The non-coding RNA gadd7 is a regulator of lipid-induced oxidative and endoplasmic reticulum stress

SnoRNAs: Exploring Their Implication in Human Diseases

Small nucleolar RNAs (snoRNAs) are earning increasing attention from research communities due to their critical role in the post-transcriptional modification of various RNAs. These snoRNAs, along with their associated proteins, are crucial in regulating the expression of a vast array of genes in different human diseases. Primarily, snoRNAs facilitate modifications such as 2'-O-methylation, N-4-acetylation, and pseudouridylation, which impact not only ribosomal RNA (rRNA) and their synthesis but also different RNAs. Functionally, snoRNAs bind with core proteins to form small nucleolar ribonucleoproteins (snoRNPs). These snoRNAs then direct the protein complex to specific sites on target RNA molecules where modifications are necessary for either standard cellular operations or the regulation of pathological mechanisms. At these targeted sites, the proteins coupled with snoRNPs perform the modification processes that are vital for controlling cellular functions. The unique characteristics of snoRNAs and their involvement in various non-metabolic and metabolic diseases highlight their potential as therapeutic targets. Moreover, the precise targeting capability of snoRNAs might be harnessed as a molecular tool to therapeutically address various disease conditions. This review delves into the role of snoRNAs in health and disease and explores the broad potential of these snoRNAs as therapeutic agents in human pathologies.

Impacts of non-coding RNAs in the pathogenesis of varicocele

Two classes of non-coding RNAs, namely lncRNAs and miRNAs have been reported to be involved in the pathogenesis of varicocele. MIR210HG, MLLT4-AS1, gadd7, and SLC7A11-AS1 are among lncRNAs whose expression has been changed in patients with varicocele in association with the sperm quality. Animal studies have also suggested contribution of NONRATG001060, NONRATG002949, NONRATG013271, NONRATG027523 and NONRATG023747 lncRNAs in this pathology. Meanwhile, expression of some miRNAs, such as miR-210-3p, miR-21, miR-34a, miR-122a, miR-181a, miR-34c and miR-192a has been altered in this condition. Some of these transcripts have the potential to predict the sperm quality. We summarize the impacts of lncRNAs and miRNAs in the pathogenesis of varicocele.

Obesity and its impact on female reproductive health: unraveling the connections

In the modern era, the escalating global prevalence of obesity has profound implications on female reproductive health. Obesity, transcending mere lifestyle choices, has evolved into a complex disorder affecting physiological and metabolic functions. Concurrently, female infertility is rising as a significant global health issue. Obesity, with its extensive systemic effects, is pinpointed as a major disruptor. The convergence of these health challenges reveals a multifaceted scenario: on one hand, obesity directly impacts female reproductive health, particularly in the context of conditions like polycystic ovary syndrome (PCOS) and menstrual disturbances; on the other, the psychosocial consequences of infertility might intensify weight-gain patterns, forming a challenging cycle. Additionally, the economic implications of treating obesity-related infertility are considerable. This review delves into the myriad ways obesity affects female reproductive health, drawing insights from epidemiological, clinical, and molecular studies. It explores the epidemiological relationship between obesity and PCOS, the influence of obesity on menstrual disturbances, and the broader impact of obesity on female infertility. Weight loss, through pharmacological interventions, surgical methods, or lifestyle adjustments, emerges as a promising strategy. Lastly, the efficacy of assisted reproductive technologies, such as IVF, is influenced by obesity, underscoring the importance of an optimal body mass index. The review also highlights the molecular and physiological mechanisms underlying the impact of obesity on female reproductive health, including the disruption of the hypothalamic-pituitary-ovary axis, altered adipokine secretion, and the role of chronic inflammation and oxidative stress.

Current understanding of structural and molecular changes in diabetic cardiomyopathy

Diabetic Mellitus has been characterized as the most prevalent disease throughout the globe associated with the serious morbidity and mortality of vital organs. Cardiomyopathy is the major leading complication of diabetes and within this, myocardial dysfunction or failure is the leading cause of the emergency hospital admission. The review is aimed to comprehend the perspectives associated with diabetes-induced cardiovascular complications. The data was collected from several electronic databases such as Google Scholar, Science Direct, ACS publication, PubMed, Springer, etc. using the keywords such as diabetes and its associated complication, the prevalence of diabetes, the anatomical and physiological mechanism of diabetes-induced cardiomyopathy, the molecular mechanism of diabetes-induced cardiomyopathy, oxidative stress, and inflammatory stress, etc. The collected scientific data was screened by different experts based on the inclusion and exclusion criteria of the study. This review findings revealed that diabetes is associated with inefficient substrate utilization, inability to increase glucose metabolism and advanced glycation end products within the diabetic heart resulting in mitochondrial uncoupling, glucotoxicity, lipotoxicity, and initially subclinical cardiac dysfunction and finally in overt heart failure. Furthermore, several factors such as hypertension, overexpression of renin angiotensin system, hypertrophic obesity, etc. have been seen as majorly associated with cardiomyopathy. The molecular examination showed biochemical disability and generation of the varieties of free radicals and inflammatory cytokines and becomes are the substantial causes of cardiomyopathy. This review provides a better understanding of the involved pathophysiology and offers an open platform for discussing and targeting therapy in alleviating diabetes-induced early heart failure or cardiomyopathy.

The Role of Long Noncoding RNAs on Male Infertility: A Systematic Review and In Silico Analysis

Male infertility is a complex disorder affecting many couples worldwide. Long noncoding RNAs (lncRNAs) regulate important cellular processes; however, a comprehensive understanding of their role in male infertility is limited. This systematic review investigates the differential expressions of lncRNAs in male infertility or variations in lncRNA regions associated with it. The PRISMA guidelines were used to search Pubmed and Web of Science (1 June 2022). Inclusion criteria were human participants, patients diagnosed with male infertility, and English language speakers. We also performed an in silico analysis investigating lncRNAs that are reported in many subtypes of male infertility. A total of 625 articles were found, and after the screening and eligibility stages, 20 studies were included in the final sample. Many lncRNAs are deregulated in male infertility, and interactions between lncRNAs and miRNAs play an important role. However, there is a knowledge gap regarding the impact of variants found in lncRNA regions. Furthermore, eight lncRNAs were identified as differentially expressed in many subtypes of male infertility. After in silico analysis, gene ontology (GO) and KEGG enrichment analysis of the genes targeted by them revealed their association with bladder and prostate cancer. However, pathways involved in general in tumorigenesis and cancer development of all types, such as p53 pathways, apoptosis, and cell death, were also enriched, indicating a link between cancer and male infertility. This evidence, however, is preliminary. Future research is needed to explore the exact mechanism of action of the identified lncRNAs and investigate the association between male infertility and cancer.

Role of systems biology and multi-omics analyses in delineating spatial interconnectivity and temporal dynamicity of ER stress mediated cellular responses

The endoplasmic reticulum (ER) is a membranous organelle involved in calcium storage, lipid biosynthesis, protein folding and processing. Many patho-physiological conditions and pharmacological agents are known to perturb normal ER function and can lead to ER stress, which severely compromise protein folding mechanism and hence poses high risk of proteotoxicity. Upon sensing ER stress, the different stress signaling pathways interconnect with each other and work together to preserve cellular homeostasis. ER stress response is a part of the integrative stress response (ISR) and might play an important role in the pathogenesis of chronic neurodegenerative diseases, where misfolded protein accumulation and cell death are common. The initiation, manifestation and progression of ER stress mediated unfolded protein response (UPR) is a complex procedure involving multiple proteins, pathways and cellular organelles. To understand the cause and consequences of such complex processes, implementation of an integrative holistic approach is required to identify novel players and regulators of ER stress. As multi-omics data-based systems analyses have shown potential to unravel the underneath molecular mechanism of complex biological systems, it is important to emphasize the utility of this approach in understanding the ER stress biology. In this review we first discuss the ER stress signaling pathways and regulatory players, along with their inter-connectivity. We next highlight the importance of systems and network biology approaches using multi-omics data in understanding ER stress mediated cellular responses. This report would help advance our current understanding of the multivariate spatial interconnectivity and temporal dynamicity of ER stress.

Melatonin restores zinc levels, activates the Keap1/Nrf2 pathway, and modulates endoplasmic reticular stress and HSP in rats with chronic hepatotoxicity

BACKGROUND

Melatonin (MLT) is a potent antioxidant molecule that is shown to have a beneficial effect in various pathological situations, due to its action against free radicals.

AIM

To evaluate the effect of MLT on carbon tetrachloride (CCl4) induced liver injury in rats in terms of oxidative stress, reticular stress, and cell damage.

METHODS

Twenty male Wistar rats (230-250 g) were divided into four groups: Control rats, rats treated with MLT alone, rats treated with CCl4 alone, and rats treated with CCl4 plus MLT. CCl4 was administered as follows: Ten doses every 5 d, ten every 4 d, and seven every 3 d. MLT was administered intraperitoneally at a dose of 20 mg/kg from the 10th wk to the end of the experiment (16th wk).

RESULTS

MLT was able to reduce the release of liver enzymes in the bloodstream and to decrease oxidative stress in CCl4 treated rats by decreasing the level of thiobarbituric acid reactive substances and increasing superoxide dismutase activity, with a lower reduction in serum zinc levels, guaranteeing a reduction in liver damage; additionally, it increased the expression of nuclear factor (erythroid-derived 2)-like 2 and decreased the expression of Kelch-like ECH-associated protein 1. MLT also decreased the expression of the proteins associated with endoplasmic reticulum stress, i.e., glucose-regulated protein 78 and activating transcription factor 6, as well as of heat shock factor 1 and heat shock protein 70.

CONCLUSION

MLT has a hepatoprotective effect in an experimental model of CCl4-induced liver injury, since it reduces oxidative stress, restores zinc levels, and modulates endoplasmic reticulum stress.

Analyses of Long Noncoding RNA and mRNA Profiles in Subjects with the Phlegm-Dampness Constitution

Background

Constitution in traditional Chinese medicine (TCM) plays a key role in the genesis, development, and prognosis of diseases. Phlegm-dampness constitution (PDC) is one of the nine constitutions in TCM, susceptible to metabolic disorders, which is mainly manifested by profuse phlegm, loose abdomen, and greasy face. Epidemiologic, genomic, and epigenetic studies have been carried out in previous works, confirming that PDC represents a distinctive population with microcosmic changes related to metabolic disorders. However, whether long noncoding RNAs (lncRNAs) play a regulatory role in metabolic disease in subjects with PDC remains largely unknown. We aimed to investigate distinct lncRNA and mRNA expression signatures and lncRNA-mRNA regulatory networks in the phlegm-dampness constitution (PDC).

Methods

The peripheral blood mononuclear cells (PBMCs) were isolated from the subjects with PDC (n = 13) and balanced constitution (BC) (n = 9). The profiles of lncRNAs and mRNAs in PBMCs were analyzed using microarray and further validated with RT-qPCR. Subsequently, pathway analysis was performed to investigate the function of differentially expressed mRNAs by using Ingenuity Pathway Analysis (IPA).

Results

Results suggested that some mRNAs, which were regulated by the differentially expressed lncRNAs, were mainly enriched in lipid metabolism and immune inflammation-related pathways. This was consistent with the molecular characteristics of previous studies, indicating that the clinical characteristics of metabolic disorders in PDC might be regulated by lncRNAs. Furthermore, by making coexpression network construction as well as cis-regulated target gene analysis, several lncRNA-mRNA pairs with potential regulatory relationships were identified by bioinformatic analyses, including RP11-317J10.2-CA3, RP11-809C18.3-PIP4K2A, LINC0069-RFTN1, TTTY15-ARHGEF9, and AC135048.13-ORAI3.

Conclusions

This study first revealed that the expression characteristics of lncRNAs/mRNAs may be potential biomarkers, indicating that the distinctive physical and clinical characteristics of PDC might be partially attributed to the specific expression signatures of lncRNAs/mRNAs.

Loss of SNORA73 reprograms cellular metabolism and protects against steatohepatitis

Dyslipidemia and resulting lipotoxicity are pathologic signatures of metabolic syndrome and type 2 diabetes. Excess lipid causes cell dysfunction and induces cell death through pleiotropic mechanisms that link to oxidative stress. However, pathways that regulate the response to metabolic stress are not well understood. Herein, we show that disruption of the box H/ACA SNORA73 small nucleolar RNAs encoded within the small nucleolar RNA hosting gene 3 (Snhg3) causes resistance to lipid-induced cell death and general oxidative stress in cultured cells. This protection from metabolic stress is associated with broad reprogramming of oxidative metabolism that is dependent on the mammalian target of rapamycin signaling axis. Furthermore, we show that knockdown of SNORA73 in vivo protects against hepatic steatosis and lipid-induced oxidative stress and inflammation. Our findings demonstrate a role for SNORA73 in the regulation of metabolism and lipotoxicity.

Noncoding RNAs: modulators and modulatable players during infection-induced stress response

The human genome has an almost equal distribution of unique and transposable genetic elements. Although at the transcriptome level, a relatively higher contribution from transposable elements derived RNA has been reported. This is further highlighted with evidence from pervasive transcription. Of the total RNA, noncoding RNAs (ncRNAs) are significant contributors to the transcriptome pool with sizeable fraction from repetitive elements of the human genome, inclusive of Long Interspersed Nuclear Elements (LINEs) and Short Interspersed Nuclear Elements (SINEs). ncRNAs are increasingly being implicated in diverse functional roles especially during conditions of stress. These stress responses are driven through diverse mediators, inclusive of long and short ncRNAs. ncRNAs such as MALAT1, GAS5, miR-204 and miR-199a-5p have been functionally involved during oxidative stress, endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Also, within SINEs, Alu RNAs derived from primate-specific Alu repeats with ~11% human genome contribution, playing a significant role. Pathogenic diseases, including the recent COVID-19, leads to differential regulation of ncRNAs. Although, limited evidence suggests the need for an inquest into the role of ncRNAs in determining the host response towards pathogen challenge.

Unraveling the dark matter, long non-coding RNAs, in male reproductive diseases: A narrative review

Recent advances in human transcriptome have revealed the fundamental and functional roles of long non-coding RNA in the susceptibility to diverse diseases and pathological conditions. They participate in wide range of biological processes such as the modulating of chromatin structure, transcription, translation, and post-translation modification. In addition, based on their unique expression profiles and their association with clinical abnormalities such as those of related to male reproductive diseases, they can be used to develop therapeutic methods and biomarkers for screening of the diseases. In this study, we will review the identified lncRNAs and their molecular functions in the pathogenesis of male reproductive diseases such as prostate cancer, benign prostatic hyperplasia, prostatitis, testicular cancer, varicocele, and sperm abnormalities.

Emerging Roles of Long Noncoding RNAs in the Cytoplasmic Milieu

While the important functions of long noncoding RNAs (lncRNAs) in nuclear organization are well documented, their orchestrating and architectural roles in the cytoplasmic environment have long been underestimated. However, recently developed fractionation and proximity labelling approaches have shown that a considerable proportion of cellular lncRNAs is exported into the cytoplasm and associates nonrandomly with proteins in the cytosol and organelles. The functions of these lncRNAs range from the control of translation and mitochondrial metabolism to the anchoring of cellular components on the cytoskeleton and regulation of protein degradation at the proteasome. In the present review, we provide an overview of the functions of lncRNAs in cytoplasmic structures and machineries und discuss their emerging roles in the coordination of the dense intracellular milieu. It is becoming apparent that further research into the functions of these lncRNAs will lead to an improved understanding of the spatiotemporal organization of cytoplasmic processes during homeostasis and disease.

Death by lipids: The role of small nucleolar RNAs in metabolic stress

Excess fatty acid accumulation in nonadipose tissues leads to cell dysfunction and cell death that is linked to the pathogenesis of inherited and acquired human diseases. Study of this process, known as lipotoxicity, has provided new insights into the regulation of lipid homeostasis and has revealed new molecular pathways involved in lipid-induced cellular stress. The discovery that disruption of specific small nucleolar RNAs protects against fatty acid-induced cell death and remodels metabolism in vivo opens new opportunities for understanding how nutrient signals influence cellular and systemic metabolic homeostasis through RNA biology.

Gene therapy targeting cardiac phosphoinositide 3-kinase (p110α) attenuates cardiac remodeling in type 2 diabetes

Diabetic cardiomyopathy is a distinct form of heart disease that represents a major cause of death and disability in diabetic patients, particularly, the more prevalent type 2 diabetes patient population. In the current study, we investigated whether administration of recombinant adeno-associated viral vectors carrying a constitutively active phosphoinositide 3-kinase (PI3K)(p110α) construct (rAAV6-caPI3K) at a clinically relevant time point attenuates diabetic cardiomyopathy in a preclinical type 2 diabetes (T2D) model. T2D was induced by a combination of a high-fat diet (42% energy intake from lipid) and low-dose streptozotocin (three consecutive intraperitoneal injections of 55 mg/kg body wt), and confirmed by increased body weight, mild hyperglycemia, and impaired glucose tolerance (all P < 0.05 vs. nondiabetic mice). After 18 wk of untreated diabetes, impaired left ventricular (LV) systolic dysfunction was evident, as confirmed by reduced fractional shortening and velocity of circumferential fiber shortening (Vcf_c, all P < 0.01 vs. baseline measurement). A single tail vein injection of rAAV6-caPI3K gene therapy (2×10¹¹vector genomes) was then administered. Mice were followed for an additional 8 wk before end point. A single injection of cardiac targeted rAAV6-caPI3K attenuated diabetes-induced cardiac remodeling by limiting cardiac fibrosis (reduced interstitial and perivascular collagen deposition, P < 0.01 vs. T2D mice) and cardiomyocyte hypertrophy (reduced cardiomyocyte size and Nppa gene expression, P < 0.001 and P < 0.05 vs. T2D mice, respectively). The diabetes-induced LV systolic dysfunction was reversed with rAAV6-caPI3K, as demonstrated by improved fractional shortening and velocity of circumferential fiber shortening (all P < 0.05 vs pre-AAV measurement). This cardioprotection occurred in combination with reduced LV reactive oxygen species (P < 0.05 vs. T2D mice) and an associated decrease in markers of endoplasmic reticulum stress (reduced Grp94 and Chop, all P < 0.05 vs. T2D mice). Together, our findings demonstrate that a cardiac-selective increase in PI3K(p110α), via rAAV6-caPI3K, attenuates T2D-induced diabetic cardiomyopathy, providing proof of concept for potential translation to the clinic.NEW & NOTEWORTHY Diabetes remains a major cause of death and disability worldwide (and its resultant heart failure burden), despite current care. The lack of existing management of heart failure in the context of the poorer prognosis of concomitant diabetes represents an unmet clinical need. In the present study, we now demonstrate that delayed intervention with PI3K gene therapy (rAAV6-caPI3K), administered as a single dose in mice with preexisting type 2 diabetes, attenuates several characteristics of diabetic cardiomyopathy, including diabetes-induced impairments in cardiac remodeling, oxidative stress, and function. Our discovery here contributes to the previous body of work, suggesting the cardioprotective effects of PI3K(p110α) could be a novel therapeutic approach to reduce the progression to heart failure and death in diabetes-affected patients.

Low-Level Saturated Fatty Acid Palmitate Benefits Liver Cells by Boosting Mitochondrial Metabolism via CDK1-SIRT3-CPT2 Cascade

Saturated fatty acids (SFAs) (the "bad" fat), especially palmitate (PA), in the human diet are blamed for potential health risks such as obesity and cancer because of SFA-induced lipotoxicity. However, epidemiological results demonstrate a latent benefit of SFAs, and it remains elusive whether a certain low level of SFAs is physiologically essential for maintaining cell metabolic hemostasis. Here, we demonstrate that although high-level PA (HPA) indeed induces lipotoxic effects in liver cells, low-level PA (LPA) increases mitochondrial functions and alleviates the injuries induced by HPA or hepatoxic agent carbon tetrachloride (CCl₄). LPA treatment in mice enhanced liver mitochondrial activity and reduced CCl₄ hepatotoxicity with improved blood levels of aspartate aminotransferase (AST), alanine transaminase (ALT), and mitochondrial aspartate transaminase (m-AST). LPA-mediated mitochondrial homeostasis is regulated by CDK1-mediated SIRT3 phosphorylation, which in turn deacetylates and dimerizes CPT2 to enhance fatty acid oxidation. Thus, an advantageous effect is suggested by the consumption of LPA that augments mitochondrial metabolic homeostasis via CDK1-SIRT3-CPT2 cascade.

Defining lncRNAs Correlated with CHO Cell Growth and IgG Productivity by RNA-Seq

How the long non-coding RNA (lncRNA) genome in recombinant protein producing Chinese hamster ovary (CHO) cell lines relates to phenotype is not well described. We therefore defined the CHO cell lncRNA transcriptome from cells grown in controlled miniature bioreactors under fed-batch conditions using RNA-Seq to identify lncRNAs and how the expression of these changes throughout growth and between IgG producers. We identify lncRNAs including Adapt15, linked to ER stress, GAS5, linked to mTOR signaling/growth arrest, and PVT1, linked to Myc expression, which are differentially regulated during fed-batch culture and whose expression correlates to productivity and growth. Changes in (non)-coding RNA expression between the seed train and the equivalent day of fed-batch culture are also reported and compared with existing datasets. Collectively, we present a comprehensive lncRNA CHO cell profiling and identify targets for engineering growth and productivity characteristics of CHO cells.

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The CHO cell lncRNA transcriptome is defined using RNA-Seq

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Correlations between lncRNA expression and CHO cell growth and IgG productivity found

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Expression of lncRNAs involved in ER stress correlates to productivity

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Expression of lncRNAs involved in mTOR signaling/growth arrest correlates to growth

Reactive oxygen species-dependent regulation of pyruvate dehydrogenase kinase-4 in white adipose tissue

Reactive oxygen species (ROS) are important signaling molecules mediating the exercise-induced adaptations in skeletal muscle. Acute exercise also drives the expression of genes involved in reesterification and glyceroneogenesis in white adipose tissue (WAT), but whether ROS play any role in this effect has not been explored. We speculated that exercise-induced ROS would regulate acute exercise-induced responses in WAT. To address this question, we utilized various models to alter redox signaling in WAT. We examined basal and exercise-induced gene expression in a genetically modified mouse model of reduced mitochondrial ROS emission [mitochondrial catalase overexpression (MCAT)]. Additionally, H₂O₂, various antioxidants, and the β3-adrenergic receptor agonist CL316243 were used to assess gene expression in white adipose tissue culture. MCAT mice have reduced ROS emission from WAT, enlarged WAT depots and adipocytes, and greater pyruvate dehydrogenase kinase-4 (Pdk4) gene expression. In WAT culture, H₂O₂ reduced glyceroneogenic gene expression. In wild-type mice, acute exercise induced dramatic but transient increases in Pdk4 and phosphoenolpyruvate carboxykinase (Pck1) mRNA in both subcutaneous inguinal WAT and epididymal WAT depots, which was almost completely absent in MCAT mice. Furthermore, the induction of Pdk4 and Pck1 in WAT culture by CL316243 was markedly reduced in the presence of antioxidants N-acetyl-cysteine or vitamin E. Genetic and nutritional approaches that attenuate redox signaling prevent exercise- and β-agonist-induced gene expression within WAT. Combined, these data suggest that ROS represent important mediators of gene expression within WAT.

Synthesis and characterization of diazirine alkyne probes for the study of intracellular cholesterol trafficking

Cholesterol is an essential structural component of cellular membranes and precursor molecule for oxysterol, bile acid, and hormone synthesis. The study of intracellular cholesterol trafficking pathways has been limited in part due to a lack of suitable cholesterol analogues. Herein, we developed three novel diazirine alkyne cholesterol probes: LKM38, KK174, and KK175. We evaluated these probes as well as a previously described diazirine alkyne cholesterol analogue, trans-sterol, for their fidelity as cholesterol mimics and for study of cholesterol trafficking. LKM38 emerged as a promising cholesterol mimic because it both sustained the growth of cholesterol-auxotrophic cells and appropriately regulated key cholesterol homeostatic pathways. When presented as an ester in lipoprotein particles, LKM38 initially localized to the lysosome and subsequently trafficked to the plasma membrane and endoplasmic reticulum. LKM38 bound to diverse, established cholesterol binding proteins. Through a detailed characterization of the cellular behavior of a panel of diazirine alkyne probes using cell biological, biochemical trafficking assays and immunofluorescence approaches, we conclude that LKM38 can serve as a powerful tool for the study of cholesterol protein interactions and trafficking.

Long Noncoding RNAs in the Regulation of Oxidative Stress

Oxidative stress takes responsibility for various diseases, such as chronic obstructive pulmonary disease (COPD), Alzheimer's disease (AD), and cardiovascular disease; nevertheless, there is still a lack of specific biomarkers for the guidance of diagnosis and treatment of oxidative stress-related diseases. In recent years, growing studies have documented that oxidative stress has crucial correlations with long noncoding RNAs (lncRNAs), which have been identified as important transcriptions involving the process of oxidative stress, inflammation, etc. and been regarded as the potential specific biomarkers. In this paper, we review links between oxidative stress and lncRNAs, highlight lncRNAs that refer to oxidative stress, and conclude that lncRNAs have played a negative or positive role in the oxidation/antioxidant system, which may be helpful for the further investigation of specific biomarkers of oxidative stress-related diseases.

Autophagy in Ovarian Follicular Development and Atresia

Autophagy is a mechanism that exists in all eukaryotes under a variety of physiological and pathological conditions. In the mammalian ovaries, less than 1% of follicles ovulate, whereas the remaining 99% undergo follicular atresia. Autophagy and apoptosis have been previously found to be involved in the regulation of both primordial follicular development as well as atresia. The relationship between autophagy, follicular development, and atresia have been summarized in this review with the aim to obtain a more comprehensive understanding of the role played by autophagy in follicular development and atresia.

Manifestations and mechanisms of myocardial lipotoxicity in obesity

Environmental and socioeconomic changes over the past thirty years have contributed to a dramatic rise in the worldwide prevalence of obesity. Heart disease is amongst the most serious health risks of obesity, with increases in both atherosclerotic coronary heart disease and heart failure among obese individuals. In this review, we focus on primary myocardial alterations in obesity that include hypertrophic remodelling and diastolic dysfunction. Obesity-associated perturbations in myocardial and systemic lipid metabolism are important contributors to cardiovascular complications of obesity. Accumulation of excess lipid in nonadipose cells of the cardiovascular system can cause cell dysfunction and cell death, a process known as lipotoxicity. Lipotoxicity has been modelled in mice using high-fat diet feeding, inbred lines with mutations in leptin receptor signalling, and in genetically engineered mice with enhanced myocardial fatty acid uptake, altered lipid droplet homoeostasis or decreased cardiac fatty acid oxidation. These studies, along with findings in cell culture model systems, indicate that the molecular pathophysiology of lipid overload involves endoplasmic reticulum stress, alterations in autophagy, de novo ceramide synthesis, oxidative stress, inflammation and changes in gene expression. We highlight recent advances that extend our understanding of the impact of obesity and altered lipid metabolism on cardiac function.

Downregulation of growth arrest‑specific transcript 5 alleviates palmitic acid‑induced myocardial inflammatory injury through the miR‑26a/HMGB1/NF‑κB axis

Palmitic acid (PA) can induce lipotoxic damage to cardiomyocytes, although its precise mechanism of action has not been completely elucidated. Growth arrest‑specific transcript 5 (GAS5) is a long noncoding RNA that serves a regulatory role in several pathological processes, including tumorigenesis, stroke, cardiac fibrosis and osteoarthritis; however, its role in PA‑induced myocardial injury remains elusive. The present study aimed to explore the role and underlying mechanism of GAS5 on PA‑induced myocardial injury. The expression of GAS5 in PA‑treated cardiomyocytes (H9c2 cells) was detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), and its effects on PA‑induced myocardial injury were measured by Cell Counting Kit‑8 and lactate dehydrogenase (LDH) assays. The activities of cytokines and nuclear factor (NF)‑κB were also detected by enzyme‑linked immunosorbent assay, while interactions between GAS5 and microRNA (miR)‑26a were evaluated by luciferase reporter assay and RT‑qPCR. The regulation of GAS5 on high mobility group box 1 (HMGB1) expression was detected by RT‑qPCR and western blotting. The results demonstrated that GAS5 was significantly upregulated in cardiomyocytes following treatment with PA. GAS5‑knockdown increased the viability of PA‑treated cardiomyocytes and reduced the activity of LDH, tumor necrosis factor‑α and interleukin‑1β. Furthermore, the present study identified that GAS5 specifically binds to miR‑26a, and a reciprocal negative regulation exists between the two. The present study also demonstrated that GAS5 downregulation inhibited HMGB1 expression and NF‑κB activation, while these suppressive effects were mediated by miR‑26a. In conclusion, the present study demonstrated that PA can induce GAS5 expression and that the downregulation of GAS5 alleviated PA‑induced myocardial inflammatory injury through the miR‑26a/HMGB1/NF‑κB axis. These data may provide a novel insight into the mechanism of myocardial lipotoxic injury.

Pilot genome-wide association study identifying novel risk loci for type 2 diabetes in a Maya population

Type 2 diabetes mellitus (T2D) is one of the two leading causes of mortality in Mexico. However, most studies have focused on Caucasians or Asians, and there are a small number of studies investigating Maya populations. Furthermore, to the best of our knowledge, there is no information on isolated Maya communities with T2D frequencies of 20% that are primarily attributed to ethnicity. Consequently, this study focused on assessing which genetic risk variants could be involved in the high rates of T2D in 92 individuals with Maya ancestry; 47 were diagnosed with T2D, and 45 were classified as healthy individuals. A pilot genome-wide association study was performed using the Affymetrix Axiom Genome-wide LAT1 array. The population structure was determined with the ADMIXTURE software using 1289 Latin American selected polymorphisms, and 39 polymorphisms associated with T2D were included for replication. Association tests were performed using the Statistical Analysis System (SAS) using the allelic, genotype and Armitage trend tests. The results indicated that population structure analysis displayed no differences between T2D patients and healthy individuals; 24 loci located were identified for probable association with T2D (p > 1.288 × 10^-7 and p < 1.348 × 10^-4); the polymorphism AGTR2 rs1914711 in chromosome X was identified by the allele test (OR = 6.824; p = 1.448 × 10^-9) as a candidate gene for association with T2D; and ARL15 rs4311394 was associated as a T2D protector by genotype and the Armitage trend test (OR = 0.318; p = 0.001). In conclusion, this study proposes 24 candidate SNPs associated with T2D for replication studies and one for protective association with T2D.

Cytoplasmic functions of long noncoding RNAs

Long noncoding RNAs (lncRNAs) are transcripts longer than 200 nucleotides found throughout the cell that lack protein-coding function. Their functions are closely linked to their interaction with RNA-binding proteins (RBPs) and nucleic acids. Nuclear lncRNAs have been studied extensively, revealing complexes with structural and regulatory roles that enable gene organization and control transcription. Cytoplasmic lncRNAs are less well understood, but accumulating evidence indicates that they also form complexes with diverse structural and regulatory functions. Here, we review our current knowledge of cytoplasmic lncRNAs and the different levels of gene regulation controlled by cytoplasmic lncRNA complexes, including mRNA turnover, translation, protein stability, sponging of cytosolic factors, and modulation of signaling pathways. We conclude by discussing areas of future study needed to elucidate comprehensively the biology of lncRNAs, to further understand the impact of lncRNAs on physiology and design lncRNA-centered therapeutic strategies. This article is categorized under: RNA Export and Localization > RNA Localization Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.

Multiple Functions of Long Non-Coding RNAs in Oxidative Stress, DNA Damage Response and Cancer Progression

In addition to aberrant alternation of transcriptome, it is now suggested that dysregulation of the non-coding transcripts, particularly long non-coding RNAs (lncRNAs), which comprise the majority of the genome, is contributed to cancer initiation and progression. As the result of recent huge efforts, the possible roles of numerous lncRNAs in the human cancers were characterized, as well as various strategies with inhibitory effects to target these transcripts on the transformed cells. Moreover, DNA damage response (DDR) pathway is a complex regulatory network responsible for the identification of disruptions in DNA structure, integrity and stability- it is reported to be associated with the up-regulation and down-regulation of lncRNAs. This review explores the involvement of the various lncRNAs in different human cancers, afterwards discusses the association of the lncRNAs expression with the DDR and oxidative stress, which are implicated in a myriad pathophysiological and physiological intra- and extracellular damages. J. Cell. Biochem. 119: 223-236, 2018. © 2017 Wiley Periodicals, Inc.

Phosphorylated CCAAT/Enhancer Binding Protein β Contributes to Rat HIV-Related Neuropathic Pain: In Vitro and In Vivo Studies

Chronic pain is increasingly recognized as an important comorbidity of HIV-infected patients, however, the exact molecular mechanisms of HIV-related pain are still elusive. CCAAT/enhancer binding proteins (C/EBPs) are expressed in various tissues, including the CNS. C/EBPβ, one of the C/EBPs, is involved in the progression of HIV/AIDS, but the exact role of C/EBPβ and its upstream factors are not clear in HIV pain state. Here, we used a neuropathic pain model of perineural HIV envelope glycoprotein gp120 application onto the rat sciatic nerve to test the role of phosphorylated C/EBPβ (pC/EBPβ) and its upstream pathway in the spinal cord dorsal horn (SCDH). HIV gp120 induced overexpression of pC/EBPβ in the ipsilateral SCDH compared with contralateral SCDH. Inhibition of C/EBPβ using siRNA against C/EBPβ reduced mechanical allodynia. HIV gp120 also increased TNFα, TNFRI, mitochondrial superoxide (mtO₂^·-), and pCREB in the ipsilateral SCDH. ChIP-qPCR assay showed that pCREB enrichment on the C/EBPβ gene promoter regions in rats with gp120 was higher than that in sham rats. Intrathecal TNF soluble receptor I (functionally blocking TNFα bioactivity) or knockdown of TNFRI using antisense oligodeoxynucleotide against TNFRI reduced mechanical allodynia, and decreased mtO₂^·-, pCREB and pC/EBPβ. Intrathecal Mito-tempol (a mitochondria-targeted O₂^·-scavenger) reduced mechanical allodynia and decreased pCREB and pC/EBPβ. Knockdown of CREB with antisense oligodeoxynucleotide against CREB reduced mechanical allodynia and lowered pC/EBPβ. These results suggested that the pathway of TNFα/TNFRI-mtO₂^·--pCREB triggers pC/EBPβ in the HIV gp120-induced neuropathic pain state. Furthermore, we confirmed the pathway using both cultured neurons treated with recombinant TNFα in vitro and repeated intrathecal injection of recombinant TNFα in naive rats. This finding provides new insights in the understanding of the HIV neuropathic pain mechanisms and treatment.SIGNIFICANCE STATEMENT Painful HIV-associated sensory neuropathy is a neurological complication of HIV infection. Phosphorylated C/EBPβ (pC/EBPβ) influences AIDS progression, but it is still not clear about the exact role of pC/EBPβ and the detailed upstream factors of pC/EBPβ in HIV-related pain. In a neuropathic pain model of perineural HIV gp120 application onto the sciatic nerve, we found that pC/EBPβ was triggered by TNFα/TNFRI-mtO₂^·--pCREB signaling pathway. The pathway was confirmed by using cultured neurons treated with recombinant TNFα in vitro, and by repeated intrathecal injection of recombinant TNFα in naive rats. The present results revealed the functional significance of TNFα/TNFRI-mtO₂^·--pCREB-pC/EBPβ signaling in HIV neuropathic pain, and should help in the development of more specific treatments for neuropathic pain.

LncRNA gadd7, increased in varicocele patients, suppresses cell proliferation and promotes cell apoptosis

Varicocele-related sperm damages are usually caused by oxidative stresses. Growing evidence indicates that lncRNA growth arrested DNA-damage inducible gene 7 (gadd7) is involved in the regulation of the oxidative stress responses. In this study, we measured the expression level of gadd7 in the sperm and found that the expression of gadd7 was significantly up-regulated in patients with varicocele compared with the healthy control. The relative expression level of gadd7 was negatively correlated with the sperm count. Overexpression of gadd7 suppressed cell proliferation and promoted cell apoptosis in mouse spermatocyte-derived cell lines GC-1 and GC-2. Furthermore, the protein level of Bax was raised while Bcl2 expression was reduced after overexpression of gadd7. This work provides a potential novel insight for the varicocele-related sperm impairment and male infertility.

Identification and analysis of a key long non-coding RNAs (lncRNAs)-associated module reveal functional lncRNAs in cardiac hypertrophy

Cardiac hypertrophy (CH) is a common disease that originates from long-term heart pressure overload and finally leads to heart failure. Recently, long non-coding RNAs (lncRNAs) have attracted attention because they have broad and crucial functions in regulating complex biological processes. Some studies had found that lncRNAs play vital roles in complex cardiovascular diseases. However, the function and mechanism of lncRNAs in CH have not been elucidated. In our study, to investigate the potential roles of lncRNAs in CH, the Cardiac Hypertrophy-associated LncRNAs-Protein coding genes Network (CHLPN) was constructed by integrating gene microarray re-annotation and subpathway enrichment analyses. After performing random walking with restart in CHLPN, we predicted 21 significant risk lncRNAs, of which 7 (Kis2, 1700110K17Rik, Gm17501, E330017L17Rik, C630043F03Rik, Gm9866 and Ube4bos1) formed a close module with their co-expressed protein-coding genes (PCGs). We found that the module might play crucial roles in the development of CH. In particular, 44 PCGs that were co-expressed with six lncRNAs were enriched in CH-related biological processes and pathways. We also found that some lncRNAs participated in the competitive endogenous RNA cross-talk that might be involved in CH. These results indicate that the functional lncRNAs are related to post-transcriptional regulation and could shed light on a new molecular diagnostic target of CH.

Hypolipidemic effects of total flavonoide extracted from the leaves of Actinidiakolomikta in rats fed a high-fat diet

OBJECTIVES

This study was to investigate the antihyperlipidemic and antioxidant effect of total flavonoid extract from Actinidiakolomikta (TFAK) in hyperlipidemia induced by a high-fat diet.

MATERIALS AND METHODS

Male SD rats were randomly divided into 6 groups: normal group, model (hyperlipidemic diet) group, hyperlipedemic diet supplemented with TFAK (50, 100 and 200 mg/kg) and simvastatin (30 mg/kg) groups. The rats were administrated TFAK by oral for 28 days. Body weight, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), superoxide dismutase (SOD), catalase(CAT), glutathione peroxidase(GSH-Px) and malondialdehyde (MDA) were measured. The atherogenic index (AI) and coronary risk index (CRI) were calculated. The activity of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase in hepatic tissue was examined. Histopathologic changes were also checked.

RESULTS

The levels of TC, TG and LDL-c were increased in model group. Compared to the model group, TFAK reduced significantly the body weight, TC, TG, LDL-c, AI, CRI and elevated the level of HDL-c. Moreover, the activity of SOD was elevated significantly, whereas the content of MDA decreased. The activity of HMG-CoA reductase was also decreased. Morphological evaluation found that rats in model group developed a severe steatosis, but the severity of liver steatosis was ameliorated in TFAK treated groups. The possible mechanism may be associated with decrease HMG-CoA reductase activity.

CONCLUSION

Our results suggest that TFAK exerts strong antioxidant and lipid-lowering effects, prevents hepatic fatty deposition and regulates the HMG-CoA reductase.

Regulation of the unfolded protein response by noncoding RNA

Cells are exposed to various intrinsic and extrinsic stresses in both physiological and pathological conditions. To adapt to those conditions, cells have evolved various mechanisms to cope with the disturbances in protein demand, largely through the unfolded protein response (UPR) in the endoplasmic reticulum (ER), but also through the integrated stress response (ISR). Both responses initiate downstream signaling to transcription factors that, in turn, trigger adaptive programs and/or in the case of prolonged stress, cell death mechanisms. Recently, noncoding RNAs, including microRNA and long noncoding RNA, have emerged as key players in the stress responses. These noncoding RNAs act as both regulators and effectors of the UPR and fine-tune the output of the stress signaling pathways. Although much is known about the UPR and the cross talk that exists between pathways, the contribution of small noncoding RNA has not been fully assessed. Herein we bring together and review the current known functions of noncoding RNA in regulating adaptive pathways in both physiological and pathophysiological conditions, illustrating how they operate within the known UPR functions and contribute to diverse cellular outcomes.

Are targeted therapies for diabetic cardiomyopathy on the horizon?

Diabetes increases the risk of heart failure approximately 2.5-fold, independent of coronary artery disease and other comorbidities. This process, termed diabetic cardiomyopathy, is characterized by initial impairment of left ventricular (LV) relaxation followed by LV contractile dysfunction. Post-mortem examination reveals that human diastolic dysfunction is closely associated with LV damage, including cardiomyocyte hypertrophy, apoptosis and fibrosis, with impaired coronary microvascular perfusion. The pathophysiological mechanisms underpinning the characteristic features of diabetic cardiomyopathy remain poorly understood, although multiple factors including altered lipid metabolism, mitochondrial dysfunction, oxidative stress, endoplasmic reticulum (ER) stress, inflammation, as well as epigenetic changes, are implicated. Despite a recent rise in research interrogating these mechanisms and an increased understanding of the clinical importance of diabetic cardiomyopathy, there remains a lack of specific treatment strategies. How the chronic metabolic disturbances observed in diabetes lead to structural and functional changes remains a pertinent question, and it is hoped that recent advances, particularly in the area of epigenetics, among others, may provide some answers. This review hence explores the temporal onset of the pathological features of diabetic cardiomyopathy, and their relative contribution to the resultant disease phenotype, as well as both current and potential therapeutic options. The emergence of glucose-optimizing agents, namely glucagon-like peptide-1 (GLP-1) agonists and sodium/glucose co-transporter (SGLT)2 inhibitors that confer benefits on cardiovascular outcomes, together with novel experimental approaches, highlight a new and exciting era in diabetes research, which is likely to result in major clinical impact.

MnSOD mediated by HSV vectors in the periaqueductal gray suppresses morphine withdrawal in rats

Morphine appears to be the most active metabolite of heroin; therefore, the effects of morphine are important in understanding the ramifications of heroin abuse. Opioid physical dependence (withdrawal response) may have very long-lasting effects on the motivation for reward, including the incubation of cue-induced drug-seeking behavior. However, the exact mechanisms of morphine withdrawal (MW) are not clear yet, and its treatment remains elusive. Periaqueductal gray (PAG) is one of the important sites in the pathogenesis of MW. Here, we used recombinant herpes simplex virus (HSV) vectors that encode the sod2 gene expressing manganese superoxide dismutase (MnSOD) to evaluate its therapeutic potential in MW. Microinjection of HSV vectors expressing MnSOD into the PAG reduced the MW syndrome. MnSOD vectors suppressed the upregulated mitochondrial superoxide, and endoplasmic reticulum stress markers (glucose-related protein 78 (GRP78) and activating transcription factor 6 alpha (ATF6α)) in the PAG induced by MW. Immunostaining showed that mitochondrial superoxide, GRP78 and ATF6α were colocalized with neuronal nuclei (a neuronal-specific marker), suggesting that they are located in the neurons in the PAG. These results suggest that overexpression of MnSOD by HSV vectors may relieve opioid dependence. This study may provide a novel therapeutic approach to morphine physical withdrawal response.

RNA Regulation of Lipotoxicity and Metabolic Stress

Noncoding RNAs are an emerging class of nonpeptide regulators of metabolism. Metabolic diseases and the altered metabolic environment induce marked changes in levels of microRNAs and long noncoding RNAs. Furthermore, recent studies indicate that a growing number of microRNAs and long noncoding RNAs serve as critical mediators of adaptive and maladaptive responses through their effects on gene expression. The metabolic environment also has a profound impact on the functions of classes of noncoding RNAs that have been thought primarily to subserve housekeeping functions in cells-ribosomal RNAs, transfer RNAs, and small nucleolar RNAs. Evidence is accumulating that these RNAs are also components of an integrated cellular response to the metabolic milieu. This Perspective discusses the different classes of noncoding RNAs and their contributions to the pathogenesis of metabolic stress.

Long Non-coding RNAs in the Cytoplasm

An enormous amount of long non-coding RNAs (lncRNAs) transcribed from eukaryotic genome are important regulators in different aspects of cellular events. Cytoplasm is the residence and the site of action for many lncRNAs. The cytoplasmic lncRNAs play indispensable roles with multiple molecular mechanisms in animal and human cells. In this review, we mainly talk about functions and the underlying mechanisms of lncRNAs in the cytoplasm. We highlight relatively well-studied examples of cytoplasmic lncRNAs for their roles in modulating mRNA stability, regulating mRNA translation, serving as competing endogenous RNAs, functioning as precursors of microRNAs, and mediating protein modifications. We also elaborate the perspectives of cytoplasmic lncRNA studies.

lncRNAs in Stress Response

All living organisms sense and respond to harmful changes in their intracellular and extracellular environment through complex signaling pathways that lead to changes in gene expression and cellular function in order to maintain homeostasis. Long non-coding RNAs (lncRNAs), a large and heterogeneous group of functional RNAs, play important roles in cellular response to stressful conditions. lncRNAs constitute a significant fraction of the genes differentially expressed in response to diverse stressful stimuli and, once induced, contribute to the regulation of downstream cellular processes, including feedback regulation of key stress response proteins. While many lncRNAs seem to be induced in response to a specific stress, there is significant overlap between lncRNAs induced in response to different stressful stimuli. In addition to stress-induced RNAs, several constitutively expressed lncRNAs also exert a strong regulatory impact on the stress response. Although our understanding of the contribution of lncRNAs to the cellular stress response is still highly rudimentary, the existing data point to the presence of a complex network of lncRNAs, miRNAs, and proteins in regulation of the cellular response to stress.

Lean heart: Role of leptin in cardiac hypertrophy and metabolism

Leptin is an adipokine that has been linked with the cardiovascular complications resulting from obesity such as hypertension and heart disease. Obese patients have high levels of circulating leptin due to increased fat mass. Clinical and population studies have correlated high levels of circulating leptin with the development of cardiac hypertrophy in obesity. Leptin has also been demonstrated to increase the growth of cultured cardiomyocytes. However, several animal studies of obese leptin deficient mice have not supported a role for leptin in promoting cardiac hypertrophy so the role of leptin in this pathological process remains unclear. Leptin is also an important hormone in the regulation of cardiac metabolism where it supports oxidation of glucose and fatty acids. In addition, leptin plays a critical role in protecting the heart from excess lipid accumulation and the formation of toxic lipids in obesity a condition known as cardiac lipotoxicity. This paper focuses on the data supporting and refuting leptin’s role in promoting cardiac hypertrophy as well as its important role in the regulation of cardiac metabolism and protection against cardiac lipotoxicity.

Biological and Nutritional Properties of Palm Oil and Palmitic Acid: Effects on Health

A growing body of evidence highlights the close association between nutrition and human health. Fat is an essential macronutrient, and vegetable oils, such as palm oil, are widely used in the food industry and highly represented in the human diet. Palmitic acid, a saturated fatty acid, is the principal constituent of refined palm oil. In the last few decades, controversial studies have reported potential unhealthy effects of palm oil due to the high palmitic acid content. In this review we provide a concise and comprehensive update on the functional role of palm oil and palmitic acid in the development of obesity, type 2 diabetes mellitus, cardiovascular diseases and cancer. The atherogenic potential of palmitic acid and its stereospecific position in triacylglycerols are also discussed.

MicroRNAs and Noncoding RNAs in Hepatic Lipid and Lipoprotein Metabolism: Potential Therapeutic Targets of Metabolic Disorders

Noncoding RNAs and microRNAs (miRNAs) represent an important class of regulatory molecules that modulate gene expression. The role of miRNAs in diverse cellular processes such as cancer, apoptosis, cell differentiation, cardiac remodeling, and inflammation has been intensively explored. Recent studies further demonstrated the important roles of miRNAs and noncoding RNAs in modulating a broad spectrum of genes involved in lipid synthesis and metabolic pathways. This overview focuses on the role of miRNAs in hepatic lipid and lipoprotein metabolism and their potential as therapeutic targets for metabolic syndrome. This includes recent advances made in the understanding of their target pathways and the clinical development of miRNAs in lipid metabolic disorders.

RNASET2 is required for ROS propagation during oxidative stress-mediated cell death

RNASET2 is a ubiquitously expressed acidic ribonuclease that has been implicated in diverse pathophysiological processes including tumorigeneis, vitiligo, asthenozoospermia, and neurodegeneration. Prior studies indicate that RNASET2 is induced in response to oxidative stress and that overexpression of RNASET2 sensitizes cells to reactive oxygen species (ROS)-induced cell death through a mechanism that is independent of catalytic activity. Herein, we report a loss-of-function genetic screen that identified RNASET2 as an essential gene for lipotoxic cell death. Haploinsufficiency of RNASET2 confers increased antioxidant capacity and generalized resistance to oxidative stress-mediated cell death in cultured cells. This function is critically dependent on catalytic activity. Furthermore, knockdown of RNASET2 in the Drosophila fat body confers increased survival in the setting of oxidative stress inducers. Together, these findings demonstrate that RNASET2 regulates antioxidant tone and is required for physiological ROS responses.

Contrasting expression patterns of coding and noncoding parts of the human genome upon oxidative stress

Oxidative stress (OS) is caused by an imbalance between pro- and anti-oxidant reactions leading to accumulation of reactive oxygen species within cells. We here investigate the effect of OS on the transcriptome of human fibroblasts. OS causes a rapid and transient global induction of transcription characterized by pausing of RNA polymerase II (PolII) in both directions, at specific promoters, within 30 minutes of the OS response. In contrast to protein-coding genes, which are commonly down-regulated, this novel divergent, PolII pausing-phenomenon leads to the generation of thousands of long noncoding RNAs (lncRNAs) with promoter-associated antisense lncRNAs transcripts (si-paancRNAs) representing the major group of stress-induced transcripts. OS causes transient dynamics of si-lncRNAs in nucleus and cytosol, leading to their accumulation at polysomes, in contrast to mRNAs, which get depleted from polysomes. We propose that si-lncRNAs represent a novel component of the transcriptional stress that is known to determine the outcome of immediate-early and later cellular stress responses and we provide insights on the fate of those novel mature lncRNA transcripts by showing that their association with polysomal complexes is significantly increased in OS.

Long non-coding RNAs, a new important regulator of cardiovascular physiology and pathology

LncRNAs were previously considered to be the 'noise' of gene transcription having no biological functions, but now it has become evident that lncRNAs function as modulators of gene expression network. LncRNAs may regulate diverse gene expression levels which were roughly summarized to epigenetic, transcriptional and post-transcriptional levels. It has been clarified that some lncRNAs were expressed differentially in cardiovascular diseases, and aberrant changes of those lncRNAs were involved in the development of heart disorders. The role of lncRNAs in this process transcended the tradition of protein regulatory platform to be the orchestrator of cardiac sophisticated governing system of heart development, adaptation and pathological reaction. This review summarizes recent advances in the study of functions and mechanisms of lncRNAs in cardiovascular physiology and pathology. The regulatory roles of lncRNAs in cardiovascular diseases provide new strategy for interventional therapy of heart diseases.

The genetic architecture of the genome-wide transcriptional response to ER stress in the mouse

Endoplasmic reticulum (ER) stress occurs when misfolded proteins accumulate in the ER. The cellular response to ER stress involves complex transcriptional and translational changes, important to the survival of the cell. ER stress is a primary cause and a modifier of many human diseases. A first step to understanding how the ER stress response impacts human disease is to determine how the transcriptional response to ER stress varies among individuals. The genetic diversity of the eight mouse Collaborative Cross (CC) founder strains allowed us to determine how genetic variation impacts the ER stress transcriptional response. We used tunicamycin, a drug commonly used to induce ER stress, to elicit an ER stress response in mouse embryonic fibroblasts (MEFs) derived from the CC founder strains and measured their transcriptional responses. We identified hundreds of genes that differed in response to ER stress across these genetically diverse strains. Strikingly, inflammatory response genes differed most between strains; major canonical ER stress response genes showed relatively invariant responses across strains. To uncover the genetic architecture underlying these strain differences in ER stress response, we measured the transcriptional response to ER stress in MEFs derived from a subset of F1 crosses between the CC founder strains. We found a unique layer of regulatory variation that is only detectable under ER stress conditions. Over 80% of the regulatory variation under ER stress derives from cis-regulatory differences. This is the first study to characterize the genetic variation in ER stress transcriptional response in the laboratory mouse. Our findings indicate that the ER stress transcriptional response is highly variable among strains and arises from genetic variation in individual downstream response genes, rather than major signaling transcription factors. These results have important implications for understanding how genetic variation impacts the ER stress response, an important component of many human diseases.

The vulnerable myocardium. Diabetic cardiomyopathy

Cardiovascular disease is the major cause of morbidity and mortality in subjects suffering from diabetes mellitus. While coronary artery disease is the leading cause of cardiac complications in diabetics, it is widely recognized that diabetes increases the risk for the development of heart failure independently of coronary heart disease and hypertension. This increased susceptibility of the diabetic heart to develop structural and functional impairment is termed diabetic cardiomyopathy. The number of different mechanisms proposed to contribute to diabetic cardiomyopathy is steadily increasing and underlines the complexity of this cardiac entity. In this review the mechanisms that account for the increased myocardial vulnerability in diabetic cardiomyopathy are discussed.

Molecular mechanisms of diabetic cardiomyopathy

In recent years, diabetes mellitus has become an epidemic and now represents one of the most prevalent disorders. Cardiovascular complications are the major cause of mortality and morbidity in diabetic patients. While ischaemic events dominate the cardiac complications of diabetes, it is widely recognised that the risk for developing heart failure is also increased in the absence of overt myocardial ischaemia and hypertension or is accelerated in the presence of these comorbidities. These diabetes-associated changes in myocardial structure and function have been called diabetic cardiomyopathy. Numerous molecular mechanisms have been proposed to contribute to the development of diabetic cardiomyopathy following analysis of various animal models of type 1 or type 2 diabetes and in genetically modified mouse models. The steady increase in reports presenting novel mechanistic data on this subject expands the list of potential underlying mechanisms. The current review provides an update on molecular alterations that may contribute to the structural and functional alterations in the diabetic heart.

Non-coding RNAs in homeostasis, disease and stress responses: an evolutionary perspective

Cells and organisms are subject to challenges and perturbations in their environment and physiology in all stages of life. The molecular response to such changes, including insulting conditions such as pathogen infections, involves coordinated modulation of gene expression programmes and has not only homeostatic but also ecological and evolutionary importance. Although attention has been primarily focused on signalling pathways and protein networks, non-coding RNAs (ncRNAs), which comprise a significant output of the genomes of prokaryotes and especially eukaryotes, are increasingly implicated in the molecular mechanisms of these responses. Long and short ncRNAs not only regulate development and cell physiology, they are also involved in disease states, including cancers, in host-pathogen interactions, and in a variety of stress responses. Indeed, regulatory RNAs are part of genetically encoded response networks and also underpin epigenetic processes, which are emerging as key mechanisms of adaptation and transgenerational inheritance. Here we present the growing evidence that ncRNAs are intrinsically involved in cellular and organismal adaptation processes, in both robustness and protection to stresses, as well as in mechanisms generating evolutionary change.

Function of lncRNAs and approaches to lncRNA-protein interactions

Long non-coding RNAs (lncRNAs), which represent a new frontier in molecular biology, play important roles in regulating gene expression at epigenetic, transcriptional and post-transcriptional levels. More and more lncRNAs have been found to play important roles in normal cell physiological activities, and participate in the development of varieties of tumors and other diseases. Previously, we have only been able to determine the function of lncRNAs through multiple mechanisms, including genetic imprinting, chromatin remodeling, splicing regulation, mRNA decay, and translational regulation. Application of technological advances to research into the function of lncRNAs is extremely important. The major tools for exploring lncRNAs include microarrays, RNA sequencing (RNA-seq), Northern blotting, real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), fluorescence in situ hybridization (FISH), RNA interference (RNAi), RNA-binding protein immunoprecipitation (RIP), chromatin isolation by RNA purification (ChIRP), crosslinking-immunopurification (CLIP), and bioinformatic prediction. In this review, we highlight the functions of lncRNAs, and advanced methods to research lncRNA-protein interactions.

Non-Coding RNAs as Potential Neuroprotectants against Ischemic Brain Injury

Over the past decade, scientific discoveries have highlighted new roles for a unique class of non-coding RNAs. Transcribed from the genome, these non-coding RNAs have been implicated in determining the biological complexity seen in mammals by acting as transcriptional and translational regulators. Non-coding RNAs, which can be sub-classified into long non-coding RNAs, microRNAs, PIWI-interacting RNAs and several others, are widely expressed in the nervous system with roles in neurogenesis, development and maintenance of the neuronal phenotype. Perturbations of these non-coding transcripts have been observed in ischemic preconditioning as well as ischemic brain injury with characterization of the mechanisms by which they confer toxicity. Their dysregulation may also confer pathogenic conditions in neurovascular diseases. A better understanding of their expression patterns and functions has uncovered the potential use of these riboregulators as neuroprotectants to antagonize the detrimental molecular events taking place upon ischemic-reperfusion injury. In this review, we discuss the various roles of non-coding RNAs in brain development and their mechanisms of gene regulation in relation to ischemic brain injury. We will also address the future directions and open questions for identifying promising non-coding RNAs that could eventually serve as potential neuroprotectants against ischemic brain injury.

Molecular mechanisms of hypolipidemic effects of curcumin

Recent evidence suggests potential benefits from phytochemicals and micronutrients in reducing the elevated oxidative and lipid-mediated stress associated with inflammation, obesity, and atherosclerosis. These compounds may either directly scavenge reactive oxygen or nitrogen species or they may modulate the activity of signal transduction enzymes leading to changes in the expression of antioxidant genes. Alternatively, they may reduce plasma lipid levels by modulating lipid metabolic genes in tissues and thus reduce indirectly lipid-mediated oxidative and endoplasmic reticulum stress through their hypolipidemic effect. Here we review the proposed molecular mechanisms by which curcumin, a polyphenol present in the rhizomes of turmeric (Curcuma longa) spice, influences oxidative and lipid-mediated stress in the vascular system. At the molecular level, mounting experimental evidence suggests that curcumin may act chemically as scavenger of free radicals and/or influences signal transduction (e.g., Akt, AMPK) and modulates the activity of specific transcription factors (e.g., FOXO1/3a, NRF2, SREBP1/2, CREB, CREBH, PPARγ, and LXRα) that regulate the expression of genes involved in free radicals scavenging (e.g., catalase, MnSOD, and heme oxygenase-1) and lipid homeostasis (e.g., aP2/FABP4, CD36, HMG-CoA reductase, and carnitine palmitoyltransferase-I (CPT-1)). At the cellular level, curcumin may induce a mild oxidative and lipid-metabolic stress leading to an adaptive cellular stress response by hormetic stimulation of these cellular antioxidant defense systems and lipid metabolic enzymes. The resulting lower oxidative and lipid-mediated stress may not only explain the beneficial effects of curcumin on inflammation, cardiovascular, and neurodegenerative disease, but may also contribute to the increase in maximum life-span observed in animal models.

Long non-coding RNA gadd7 interacts with TDP-43 and regulates Cdk6 mRNA decay

Long non-coding RNAs (lncRNAs) transcribed extensively from the genome have been proposed to be key regulators of diverse biological processes. However, little is known about the role of lncRNAs in regulation of the cell-cycle G1/S checkpoint following DNA damage, a key step in the maintenance of genomic fidelity. Here we show that growth-arrested DNA damage-inducible gene 7 (gadd7), a DNA damage-inducible lncRNA, regulates the G1/S checkpoint in response to UV irradiation. Interestingly, UV-induced gadd7 directly binds to TAR DNA-binding protein (TDP-43) and interferes with the interaction between TDP-43 and cyclin-dependent kinase 6 (Cdk6) mRNA, resulting in Cdk6 mRNA degradation. These findings demonstrate a role for gadd7 in controlling cell-cycle progression and define a novel mechanism by which lncRNAs modulate mRNA expression at the post-transcriptional level by altering mRNA stability.