A microRNA signature of hypoxia

Recent advances of miR-23 in human diseases and growth development

MicroRNA (miRNA) is broadly manifested in eukaryotes and serves as a critical function in biological development and disease occurrence. With the rapid advancement of experimental research tools, researchers have discovered functional correlations among different miRNA isoforms and clusters within the same miRNA family. As a highly conserved member in the miR-23-27-24 cluster, miR-23 exhibits different isoforms and participates in various essential development. Although the miR-23-27-24 cluster has overlapping target sites, their differential expression can demonstrate independent biological functions. Furthermore, the untapped effects of miR-23 on organisms, whether as a functional cluster or a single regulator, has not been systematically elucidated yet. In this review article, we analyze the genomic location of miR-23 and its sequence variances among its isoforms or family members while summarizing its regulatory functions in metabolic diseases, immune responses, cardiovascular diseases, cancer, organ development as well as nervous system function. This review highlights the significant role of miR-23 as a biomarker for disease diagnosis and a key regulatory factor in pathogenesis, which can help us comprehend the diverse functions of miRNAs and provide a theoretical reference for the functional differences among miRNA isoforms.

The miR-21-5p/DUSP8/MAPK signaling pathway mediates inflammation and apoptosis in vascular endothelial cells induced by intermittent hypoxia and contributes to the protective effects of N-acetylcysteine

Obstructive sleep apnoea hypopnea syndrome (OSAHS) is a sleep disorder associated with significant cardiovascular complications, characterized by intermittent hypoxia (IH). IH causes endothelial dysfunction, an early event in cardiovascular disease. We investigated the role of dual-specificity phosphatase 8 (DUSP8), a key negative regulator of the mitogen-activated protein kinase (MAPK) signalling pathway, in IH-induced endothelial cell damage, and the therapeutic effects of N-acetylcysteine (NAC) by establishing IH models in human umbilical vein endothelial cells and C57BL/6 mice. DUSP8 and MAPK signalling pathway-related proteins were analysed by western blotting, and DUSP8 mRNA and miR-21-5p expression was assessed by RT-qPCR. Inflammatory cytokines were detected by an enzyme-linked immunosorbent assay, apoptosis-related proteins were analysed by western blotting, and apoptosis was assessed using flow cytometry. IH stimulation induced inflammation and apoptosis in endothelial cells, downregulated DUSP8 expression, and upregulated the phosphorylation of key molecules involved in the MAPK signalling pathway. However, DUSP8 overexpression alleviated IH-induced inflammation and apoptosis in endothelial cells and reduced the phosphorylation of key molecules in the MAPK signalling pathway. Bioinformatic analysis and dual-luciferase reporter assays confirmed that DUSP8 is a direct target of miR-21-5p. DUSP8 overexpression effectively reversed the damage caused by miR-21-5p upregulation under IH conditions. Furthermore, in cell and animal models of IH, NAC demonstrated protective effects against inflammation, apoptosis, and oxidative stress through a mechanism linked to the miR-21-5p/DUSP8/MAPK signalling pathway. Overall, this study elucidated the protective role of DUSP8 against IH-induced endothelial injury and confirmed the potential of NAC as a therapeutic agent for OSAHS-related diseases.

Developing a Personalized Approach to Obstructive Sleep Apnea

All areas of medicine are focused on developing a personalized approach to diagnosis and treatment of specific conditions. This is based on the fundamental concept that all subjects with apparently the same disorder are different. There are multiple reasons for these differences. These include differences in the sequence of DNA, differences in the environment, differences in epigenetics, some of which may be driven by environmental differences and differences in the microbiome. These different factors will result in variations in multiple aspects of the phenotype. This includes different pathways to disease, different symptoms, different pattern of comorbidities and risk for adverse outcomes, and different physiological changes during sleep as a result of breathing episodes.

Acidity and hypoxia of tumor microenvironment, a positive interplay in extracellular vesicle release by tumor cells

The complex and continuously evolving features of the tumor microenvironment, varying between tumor histotypes, are characterized by the presence of host cells and tumor cells embedded in a milieu shaped by hypoxia and low pH, resulting from the frequent imbalance between vascularity and tumor cell proliferation. These microenvironmental metabolic stressors play a crucial role in remodeling host cells and tumor cells, contributing to the stimulation of cancer cell heterogeneity, clonal evolution, and multidrug resistance, ultimately leading to progression and metastasis. The extracellular vesicles (EVs), membrane-enclosed structures released into the extracellular milieu by tumor/host cells, are now recognized as critical drivers in the complex intercellular communication between tumor cells and the local cellular components in a hypoxic/acidic microenvironment. Understanding the intricate molecular mechanisms governing the interactions between tumor and host cells within a hypoxic and acidic microenvironment, triggered by the release of EVs, could pave the way for innovative strategies to disrupt the complex interplay of cancer cells with their microenvironment. This approach may contribute to the development of an efficient and safe therapeutic strategy to combat cancer progression. Therefore, we review the major findings on the release of EVs in a hypoxic/acidic tumor microenvironment to appreciate their role in tumor progression toward metastatic disease.

MiRNA expression affects survival in patients with obstructive sleep apnea and metastatic colorectal cancer

Introduction

The relationship between obstructive sleep apnea (OSA) and cancer has been recognized for some time now. However, little is known about the mechanisms by which sleep apnea promotes tumorigenesis and the impact of OSA on survival after cancer diagnosis. In the last few years, research has focused on the exploration of different biomarkers to understand the mechanisms underlying this relationship and miRNAs, non-coding single strands of about 22 nucleotides that post-transcriptionally regulate gene expression, have emerged as possible actors of this process.The aim of the study was to evaluate the impact of OSA on survival of metastatic colorectal cancer (mCRC) patients based on the expression of specific miRNAs.

Methods

The expression of 6 miRNAs, respectively miR-21, miR-23b, miR-26a, miR-27b, miR-145 and miR-210, was analyzed by qRT-PCR in patients' sera. Response to first-line therapy, Kaplan-Meier curves of overall and progression-free survival were used to evaluate survival in mCRC patients with and without OSA stratified for the expression of miRNAs.

Results

The expression of miR-21, miR-23b, miR-26a and miR-210 was significantly upregulated in mCRCs with OSA compared to no OSA. In mCRC patients with OSA and increasing expression of miR-21, miR-23b, miR-26a and miR-210 risk of progression after first-line therapy was higher and both overall and progression-free survival were significantly worst. Conversely, as miR-27b and miR-145 expression increased, the life expectancy of patients diagnosed with OSA and mCRC improved markedly.

Conclusions

This study highlights the relevance of specific miRNAs on OSA in mCRCs and their significance as non-invasive biomarkers in predicting the prognosis in patients with mCRC and OSA.

Discovery of paradoxical genes: reevaluating the prognostic impact of overexpressed genes in cancer

Oncogenes are typically overexpressed in tumor tissues and often linked to poor prognosis. However, recent advancements in bioinformatics have revealed that many highly expressed genes in tumors are associated with better patient outcomes. These genes, which act as tumor suppressors, are referred to as "paradoxical genes." Analyzing The Cancer Genome Atlas (TCGA) confirmed the widespread presence of paradoxical genes, and KEGG analysis revealed their role in regulating tumor metabolism. Mechanistically, discrepancies between gene and protein expression-affected by pre- and post-transcriptional modifications-may drive this phenomenon. Mechanisms like upstream open reading frames and alternative splicing contribute to these inconsistencies. Many paradoxical genes modulate the tumor immune microenvironment, exerting tumor-suppressive effects. Further analysis shows that the stage- and tumor-specific expression of these genes, along with their environmental sensitivity, influence their dual roles in various signaling pathways. These findings highlight the importance of paradoxical genes in resisting tumor progression and maintaining cellular homeostasis, offering new avenues for targeted cancer therapy.

Tumor Suppressor miR-34a: Potential Biomarker of TACE Response in HCC

PURPOSE

TACE induces variable systemic effects by producing factors that promote inflammation, oncogenesis, and angiogenesis. Here we compare concentrations of microRNAs (miR-21, miR-210 and miR-34a) and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) patients undergoing TACE with degradable (DSM) and nondegradable (DEB) particles and potential use of these biomarker changes for prediction of patient outcomes.

MATERIALS AND METHODS

Overall, 52 patients with HCC treated with DSM TACE (24 patients) and DEB TACE (28 patients) were included in this prospective study. Concentrations of studied biomarkers were measured from blood plasma preprocedurally, immediately (< 90 min) postprocedurally, and 24-h after TACE. Levels were compared between DSM and DEB TACE and correlated with treatment response six and 12 months after the first TACE.

RESULTS

Both DSM and DEB TACE elevated plasma levels of miR-21, miR-34a, and miR-210 at 24 h post-procedure compared to baseline levels (FC 1.25-4.0). MiR-34a elevation immediately after TACE was significantly associated with nonprogressive disease compared to those with progressive disease at both six months (FCa: p = 0.014) and 12 months (FCa: p = 0.029) post-TACE. No significant biomarker changes were found between the embolization particle groups. However, VEGF levels showed a decrease only in the DSM TACE group (FC24: p =  < 0.001).

CONCLUSION

Embolization particle type did not significantly impact miRNA or VEGF changes post-TACE. However, miR-34a elevation immediately after the procedure predicts better patient outcome and may prove useful as a biomarkers for the monitoring of clinical outcomes.

LEVEL OF EVIDENCE

Level 3 Prospective cohort study.

miR-210 loss leads to widespread phenotypic and gene expression changes in human 293T cells

Introduction

Hypoxia responses are critical for myriad physiological and pathological processes, such as development, tissue repair, would healing, and tumorigenesis. microRNAs (miRNAs) are a class of small non-coding RNAs that exert their functions by inhibiting the expression of their target genes, and miR-210 is the miRNA universally and most conspicuously upregulated by hypoxia in mammalian systems. For its relationship to hypoxia, miR-210 has been studied extensively, yet no consensus exists on the roles and mechanisms of miR-210 in human physiological processes or diseases, and we know little about genuine miR-210 target genes in humans.

Methods

To better investigate the functions and mechanisms of human miR-210, therefore, we derived the human miR-210 gene knockout (KO) 293T cell lines using the CRISPR/Cas9 technology. We then examined the cellular phenotypes and gene expression profiles of 293T cells under normoxia and hypoxia conditions.

Results and Discussion

We found that the loss of miR-210 altered a variety of cellular phenotypes including proliferation and apoptosis. Subsequent global gene expression analyses identified plausible mechanisms underlying these phenotypic changes in 293T cells. In particular, we showed that miR-210 might target the expression of BNIP3L as a potential mechanism to suppress apoptosis. Surprisingly, the mRNA levels of most previously reported miR-210 target genes were not induced upon miR-210 KO, suggesting a need to reexamining and studying human miR-210 functions directly and comprehensively. Thus, our work established a human cellular system and opportunity to unravel the complexity of the regulatory networks by miR-210.

Cross-Sectional Analysis of Hypoxia-Regulated miRNA-181a, miRNA-199a, HIF-1α, and SIRT1 in the Development of Type 2 Diabetes in Patients with Obstructive Sleep Apnea-Preliminary Study

Introduction: Obstructive sleep apnea (OSA) is recognized as an independent risk factor for diabetes mellitus type 2 (T2DM) development, which is twice as common in patients with OSA compared to non-OSA patients. Objectives: This study aimed to investigate changes in oxygen metabolism and their role in T2DM development among OSA patients through epigenetic processes via miRNA-181a, miRNA-199a, and enzymatic processes via SIRT1 and HIF-1α. Methods: Based on polysomnography, apnea-hypopnea index and the presence of T2DM patients were divided into three groups: control group (n = 17), OSA group (n = 11), OSA&T2DM (n = 20) group. Total RNA was extracted from the buffy coat. Moreover, HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) was counted. Results: Morning miRNA-181a expression was significantly higher in the OSA&T2DM group than in the control group: 67.618 vs. 32.685 (p = 0.036). Evening miRNA-199a expression was significantly higher in the OSA group than in the control group: 5.043 vs. 2.081 (p = 0.042), while its morning expression was significantly higher in the OSA&T2DM group when compared to the control: 4.065 vs. 1.605 (p = 0.036). MiRNA-181a evening expression revealed a negative correlation with the SIRT1 evening and morning expressions (R = -0.367, p = 0.010 and R = -0.405, p = 0.004, respectively). Moreover, morning miRNA-181a was positively correlated with HOMA-IR (R = 0.321, p = 0.034). MiRNA-199a evening expression presented a moderate positive correlation with the SIRT1 morning expressions (R = 0.48, p < 0.001) and HOMA-IR (R = 0.35, p = 0.02). Conclusions: Patients suffering from OSA and T2DM had an increased expression of miRNA-181a. Moreover, a negative correlation between miRNA-181a and SIRT1 expression was observed, while a correlation between miRNA-181a and insulin resistance was positive. This phenomenon might suggest a possible epigenetic pathway for an increased incidence of T2DM in OSA patients however further research is needed.

miR-210 is essential to retinal homeostasis in fruit flies and mice

BACKGROUND

miR-210 is one of the most evolutionarily conserved microRNAs. It is known to be involved in several physiological and pathological processes, including response to hypoxia, angiogenesis, cardiovascular diseases and cancer. Recently, new roles of this microRNA are emerging in the context of eye and visual system homeostasis. Recent studies in Drosophila melanogaster unveiled that the absence of miR-210 leads to a progressive retinal degeneration characterized by the accumulation of lipid droplets and disruptions in lipid metabolism. However, the possible conservation of miR-210 knock-out effect in the mammalian retina has yet to be explored.

RESULTS

We further investigated lipid anabolism and catabolism in miR-210 knock-out (KO) flies, uncovering significant alterations in gene expression within these pathways. Additionally, we characterized the retinal morphology of flies overexpressing (OE) miR-210, which was not affected by the increased levels of the microRNA. For the first time, we also characterized the retinal morphology of miR-210 KO and OE mice. Similar to flies, miR-210 OE did not affect retinal homeostasis, whereas miR-210 KO mice exhibited photoreceptor degeneration. To explore other potential parallels between miR-210 KO models in flies and mice, we examined lipid metabolism, circadian behaviour, and retinal transcriptome in mice, but found no similarities. Specifically, RNA-seq confirmed the lack of involvement of lipid metabolism in the mice's pathological phenotype, revealing that the differentially expressed genes were predominantly associated with chloride channel activity and extracellular matrix homeostasis. Simultaneously, transcriptome analysis of miR-210 KO fly brains indicated that the observed alterations extend beyond the eye and may be linked to neuronal deficiencies in signal detection and transduction.

CONCLUSIONS

We provide the first morphological characterization of the retina of miR-210 KO and OE mice, investigating the role of this microRNA in mammalian retinal physiology and exploring potential parallels with phenotypes observed in fly models. Although the lack of similarities in lipid metabolism, circadian behaviour, and retinal transcriptome in mice suggests divergent mechanisms of retinal degeneration between the two species, transcriptome analysis of miR-210 KO fly brains indicates the potential existence of a shared upstream mechanism contributing to retinal degeneration in both flies and mammals.

miR-210 in ischaemic stroke: biomarker potential, challenges and future perspectives

Ischaemic stroke, a leading cause of global morbidity and mortality, necessitates effective biomarkers for enhanced diagnostic and prognostic stratification. MicroRNAs (miRNAs), particularly miR-210, have emerged as promising candidates due to their intricate regulatory roles in cellular responses to hypoxia and neuroprotective effects. This study explores the potential of miR-210 as a biomarker for ischaemic stroke, considering its expression patterns, regulatory functions and diagnostic/prognostic implications. A literature search was conducted on PubMed, Scopus, Google Scholar and Web of Science to identify studies focusing on miR-210 in ischaemic stroke. Inclusion criteria comprised reports on miR-210 expression in ischaemic stroke patients, excluding non-English studies, reviews, commentaries and conference abstracts lacking primary data. Studies investigating miR-210 levels in ischaemic stroke patients revealed significant alterations in expression patterns compared to healthy controls. Diagnostic potential was explored, indicating miR-210's sensitivity and specificity in distinguishing ischaemic stroke from other neurological conditions. Prognostic value was evident through associations with infarct size, functional outcomes and long-term survival. Challenges included variability in miR-210 levels, limited diagnostic specificity, absence of standardised assays and concerns regarding cost-effectiveness and accessibility. While miR-210 holds promise as an ischaemic stroke biomarker, challenges must be addressed for its successful integration into clinical practice. Standardised reference ranges, validation studies in diverse populations and collaborative efforts for assay standardisation are crucial. Despite challenges, miR-210's diagnostic and prognostic potential, particularly in predicting therapeutic responses, suggests a significant role in advancing ischaemic stroke management.

MiR-26a and miR-191 are upregulated while PLAG1 and HIF2 are downregulated in pleomorphic adenomas of the salivary glands compared to Warthin tumors

BACKGROUND

Salivary gland tumors (SGTs) are a heterogenous group of pathologies, which still represents a challenge regarding differential diagnosis and therapy. Although histological findings govern SGTs management, detection of molecular alterations is emerging as an effective additional tool. The aim of this study was to analyze the relative expression levels of three micro RNAs (miR-26a, miR-26b, and miR-191), and three pro-oncogenic molecular markers (PLAG1, MTDH, and HIF2) in SGTs and normal salivary gland (NSG) tissues and evaluate them as potential differential diagnosis markers.

METHODS

This cross-sectional study included 58 patients with SGTs (23 pleomorphic adenomas, 27 Warthin tumors, and 8 malignant SGTs) and 10 controls (normal salivary gland tissues). Relative gene expression levels of all investigated molecules were determined by reverse transcriptase-real-time polymerase chain reaction.

RESULTS

All three micro RNAs exhibited highest expression levels in benign SGTs, whereas miR-26a And miR-191 were significantly more expressed in PAs compared to WTs (p = 0.045 and p = 0.029, respectively). PLAG1 And HIF2 were both overexpressed in WTs compared to PAs (p = 0.048 and p = 0.053, respectively). Bioinformatic analysis suggested that all investigated micro RNAs function as negative regulators of MTDH.

CONCLUSION

The results of this study suggest that all three micro RNAs have a considerable negative impact on MTDH oncogene expression in malignant tumors, while the differences between levels of miR-26a, miR-191, PLAG1, and HIF2 in PA and WT represent possible differential diagnosis markers.

Urinary microRNA-210-3p as a novel and non-invasive biomarker for the detection of pancreatic cancer, including intraductal papillary mucinous carcinoma

BACKGROUND

This study aims to explore novel microRNAs in urine for screening and predicting clinical characteristics in pancreatic cancer (PC) patients using a microRNA array-based approach.

METHODS

We used the Toray® 3D-Gene microRNA array-based approach to compare urinary levels between PC patients and healthy volunteers.

RESULTS

(1) Four oncogenic microRNAs (miR-744-5p, miR-572, miR-210-3p, and miR-575) that were highly upregulated in the urine of PC patients compared to healthy individuals were identified by comprehensive microRNA array analysis. (2) Test-scale analysis by quantitative RT-PCR for each group of 20 cases showed that miR-210-3p was significantly upregulated in the urine of PC patients compared to healthy individuals (P = 0.009). (3) Validation analysis (58 PC patients and 35 healthy individuals) confirmed that miR-210-3p was significantly upregulated in the urine of PC patients compared to healthy individuals (P < 0.001, area under the receiver operating characteristic curve = 0.79, sensitivity: 0.828, specificity: 0.743). We differentiated PC patients into invasive ductal carcinoma (IDCa) and intraductal papillary mucinous carcinoma (IPMC) groups. In addition to urinary miR-210-3p levels being upregulated in IDCa over healthy individuals (P = 0.009), urinary miR-210-3p levels were also elevated in IPMC over healthy individuals (P = 0.0018). Urinary miR-210-3p can differentiate IPMC from healthy individuals by a cutoff of 8.02 with an AUC value of 0.762, sensitivity of 94%, and specificity of 63%. (4) To test whether urinary miR210-3p levels reflected plasma miR-210-3p levels, we examined the correlation between urinary and plasma levels. Spearman's correlation analysis showed a moderate positive correlation (ρ = 0.64, P = 0.005) between miR-210-3p expression in plasma and urine.

CONCLUSIONS

Urinary miR-210-3p is a promising, non-invasive diagnostic biomarker of PC, including IPMC.

TRIAL REGISTRATION

Not applicable.

Investigating Expression Dynamics of miR-21 and miR-10b in Glioblastoma Cells In Vitro: Insights into Responses to Hypoxia and Secretion Mechanisms

Glioblastoma poses significant challenges in oncology, with bevacizumab showing promise as an antiangiogenic treatment but with limited efficacy. microRNAs (miRNAs) 10b and 21 have emerged as potential biomarkers for bevacizumab response in glioblastoma patients. This study delves into the expression dynamics of miR-21 and miR-10b in response to hypoxia and explores their circulation mechanisms. In vitro experiments exposed glioma cells (A172, U87MG, U251) and human umbilical vein endothelial cells (HUVEC) to hypoxic conditions (1% oxygen) for 24 h, revealing heightened levels of miR-10b and miR-21 in glioblastoma cells. Manipulating miR-10b expression in U87MG, demonstrating a significant decrease in VEGF alpha (VEGFA) following miR-10b overexpression under hypoxic conditions. Size exclusion chromatography illustrated a notable shift towards miR-21 and miR-10b exosomal packaging during hypoxia. A proposed model suggests that effective bevacizumab treatment reduces VEGFA levels, heightening hypoxia and subsequently upregulating miR-21 and miR-10b expression. These miRNAs, released via exosomes, might impact various cellular processes, with miR-10b notably contributing to VEGFA level reduction. However, post-treatment increases in miR-10b and miR-21 could potentially restore cells to normoxic conditions through the downregulation of VEGF. This study highlights the intricate feedback loop involving miR-10b, miR-21, and VEGFA in glioblastoma treatment, underscoring the necessity for personalized therapeutic strategies. Further research should explore clinical implications for personalized glioma treatments.

MicroRNA-138 inhibits hypoxia-inducible factor 1α expression in breast cancer cells

BACKGROUND

Hypoxia, a critical feature during cancer development, leads to the stabilization and activation of the hypoxia-inducible factor 1-alpha (HIF-1α) to drive the expression of many target genes which in turn can promote many aspects of breast cancer biology, mainly metastasis and resistance to therapy. MicroRNAs are known to modulate the expression of many genes involved in breast cancer tumorigenesis. In this study, we examined the regulatory effect of miRNAs on HIF1α expression.

METHODS

MCF-7 and MDA-MB-231 were cultivated under normoxia or hypoxia conditions. TaqMan-Low Density Array (TLDA) was used to characterize the miRNA signatures. Wild-Type (WT) or mutated fragments of HIF-1α 3'UTR containing the miR-138 potential target site were cloned downstream of the Renilla luciferase gene in the psiCHECK-1 plasmid. Luciferase assays were then carried out. A lentiviral vector containing copGFP as a reporter gene was prepared and transduced into MCF-7 and MDA-MB-231 cells to assess the effect of identified deregulated miRNAs on HIF-1α expression.

RESULTS

Under hypoxic conditions, MCF-7 cells showed deregulated expression for 12 miRNAs. In the case of MDA-MB-231 cells, 16 miRNAs were deregulated in response to hypoxia. Interestingly, miR-138 that was downregulated in both MCF-7 and MDA-MB-231 cells cultivated under hypoxic conditions appeared to have a binding site in 3'UTR of HIF-1α. Moreover, our results indicated that miR-138 could down regulate HIF-1α expression, upon binding directly to its 3'UTR.

CONCLUSIONS

Interestingly, our data highlights miR-138 as a potential therapeutic target to reduce HIF-1α expression and subsequently restrain breast cancer invasion and metastasis.

PIEZO1 as a new target for hyperglycemic stress-induced neuropathic injury: The potential therapeutic role of bezafibrate

Hyperglycemic stress can directly lead to neuronal damage. The mechanosensitive ion channel PIEZO1 can be activated in response to hyperglycemia, but its role in hyperglycemic neurotoxicity is unclear. The role of PIEZO1 in hyperglycemic neurotoxicity was explored by constructing a hyperglycemic mouse model and a high-glucose HT22 cell model. The results showed that PIEZO1 was significantly upregulated in response to high glucose stress. In vitro experiments have shown that high glucose stress induces changes in neuronal cell morphology and membrane tension, a key mechanism for PIEZO1 activation. In addition, high glucose stress upregulates serum/glucocorticoid-regulated kinase-1 (SGK1) and activates PIEZO1 through the Ca2+ pool and store-operated calcium entry (SOCE). PIEZO1-mediated Ca2+ influx further enhances SGK1 and SOCE, inducing intracellular Ca2+ peaks in neurons. PIEZO1 mediated intracellular Ca2+ elevation leads to calcium/calmodulin-dependent protein kinase 2α (CaMK2α) overactivation, which promotes oxidative stress and apoptosis signalling through p-CaMK2α/ERK/CREB and ox-CaMK2α/MAPK p38/NFκB p65 pathways, subsequently inducing synaptic damage and cognitive impairment in mice. The intron miR-107 of pantothenic kinase 1 (PANK1) is highly expressed in the brain and has been found to target PIEZO1 and SGK1. The PANK1 receptor is activated by peroxisome proliferator-activated receptor α (PPARα), an activator known to upregulate miR-107 levels in the brain. The clinically used lipid-lowering drug bezafibrate, a known PPARα activator, may upregulate miR-107 through the PPARɑ/PANK1 pathway, thereby inhibiting PIEZO1 and improving hyperglycemia-induced neuronal cell damage. This study provides a new idea for the pathogenesis and drug treatment of hyperglycemic neurotoxicity and diabetes-related cognitive dysfunction.

Regulation of the HIF switch in human endothelial and cancer cells

Hypoxia-inducible factors (HIFs) are transcription factors that reprogram the transcriptome for cells to survive hypoxic insults and oxidative stress. They are important during embryonic development and reprogram the cells to utilize glycolysis when the oxygen levels are extremely low. This metabolic change facilitates normal cell survival as well as cancer cell survival. The key feature in survival is the transition between acute hypoxia and chronic hypoxia, and this is regulated by the transition between HIF-1 expression and HIF-2/HIF-3 expression. This transition is observed in many human cancers and endothelial cells and referred to as the HIF Switch. Here we discuss the mechanisms involved in the HIF Switch in human endothelial and cancer cells which include mRNA and protein levels of the alpha chains of the HIFs. A major continuing effort in this field is directed towards determining the differences between normal and tumor cell utilization of this important pathway, and how this could lead to potential therapeutic approaches.

Non-coding RNA and gene expression analyses of papillary renal neoplasm with reverse polarity (PRNRP) reveal distinct pathological mechanisms from other renal neoplasms

Papillary renal neoplasm with reversed polarity (PRNRP) is a recently described rare renal neoplasm. Traditionally, it was considered a variant of papillary renal cell carcinoma (PRCC). However, several studies reported significant differences between PRNRP and PRCC in terms of clinical, morphological, immunohistochemical and molecular features. Nonetheless, PRNRP remains a poorly understood entity. We used microarray analysis to elucidate the non-coding RNA (ncRNA) and gene expression profiles of 10 PRNRP cases and compared them with other renal neoplasms. Unsupervised cluster analysis showed that PRNRP had distinct expression profiles from either clear cell renal cell carcinoma (ccRCC) or PRCC cases at the level of ncRNA but were less distinct at the level of gene expression. An integrated omic approach determined miRNA:gene interactions that distinguished PRNRP from PRCC and we validated 10 differentially expressed miRNAs and six genes by quantitative RT-PCR. We found that levels of the miRNAs, miR-148a, miR-375 and miR-429, were up-regulated in PRNRP cases compared to ccRCC and PRCC. miRNA target genes, including KRAS and VEGFA oncogenes, and CXCL8, which regulates VEGFA, were also differentially expressed between renal neoplasms. Gene set enrichment analysis (GSEA) determined different activation of metabolic pathways between PRNRP and PRCC cases. Overall, this study is by far the largest molecular study of PRNRP cases and the first to investigate either ncRNA expression or their gene expression by microarray assays.

Aptamer-RIBOTAC Strategy Enabling Tumor-Specific Targeted Degradation of MicroRNA for Precise Cancer Therapy

MicroRNA (miRNA) molecules play crucial roles in a variety of diseases, making miRNA targeting a burgeoning field in medicinal chemistry. Ribonuclease targeting chimeras (RIBOTACs) present a compelling approach for RNA degradation. However, small molecule-based RIBOTAC requires an expensive and time-consuming screening process, and is difficult to directly target miRNA due to its short length lacking secondary structure. Antisense oligonucleotide (ASO)-based RIBOTAC is easy to design but with poor cell permeability. While both of them lack the specificity for tumor targeting. In this study, the first Aptamer-RIBOTAC (ARIBOTAC) chimera is designed based on ASO to achieve precise degradation of miRNA in a tumor cell-specific manner for precise cancer therapy. This chimera exhibits a remarkable ability to specifically identify and enter cancer cells, trigger localized activation of endogenous RNase L, and selectively cleave miRNAs that are complementary to ASO. The efficacy and universality of the ARIBOTAC strategy both in vitro and in vivo by degrading oncogenic miR-210-3p and miR-155-5p are validated. These findings underscore the potential of the ARIBOTAC strategy as a promising avenue for cancer therapy by precisely targeting cancer-associated miRNAs.

Deciphering the Role of microRNAs: Unveiling Clinical Biomarkers and Therapeutic Avenues in Atrial Fibrillation and Associated Stroke-A Systematic Review

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression by binding to target messenger RNAs (mRNAs). miRNAs have been implicated in a variety of cardiovascular and neurological diseases, such as myocardial infarction, cardiomyopathies of various geneses, rhythmological diseases, neurodegenerative illnesses and strokes. Numerous studies have focused on the expression of miRNA patterns with respect to atrial fibrillation (AF) or acute ischemic stroke (AIS) However, only a few studies have addressed the expression pattern of miRNAs in patients with AF and AIS in order to provide not only preventive information but also to identify therapeutic potentials. Therefore, the aim of this review is to summarize 18 existing manuscripts that have dealt with this combined topic of AF and associated AIS in detail and to shed light on the most frequently mentioned miRNAs-1, -19, -21, -145 and -146 with regard to their molecular mechanisms and targets on both the heart and the brain. From this, possible diagnostic and therapeutic consequences for the future could be derived.

Regulation of Cancer-Associated miRNAs Expression under Hypoxic Conditions

Solid tumors frequently experience hypoxia or low O2 levels. In these conditions, hypoxia-inducible factor 1 alpha (HIF-1α) is activated and acts as a transcription factor that regulates cancer cell adaptation to O2 and nutrient deprivation. HIF-1α controls gene expression associated with various signaling pathways that promote cancer cell proliferation and survival. MicroRNAs (miRNAs) are 22-nucleotide noncoding RNAs that play a role in various biological processes essential for cancer progression. This review presents an overview of how hypoxia regulates the expression of multiple miRNAs in the progression of cancer cells.

miR-210-5p Promotes Pulmonary Hypertension by Blocking ATP2A2

AIM

Aberrant expression of ATPase sarcoplasmic/endoplasmic retic Ca2+ transporting 2 (ATP2A2) has attracted attention for its pathophysiologic role in pulmonary hypertension (PH). Several miRNAs, including miR-210-5p, have also been reported to be pathogenic factors in PH, but their exact mechanisms remain unknown. This study aimed to elucidate the potential mechanisms of miR-210-5p and ATP2A2 in MCT-induced PH.

METHODS

Eighteen Sprague-Dawley rats were randomly divided into two groups-monoclonal (MCT) group and control group-and then administered MCT (60 mg/kg) and saline, respectively. mPAP, PVR, RVHI, WT%, and WA% were significantly increased in PH rats after 3 weeks, confirming that the modeling of PH rats was successful. Subsequently, we determined the expression of ATP2A2 and miR-210-5p in lung tissues using WB and qRT-PCR methods. We established an in vitro model using BMP4 and TGF-β1 treatment of pulmonary artery smooth muscle cells (PASMCs) and examined the expression of ATP2A2 and miR-210-5p using the same method. To further elucidate the regulatory relationship between ATP2A2 and miR-210-5p, we altered the expression level of miR-210-5p and detected the corresponding changes in ATP2A2 levels. In addition, we demonstrated the relationship by dual luciferase experiments. Finally, the effect of silencing ATP2A2 could be confirmed by the level of cell membrane Ca2+ in PAMSCs.

RESULTS

Up-regulation of miR-210-5p and down-regulation of ATP2A2 were observed in the MCT group compared with the control group, which was confirmed in the in vitro model. In addition, elevated miR-210-5p expression decreased the level of ATP2A2 while increasing the proliferation of PASMCs, and the results of the dual luciferase assay further confirmed that ATP2A2 is a downstream target of miR-210-5p. Additionally, silencing ATP2A2 resulted in increased cytoplasmic Ca2+ levels in PAMSCs.

CONCLUSION

In MCT-induced PH, miR-210-5p promotes pulmonary vascular remodeling by inhibiting ATP2A2.

Metabolite and protein shifts in mature erythrocyte under hypoxia

As the only cell type responsible for oxygen delivery, erythrocytes play a crucial role in supplying oxygen to hypoxic tissues, ensuring their normal functions. Hypoxia commonly occurs under physiological or pathological conditions, and understanding how erythrocytes adapt to hypoxia is fundamental for exploring the mechanisms of hypoxic diseases. Additionally, investigating acute and chronic mountain sickness caused by plateaus, which are naturally hypoxic environments, will aid in the study of hypoxic diseases. In recent years, increasingly developed proteomics and metabolomics technologies have become powerful tools for studying mature enucleated erythrocytes, which has significantly contributed to clarifying how hypoxia affects erythrocytes. The aim of this article is to summarize the composition of the cytoskeleton and cytoplasmic proteins of hypoxia-altered erythrocytes and explore the impact of hypoxia on their essential functions. Furthermore, we discuss the role of microRNAs in the adaptation of erythrocytes to hypoxia, providing new perspectives on hypoxia-related diseases.

The emerging role of hypoxia and environmental factors in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and debilitating disorder characterized by inflammation of the gastrointestinal tract. Despite extensive research, the exact cause of IBD remains unknown, hampering the development of effective therapies. However, emerging evidence suggests that hypoxia, a condition resulting from inadequate oxygen supply, plays a crucial role in intestinal inflammation and tissue damage in IBD. Hypoxia-inducible factors (HIFs), transcription factors that regulate the cellular response to low oxygen levels, have gained attention for their involvement in modulating inflammatory processes and maintaining tissue homeostasis. The two most studied HIFs, HIF-1α and HIF-2α, have been implicated in the development and progression of IBD. Toxicological factors encompass a wide range of environmental and endogenous agents, including dietary components, microbial metabolites, and pollutants. These factors can profoundly influence the hypoxic microenvironment within the gut, thereby exacerbating the course of IBD and fostering the progression of colitis-associated colorectal cancer. This review explores the regulation of hypoxia signaling at the molecular, microenvironmental, and environmental levels, investigating the intricate interplay between toxicological factors and hypoxic signaling in the context of IBD, focusing on its most concerning outcomes: intestinal fibrosis and colorectal cancer.

Next-Generation Sequencing of microRNAs in Small Abdominal Aortic Aneurysms: MiR-24 as a Biomarker

BACKGROUND

Small abdominal aortic aneurysms (AAAs) are asymptomatic but can potentially lead to rupture if left undetected. To date, there is a lack of simple nonradiologic routine tests available for diagnosing AAAs. MicroRNAs (miRNAs) have been proven to be good-quality biomarkers in several diseases, including AAA.

METHODS

An attempt to identify a panel of circulating miRNAs with differential expression in AAAs via next-generation sequencing (NGS) was performed in serum samples: small AAAs (n = 3), large AAAs (n = 3), and controls (n = 3). For miR-24, validation with real-time polymerase chain reaction (PCR) was undertaken in a larger group (n = 80).

RESULTS

In the NGS study, 23 miRNAs were identified as differentially expressed (with statistical significance) in small AAAs in comparison with controls. Among them, miR-24 showed the largest upregulation with 23-fold change (log2FC 4.5, P = 0.024). For large AAAs compared with controls, and small AAAs compared with large AAAs, a panel of 33 and 131 miRNAs showed statistically significant differential expression, respectively. Based on the results of the NGS stage, a literature search was performed, and information regarding AAA pathogenesis, coronary artery disease, and peripheral arterial disease was documented where applicable: miR-24, miR-103, miR-193a, miR-486, miR-582, and miR-3663. Of these 6 miRNAs, miR-24 was chosen for further validation with real-time PCR. Additionally, in the NGS study analysis, 17 miRNAs were common between the small-large AAAs, small AAAs-controls, and large AAAs-controls comparisons: miR-7846, miR-3195, miR-486-2, miR-3194, miR-5589, miR-1538, miR-3178, miR-4771-1, miR-5695, miR-6504, miR-1908, miR-6823, miR-3159, miR-23a, miR-7853, miR-496, and miR-193a. Interestingly, in the validation stage with real-time PCR, miR-24 was found downregulated in small and large AAAs compared with controls (fold-changes: 0.27, P = 0.015 and 0.15, P = 0.005, respectively). No correlation was found between average Ct values, aneurysm diameter, and patients' age.

CONCLUSIONS

Our findings further highlight the importance of miR-24 as a potential biomarker as well as a therapeutic target for abdominal aneurysmal disease. Future research and validation of a panel of miRNAs for AAA would aid in diagnosis and discrimination between diseases with overlapping pathogeneses.

Profiling canine mammary tumors: A potential model for studying human breast cancer

Despite all clinical progress recorded in the last decades, human breast cancer (HBC) remains a major challenge worldwide both in terms of its incidence and its management. Canine mammary tumors (CMTs) share similarities with HBC and represent an alternative model for HBC. The utility of the canine model in studying HBC relies on their common features, include spontaneous development, subtype classification, mutational profile, alterations in gene expression profile, and incidence/prevalence. This review describes the similarities between CMTs and HBC regarding genomic landscape, microRNA expression alteration, methylation, and metabolomic changes occurring during mammary gland carcinogenesis. The primary purpose of this review is to highlight the advantages of using the canine model as a translational animal model for HBC research and to investigate the challenges and limitations of this approach.

MicroRNA miR-27a as a possible regulator of anti-inflammatory macrophage phenotype in preeclamptic placenta

INTRODUCTION

The role of the TGFβ signaling pathway, an important cascade responsible for the anti-inflammatory polarization of macrophages, in the development of both early- and late-onset preeclampsia (eoPE and loPE), remains poorly understood. In this study, we examined the components of the TGFβ signaling cascade and macrophage markers within placental tissue in normal pregnancy and in PE.

METHODS

Patients with eoPE, loPE, and normal pregnancy were enrolled in the study (n = 10 in each group). Following techniques were used for the investigation: immunohistochemistry analysis, western blotting, qRT-PCR, isolation of monocytes by magnetic sorting, transfection, microRNA sequencing, and bioinformatic analysis.

RESULTS

We observed a significant decrease in the anti-inflammatory macrophage marker CD206 in the loPE group, alongside with a significant down-regulation of CD206 protein production in both eoPE and loPE groups. The level of CD68-positive cells and relative levels of CD163 and MARCO production were comparable across the groups. However, we identified a significant decrease in the TGFβ receptor 2 production and its gene expression in the PE group. Further analysis revealed a link between TGFBR2 and MRC1 (CD206) genes through a single miRNA, hsa-miR-27a-3p. Transfecting CD14-derived macrophages with the hsa-miR-27a-3p mimic significantly changed TGFBR2 production, indicating the potential role of this miRNA in regulating the TGFβ signaling pathway. We also revealed the up-regulation of hsa-miR-27a-5p and hsa-miR-27a-3p in the trophoblast BeWo b30 cell line under the severe hypoxia condition and the fact that TGFBR2 3' UTR could serve as a potential target for these miRNAs.

DISCUSSION

Our findings uncover a novel potential therapeutic target for managing patients with PE, significantly contributing to a deeper comprehension of the underlying mechanisms involved in the development of this pathology.

Hypoxia A Typical Target in Human Lung Cancer Therapy

Lung cancer (LC) is the leading cause of cancer-related death globally. Comprehensive knowledge of the cellular and molecular etiology of LC is perilous for the development of active treatment approaches. Hypoxia in cancer is linked with malignancy, and its phenotype is implicated in the hypoxic reaction, which is being studied as a prospective cancer treatment target. The hypervascularization of the tumor is the main feature of human LC, and hypoxia is a major stimulator of neo-angiogenesis. It was seen that low oxygen levels in human LC are a critical aspect of this lethal illness. However, as there is a considerable body of literature espousing the presumed functional relevance of hypoxia in LC, the direct measurement of oxygen concentration in Human LC is yet to be determined. This narrative review aims to show the importance and as a future target for novel research studies that can lead to the perception of LC therapy in hypoxic malignancies.

P53‑microRNA interactions regulate the response of colorectal tumor cells to oxaliplatin under normoxic and hypoxic conditions

Oxaliplatin (OXA)‑containing regimens are used as first‑line chemotherapy in colorectal cancer (CRC). However, OXA resistance remains a major challenge in CRC treatment. CRC cells that adapt to hypoxia can potentially develop OXA resistance, and the underlying molecular mechanisms still need to be further investigated. In the current study, the OXA drug sensitivity of two CRC cell lines, HCT116 (TP53WT) and HT29 (TP53MT), was compared under both normoxic and hypoxic conditions. It was found that under normoxic condition, HCT116 cells showed significantly higher OXA sensitivity than HT29 cells. However, both cell lines showed remarkable OXA resistance under hypoxic conditions. It was also revealed that P53 levels were increased after OXA and hypoxia treatment in HCT116 cells but not in HT29 cells. Notably, knocking down P53WT decreased normoxic but increased hypoxic OXA sensitivity in HCT116 cells, which did not exist in HT29 cells. Molecular analysis indicated that P53WT activated microRNA (miR)‑26a and miR‑34a in OXA treatment and activated miR‑23a in hypoxia treatment. Cell proliferation experiments indicated that a high level of miR‑23a decreased OXA sensitivity and that a high level of miR‑26a or miR‑34a increased OXA sensitivity in HCT116 cells. Additionally, it was demonstrated that miR‑26a, miR‑34a and miR‑23a affect cell apoptosis through regulation of MCL‑1, EZH2, BCL‑2, SMAD 4 and STAT3. Taken together, the present findings revealed the dual function of P53 in regulating cellular chemo‑sensitivity and highlighted the role of P53‑miR interactions in the response of CRC cells to OXA chemotherapy under normoxic and hypoxic conditions.

Jackfruit waste: an invented anticancer therapy using Jacalin lectin from jackfruit seed

Every food source contains both edible and inedible waste components. Millions of tonnes of trash from the food business are made from fruits, and these wastes are containing higher-value medicinal components, such as alkaloids, flavonoids, phenolic contents, a huge amount of proteins and secondary metabolites. These bioactive phytoconstituents are being used for the treatment of many serious fatal diseases. So, utilizing the recovered bioactive molecules from food wastes as functional ingredients offers a long-term alternative source of therapeutically active components that will lead to the discovery of novel phytoconstituents or novel treatment approaches. The goal of this systematic study is to provide an overview of the jackfruit (Artocarpus heterophyllus Lam, Moraceae) edible byproducts, such as jackfruit seeds that are largely neglected. This seed contains numerous bioactive lead molecules, such as carbohydrate-binding protein jacalin, which exhibits potent anticancer activity against colon cancer, blood cancer and breast cancer as well as can enlighten the new possible treatment approaches in targeted therapy and photodynamic chemotherapy. Moreover, jackfruit waste seed can be taken as a dietary food, which is having property to prevent and treat cancer and other lifestyle diseases. The works that have been carried out to utilize jackfruit waste other than the juicy edible bulbs have been reviewed in this article.

Effects of Hyperbaric Oxygen Intervention on the Degenerated Intervertebral Disc: From Molecular Mechanisms to Animal Models

MicroRNA (miRNA) 107 expression is downregulated but Wnt3a protein and β-catenin are upregulated in degenerated intervertebral disc (IVD). We investigated mir-107/Wnt3a-β-catenin signaling in vitro and in vivo following hyperbaric oxygen (HBO) intervention. Our results showed 96 miRNAs were upregulated and 66 downregulated in degenerated nucleus pulposus cells (NPCs) following HBO treatment. The 3' untranslated region (UTR) of the Wnt3a mRNA contained the "seed-matched-sequence" for miR-107. MiR-107 was upregulated and a marked suppression of Wnt3a was observed simultaneously in degenerated NPCs following HBO intervention. Knockdown of miR-107 upregulated Wnt3a expression in hyperoxic cells. HBO downregulated the protein expression of Wnt3a, phosphorylated LRP6, and cyclin D1. There was decreased TOP flash activity following HBO intervention, whereas the FOP flash activity was not affected. HBO decreased the nuclear translocation of β-catenin and decreased the secretion of MMP-3 and -9 in degenerated NPCs. Moreover, rabbit serum KS levels and the stained area for Wnt3a and β-catenin in repaired cartilage tended to be lower in the HBO group. We observed that HBO inhibits Wnt3a/β-catenin signaling-related pathways by upregulating miR-107 expression in degenerated NPCs. HBO may play a protective role against IVD degeneration and could be used as a future therapeutic treatment.

Integrated transcriptome and miRNA sequencing analyses reveal that hypoxia stress induces immune and metabolic disorders in gill of genetically improved farmed tilapia (GIFT, Oreochromis niloticus)

The survival and growth of fish are significantly impacted by a hypoxic environment (low dissolved oxygen). In this study, we compared tissue structure, physiological changes, and mRNA/miRNA transcriptome, in gills of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) between the hypoxic group (DO: 0.55 mg/L, HG) and the control group (DO: 5 mg/L, CG). The results showed that the gill filaments in the hypoxic group showed curling, engorgement, and apoptotic cells increased, and that exposure for 96 h resulted in a reduction in the antioxidant capacity. We constructed and sequenced miRNA and mRNA libraries from gill tissues of GIFT at 96 h of hypoxia stress. Between the HG and CG, a total of 14 differentially expressed (DE) miRNAs and 1557 DE genes were obtained. GO and KEGG enrichment showed that DE genes were mainly enriched in immune and metabolic pathways such as natural killer cell mediated cytotoxicity, steroid biosynthesis, primary immunodeficiency, and synthesis and degradation of ketone bodies. Based on the results of mRNA sequencing and screening for miRNA-mRNA pairs, we selected and verified six DE miRNAs and their probable target genes. The sequencing results were consistent with the qRT-PCR validation results. The result showed that under hypoxia stress, the innate immune response was up-regulated, and the adaptive immune response was down-regulated in the gill of GIFT. The synthesis of cholesterol in gill cells is reduced, which is conducive to the absorption of solvent oxygen. These findings offer fresh information about the processes of fish adaptation to hypoxic stress.

Connecting the dots in the associations between diet, obesity, cancer, and microRNAs

The prevalence of obesity has reached pandemic levels worldwide, leading to a lower quality of life and higher health costs. Obesity is a major risk factor for noncommunicable diseases, including cancer, although obesity is one of the major preventable causes of cancer. Lifestyle factors, such as dietary quality and patterns, are also closely related to the onset and development of obesity and cancer. However, the mechanisms underlying the complex association between diet, obesity, and cancer remain unclear. In the past few decades, microRNAs (miRNAs), a class of small non-coding RNAs, have been demonstrated to play critical roles in biological processes such as cell differentiation, proliferation, and metabolism, highlighting their importance in disease development and suppression and as therapeutic targets. miRNA expression levels can be modulated by diet and are involved in cancer and obesity-related diseases. Circulating miRNAs can also mediate cell-to-cell communications. These multiple aspects of miRNAs present challenges in understanding and integrating their mechanism of action. Here, we introduce a general consideration of the associations between diet, obesity, and cancer and review the current knowledge of the molecular functions of miRNA in each context. A comprehensive understanding of the interplay between diet, obesity, and cancer could be valuable for the development of effective preventive and therapeutic strategies in future.

A Tale of Two: When Neural Stem Cells Encounter Hypoxia

Normoxia is defined as an oxygen concentration of 20.9%, as in room air, whereas hypoxia refers to any oxygen concentration less than this. Any physiological oxygen deficiency or tissue oxygen deficiency relative to demand is called hypoxia. Neural stem cells (NSCs) are multipotent stem cells that can differentiate into multiple cell lines such as neurons, oligodendrocytes, and astrocytes. Under hypoxic conditions, the apoptosis rate of NSCs increases remarkably in vitro or in vivo. However, some hypoxia promotes the proliferation and differentiation of NSCs. The difference is related to the oxygen concentration, the duration of hypoxia, the hypoxia tolerance threshold of the NSCs, and the tissue source of the NSCs. The main mechanism of hypoxia-induced proliferation and differentiation involves an increase in cyclin and erythropoietin concentrations, and hypoxia-inducible factors play a key role. Multiple molecular pathways are activated during hypoxia, including Notch, Wnt/β-catenin, PI3K/Akt, and altered microRNA expression. In addition, we review the protective effect of exogenous NSCs transplantation on ischemic or anoxic organs, the therapeutic potential of hypoxic preconditioning on exogenous NSCs and clinical application of NSCs.

Hypoxia-induced loss of SRSF2-dependent DNA methylation promotes CTCF-mediated alternative splicing of VEGFA in breast cancer

Alternative splicing of vascular endothelial growth factor A (VEGFA) generates numerous isoforms with unique roles in tumor angiogenesis, and investigating the underlying mechanism during hypoxia necessitates diligent pursuance. Our research systematically demonstrated that the splicing factor SRSF2 causes the inclusion of exon-8b, leading to the formation of the anti-angiogenic VEGFA-165b isoform under normoxic conditions. Additionally, SRSF2 interacts with DNMT3A and maintains methylation on exon-8a, inhibiting CCCTC-binding factor (CTCF) recruitment and RNA polymerase II (pol II) occupancy, causing exon-8a exclusion and decreased expression of pro-angiogenic VEGFA-165a. Conversely, SRSF2 is downregulated by HIF1α-induced miR-222-3p under hypoxic conditions, which prevents exon-8b inclusion and reduces VEGFA-165b expression. Furthermore, reduced SRSF2 under hypoxia promotes hydroxymethylation on exon-8a, increasing CTCF recruitment, pol II occupancy, exon-8a inclusion, and VEGFA-165a expression. Overall, our findings unveil a specialized dual mechanism of VEGFA-165 alternative splicing, instrumented by the cross-talk between SRSF2 and CTCF, which promotes angiogenesis under hypoxic conditions.

The potential of using non-coding RNAs in forensic science applications

With the continuous development and integration of molecular biology and forensic science, non-coding RNAs (ncRNAs), especially ncRNAs with regulatory functions such as microRNA, long non-coding RNA, and circular RNA, have recently been actively explored by forensic scholars. In this study, we review the literature on these ncRNAs in various fields of forensic science, including postmortem interval determination, wound age estimation, forensic age assessment, cause of death analysis, and body fluid identification, aiming to evaluate the current research and provide a perspective for future applications.

Orthometric multicolor encoded hybridization chain reaction amplifiers for multiplexed microRNA profiling in living cells

Multiplexed microRNA (miRNA) profiling of more than four types in living cells is challenging due to fluorescent spectral overlap, representing a significant limitation in studying the complex interactions related to the occurrence and development of diseases. Herein, we report a multiplexed fluorescent imaging strategy based on an orthometric multicolor encoded hybridization chain reaction amplifier named multi-HCR. The targeting miRNA can trigger this multi-HCR strategy due to the specific sequence recognition, and then its self-assembly to amplify the programmability signals. We take the four-colored chain amplifiers, showing that the multi-HCR can form 15 combinations simultaneously. In a living process of hypoxia-induced apoptosis and autophagy under complicated mitochondria and endoplasmic reticulum stress, the multi-HCR demonstrates excellent performance in detecting eight different miRNA changes. The multi-HCR provides a robust strategy for simultaneously profiling multiplexed miRNA biomarkers in studying complicated cellular processes.

The HIF-1α/miR-26a-5p/PFKFB3/ULK1/2 axis regulates vascular remodeling in hypoxia-induced pulmonary hypertension by modulation of autophagy

Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease characterized by pulmonary vascular remodeling, which may cause right heart failure and even death. Accumulated evidence confirmed that microRNA-26 family play critical roles in cardiovascular disease; however, their function in PAH remains largely unknown. Here, we investigated the expression of miR-26 family in plasma from PAH patients using quantitative RT-PCR, and identified miR-26a-5p as the most downregulated member, which was also decreased in hypoxia-induced pulmonary arterial smooth muscle cell (PASMC) autophagy models and lung tissues of PAH patients. Furthermore, chromatin immunoprecipitation (ChIP) analysis and luciferase reporter assays revealed that hypoxia-inducible factor 1α (HIF-1α) specifically interacted with the promoter of miR-26a-5p and inhibited its expression in PASMCs. Tandem mRFP-GFP-LC3B fluorescence microscopy demonstrated that miR-26a-5p inhibited hypoxia-induced PAMSC autophagy, characterized by reduced formation of autophagosomes and autolysosomes. In addition, results showed that miR-26a-5p overexpression potently inhibited PASMC proliferation and migration, as determined by cell counting kit-8, EdU staining, wound-healing, and transwell assays. Mechanistically, PFKFB3, ULK1, and ULK2 were direct targets of miR-26a-5p, as determined by dual-luciferase reporter gene assays and western blots. Meanwhile, PFKFB3 could further enhance the phosphorylation level of ULK1 and promote autophagy in PASMCs. Moreover, intratracheal administration of adeno-miR-26a-5p markedly alleviated right ventricular hypertrophy and pulmonary vascular remodeling in hypoxia-induced PAH rat models in vivo. Taken together, the HIF-1α/miR-26a-5p/PFKFB3/ULK1/2 axis plays critical roles in the regulation of hypoxia-induced PASMC autophagy and proliferation. MiR-26a-5p may represent as an attractive biomarker for the diagnosis and treatment of PAH.

NF-κB Transcriptional Activity Indispensably Mediates Hypoxia–Reoxygenation Stress-Induced microRNA-210 Expression

Ischemia–reperfusion (I-R) injury is a cardinal pathophysiological hallmark of ischemic heart disease (IHD). Despite significant advances in the understanding of what causes I-R injury and hypoxia–reoxygenation (H-R) stress, viable molecular strategies that could be targeted for the treatment of the deleterious biochemical pathways activated during I-R remain elusive. The master hypoxamiR, microRNA-210 (miR-210), is a major determinant of protective cellular adaptation to hypoxia stress but exacerbates apoptotic cell death during cellular reoxygenation. While the hypoxia-induced transcriptional up-regulation of miR-210 is well delineated, the cellular mechanisms and molecular entities that regulate the transcriptional induction of miR-210 during the cellular reoxygenation phase have not been elucidated yet. Herein, in immortalized AC-16 cardiomyocytes, we delineated the indispensable role of the ubiquitously expressed transcription factor, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in H-R-induced miR-210 expression during cellular reoxygenation. Using dominant negative and dominant active expression vectors encoding kinases to competitively inhibit NF-κB activation, we elucidated NF-κB activation as a significant mediator of H-R-induced miR-210 expression. Ensuing molecular assays revealed a direct NF-κB-mediated transcriptional up-regulation of miR-210 expression in response to the H-R challenge that is characterized by the NF-κB-mediated reorchestration of the entire repertoire of histone modification changes that are a signatory of a permissive actively transcribed miR-210 promoter. Our study confers a novel insight identifying NF-κB as a potential novel molecular target to combat H-R-elicited miR-210 expression that fosters augmented cardiomyocyte cell death.

Micro RNA210 expression in pregnancies with preeclampsia

Preeclampsia is one of the major causes of perinatal mortality and morbidity even in developed countries, the aetiology of which is not yet understood completely. In recent times, mi RNAs have gained prominence as regulators of the expressions of their target genes in health and pathological condition. mi RNA210, one of the important hypoxamirs, is reported to be a regulator of many cellular mechanisms including cell division, differentiation, apoptosis, cell cycle regulation, mitochondrial function, metabolism etc. Since hypoxia is the microenvironment that prevailed in preeclampsia it is worth full to see the expression pattern of mi RNA 210 as an attempt to unearth the preeclampsia pathogenesis. The placental tissue is collected from age-matched control and preeclamptic patients after strictly applying the inclusion and exclusion criteria. The present result shows 2.7 fold-up regulation of miRNA210 in preeclampsia in rt PCR study, the role of which need to be studied further to understand the pathogenesis of preeclampsia.

Nucleolin Regulates Pulmonary Artery Smooth Muscle Cell Proliferation under Hypoxia by Modulating miRNA Expression

Hypoxia induces the abnormal proliferation of vascular smooth muscle cells (VSMCs), resulting in the pathogenesis of various vascular diseases. RNA-binding proteins (RBPs) are involved in a wide range of biological processes, including cell proliferation and responses to hypoxia. In this study, we observed that the RBP nucleolin (NCL) was downregulated by histone deacetylation in response to hypoxia. We evaluated its regulatory effects on miRNA expression under hypoxic conditions in pulmonary artery smooth muscle cells (PASMCs). miRNAs associated with NCL were assessed using RNA immunoprecipitation in PASMCs and small RNA sequencing. The expression of a set of miRNAs was increased by NCL but reduced by hypoxia-induced downregulation of NCL. The downregulation of miR-24-3p and miR-409-3p promoted PASMC proliferation under hypoxic conditions. These results clearly demonstrate the significance of NCL-miRNA interactions in the regulation of hypoxia-induced PASMC proliferation and provide insight into the therapeutic value of RBPs for vascular diseases.

miR-210 Expression Is Strongly Hypoxia-Induced in Anaplastic Thyroid Cancer Cell Lines and Is Associated with Extracellular Vesicles and Argonaute-2

Hypoxia, or low oxygen tension, is frequently found in highly proliferative solid tumors such as anaplastic thyroid carcinoma (ATC) and is believed to promote resistance to chemotherapy and radiation. Identifying hypoxic cells for targeted therapy may thus be an effective approach to treating aggressive cancers. Here, we explore the potential of the well-known hypoxia-responsive microRNA (miRNA) miR-210-3p as a cellular and extracellular biological marker of hypoxia. We compare miRNA expression across several ATC and papillary thyroid cancer (PTC) cell lines. In the ATC cell line SW1736, miR-210-3p expression levels indicate hypoxia during exposure to low oxygen conditions (2% O2). Furthermore, when released by SW1736 cells into the extracellular space, miR-210-3p is associated with RNA carriers such as extracellular vesicles (EVs) and Argonaute-2 (AGO2), making it a potential extracellular marker for hypoxia.

In silico analysis reveals hypoxia-induced miR-210-3p specifically targets SARS-CoV-2 RNA

Human coronaviruses (HCoVs) until the emergence of SARS in 2003 were associated with mild cold and upper respiratory tract infections. The ongoing pandemic caused by SARS-CoV-2 has enhanced the potential for infection and transmission as compared to other known members of this family. MicroRNAs (miRNA) are 21-25 nucleotides long non-coding RNA that bind to 3' UTR of genes and regulate almost every aspect of cellular function. Several human miRNAs have been known to target viral genomes, mostly to downregulate their expression and sometimes to upregulate also. In some cases, host miRNAs could be sequestered by the viral genome to create a condition for favourable virus existence. The ongoing SARS CoV-2 pandemic is unique based on its transmissibility and severity and we hypothesised that there could be a unique mechanism for its pathogenesis. In this study, we exploited in silico approach to identify human respiratory system-specific miRNAs targeting the viral genome of three highly pathogenic HCoVs (SARS-CoV-2 Wuhan strain, SARS-CoV, and MERS-CoV) and three low pathogenic HCoVs (OC43, NL63, and HKU1). We identified ten common microRNAs that target all HCoVs studied here. In addition, we identified unique miRNAs which targeted specifically one particular HCoV. miR-210-3p was the single unique lung-specific miRNA, which was found to target the NSP3, NSP4, and NSP13 genes of SARS-CoV-2. Further miR-210-NSP3, miR-210-NSP4, and miR-210-NSP13 SARS-CoV-2 duplexes were docked with the hAGO2 protein (PDB ID 4F3T) which showed Z-score values of -1.9, -1.7, and -1.6, respectively. The role of miR-210-3p as master hypoxia regulator and inflammation regulation may be important for SARS-CoV-2 pathogenesis. Overall, this analysis advocates that miR-210-3p be investigated experimentally in SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.

Suppression of RBFox2 by Multiple MiRNAs in Pressure Overload-Induced Heart Failure

Heart failure is the final stage of various cardiovascular diseases and seriously threatens human health. Increasing mediators have been found to be involved in the pathogenesis of heart failure, including the RNA binding protein RBFox2. It participates in multiple aspects of the regulation of cardiac function and plays a critical role in the process of heart failure. However, how RBFox2 itself is regulated remains unclear. Here, we dissected transcriptomic signatures, including mRNAs and miRNAs, in a mouse model of heart failure after TAC surgery. A global analysis showed that an asymmetric alternation in gene expression and a large-scale upregulation of miRNAs occurred in heart failure. An association analysis revealed that the latter not only contributed to the degradation of numerous mRNA transcripts, but also suppressed the translation of key proteins such as RBFox2. With the aid of Ago2 CLIP-seq data, luciferase assays verified that RBFox2 was targeted by multiple miRNAs, including Let-7, miR-16, and miR-200b, which were significantly upregulated in heart failure. The overexpression of these miRNAs suppressed the RBFox2 protein and its downstream effects in cardiomyocytes, which was evidenced by the suppressed alternative splicing of the Enah gene and impaired E-C coupling via the repression of the Jph2 protein. The inhibition of Let-7, the most abundant miRNA family targeting RBFox2, could restore the RBFox2 protein as well as its downstream effects in dysfunctional cardiomyocytes induced by ISO treatment. In all, these findings revealed the molecular mechanism leading to RBFox2 depression in heart failure, and provided an approach to rescue RBFox2 through miRNA inhibition for the treatment of heart failure.

Druggable Biomarkers Altered in Clear Cell Renal Cell Carcinoma: Strategy for the Development of Mechanism-Based Combination Therapy

Targeted therapeutics made significant advances in the treatment of patients with advanced clear cell renal cell carcinoma (ccRCC). Resistance and serious adverse events associated with standard therapy of patients with advanced ccRCC highlight the need to identify alternative 'druggable' targets to those currently under clinical development. Although the Von Hippel-Lindau (VHL) and Polybromo1 (PBRM1) tumor-suppressor genes are the two most frequently mutated genes and represent the hallmark of the ccRCC phenotype, stable expression of hypoxia-inducible factor-1α/2α (HIFs), microRNAs-210 and -155 (miR_S), transforming growth factor-beta (TGF-ß), nuclear factor erythroid 2-related factor 2 (Nrf2), and thymidine phosphorylase (TP) are targets overexpressed in the majority of ccRCC tumors. Collectively, these altered biomarkers are highly interactive and are considered master regulators of processes implicated in increased tumor angiogenesis, metastasis, drug resistance, and immune evasion. In recognition of the therapeutic potential of the indicated biomarkers, considerable efforts are underway to develop therapeutically effective and selective inhibitors of individual targets. It was demonstrated that HIF_S, miR_S, Nrf2, and TGF-ß are targeted by a defined dose and schedule of a specific type of selenium-containing molecules, seleno-L-methionine (SLM) and methylselenocystein (MSC). Collectively, the demonstrated pleiotropic effects of selenium were associated with the normalization of tumor vasculature, and enhanced drug delivery and distribution to tumor tissue, resulting in enhanced efficacy of multiple chemotherapeutic drugs and biologically targeted molecules. Higher selenium doses than those used in clinical prevention trials inhibit multiple targets altered in ccRCC tumors, which could offer the potential for the development of a new and novel therapeutic modality for cancer patients with similar selenium target expression. Better understanding of the underlying mechanisms of selenium modulation of specific targets altered in ccRCC could potentially have a significant impact on the development of a more efficacious and selective mechanism-based combination for the treatment of patients with cancer.

Effect of positive pressure ventilation and bariatric surgery on extracellular vesicle microRNAs in patients with severe obesity and obstructive sleep apnea

INTRODUCTION

Obstructive sleep apnea (OSA) and severe obesity share a common pathophysiological phenomenon, systemic and tissue hypoxia. Hypoxaemia modifies microRNA expression, particularly, extracellular vesicles microRNAs which are involved in the progression of cardiovascular diseases, metabolic syndrome and cancer. We aim to evaluate extracellular vesicle miRNAs among patients with severe obesity with and without OSA and the effect of OSA and severe obesity treatment: continuous positive airway pressure (CPAP) and bariatric surgery.

METHODS

Patients were selected from the Epigenetics Modification in Morbid Obesity and Obstructive Sleep Apnea (EPIMOOSA) study (NCT03995836), a prospective observational study of patients undergoing bariatric surgery. Patients were divided into OSA (Apnea-hyponea index (AHI) > 10) and non-OSA (AHI < 10). Patients with OSA were treated with CPAP for 6 months. Then, all patients had bariatric surgery and re-evaluated 12 months later. At each visit, blood samples were obtained for biobanking. Subsequently, extracellular vesicles were extracted, and then, miRNA expression was analysed.

RESULTS

15 patients with OSA and 9 without OSA completed the protocol. At baseline, patients with OSA showed higher miR16, miR126 and miR320 (p < 0.05) and lower miR223 expression (p < 0.05) than those without OSA. In patients with severe obesity and OSA, after 6 months with CPAP, we observed a significant decrease in miR21 (p < 0.01), miR126 (p < 0.001) and miR320 (p < 0.001), with no changes in any miRNA in patients without OSA. No changes were detected in any miRNA after 6 months of bariatric surgery in patients with or without OSA.

CONCLUSION

Co-existance of OSA and severe obesity alters the profile of extracellular vesicle miRNAs. Bariatric surgery and weight loss did not reverse this effect meanwhile the treatment with CPAP in patients with severe obesity and OSA showed a recovery outcome in those extracellular vesicle miRNAs. Those facts remark the need for OSA screening in patients with severe obesity.

CLINICAL TRIAL REGISTRATION

The study has also been registered at ClinicalTrials.gov identifier: NCT03995836.

In silico Identification of Hypoxic Signature followed by reverse transcription-quantitative PCR Validation in Cancer Cell Lines

Background

Hypoxic tumor microenvironment is one of the important impediments for conventional cancer therapy. This study aimed to computationally identify hypoxia-related messenger RNA (mRNA) signatures in nine hypoxic-conditioned cancer cell lines and investigate their role during hypoxia.

Methods

Nine RNA sequencing (RNA-Seq) expression data sets were retrieved from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified in each cancer cell line. Then 23 common DEGs were selected by comparing the gene lists across the nine cancer cell lines. Reverse transcription-quantitative PCR (qRT-PCR) was performed to validate the identified DEGs.

Results

By comparing the data sets, GAPDH, LRP1, ALDOA, EFEMP2, PLOD2, CA9, EGLN3, HK, PDK1, KDM3A, UBC, and P4HA1 were identified as hub genes. In addition, miR-335-5p, miR-122-5p, miR-6807-5p, miR-1915-3p, miR-6764-5p, miR-92-3p, miR-23b-3p, miR-615-3p, miR-124-3p, miR-484, and miR-455-3p were determined as common micro RNAs. Four DEGs were selected for mRNA expression validation in cancer cells under normoxic and hypoxic conditions with qRT-PCR. The results also showed that the expression levels determined by qRT-PCR were consistent with RNA-Seq data.

Conclusion

The identified protein-protein interaction network of common DEGs could serve as potential hypoxia biomarkers and might be helpful for improving therapeutic strategies.

Paracrine effects of mir-210-3p on angiogenesis in hypoxia-treated c-kit-positive cardiac cells

Objective: Treatment with c-kit-positive cardiac cells (CPCs) has been shown to improve the prognosis of ischemic heart disease. MicroRNAs (miRNAs) confer protection by enhancing the cardiac repair process, but their specific functional mechanisms remain unclear. This study aimed to screen for differentially expressed miRNAs in CPCs under hypoxia and explore their effects on the function of CPCs.Methods: We harvested CPCs from C57 adult mice and later performed a high-throughput miRNA sequencing for differential expression profiling analysis. Subsequently, we intervened with the differentially expressed gene miR-210-3p in CPCs and detected changes in the secretion of angiogenesis-related factors through a protein-chip analysis. Finally, we applied CPC supernatants of different groups as conditioned medium to treat mouse cardiac microvascular endothelial cells (CMECs) and further investigated the functional effects of miR-210-3p on c-kit+CPCs under ischemia and hypoxia conditions.Results: The miR-210-3p was highly increased in hypoxia-treated CPCs. Protein-chip detection revealed that CPCs expressed cytokines such as FGF basic, angiogenin, and vascular endothelial growth factor (VEGF) and that hypoxia enhanced their release. Silencing miR-210-3p resulted in a reduction in the release of these angiogenesis-related factors. In addition, the conditioned medium of hypoxia-treated CPCs promoted the proliferation, migration, and tube-forming capabilities of CMECs. In contrast, the conditioned media of CPCs with silenced miR-210-3p after hypoxia decreased the proliferation, migration, and tube-forming ability of CMEC.Conclusions: The CPCs exert proangiogenic effects via paracrine pathways mediated by miR-210-3p. Upregulation of miR-210-3p in hypoxia-treated CPCs may enhance their paracrine function by regulating the secretion of angiogenic factors, thereby promoting angiogenesis in ischemic heart disease.

Obstructive Sleep Apnea, Circadian Clock Disruption, and Metabolic Consequences

Obstructive sleep apnea (OSA) is a chronic disorder characterized by recurrent episodes of apnea and hypopnea during sleep. It is associated with various cardiovascular and metabolic complications, including type 2 diabetes mellitus (T2DM) and obesity. Many pathways can be responsible for T2DM development in OSA patients, e.g., those related to HIF-1 and SIRT1 expression. Moreover, epigenetic mechanisms, such as miRNA181a or miRNA199, are postulated to play a pivotal role in this link. It has been proven that OSA increases the occurrence of circadian clock disruption, which is also a risk factor for metabolic disease development. Circadian clock disruption impairs the metabolism of glucose, lipids, and the secretion of bile acids. Therefore, OSA-induced circadian clock disruption may be a potential, complex, underlying pathway involved in developing and exacerbating metabolic diseases among OSA patients. The current paper summarizes the available information pertaining to the relationship between OSA and circadian clock disruption in the context of potential mechanisms leading to metabolic disorders.

Tissue origin of circulating microRNAs and their response to nutritional and environmental stress in rainbow trout (Oncorhynchus mykiss)

Stresses associated with changes in diet or environmental disturbances are common situations that fish encounter during their lifetime. The stability and ease of measuring microRNAs (miRNAs) present in biological fluids make these molecules particularly interesting biomarkers for non-lethal assessment of stress in animals. Rainbow trout were exposed for four weeks to abiotic stress (moderate hypoxia) and/or nutritional stress (a high-carbohydrate/low-protein diet). Blood plasma and epidermal mucus were sampled at the end of the experiment, and miRNAs were assessed using small RNA sequencing. We identified four miRNAs (miR-122-5p, miR-184-3p, miR-192-5p and miR-194a-5p) and three miRNAs (miR-210-3p, miR-153a-3p and miR-218c-5p) that accumulated in response to stress in blood plasma and epidermal mucus, respectively. In particular, the abundance of miR-210-3p, a hypoxamiR in mammals, increased strongly in the epidermal mucus of rainbow trout subjected to moderate hypoxia, and can thus be considered a relevant biomarker of hypoxic stress in trout. We explored the contribution of 22 tissues/organs to the abundance of circulating miRNAs (c-miRNAs) in blood plasma and epidermal mucus influenced by the treatments. Some miRNAs were tissue-specific, while others were distributed among several tissues. Some c-miRNAs (e.g., miR-210-3p, miR184-3p) showed similar variations in both tissues and fluids, while others showed an inverse trend (e.g., miR-122-5p) or no apparent relationship (e.g. miR-192-5p, miR-194a-5p. Overall, these results demonstrate that c-miRNAs can be used as non-lethal biomarkers to study stress in fish. In particular, the upregulation of miR-210-3p in epidermal mucus induced by hypoxia demonstrates the potential of using epidermal mucus as a matrix for identifying non-invasive biomarkers of stress. This study provides information about the tissue sources of c-miRNAs and highlights the potential difficulty in relating variations in miRNA abundance in biological fluids to that in tissues.