell death. Since obesity is associated with functional and morphological alterations in the adipose tissues, the resulting peripheral immune response augments the development and progression of cognitive decline and increases susceptibility of neurodegenerative disorders, such as Alzheimer's Disease (AD) and Parkinson's Disease (PD). Studies have also elucidated an important role of high fat diet in the exacerbation of these clinical conditions. However, the underlying factors that propel and sustain this obesity associated cognitive decline and neurodegeneration, remains highly elusive. Moreover, the mechanisms linking these phenomena are not well-understood. The cumulative line of evidence have demonstrated an important role of microRNAs (miRNAs), a class of small non-coding RNAs that regulate gene expression and transcriptional changes, as biomarkers of pathophysiological conditions. Despite the lack of utility in current clinical practices, miRNAs have been shown to be highly specific and sensitive to the clinical condition being studied. Based on these observations, this review aims to assess the role of several miRNAs and aim to elucidate underlying mechanisms that link obesity with cognitive decline and neurodegenerative disorders. Furthermore, this review will also provide evidence for the effect of dietary modulation which can potentially ameliorate cognitive decline and neurodegenerative diseases associated with obesity.

MicroRNA-26a/b-5p promotes myocardial infarction-induced cell death by downregulating cytochrome c oxidase 5a

Myocardial infarction (MI) damage induces various types of cell death, and persistent ischemia causes cardiac contractile decline. An effective therapeutic strategy is needed to reduce myocardial cell death and induce cardiac recovery. Therefore, studies on molecular and genetic biomarkers of MI, such as microRNAs (miRs), have recently been increasing and attracting attention due to the ideal characteristics of miRs. The aim of the present study was to discover novel causative factors of MI using multiomics-based functional experiments. Through proteomic, MALDI-TOF-MS, RNA sequencing, and network analyses of myocardial infarcted rat hearts and in vitro functional analyses of myocardial cells, we found that cytochrome c oxidase subunit 5a (Cox5a) expression is noticeably decreased in myocardial infarcted rat hearts and myocardial cells under hypoxic conditions, regulates other identified proteins and is closely related to hypoxia-induced cell death. Moreover, using in silico and in vitro analyses, we found that miR-26a-5p and miR-26b-5p (miR-26a/b-5p) may directly modulate Cox5a, which regulates hypoxia-related cell death. The results of this study elucidate the direct molecular mechanisms linking miR-26a/b-5p and Cox5a in cell death induced by oxygen tension, which may contribute to the identification of new therapeutic targets to modulate cardiac function under physiological and pathological conditions.

Monitoring the activity of two microRNAs, small non-coding RNAs, may provide a useful biomarker for heart attack prognosis and inform novel treatments for repairing heart cells. Ki-Chul Hwang and Jung-Won Choi at the Catholic Kwandong University in Gangwon-do, South Korea, and co-workers examined potential causative factors for heart attacks by exploring the activity of microRNAs in rat models and heart cell cultures. They found that levels of a key protein involved in maintaining mitochondrial function and energy metabolism, cytochrome c oxidase subunit 5a (Cox5a), were significantly decreased in heart cells during oxygen deprivation. Further, they identified two microRNAs that acted to inhibit Cox5a after a heart attack. Suppressing these two microRNAs could boost Cox5a activity and limit cell death, although the authors urge caution because microRNAs also play physiological roles in the body.

Silencing the lncRNA NORAD inhibits EMT of head and neck squamous cell carcinoma stem cells via miR‑26a‑5p

Cancer stem cells are closely associated with tumor metastasis or recurrence. According to previous literature reports, microRNA (miR)‑26a has an inhibitory effect on head and neck squamous cell carcinoma (HNSCC), and the long non‑coding RNA (lncRNA) non‑coding RNA activated by DNA damage (NORAD) has been found to interact with miR‑26a‑5p. The present study aimed to investigate the regulation and mechanism of NORAD and miR‑26a‑5p in the epithelial‑mesenchymal transition (EMT) of HNSCC stem cells. An ALDEFLUOR stem cell detection kit, a flow cytometer, a self‑renewal ability test and western blotting were used to sort and identify HNSCC stem cells. The ENCORI website and a dual‑luciferase assay were used to assess the relationship between genes. The mRNA and protein expression levels of NORAD, miR‑26a‑5p and EMT‑related genes were detected via reverse transcription‑quantitative PCR and western blotting. Functional experiments (MTT assay, flow cytometry, wound healing assay and Transwell assay) were conducted to analyze the effects of NORAD and miR‑26a‑5p on HNSCC stem cells. The successfully sorted aldehyde dehydrogenase (ALDH)⁺ cells had a self‑renewal capacity and displayed upregulated expression levels of CD44, Oct‑4 and Nanog. NORAD knockdown, achieved using small interfering (si)RNA, downregulated the expression levels of tumor markers in ALDH⁺ cells. siNORAD inhibited cell vitality, migration and invasion, as well as promoted apoptosis, increased the expression of epithelial cell markers and decreased the expression of interstitial cell markers in HNSCC stem cells. miR‑26a‑5p was a downstream gene of NORAD, and knockdown of miR‑26a‑5p partially offset the regulatory effect of siNORAD on HNSCC stem cells. Collectively, the present study demonstrated that NORAD knockdown attenuated the migration, invasion and EMT of HNSCC stem cells via miR‑26a‑5p.

Long Noncoding RNA OIP5-AS1 Contributes to the Progression of Atherosclerosis by Targeting miR-26a-5p Through the AKT/NF-κB Pathway

Atherosclerosis (AS) is a cardiovascular disease caused by multiple factors, leading to high mortality and morbidity in aged people. Some long noncoding RNAs have been reported to be associated with AS progression. However, the roles of OIP5-AS1 in AS development are still little known. In this study, the levels of OIP5-AS1 and miR-26a-5p in oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs) were determined by quantitative real-time polymerase chain reaction. Cell proliferation and apoptosis were evaluated by Cell Counting Kit-8 assay and flow cytometric analysis, respectively. The protein levels of proliferating cell nuclear antigen, B-cell lymphoma-2, cleaved caspase 3, inflammatory cytokines (IL-6 and IL-1β), protein kinase B (AKT), p-AKT, p65, p-p65, IκBα, and p-IκBα were detected by Western blot analysis. The targeting relationship between OIP5-AS1 and miR-26a-5p was verified by dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA pull-down assay. As a result, the expression of OIP5-AS1 was upregulated and miR-26a-5p was downregulated in ox-LDL-treated HUVECs. MiR-26a-5p was identified as a direct target of OIP5-AS1. OIP5-AS1 knockdown reversed the inhibitory effect on cell proliferation and the promotional effects on apoptosis and inflammation induced by ox-LDL treatment in HUVECs. Interestingly, the effects caused by OIP5-AS1 knockdown were further attenuated by miR-26a-5p inhibition. Furthermore, OIP5-AS1 knockdown blocked the AKT/NF-κB pathway by regulating miR-26a-5p expression. In conclusion, OIP5-AS1 knockdown promoted cell proliferation and suppressed apoptosis and inflammatory response in ox-LDL-treated HUVECs by targeting miR-26a-5p through blocking the AKT/NF-κB pathway, indicating a promising strategy for AS treatment.

Serum miR-137 serves as a novel biomarker for cerebral atherosclerosis diagnosis and cerebrovascular event prediction

MicroRNAs have been reported as biomarkers for various diseases, including cerebral atherosclerosis (AS). In this study, whether serum microRNA-137 (miR-137) could be used as a biomarker for diagnosing cerebral AS and predicting cerebrovascular event was investigated. Quantitative real-time PCR was used to measure the expression of miR-137 in serum. Logistic analysis was used to evaluate the risk factors for the occurrence of cerebral AS, and receiver operating characteristic curves were used to estimate the diagnostic value of miR-137 and other risk factors for AS occurrence. Furthermore, the prognostic value of miR-137 for patients with AS was estimated using Kaplan–Meier survival analysis and Cox regression analysis. The results indicated that serum miR-137 levels were decreased in patients with cerebral AS. The expression of miR-137 was negatively correlated with total cholesterol and low-density lipoprotein cholesterol levels in patients with cerebral AS. The levels of miR-137, total cholesterol, low-density lipoprotein cholesterol, and hypersensitivity C response protein may serve as risk factors for the occurrence of cerebral AS, and miR-137 had diagnostic value for AS screening. Cerebral AS patients with positive cerebrovascular events have low miR-137 expression. Patients with high miR-137 expression had a lower incidence of cerebrovascular adverse events (log-rank P = 0.013), and miR-137 was an independent prognostic marker for the prediction of cerebrovascular event occurrence in patients with cerebral AS. In conclusions, our findings indicate that serum miR-137 levels are decreased in patients with cerebral AS and may be a new biomarker for diagnosing cerebral AS and predicting cerebrovascular events.

Long non-coding RNA MIAT regulates ox-LDL-induced cell proliferation, migration and invasion by miR-641/STIM1 axis in human vascular smooth muscle cells

Background

Atherosclerosis (AS) is a primary cause of coronary heart and vascular diseases. Long non-coding RNAs (lncRNAs) are indicated to regulate AS progression. This study aimed to reveal the biological roles of lncRNA myocardial infarction associated transcript (MIAT) in oxidized low-density lipoprotein (ox-LDL)-induced human vascular smooth muscle cells (VSMCs).

Methods

The RNA levels of MIAT, microRNA-641 (miR-641) and stromal interaction molecule 1 (STIM1) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels were determined by western blot analysis. Cell proliferation was assessed by cell colony formation and DNA content quantitation assays. Cell migration and invasion were demonstrated by wound-healing and transwell assays. The putative binding relationships between miR-641 and MIAT or STIM1 were predicted by starbase online database, and identified by dual-luciferase reporter and RNA immunoprecipitation assays.

Results

MIAT and STIM1 expression were substantially upregulated, whereas miR-641 expression was downregulated in ox-LDL-induced VSMCs compared with control groups. Functionally, MIAT silencing attenuated ox-LDL-induced cell proliferation, migration and invasion in VSMCs; however, these effects were impaired by miR-641 inhibitor. STIM1 overexpression also restrained miR-641-mediated impacts on cell proliferation and metastasis under ox-LDL. Mechanistically, MIAT acted as a sponge for miR-641, and miR-641 was associated with STIM1.

Conclusions

MIAT silencing hindered ox-LDL-induced cell proliferation, migration and invasion by downregulating STIM1 expression through binding to miR-641 in VSMCs. The mechanism provided us with a new target for AS therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02048-9.

Circ_0000345 Protects Endothelial Cells From Oxidized Low-Density Lipoprotein-Induced Injury by miR-129-5p/Ten-Eleven Translocation Axis

ABSTRACT

Circular RNAs have shown regulatory functions in atherosclerosis (AS) progression. Here, we explored the role and working mechanism of circ_0000345 in the AS cell model in vitro. Quantitative real-time polymerase chain reaction was applied to measure the enrichment of circ_0000345, microRNA-129-5p (miR-129-5p), and ten-eleven translocation-2 (TET2) messenger RNA. Cell Counting Kit 8 assay was used to analyze cell viability of human umbilical vein endothelial cells (HUVECs). Flow cytometry was conducted to assess cell apoptosis and cell cycle progression. The target relationship between miR-129-5p and circ_0000345 or TET2 was verified by the dual-luciferase reporter assay. The Western blot assay was used to analyze the protein level of TET2. Circ_0000345 abundance was reduced in serum samples of AS patients and AS cell model compared with their matching counterparts. Circ_0000345 overexpression promoted cell viability and cell cycle progression and hampered cell apoptosis in HUVECs induced by oxidized low-density lipoprotein. MiR-129-5p was a target of circ_0000345 and circ_0000345 attenuated ox-LDL-induced damage in HUVECs through sponging miR-129-5p. MiR-129-5p bound to the 3' untranslated region (3'UTR) of TET2, and miR-129-5p functioned in ox-LDL-induced HUVECs by targeting TET2. Circ_0000345 enhanced TET2 messenger RNA and protein expression through sponging miR-129-5p in HUVECs. Circ_0000345 attenuated ox-LDL-mediated injury in HUVECs through targeting miR-129-5p/TET2 axis. Increasing the levels of circ_0000345 and TET2 might be a novel insight into AS treatment.

Circ_0004872 promotes platelet-derived growth factor-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs via miR-513a-5p/TXNIP axis

The proliferation, migration and dedifferentiation of vascular smooth muscle cells (VSMCs) exert crucial roles in atherosclerosis (AS) progression. The aim of our study was to explore the influences of circular RNA 0004872 (circ_0004872) in platelet-derived growth factor-BB (PDGF-BB)-induced AS cell model and investigate the underlying mechanisms. Real-time quantitative polymerase chain reaction (RT-qPCR) was implemented for the expression detection of circ_0004872, mitogen-activated protein kinase 1 (MAPK1) messenger RNA (mRNA), microRNA-513a-5p (miR-513a-5p) and thioredoxin interacting protein (TXNIP). Cell proliferation was analyzed via Cell Counting Kit 8 (CCK8) assay. Cell migration was assessed via wound healing assay and transwell migration assay. Western blot assay was used to measure the expression of alpha smooth muscle actin (α-SMA), osteopontin (OPN), calponin and TXNIP. Dual-luciferase reporter assay and RNA-pull down assay were used for confirmation of interaction between miR-513a-5p and circ_0004872 or TXNIP. Circ_0004872 expression was elevated in PDGF-BB-induced human aortic vascular smooth muscle cells (HA-VSMCs) and carotid plaque tissues. Circ_0004872 silencing alleviated PDGF-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs. MiR-513a-5p bound to circ_0004872, and circ_0004872 knockdown-induced effects in PDGF-BB-treated HA-VSMCs were largely attenuated by the silencing of miR-513a-5p. MiR-513a-5p bound to the 3' untranslated region (3'UTR) of TXNIP, and miR-513a-5p overexpression-mediated effects were counteracted by the transfection of pcDNA-TXNIP in PDGF-BB-induced HA-VSMCs. TXNIP was modulated by circ_0004872/miR-513a-5p signaling cascade in HA-VSMCs. Circ_0004872 accelerated PDGF-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs through enhancing TXNIP level via sponging miR-513a-5p.

miR-454-3p prevents ox-LDL-induced apoptosis in HAECs by targeting TRPC3

Endothelial-cell (EC) apoptosis serves a vital role in the pathogenesis of atherosclerosis. Accumulating evidence has implicated microRNA (miRNA/miR) dysregulation in EC apoptosis. Although the role of miR-454-3p in carcinogenesis has been well documented, its role and underlying mechanism in EC apoptosis remain unclear. In the present study, the results revealed that miR-454-3p expression was substantially downregulated in human aortic endothelial cells (HAECs) following oxidized low-density lipoprotein (ox-LDL) treatment. miR-454-3p suppression significantly attenuated the viability of HAECs, while miR-454-3p overexpression repressed ox-LDL-induced HAEC apoptosis. Bioinformatics analysis and luciferase reporter assays revealed that transient receptor potential canonical 3 (TRPC3), a key regulator of atherosclerosis development, was the direct target of miR-454-3p. Furthermore, TRPC3 overexpression abolished the anti-apoptotic effect of miR-454-3p on HAECs. These results revealed a novel role of miR-454-3p in ox-LDL-induced apoptosis in HAECs.

MicroRNA regulation of cholesterol metabolism

MicroRNAs are small noncoding RNAs that regulate gene expression at the posttranscriptional level. Since many microRNAs have multiple mRNA targets, they are uniquely positioned to regulate the expression of several molecules and pathways simultaneously. For example, the multiple stages of cholesterol metabolism are heavily influenced by microRNA activity. Understanding the scope of microRNAs that control this pathway is highly relevant to diseases of perturbed cholesterol metabolism, most notably cardiovascular disease (CVD). Atherosclerosis is a common cause of CVD that involves inflammation and the accumulation of cholesterol-laden cells in the arterial wall. However, several different cell types participate in atherosclerosis, and perturbations in cholesterol homeostasis may have unique effects on the specialized functions of these various cell types. Therefore, our review discusses the current knowledge of microRNA-mediated control of cholesterol homeostasis, followed by speculation as to how these microRNA-mRNA target interactions might have distinctive effects on different cell types that participate in atherosclerosis.

Potential role of specific microRNAs in the regulation of thermal stress response in livestock

Thermal stress is known to have harmful effects on livestock productivity and can cause livestock enterprises considerable financial loss. These effects may be aggravated by climate change. Stress responses to nonspecific systemic actions lead to perturbation of molecular pathways in the organism. The molecular response is regulated in a dynamic and synchronized manner that assurances robustness and flexibility for the restoration of functional and structural homeostasis in stressed cells and tissues. MicroRNAs (miRNAs) are micro molecules of small non-coding RNA that control gene expression at the post-transcriptional level. Recently, various studies have discovered precise types of miRNA that regulate cellular machinery and homeostasis under various types of stress, suggesting a significant role of miRNA in thermal stress responses in animals. The miRNAs revealed in this paper could serve as promising candidates and biomarkers for heat stress and could be used as potential pharmacological targets for mitigating the consequences of thermal stress. Stress miRNA pathways may be associated with thermal stress, which offers some potential approaches to combat the negative impacts of thermal stress in livestock. The review provides new data that can assist the elucidation of the miRNA mechanisms that mediate animals' responses to thermal stress.

MiR-26a-5p inhibits GSK3β expression and promotes cardiac hypertrophy in vitro

Background

The role of miR-26a-5p expression in cardiac hypertrophy remains unclear. Herein, the effect of miR-26a-5p on cardiac hypertrophy was investigated using phenylephrine (PE)-induced cardiac hypertrophy in vitro and in a rat model of hypertension-induced hypertrophy in vivo.

Methods

The PE-induced cardiac hypertrophy models in vitro and vivo were established. To investigate the effect of miR-26a-5p activation on autophagy, the protein expression of autophagosome marker (LC3) and p62 was detected by western blot analysis. To explore the effect of miR-26a-5p activation on cardiac hypertrophy, the relative mRNA expression of cardiac hypertrophy related mark GSK3β was detected by qRT-PCR in vitro and vivo. In addition, immunofluorescence staining was used to detect cardiac hypertrophy related mark α-actinin. The cell surface area was measured by immunofluorescence staining. The direct target relationship between miR-26a-5p and GSK3β was confirmed by dual luciferase report.

Results

MiR-26a-5p was highly expressed in PE-induced cardiac hypertrophy. MiR-26a-5p promoted LC3II and decreased p62 expression in PE-induced cardiac hypertrophy in the presence or absence of lysosomal inhibitor. Furthermore, miR-26a-5p significantly inhibited GSK3β expression in vitro and in vivo. Dual luciferase report results confirmed that miR-26a-5p could directly target GSK3β. GSK3β overexpression significantly reversed the expression of cardiac hypertrophy-related markers including ANP, ACTA1 and MYH7. Immunofluorescence staining results demonstrated that miR-26a-5p promoted cardiac hypertrophy related protein α-actinin expression, and increased cell surface area in vitro and in vivo.

Conclusion

Our study revealed that miR-26a-5p promotes myocardial cell autophagy activation and cardiac hypertrophy by regulating GSK3β, which needs further research.

TRPC and TRPV Channels' Role in Vascular Remodeling and Disease

Transient receptor potentials (TRPs) are non-selective cation channels that are widely expressed in vascular beds. They contribute to the Ca²⁺ influx evoked by a wide spectrum of chemical and physical stimuli, both in endothelial and vascular smooth muscle cells. Within the superfamily of TRP channels, different isoforms of TRPC (canonical) and TRPV (vanilloid) have emerged as important regulators of vascular tone and blood flow pressure. Additionally, several lines of evidence derived from animal models, and even from human subjects, highlighted the role of TRPC and TRPV in vascular remodeling and disease. Dysregulation in the function and/or expression of TRPC and TRPV isoforms likely regulates vascular smooth muscle cells switching from a contractile to a synthetic phenotype. This process contributes to the development and progression of vascular disorders, such as systemic and pulmonary arterial hypertension, atherosclerosis and restenosis. In this review, we provide an overview of the current knowledge on the implication of TRPC and TRPV in the physiological and pathological processes of some frequent vascular diseases.

Overexpressed lncRNA AC068039.4 Contributes to Proliferation and Cell Cycle Progression of Pulmonary Artery Smooth Muscle Cells Via Sponging miR-26a-5p/TRPC6 in Hypoxic Pulmonary Arterial Hypertension

BACKGROUND

Hypoxic pulmonary hypertension (HPH) is a devastating and incurable disease characterized by pulmonary vascular remodeling, resulting in right heart failure and even death. Accumulated evidence has confirmed long coding RNAs (lncRNAs) are involved in hypoxia-induced pulmonary vascular remodeling in HPH. The exact mechanism of lncRNA in hypoxic pulmonary hypertension remains unclear.

METHODS

Microarray analysis was applied to investigate the profiles of lncRNA expression in pulmonary artery smooth muscle cells (PASMCs) cultured under hypoxia and normoxia condition. qRT-PCR was performed for the expression of lncRNAs, miRNA, and mRNAs, western blot analysis was employed for the detection of the expression of proteins. CCK-8 and transwell chamber assay were applied for the assessment of PASMC proliferation and migration, respectively. Besides, flow cytometry was performed for assessments of cell cycle progression. The binding between AC068039.4 and miR-26a-5p, miR-26a-5p, and TRPC6 3'UTR was detected by dual luciferase reporter assay.

RESULTS

A total of 1,211 lncRNAs (698 up-regulated and 513 down-regulated) were differently expressed in hypoxia-induced PASMCs. Consistent with microarray analysis, quantitative PCR verified that AC068039.4 was obviously up-regulated in hypoxia-induced PASMCs. Knocking down AC068039.4 alleviated proliferation and migration of PASMCs and regulated cell cycle progression through inhibiting cells entering the G0/G1 cell cycle phase. Further experiment indicated AC068039.4 promoted hypoxic PASMCs proliferation via sponging miR-26-5p. In addition, transient receptor potential canonical 6 (TRPC6) was confirmed to be a target gene of miR-26a-5p.

CONCLUSION

In conclusion, downregulation of lncRNA AC068039.4 inhibited pulmonary vascular remodeling through AC068039.4/miR-26a-5p/TRPC6 axis, providing new therapeutic insights for the treatment of HPH.

Approaches to Manipulate Ephrin-A:EphA Forward Signaling Pathway

Erythropoietin-producing hepatocellular carcinoma A (EphA) receptors and their ephrin-A ligands are key players of developmental events shaping the mature organism. Their expression is mostly restricted to stem cell niches in adults but is reactivated in pathological conditions including lesions in the heart, lung, or nervous system. They are also often misregulated in tumors. A wide range of molecular tools enabling the manipulation of the ephrin-A:EphA system are available, ranging from small molecules to peptides and genetically-encoded strategies. Their mechanism is either direct, targeting EphA receptors, or indirect through the modification of intracellular downstream pathways. Approaches enabling manipulation of ephrin-A:EphA forward signaling for the dissection of its signaling cascade, the investigation of its physiological roles or the development of therapeutic strategies are summarized here.

Circular RNA-9119 protects IL-1β-treated chondrocytes from apoptosis in an osteoarthritis cell model by intercepting the microRNA-26a/PTEN axis

AIMS

Osteoarthritis (OA) is a common degenerative joint disease characterized by cartilage degeneration and joint inflammation. As its pathogenesis remains unclear, there are no effective treatments established. Circular RNA (circRNA), microRNA (miRNA), and other noncoding RNAs participate in OA development; however, the effects and mechanisms of circRNA and miRNA in OA remain unknown.

MAIN METHODS

Cartilage miRNA was examined in patients with and without OA.

KEY FINDINGS

CircRNA-9119 and phosphatase and tensin homolog (PTEN) expression decreased in OA-affected cartilage and interleukin (IL)-1β-induced chondrocytes, and miR-26a expression significantly decreased in normal cells and tissues. CircRNA-9119 overexpression restored chondrocyte growth, whereas IL-1β treatment impaired chondrocyte growth. Annexin V-FITC & PI flow cytometry and Bcl-2/Bax ratio measurement indicated that the apoptosis of IL-1β-treated articular chondrocytes was decreased by circRNA-9119 upregulation. Bioinformatic prediction and the dual-luciferase reporter assay indicated that circRNA-9119 served as a miR-26a sponge and that miR-26a targeted the 3'-UTR of PTEN. Transfection of chondrocytes with a circRNA-9119-overexpressing vector revealed downregulation of miR-26a expression. Furthermore, circRNA-9119 overexpression induced PTEN expression. In addition, a miR-26a mimic induced IL-1β-induced chondrocyte apoptosis, and circRNA-9119 overexpression inhibited IL-1β-induced chondrocyte apoptosis.

SIGNIFICANCE

CircRNA-9119 is an important regulator of IL-1β-treated chondrocytes through the miR-26a/PTEN axis, possibly contributing to OA development.

RNA-seq analysis reveals TRPC genes to impact an unexpected number of metabolic and regulatory pathways

The seven-member transient receptor potential canonical genes (TRPC1-7) encode cation channels linked to several human diseases. There is little understanding of the participation of each TRPC in each pathology, considering functional redundancy. Also, most of the inhibitors available are not specific. Thus, we developed mice that lack all of the TRPCs and performed a transcriptome analysis in eight tissues. The aim of this research was to address the impact of the absence of all TRPC channels on gene expression. We obtained a total of 4305 differentially expressed genes (DEGs) in at least one tissue where spleen showed the highest number of DEGs (1371). Just 21 genes were modified in all the tissues. Performing a pathway enrichment analysis, we found that many important signaling pathways were modified in more than one tissue, including PI3K (phosphatidylinositol 3-kinase/protein kinase-B) signaling pathway, cytokine-cytokine receptor interaction, extracellular matrix (ECM)-receptor interaction and circadian rhythms. We describe for the first time the changes at the transcriptome level due to the lack of all TRPC proteins in a mouse model and provide a starting point to understand the function of TRPC channels and their possible roles in pathologies.

TRPC channels: Structure, function, regulation and recent advances in small molecular probes

Transient receptor potential canonical (TRPC) channels constitute a group of receptor-operated calcium-permeable nonselective cation channels of the TRP superfamily. The seven mammalian TRPC members, which can be further divided into four subgroups (TRPC1, TRPC2, TRPC4/5, and TRPC3/6/7) based on their amino acid sequences and functional similarities, contribute to a broad spectrum of cellular functions and physiological roles. Studies have revealed complexity of their regulation involving several components of the phospholipase C pathway, G_i and G_o proteins, and internal Ca²⁺ stores. Recent advances in cryogenic electron microscopy have provided several high-resolution structures of TRPC channels. Growing evidence demonstrates the involvement of TRPC channels in diseases, particularly the link between genetic mutations of TRPC6 and familial focal segmental glomerulosclerosis. Because TRPCs were discovered by the molecular identity first, their pharmacology had lagged behind. This is rapidly changing in recent years owning to great efforts from both academia and industry. A number of potent tool compounds from both synthetic and natural products that selective target different subtypes of TRPC channels have been discovered, including some preclinical drug candidates. This review will cover recent advancements in the understanding of TRPC channel regulation, structure, and discovery of novel TRPC small molecular probes over the past few years, with the goal of facilitating drug discovery for the study of TRPCs and therapeutic development.

Diagnostic and theranostic microRNAs in the pathogenesis of atherosclerosis

MicroRNAs (miRNAs) are a group of small single strand and noncoding RNAs that regulate several physiological and molecular signalling pathways. Alterations of miRNA expression profiles may be involved with pathophysiological processes underlying the development of atherosclerosis and cardiovascular diseases, including changes in the functions of the endothelial cells and vascular smooth muscle cells, such as cell proliferation, migration and inflammation, which are involved in angiogenesis, macrophage function and foam cell formation. Thus, miRNAs can be considered to have a crucial role in the progression, modulation and regulation of every stage of atherosclerosis. Such potential biomarkers will enable us to predict therapeutic response and prognosis of cardiovascular diseases and adopt effective preclinical and clinical treatment strategies. In the present review article, the current data regarding the role of miRNAs in atherosclerosis were summarized and the potential miRNAs as prognostic, diagnostic and theranostic biomarkers in preclinical and clinical studies were further discussed. The highlights of this review are expected to present opportunities for future research of clinical therapeutic approaches in vascular diseases resulting from atherosclerosis with an emphasis on miRNAs.

Notoginsenoside R1 protects human renal proximal tubular epithelial cells from lipopolysaccharide-stimulated inflammatory damage by up-regulation of miR-26a

BACKGROUND

Notoginsenoside R1 (NGR1) is the main saponin isolated from the roots of Panax notoginseng (Burk.) F.H. Chen (Araliaceae). This study explored the protective effects of NGR1 on human renal proximal tubular epithelial cell inflammatory damage caused by lipopolysaccharide (LPS), as well as possible internal molecular mechanisms.

METHODS

Cell viability and apoptosis were assessed using CCK-8 assay and Annexin V-FITC/PI Apoptosis Detection kit, respectively. Reactive oxygen species (ROS) level was tested using DCFH-DA staining. qRT-PCR was used to measure microRNA-26a (miR-26a), interleukin 1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) expressions. miRNA transfection was conducted to knock down miR-26a. The protein expression levels of key molecules related to cell apoptosis, inflammatory response and nuclear factor kappa B (NF-κB) pathway were detected using western blotting.

RESULTS

LPS stimulation caused human renal proximal tubular epithelial cell viability reduction, apoptosis and inflammatory cytokines expression. NGR1 treatment protected human renal proximal tubular epithelial cells from LPS-caused viability reduction, ROS level elevation, apoptosis and inflammatory cytokines expression. Mechanistically, NGR1 enhanced miR-26a expression in LPS-treated human renal proximal tubular epithelial cells. Knockdown of miR-26a reversed the protective effect of NGR1 on LPS-treated cells. Besides, NGR1 inactivated NF-κB pathway in LPS-treated human renal proximal tubular epithelial cells via up-regulating miR-26a.

CONCLUSION

NGR1 protected human renal proximal tubular epithelial cells from LPS-caused inflammatory damage at least partially via up-regulating miR-26a and then inactivating NF-κB pathway.

MicroRNA-26a reduces synovial inflammation and cartilage injury in osteoarthritis of knee joints through impairing the NF-κB signaling pathway

Objective: Inflammation is closely implicated in the process of osteoarthritis (OA) and affects disease progression and pain. Herein, the present study explored the effect of microRNA-26a (miR-26a) on the synovial inflammation and cartilage injury in OA, with the involvement with the NF-κB signaling pathway.Methods: Rat models of OA were established by anterior cruciate ligament transection, which were then treated with miR-26a mimics/inhibitors or BMS-345541 (inhibitor of NF-κB pathway). The expression of miR-26a and activator proteins of NF-κB pathway (P-IκBα and P-P65) in synovial tissues was determined. Hematoxylin-eosin (HE) staining was adopted to observe pathological changes of knee joints, synovial tissues, and cartilage of femoral condyle. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining was used to detect the apoptosis of synoviocytes and chondrocytes.Results: Poorly expressed miR-26a and increased protein levels of P-IκBα and P-P65 were identified in synovial tissues of OA rats. Besides, OA rats showed obvious synovial tissue hyperplasia, inflammation and cartilage injury of femoral condyle, as well as increased inflammation and cartilage injury scores, and apoptosis of synoviocytes and chondrocytes. In response to miR-26a mimics, protein levels of P-IκBα and P-P65 were reduced; meanwhile, synovial tissue hyperplasia, inflammation and cartilage injury of femoral condyle were ameliorated, with decreased inflammation and cartilage injury scores, and apoptosis of synoviocytes and chondrocytes.Conclusion: MiR-26a suppressed the activation of the NF-κB signaling pathway, by which mechanism the synovial inflammation and cartilage injury in OA rats were alleviated.

Kaempferol alleviates ox-LDL-induced apoptosis by up-regulation of miR-26a-5p via inhibiting TLR4/NF-κB pathway in human endothelial cells

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL) has been well-documented to induce endothelial cell (EC) apoptosis and contribute to the progression of atherosclerosis. Kaempferol was reported to alleviate ox-LDL-induced apoptosis of human umbilical vein endothelial cells. However, the detailed mechanism by which kaempferol alleviated ox-LDL-induced EC apoptosis remains largely elusive.

METHODS

The expression of miR-26a-5p in human aortic endothelial cells (HAECs) treated with either ox-LDL alone or in combination with kaempferol was detected by qRT-PCR. Cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. The interaction between miR-26a-5p and toll-like receptor 4 (TLR4) mRNA was examined by luciferase reporter assay. The protein levels of TLR4, phosphorylated-p65, p65, phosphorylated-IκBα and IκBα were determined by western blot.

RESULTS

Kaempferol upregulated miR-26a-5p expression in ox-LDL-stimulated HAECs. Moreover, kaempferol alleviated ox-LDL-induced apoptosis in HAECs by upregulating miR-26a-5p. Additionally, TLR4 mRNA was identified as a target of miR-26a-5p in ox-LDL-treated HAECs. TLR4 overexpression partially counteracted the anti-apoptotic role of miR-26a-5p in ox-LDL-treated HAECs. Furthermore, kaempferol inactivated the TLR4/nuclear factor kappa B (NF-κB) signaling pathway in ox-LDL-treated HAECs by upregulating miR-26a-5p.

CONCLUSION

Kaempferol alleviated ox-LDL-induced apoptosis in HAECs by upregulating miR-26a-5p via inactivation of the TLR4/NF-κB signaling pathway, shedding light on the molecular mechanism by which kaempferol alleviated ox-LDL-induced EC apoptosis.

Ion Channels and Transporters in Inflammation: Special Focus on TRP Channels and TRPC6

Allergy and autoimmune diseases are characterised by a multifactorial pathogenic background. Several genes involved in the control of innate and adaptive immunity have been associated with diseases and variably combine with each other as well as with environmental factors and epigenetic processes to shape the characteristics of individual manifestations. Systemic or local perturbations in salt/water balance and in ion exchanges between the intra- and extracellular spaces or among tissues play a role. In this field, usually referred to as elementary immunology, novel evidence has been recently acquired on the role of members of the transient potential receptor (TRP) channel family in several cellular mechanisms of potential significance for the pathophysiology of the immune response. TRP canonical channel 6 (TRPC6) is emerging as a functional element for the control of calcium currents in immune-committed cells and target tissues. In fact, TRPC6 influences leukocytes’ tasks such as transendothelial migration, chemotaxis, phagocytosis and cytokine release. TRPC6 also modulates the sensitivity of immune cells to apoptosis and influences tissue susceptibility to ischemia-reperfusion injury and excitotoxicity. Here, we provide a view of the interactions between ion exchanges and inflammation with a focus on the pathogenesis of immune-mediated diseases and potential future therapeutic implications.