Roles of m6A modification in regulating PPER pathway in cadmium-induced pancreatic ß cell death.

Cadmium can lead to the death of pancreatic ß cells, thus affecting the synthesis and secretion of insulin. However, the specific mechanisms underlying the cadmium-induced pancreatic ß cell death have not been fully understood. In this study, roles of m6A modification in regulating protein processing in endoplasmic reticulum (PPER) pathway in cadmium-induced pancreatic ß cell death were explored. Our results demonstrated that cell viability and RNA m6A modification level were decreased, while apoptosis rates increased after CdSO4 treatment in pancreatic ß cells (NIT-1). In addition, expressions of Bcl-2, Xbp1, Col3a1, Bax, Chop, Dnajb1, and Hsp90aa1 were all significantly changed in CdSO4 treatment cells. The m6A agonist entacapone (Ent) can prominently reverse the cytotoxicity effects of CdSO4 and alleviate the changes of protein expression induced by CdSO4 treatment. By contrast, m6A inhibitor 3-Deazaadenosine (DAA) can synergistically enhance the cytotoxicity of CdSO4 and aggravate the disorder of protein levels caused by CdSO4 treatment. Interestingly, the results of the immunoprecipitation experiment indicate that Ythdc2, one of m6A binding proteins, may regulate the PPER pathway molecules in an m6A-dependent manner. In summary, our findings provide new directions for the prevention and treatment of the impairment of pancreatic ß cell function induced by cadmium.

Novel insights into mutual regulation between N6-methyladenosine modification and LncRNAs in tumors.

N6-methyladenosine (m6A), one of the most common RNA methylation modifications, has emerged in recent years as a new layer of the regulatory mechanism controlling gene expression in eukaryotes. As a reversible epigenetic modification, m6A not only occurs on mRNAs but also on Long non-coding RNAs (LncRNAs). As we all known, despite LncRNAs cannot encode proteins, they affect the expression of proteins by interacting with mRNAs or miRNAs, thus playing important roles in the occurrence and development of a variety of tumors. Up to now, it has been widely accepted that m6A modification on LncRNAs affects the fate of the corresponding LncRNAs. Interestingly, levels and functions of m6A modifications are also mediated by LncRNAs through affecting the m6A methyltransferases (METTL3, METTL14, WTAP, METTL16, etc.), demethylases (FTO, ALKBH5) and methyl-binding proteins (YTHDFs, YTHDCs, IGF2BPs, HNRNPs, etc.), which are collectively referred to as "m6A regulators". In this review, we summarized the mutual regulation mechanisms between N6-methyladenosine modification and LncRNAs in cancer progression, metastasis, invasion and drug resistance. In detail, we focus on the specific mechanisms of m6A modification, which is mediated by methyltransferases and demethylases, involves in the regulation of LncRNA levels and functions in the first part. And section two intensively displays the mediation roles of LncRNAs in m6A modification via changing the regulatory proteins. At last part, we described the interaction effects between LncRNAs and methyl-binding proteins of m6A modification during various tumor occurrence and development.

Emerging Mutual Regulatory Roles between m6A Modification and microRNAs.

N6-metyladenosine (m6A), one of the most common RNA methylation modifications in mammals, has attracted extensive attentions owing to its regulatory roles in a variety of physiological and pathological processes. As a reversible epigenetic modification on RNAs, m6A is dynamically mediated by the functional interplay among the regulatory proteins of methyltransferases, demethylases and methyl-binding proteins. In recent years, it has become increasingly clear that m6A modification is associated with the production and function of microRNAs (miRNAs). In this review, we summarize the specific kinds of m6A modification methyltransferases, demethylases and methyl-binding proteins. In particular, we focus on describing the roles of m6A modification and its regulatory proteins in the production and function of miRNAs in a variety of pathological and physiological processes. More importantly, we further discuss the mediating mechanisms of miRNAs in m6A modification and its regulatory proteins during the occurrence and development of various diseases.

The association of high-fluoride and high-iodine combined exposure with dental fluorosis and goiter: a meta-analysis.

It is controversial that high-fluoride and high-iodine combined exposure affects the prevalence of dental fluorosis and goiter. The aim of this study was to explore the potential association between high-fluoride and high-iodine combined exposure with dental fluorosis and goiter. We retrieved relevant articles from PubMed, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database and China Science and Technology Journal Database (VIP). The query format was 1 # "Fluorosis" OR "Fluoride," 2 # "Iodine" OR "Iodide," and 3 # 1 AND 2. A total of 20 papers were included in this study after independent review by two investigators. Our analysis showed that high-fluoride and high-iodine biphasic exposure was significantly associated with the prevalence of goiter (OR = 4.69, 95% CI 2.82-7.80, P < 0.001). The prevalence of dental fluorosis was also significantly raised (OR = 11.71, 95% CI 7.57-18.14, P < 0.001). Sensitivity analysis suggested that combined statistics of multiple studies were reliable. For goiter, subgroup analysis revealed study province, sample size and published year as sources of heterogeneity (P < 0.001). For dental fluorosis, only sample size was the impact factor of heterogeneity. As well, funnel plot, Begg's test and Egger's test suggested there was no publication bias (P > 0.05). Overall, our study demonstrates that high-fluoride and high-iodine combined exposure is a risk factor for occurrence of dental fluorosis and goiter. The chronic of high-fluoride and high-iodine combined exposure is a significant higher risk of disease than normal.

Controlled Release of Insulin Based on Temperature and Glucose Dual Responsive Biomicrocapsules.

The treatment of diabetes lies in developing novel functional carriers, which are expected to have the unique capability of monitoring blood glucose levels continuously and dispensing insulin correctly and timely. Hence, this study is proposing to create a smart self-regulated insulin delivery system according to changes in glucose concentration. Temperature and glucose dual responsive copolymer microcapsules bearing N-isopropylacrylamide and 3-acrylamidophenylboronic acid as main components were developed by bottom-spray coating technology and template method. The insulinoma ß-TC6 cells were trapped in the copolymer microcapsules by use of temperature sensitivity, and then growth, proliferation, and glucose-responsive insulin secretion of microencapsulated cells were successively monitored. The copolymer microcapsules showed favorable structural stability and good biocompatibility against ß-TC6 cells. Compared with free cells, the biomicrocapsules presented a more effective and safer glucose-dependent insulin release behavior. The bioactivity of secreted and released insulin did not differ between free and encapsulated ß-TC6 cells. The results demonstrated that the copolymer microcapsules had a positive effect on real-time sensing of glucose and precise controlled release of insulin. The intelligent drug delivery system is supposed to mimic insulin secretion in a physiological manner, and further provide new perspectives and technical support for the development of artificial pancreas.

Effects of different low temperature conditions on anaerobic digestion efficiency of pig manure and composition of archaea community.

To explore the effect of low temperature on the anaerobic digestion of pig manure, the anaerobic digestion experiment was carried out under the conditions of inoculum concentration of 30% and TS of 8%. Five low-temperature gradients of 4, 8, 12, 16 and 20 °C were set to study the activities of gas production, pH, solluted chemical oxygen demand (SCOD), volatile fatty acids (VFAs), coenzymes F420 and archaea community composition in the digestion process. The results were demonstrated: as the temperature decreased, the more unstable the gas production became, the less gas production produced, and the later the gas peak occurred. There were no significant peaks at either 4 °C or 8 °C, and the SCOD was unstable over time. From 12 °C, the SCOD increased over time, and the higher the temperature, the faster the growth trend. The pH was always greater than 7.6. 8, 12, 16, 20 °C had different degrees of VFAs accumulation at the late digestion stage. The higher the temperature, the greater the amount of volatile acid accumulation. When the VFAs of each reactor reached the maximum, the proportion of acetic acid also reached the highest. The digestion system of the five treatment groups was dominated by hydrogen-nutrient methanogenic pathway. The results could provide a further reference for the mechanism of anaerobic digestion of pig manure at low temperatures.

Arsenite-induced endoplasmic reticulum-dependent apoptosis through disturbance of calcium homeostasis in HBE cell line.

Calcium (Ca2+ ) is a ubiquitous cell signal responsible for multiple fundamental cellular functions, including apoptosis. Whether the homeostasis of Ca2+ is involved in arsenite-induced apoptosis remains unclear. In this study, we observed that arsenite significantly elevated the intracellular Ca2+ concentration in a dose- and time-dependent manner. By using the Ca2+ -ATPase inhibitor, thapsigargin, and the inositol 1,4,5- trisphosphate receptors (IP3Rs) inhibitor, heparin, we further confirmed that the disturbance of endoplasmic reticulum (ER) Ca2+ homeostasis caused Ca2+ overload in the cells. Moreover, loss of ER Ca2+ homeostasis also led to ER stress, mitochondrial dysfunction, and NF-κB activation. Importantly, pretreatment of cells with heparin remarkably attenuated the elevated cell apoptosis induced by arsenite, but inhibition of ER Ca2+ uptake with thapsigargin exacerbated arsenite-induced cell damage significantly. Together, we demonstrated for the first time that arsenite disturbed the Ca2+ homeostasis in ER, which subsequently led to ER stress, mitochondrial dysfunction, and NF-κB nuclear translocation, and thus consequently triggering cell apoptosis. Our findings indicate regulation of disrupted Ca2+ homeostasis in ER may be a potential strategy for prevention of arsenite toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 197-216, 2017.

Protection of Nrf2 against arsenite-induced oxidative damage is regulated by the cyclic guanosine monophosphate-protein kinase G signaling pathway.

Arsenite has been shown to induce a variety of oxidative damage in mammalian cells. However, the mechanisms underlying cellular responses to its adverse effects remain unknown. We previously showed that the level of Nrf2, a nuclear transcription factor significantly increased in arsenite-treated human bronchial epithelial (HBE) cells suggesting that Nrf2 is involved in responding to arsenite-induced oxidative damage. To explore how Nrf2 can impact arsenite-induced oxidative damage, in this study, we examined Nrf2 activation and its regulation upon cellular arsenite exposure as well as its effects on arsenite-induced oxidative damage in HBE cells. We found that Nrf2 mRNA and protein levels were significantly increased by arsenite in a dose- and time-dependent manner. Furthermore, we showed that over-expression of Nrf2 significantly reduced the level of arsenite-induced oxidative damage in HBE cells including DNA damage, chromosomal breakage, lipid peroxidation and depletion of antioxidants. This indicates a protective role of Nrf2 against arsenite toxicity. This was further supported by the fact that activation of Nrf2 by its agonists, tertiary butylhydroquinone (t-BHQ) and sulforaphane (SFN) resulted in the same protective effects against arsenite toxicity. Moreover, we demonstrated that arsenite-induced activation of Nrf2 was mediated by the cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling pathway. This is the first evidence showing that Nrf2 protects against arsenite-induced oxidative damage through the cGMP-PKG pathway. Our study suggests that activation of Nrf2 through the cGMP-PKG signaling pathway in HBE cells may be developed as a new strategy for prevention of arsenite toxicity. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 2004-2020, 2017.

[Inhibition of WIP1 in A549 cells enhances the sensitivity of cells to arsenic treatment].

OBJECTIVE: To explore if inhibiting the expression of wild-type p53-induced phosphatase 1( WIP1) could enhance the sensitivity of A549 cells to arsenic. METHODS: To inhibit expression of WIP1, WIP1 siRNA was transferred into A549 cells by using Lipofectamine 2000. Then the protein expression levels of P53 phosphorylation proteins and their downstream effectors were detected by western-blot analysis. Cell apoptosis were assessed by Annexin V-FITC stain assay. The sensitivity of transferred cells to arsenic was detected by using MTT assay. RESULTS: The mRNA and protein expression level of WIP1 were all decreased by 70 % in A549 cells transferred with WIP1 siRNA. Western-blot analysis indicated that P53 phosphorylation process was much accelerated in WIP1-inhibited cells after arsenic treatment. For example, compared to control cells, an significant decrease in P53 ser15 expression and an increase in P53 ser46 expression was found in WIP1-inhibited cells when treated with As_2O_3( 5-40 µmol/L). In addition, compared to control group, the expression of P21 decreased whereas PUMA increased in WIP1-inhibited cells when treated with As_2O_3( 10-40 µmol/L). Cell viability of WIP1-inhibited cells after As_2O_3 treatment( 5-40 µmol/L) was significantly higher than that of the control group, which may be due to a high apoptosis rate in WIP1-inhibited cells. CONCLUSION: WIP1 could be used as a new target in arsenic-base anticancer therapies.

[Improving the expression of TP53INP1 in A549 cells enhances the sensitivity of cells to arsenic treatment].

OBJECTIVE: To explore if improving the expression of TP53INP1 could enhance the sensitivity of A549 cells to arsenic. METHODS: The eukaryotic express vector containing TP53INP1 gene was transferred into A549 cells by using lentivirus vector. Cell apoptosis and cell viability after arsenic treatment were assessed by flow cytometry and MTT assay, respectively. RESULTS: The protein expression level of TP53INP1 was increased in A549 cells transferred with eukaryotic express vector containing TP53INP1 gene, which led to an increase in apoptosis and a decrease in cell viability. Compared with A549 cells, significant increase in apoptosis was found in A549-TP53INP1 cells when treated with As_2O_3( 5- 40 µmol/L). In addiation, the IC50 of As_2O_3 in A549-TP53INP1(( 44. 64 ± 6. 84) µmol/L) cells was significantly lower than that of the A549 group(( 54. 25 ± 6. 13) µmol/L)( P < 0. 05). CONCLUSION: Enhancement of TP53INP1 can significantly improve apoptosis response and enhance sensitivity of A549 cells to arsenic. It is suggested that TP53INP1 could be used as a new target in arsenic-based cancer treatment.

[Effect of Cell Autophagy on the Apoptosis of Hepatocellular Carcinoma Cells Induced by Arsenic Trioxide].

OBJECTIVES: To determine the effect of autophagy on the apoptosis of hepatocellular carcinoma cells induced by arsenic trioxide (ATO). METHODS: Hepatocellular carcinoma HepG2 cells were exposed to ATO. The cell viability was detected by MTT after adjustments for autophagy agonist (Rap) and autophagy inhibitor (3-MA). The autophagosome was observed under electronic microscope. The autophagy related proteins (LC3 and Beclin1) were detected by immunofluorescence. The cell apoptosis was measured by flow cytometry. RESULTS: With 5-20 µmol/Lof ATO, HepG2 cells exposed to 3-MA had significantly lower viability (P <0.05) and higher early apoptosis (P <0.05) than those without exposure to 3-MA. Exposure to 3-MA was also associated with lower expressions of LC3 and Beclin1, with HepG2 cells showing typical apoptotic characteristics. By contrast, with 5-20 µmol/Lof ATO, the cells exposed to Rap showed significantly higher viability (P <0.05) and lower early apoptosis (P<0.05) than those without exposure to Rap. A large number of autophagosome appeared in the cells exposed to Rap. Exposure to Rap was associated with increased expressions of LC3 and Beclin1, but with no statistical significance (P >0.05). CONCLUSION: Targeted autophagy inhibition can significantly increase the sensitivity of HepG2 to ATO. The underlining mechanism is associated with enhanced apoptosis of hepatocellular carcinoma cells.

[miR-155/BACH1 Signaling Pathway in Human Lung Adenocarcinoma Cell Death Induced by Arsenic Trioxide].

OBJECTIVE: To explore the changes of micro RNA 155 (miR-155),BTB and CNC homologous protein 1 (BACH1),quinone oxidoreductase 1 (NQO1) and heme-oxygenase-1 (HO-1) in the process of arsenic trioxide-induced cell death,and to clarify the relationship between miR-155 and BACH1,providing experimental basis for the sensitivity of arsenic trioxide (ATO) treatment. METHODS: Human lung adenocarcinoma cell line A549 cells were treated with different concentrations of ATO. MTT assay and total antioxidant capacity detection kit were used to determine cell viability and total antioxidant capacity,respectively. BACH1,NQO1 and HO-1 protein expression were probed by Western blot and real-time fluorescence quantitative (qRT-PCR) was utilized to test the miR-155 level. A549 cells were transfected with miR-155 mimic and its negative control,then the expression level of miR-155 was detected by qRT-PCR,and these cells were treated with 20 µmol/L for 24 h followed by MTT and Western blot detection. RESULTS: 10 µmol/L ATO significantly reduced the cell viability in A549 cells. 10 µmol/L and 20 µmol/L ATO treatment activated BACH1 expression and inhibited miR-155,NQO1 and HO-1 expression,leading to decreased total antioxidant capacity. Importantly,the cell death induced by 20 µmol/L ATO was significantly decreased in miR-155 mimic transfection cells in comparison with non-transfected cells and miR-155 mimic negative control transfected cells. Moreover,high expression of miR-155 reduced BACH1 activation and increased NQO1 and HO-1 expression in cells treated with 20 µmol/L ATO ( P<0.05). CONCLUSION: Restraining total antioxidant capacity contributes to ATO induced cell death,the underlying mechanisms may be that ATO can activate BACH1 expression through inhibition of the miR-155 level,leading to subsequent inhibition of NQO1 and HO-1 expression. Taken together,these data suggest that miR-155 and BACH1 could be used as sensitivity targets for ATO treatment in lung cancer.

Nuclear translocation of nuclear factor kappa B is regulated by G protein signaling pathway in arsenite-induced apoptosis in HBE cell line.

Arsenite is a certainly apoptosis inducer in various cell types. However, the detailed mechanism underlying how arsenite trigger apoptosis remains elusive. In this study, using human bronchial epithelial cell as a culture system, we demonstrated that arsenite-induced nuclear translocation of nuclear factor kappa B (NF-κB) resulted in the release of cytochrome c, the modulation of Fas and FasL, caspase activation, and ultimately leading to cell apoptosis. Importantly, we showed for the first time that the NF-κB-mediated apoptosis induced by arsenite was regulated by G protein-adenylate cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway. Inhibition of this classical G protein signaling pathway by a typical PKA inhibitor, H-89, caused the inactivation of NF-κB, the depletion of caspase-3, 8 and 9 activities, and thus reducing the level of cell apoptosis. Taken together, our results indicate that arsenite is able to trigger cell apoptosis in human bronchial epithelial cells through the nuclear translocation of NF-κB, which can be modulated by G protein signaling pathway. These findings further suggest that inhibition of G protein-mediated pathway by specific inhibitors may be a potential strategy for the prevention of arsenite toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1819-1833, 2016.

[Role of nuclear factor E2 related factor 2 signaling pathway in malignant transformation induced by sodium arsenite].

OBJECTIVE: To construct the malignant transformation model of human bronchial epithelial (HBE) cell line by exposing to low level of sodium arsenite and determine if the nuclear factor E2 related factor 2 (Nrf2) signaling pathway is involved in this process. METHODS: HBE cells were continuously exposed to 2.5 micromol/L sodium arsenite and malignant transformation occurred as evidenced by the MTT assay, colony formation assay and cell migration assay. Western blot was used to evaluate the expression of Nrf2, quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (10-1) during sodium arsenite-induced transformation of HBE cells. RESULTS: MTT assay demonstrated that the proliferation of HBE cells was out of control with increasing passages of sodium arsenite exposure. In As-HBE-T25 and As-HBE-T50 cells, the cell invasion ability was 2.04 and 4.17 times than that in normal HBE cells and colony formation rate was 1.33% depedent manner (P < 0.5). Also, the expresion of QO1 and HO-1, downstream of Nrf2 target proteins, were also decreased with the expression of Nrf2. CONCLUSION: The transformation of HBE cells induced by chronic exposure to sodium arsenite is mediated by decreased Nrf2 level and its downstream NQO1 and HO-1 protein, which subsequently promote the malignant proliferation.

[Study on the resveratrol and arsenic trioxide combination induced apoptosis and its mechanism on lung adenocarcinoma cells].

OBJECTIVE: To explore the synergistically effects and mechanisms of resveratrol (RES) enhanced the oxidative stress and apoptotic cell death induced by As2O3 (arsenic trioxide). METHODS: According to the result of MTT assay, human lung adenocarcinoma A549 cells were divided into four treatment groups as follow: control group, single RES or As2O3 treated group and the group treated with RES and As2O3. Then the differences of cell viability, colony formation, level of ROS, GSH content, mitochondrial membrane potential and apoptosis rate were compared with single or combined treatment. In addition, pre-treatment with L-buthionine sulfoximine (L-BSO), the inhibitory of GSH synthesis, was used to identify the role of GSH in synergistically apoptosis induced by RES and As2O3. RESULTS: The detected results demonstrated that RES could effectively inhibited the growth of A549 cells when its concentration above 20 µmol/L, and inhibition effects was concentration dependent manner. The rate of colony formation, GSH content, mitochondrial membrane potential and apoptosis rate in combination group were significantly lower than that of single RES or As2O3 treatment group (P < 0.05), whereas, RES markedly increased the level of ROS, the expression of cytochrome c and caspase 3 induced by As2O3. When pre-treatment with BSO before RES and As2O3 combination incubation, beside the apoptosis rate was increased from 30.0% to 77.7%, the GSH content was sharply depleted while ROS massively accumulated in intracellular. CONCLUSION: RES could significantly intensified the effects of As2O3 in inhibiting the proliferation, depleting GSH content, ROS accumulation, mitochondrial membrane potential decline and cytochrome c releasing, thus leading to cells apoptosis via Cas-3 activation in a mitochondria-dependent pathway.

[The Experiment Study and Mechanism of Aspirin Enhances Cellular Sensitivity of Hepatocellular Carcinoma Cell Line to Arsenic Trioxide].

OBJECTIVE: To explore whether aspirin could sensitize arsenic trioxide on human hepatocelluar carcinoma cell line and understanding the combination mechanisms underlying co-treatment. METHODS: Cell viability was detected by MTT assay, cell apoptosis rate and reactive oxygen species (ROS) level were measured by flow cytometry, and Western blot assay was used to estimated the protein expression of heme oxygenase-1 (HO-1) in total protein and NF-E2-related factor 2 (Nrf2) in nuclear protein. RESULTS: 10 µmol/L arsenic trioxide can decreased the cell viability, while cell apoptosis rate, ROS level, HO-1 and Nrf2 protein expression was increased (P < 0.05). When compared with arsenic trioxide alone, co-treatment of arsenic trioxide with aspirin in different concentration (0, 0.1, 1.0, 2.5, 5.0 mmol/L) exhibited dual effects in intracellular ROS level, HO-1 and Nrf2 expression. Specifically, with the increasing of aspirin concentrations, the level of ROS induced by arsenic trioxide showed a rising trend after the first reduction, whereas, HO-1 and Nrf2 protein expression were decreased at first and then increased. CONCLUSION: Low concentration, less than 2.5 mmol/L, of aspirin may reduce the ROS accumulation through activating of Nrf2-HO-1 pathway, therefore decreasing the apoptotic cell death induced by arsenic trioxide. On the contrary, 5 mmol/L aspirin could increase the sensitivity of HepG2 to arsenic trioxide through enhancing the arsenic trioxide-induced apoptosis by ROS accumulation resulting in inhibiting the Nrf2-HO-1 pathway.

Changes of LncRNAs during the Process of Antioxidants Antagonize Cadmium-Induced Oxidative Damage in Islet ß Cells.

Long non-coding RNAs (LncRNAs) play important regulatory roles in oxidative damage. Resveratrol, curcumin, and cyanidin are phytogenic antioxidants widely existing in nature and they have been proved to antagonize certain heavy metal-induced oxidative damage in cells. However, can they antagonize oxidative damage induced by cadmium in islet ß cells? Are their mechanisms of antagonizing oxidative damage related to LncRNAs? In this study, we first detected the cell viability of each group by CCK8 assay. Next, reactive oxygen species (ROS) were detected by the fluorescent probe. The contents of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) were detected according to the instructions of corresponding kits. At last, the levels of LncRNAs were detected by fluorescence quantitative real-time polymerase chain reaction (qPCR). The results showed that resveratrol, curcumin and cyanidin were able to reverse the reduction of cell viability induced by cadmium (CdSO4). Further determination revealed that SOD activities of the resveratrol+CdSO4, curcumin+CdSO4, and cyanidin+CdSO4 treatment groups increased significantly, and ROS levels and MDA contents dramatically decreased when compared with single CdSO4-treated group. More importantly, the levels of three CdSO4-elevated LncRNAs (NONMMUT029382, ENSMUST00000162103, ENSMUST00000117235) were all decreased and levels of three CdSO4-inhibited LncRNAs (NONMMUT036805, NONMMUT014565, NONMMUT065427) were increased after the pretreatment of resveratrol, curcumin and cyanidin. In summary, resveratrol, curcumin and cyanidin may effectly reverse the cadmium-induced oxidative damage and suggest that phytogenic antioxidants may prevent cells from cadmium-induced oxidative damage through changing the levels of LncRNAs.

Changes of RNA m6A/m5C Modification Regulatory Molecules in Ferroptosis of T2DM Rat Pancreas.

N6-methyladenine (m6A) and 5-methylcytosine (m5C) are two common forms of RNA methylation that play an important role in the epigenetics of type 2 diabetes mellitus (T2DM). One type of cell death, ferroptosis, has been implicated in islet ß-cell damage in T2DM. Notably, RNA methylation, an upstream regulatory mechanism of mRNAs, can regulate the expression of ferroptosis signaling molecules, thereby affecting cell proliferation and death. Here, we found that the ferroptosis signaling pathway was activated in pancreas of T2DM rats, followed by significant changes in m6A/m5C modification regulatory molecules. These detection data together with the prediction results that m6A and m5C exist in the mRNAs of ferroptosis molecules, we speculate that m6A and m5C are probably involved in pancreatic cell damage by modifying of ferroptosis signaling molecules. In short, our findings provide a new research idea for future studies on the molecular mechanisms of pancreatic cell damage and point to a new direction for exploring the mechanisms of ferroptosis from the perspective of RNA methylation modification.

Changes of m6A Regulatory Proteins and Nrf2 Signaling Molecules in Liver Tissue of Type 2 Diabetes Mellitus Rats.

Both dysregulation of N6-methyladenosine (m6A) regulatory proteins and Nrf2 signaling molecules are involved in the process of injury to multiple tissues. However, changes of m6A regulatory proteins and Nrf2 signaling molecules in liver tissue of T2DM remain unclear. In present study, changes of m6A regulatory proteins (Mettl3, Mettl16, Fto, Alkbh5 and Ythdc2) and Nrf2 signaling molecules (Nrf2, Sod1, Ho-1, Gclc) were detected in the liver tissues of T2DM rats, which constructed by high fat-diet feeding and intraperitoneal injection of streptozotocin. Our results indicated that the morphology of liver tissues from T2DM rats showed obvious abnormalities, as well as levels of liver function indicators and expressions of Nrf2 signaling molecules Nrf2, Sod1, Ho-1 were significantly increased in T2DM rats when compared with those in corresponding control rats. More importantly, m6A regulatory proteins such as Mettl3, Mettl16, Fto, Alkbh5 and Ythdc2 were dramatically higher than those in control rat. In a word, m6A regulatory proteins and Nrf2 signaling molecules may significantly change in liver tissue of T2DM rats. And This provides clues and ideas for the study of liver injury in T2DM from the perspective of RNA epigenetics in the future.

Screening of differentially expressed RNAs and identifying a ceRNA axis during cadmium-induced oxidative damage in pancreatic ß cells.

Cadmium, a common metal pollutant, has been demonstrated to induce type 2 diabetes by disrupting pancreatic ß cells function. In this study, transcriptome microarray was utilized to identify differential gene expression in oxidative damage to pancreatic ß cells following cadmium exposure. The results indicated that a series of mRNAs, LncRNAs, and miRNAs were altered. Of the differentially expressed miRNAs, miR-29a-3p exhibited the most pronounced alteration, with an 11.62-fold increase relative to the control group. Following this, the target gene of miR-29a-3p was identified as Col3a1 through three databases (miRDB, miRTarbase and Tarbase), which demonstrated a decrease across the transcriptome microarray. The upstream target gene of miR-29a-3p was identified as NONMMUT036805, with decreased expression observed in the microarray. Finally, the expression trend of NONMMUT036805/miR-29a-3p/Col3a1 was reversed following NAC pretreatment. This was accompanied by a reduction in oxidative damage indicators, MDA/ROS/GSH-Px appeared to be negatively affected to varying degrees. In conclusion, this study has demonstrated that multiple RNAs are altered during cadmium exposure-induced oxidative damage in pancreatic ß cells. The NONMMUT036805/miR-29a-3p/Col3a1 axis has been shown to be involved in this process, which provides a foundation for the identification of potential targets for cadmium toxicity intervention.