Transferase-mediated Deoxyuridine Triphosphate-biotin Nick Research Articles

Multi-parametric MRI assessment of melatonin regulating the polarization of microglia in rats after cerebral ischemia/reperfusion injury

ObjectivesMulti-parametric magnetic resonance imaging (MRI) can provide comprehensive and valuable information for precise diagnosis and treatment evaluation of a number of diseases. In this study, the neuroprotective effects of melatonin (Mel) on a rat model of cerebral ischemia/reperfusion injury (CIRI) were assessed by multi-parametric MRI combined with histopathological techniques for longitudinal monitoring of the lesion microenvironment. MethodsSixty Sprague Dawley (SD) rats were randomly divided into three groups: the Sham, CIRI and CIRI + Mel groups. At multiple time points after ischemia, MRI scanning was performed on a 7.0 Tesla MRI scanner. Multi-parametric MRI includes T2-weighted imaging (T2WI), diffusion weighted imaging (DWI), and chemical exchange saturation transfer (CEST)-MRI. CEST effects were calculated by the Lorentzian difference method, 3.5 ppm indicates amide protons of mobile proteins/peptide (Amide-CEST) and 2.0 ppm indicates amine protons (Guan-CEST). Multiple histopathological techniques were used to examine the histopathological changes and explore the therapeutic effects of Mel. ResultsT2WI and DWI-MRI could localize the infarct foci and areas in CIRI rats, which was further validated by staining, 2, 3, 5-triphenyl tetrazolium chloride (TTC) staining, hematoxylin and eosin (H&E) staining, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) staining. After Mel treatment, T2WI and DWI-MRI showed smaller infarct volume, and neurons displayed improved morphology with less apoptosis rates. Notably, Amide-CEST and Guan-CEST signal decreased as early as 2 h after CIRI (all P <0.001), reflecting the change of pH after ischemia. After Mel treatment, both Amide-CEST and Guan-CEST signal increased in ischemic cortex and striatum compared with control group (all P < 0.001). The immunofluorescence staining and western blotting analysis suggested the expression of M2 microglia increased after Mel treatment; While，after Mel treatment the inflammatory factor interleukin-1β (IL-1β) decreased compared with control CIRI rats. ConclusionsMulti-parametric MRI was shown to be an effective method to monitor the brain damage in a rat model of CIRI and assess the therapeutic effects of Mel treatment. Amide-CEST and Guan-CEST were especially sensitive to the changes in brain microenvironment during the early stage after CIRI. Furthermore, the neuroprotective effect of Mel treatment is associated with its promotion of the microglia polarized to M2 type in CIRI rats.

Tilianin alleviates lipid deposition and fibrosis in mice with nonalcoholic steatohepatitis by activating the PPARα/Nnat axis.

The understanding and treatment of nonalcoholic steatohepatitis (NASH) are still very limited. This study reports the therapeutic effect of tilianin on mice with NASH and further explores its possible molecular mechanisms. A mice model of NASH was established using low-dose streptozotocin combined with a high-fat diet and tilianin treatment. Liver function was assessed by determining serum aspartate aminotransferase and alanine aminotransferase in serum. Interleukin (IL)-1β, IL-6, transforming growth factor β1 (TGF-β1), and tumor necrosis factor α (TNF-α) levels in serum were determined. Hepatocyte apoptosis was assessed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining. Oil Red O staining and boron dipyrrin staining were used to determine lipid deposition in liver tissues. Masson staining was used to evaluate liver fibrosis, and immunohistochemistry and western blot analysis were used to determine the expression of target proteins. Tilianin treatment significantly ameliorated liver function, inhibited hepatocyte apoptosis, and reduced lipid deposition and liver fibrosis in mice with NASH. The expression of neuronatin (Nnat) and peroxisome proliferator-activated receptor (PPAR) α was upregulated, whereas that of sterol regulatory element-binding protein 1 (SREBP-1), TGF-β1, nuclear factor (NF)-κB p65, and phosphorylated p65 was downregulated in the liver tissues of mice with NASH after tilianin treatment. The above effects of tilianin were significantly reversed after Nnat knock-down, but its effect on PPARα expression was unaffected. Thus, the natural drug tilianin shows potential in treatig NASH. Its mechanism of action may be related to the targeted activation of PPARα/Nnat, thereby inhibiting the activation of the NF-κB signaling pathway.

MicroRNA-489-3p aggravates neuronal apoptosis and oxidative stress after cerebral ischemia-reperfusion injury

ABSTRACT Cerebral ischemia-reperfusion injury (CIRI) mostly occurs in the treatment stage of ischemic diseases and aggravate brain tissue damage. Although studies have demonstrated that miR-489-3p is closely related to CIRI, the effects of miR-489-3p on neural function in CIRI have not been directly studied. The transient middle cerebral artery occlusion (tMCAO) model was established by suture method, and the corresponding plasmids that interfered with the expression of miR-489-3p or Sirtuin1 (SIRT1) were injected into the model mice, and the behavioral changes of the mice were observed. Then the concentration of serum neuronal injury markers and oxidative stress indices were examined. Next, the pathological conditions, neuronal loss and apoptosis of brain tissue were observed by hematoxylin-eosin staining, Nissl staining, and Transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining. Finally, the hemoglobin content and cerebral edema in the mouse brain were determined. In addition, the expression levels of miR-489-3p and SIRT1 were detected by reverse transcription quantitative polymerase chain reaction or Western blot, and the targeting relationship between miR-489-3p and SIRT1 was verified by bioinformatics analysis and luciferase reporter assay. The experimental results found that in tMCAO mice, miR-489-3p in brain tissue was up-regulated and SIRT1 was down-regulated. Down-regulating miR-489-3p or up-regulating SIRT1 ameliorated behavioral dysfunction, neuronal damage and apoptosis, oxidative stress and brain histopathology. miR-489-3p targeted the regulation of SIRT1 expression, and down-regulating SIRT1 can reverse the protective effect of silenced miR-489-3p on brain injury. Taken together, by targeting SIRT1, elevated miR-489-3p aggravates CIRI-induced neuronal apoptosis and oxidative stress.

Electroacupuncture at "Zusanli"(ST36) protects intestinal mucosal immune barrier by suppre-ssing apoptosis of intestinal lymphocytes and regulating expression of Bcl-2 and Bax in sepsis rats

To observe the effect of electroacupuncture (EA) at "Zusanli" (ST36) on apoptosis of intestinal T lymphocytes, translocation of intestinal bacteria and expression of intestinal Bcl-2 and Bax proteins and intestinal mucosal immune barrier in sepsis rats, so as to explore its underlying mechanism in relieving sepsis. SD rats were randomly divided into sham operation (n=6), model (n=15), non-meridian and non-acupoint (non-acupoint, n=15) and acupoint EA(n=15) groups by using random number table method. The sepsis model was established by using cecal ligation and perforation(CLP) method. EA (2 Hz, 2 mA) was applied to bilateral ST36 or non-acupoint for 30 min one hour after modeling, once every day for 3 days. The rats' general conditions and fatality rate in 3 days after modeling were recorded. The liver, spleen and mesenteric lymph nodes were taken for bacterial culture to detect the translocation rate of intestinal bacteria. The small intestinal tissue was taken for observing histopathological changes (Chiu's score: 0-5 points) after HE staining, and for determining the expression levels of Bcl-2 and Bax proteins using Western blot. The intestinal mucosa was sampled for detecting the apop-tosis (apoptotic index) of lymphocytes by using terminal deoxynucleoitidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) assay, and the counts of CD4+ and CD8+T cells using flow cytometry. The contents of IL-4 in the small intestine and that of secretory IgA (sIgA) in the small intestinal mucus were determined by using ELISA. After modeling, of the 15 rats in each of the 3 groups, 7, 7 and 2 in the model, non-acupoint and EA groups were dead in the first 3 days, with the fatality rate being 46.67% (7/15), 46.67% (7/15) and 13.33% (2/15), respectively (being obviously lower in the EA group than in the former two groups, P<0.05). Compared with the sham operation group, the incidence of intestinal bacterial translocation, apoptotic index, Chiu's score, and Bax expression were significantly increased (P<0.05), and the percentages of CD4+ and CD8+T cells, IL-4 and sIgA contents and Bcl-2 expression considerably decreased (P<0.05) in the model group. In comparison with the model group, modeling-induced increase of incidence of bacterial translocation, apoptotic index and Bax expression, and decrease of percentages of CD4+ and CD8+T cells, IL-4 and sIgA contents and Bcl-2 expression were reversed (P<0.05) in the EA group. EA at ST36 can reduce death rate and intestinal bacteria translocation incidence in sepsis rats, which may be related to its functions in regulating the expression of intestinal Bcl-2 and Bax proteins and inhibiting the apoptosis of intestinal mucosal T lymphocytes, thereby protecting the immune barrier function of intestinal mucosa to reduce the intestinal permeability.

The effect of mechanical stress on enthesis homeostasis in a rat Achilles enthesis organ culture model.

Tendons and ligaments are jointed to bones via an enthesis that is essential to the proper function of the muscular and skeletal structures. The aim of the study is to investigate the effect of mechanical stress on the enthesis. We used ex vivo models in organ cultures of rat Achilles tendons with calcaneus including the enthesis. The organ was attached to a mechanical stretching apparatus that can conduct cyclic tensile strain. We made the models of 1-mm elongation (0.5 Hz, 3% elongation), 2-mm elongation (0.5 Hz, 5% elongation), and no stress. Histological evaluation by Safranin O staining and Toluidin Blue and Picro Sirius red staining was conducted. Expression of sex-determining region Y-box 9 (Sox9), scleraxis (Scx), Runt-related transcription factor 2 (Runx2), and matrix metalloproteinase 13 (Mmp13) were examined by real-time polymerase chain reaction and immunocytochemistry. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labeling and live/dead staining and was conducted for evaluation of the apoptosis and cell viability. The structure of the enthesis was most maintained in the model of 1-mm elongation. The electronic microscope showed that the enthesis of the no stress model had ill-defined borders between fibrocartilage and mineralized fibrocartilage, and that calcification of mineralized fibrocartilage occurred in the model of 2-mm elongation. Sox9 and Scx was upregulated by 1-mm elongation, whereas Runx2 and Mmp13 were upregulated by 2-mm elongation. Apoptosis was inhibited by low stress. The results of this study suggested that 1-mm elongation can maintain the structure of the enthesis, while 2-mm elongation promotes degenerative changes.

MicroRNA miR-215-5p Regulates Doxorubicin-induced Cardiomyocyte Injury by Targeting ZEB2.

Doxorubicin (DOX) is a chemotherapeutic drug for treating various cancers. However, the DOX-induced cardiotoxicity greatly limits its clinical application. MicroRNAs are emerged as critical mediators of cardiomyocyte injury. This work explored the function of miR-215-5p in the regulation of DOX-induced mouse HL-1 cardiomyocyte injury. An in vitro model of DOX-treated cardiotoxicity was established in cardiac mouse cell line HL-1. Gene expression was measured by reverse transcription quantitative polymerase chain reaction. Cell viability was detected using CCK-8. Cell death and apoptosis were tested using transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL), flow cytometry, and caspase-3/7 activity assays. Luciferase reporter assay was used to examine the target of miR-215-5p. We found that DOX induced cardiomyocyte injury and upregulated miR-215-5p in HL-1 cells. Inhibition of miR-215-5p attenuated DOX-induced cardiomyocyte death and apoptosis in vitro. Mechanistical experiments indicated that zinc finger E-box-binding homeobox (ZEB2) was targeted by miR-215-5p. In addition, ZEB2 expression was reduced in DOX-treated HL-1 cells. Rescue assays indicated that ZEB2 knockdown reversed the effects of miR-215-5p inhibition. In conclusion, miR-215-5p inhibition protects HL-1 cells against DOX-induced injury by upregulating ZEB2 expression.

Characterization of the Developing Lacunocanalicular Network During Fracture Repair.

ABSTRACTFracture repair is a normal physiological response to bone injury. During the process of bony callus formation, a lacunocanalicular network (LCN) is formed de novo that evolves with callus remodeling. Our aim was the longitudinal assessment of the development and evolution of the LCN during fracture repair. To this end, 45 adult wild‐type C57BL/6 mice underwent closed tibial fracture surgery. Fractured and intact contralateral tibias were harvested after 2, 3, and 6 weeks of bone healing (n = 15/group). High‐resolution micro–computed tomography (μCT) and deconvolution microscopy (DV) approaches were applied to quantify lacunar number density from the calluses and intact bone. On histological sections, Goldner's trichrome staining was used to assess lacunar occupancy, fluorescein isothiocyanate staining to visualize the canalicular network, and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate‐biotin nick end labeling (TUNEL) staining to examine osteocyte apoptosis. Analysis of μCT scans showed progressive decreases in mean lacuna volume over time (−27% 2–3 weeks; −13% 3–6 weeks). Lacunar number density increased considerably between 2 and 3 weeks (+156%). Correlation analysis was performed, showing a positive linear relationship between canalicular number density and trabecular thickness (R 2 = 0.56, p < 0.001) and an inverse relationship between mean lacuna volume and trabecular thickness (R 2 = 0.57, p < 0.001). Histology showed increases in canalicular number density over time (+22% 2–3 weeks, +51% 3–6 weeks). Lacunar occupancy in new bone of the callus was high (>90%), but the old cortical bone within the fracture site appeared necrotic as it underwent resorption. In conclusion, our data shows a progressive increase in the complexity of the LCN over time during fracture healing and demonstrates that this network is initiated during the early stages of repair. Further studies are needed to address the functional importance of osteocytes in bone healing, particularly in detecting and translating the effects of micromotion in the fracture. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Curcumin protects radiation-induced liver damage in rats through the NF-\u03baB signaling pathway

BackgroundCurcumin has been demonstrated to exert anti-oxidant, anti-fibrotic, anti-inflammatory, and anti-cancer activities. This study was conducted to observe the effect and inner mechanism of curcumin in rats with radiation-induced liver damage (RILD).MethodsThirty SD rats were classified into Control, Radiation group and Curcumin (Cur) + Radiation group (n = 10 in each group). The changes in body weight of the rats were observed on the 3rd, 7th and 14th days after the treatment with curcumin. On the 14th day post treatment, the heart blood of the rats was drawn for measurement of liver function indices including total protein (TP), alanine aminotransfetase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) as well as aspartate aminotransfetase (AST). Subsequently, the rats were euthanized and liver tissues were taken to observe liver morphological changes using hematoxylin-eosin (HE), and to analyze apoptosis condition using transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assays. Meanwhile, the oxidative stress level in liver tissue homogenate was determined by biochemical analysis. The expression of nuclear factor kappa B (NF-κB) pathway-associated and apoptosis-associated proteins was detected using Western blot analysis, and the expression levels of inflammatory factors were measured by Enzyme-linked immunosorbent assay (ELISA).ResultsThe reduced body weight was observed in rats of the Radiation group compared to the Control and Cur + Radiation groups on day 14. In the Radiation group, hepatic cell edema and inflammatory cell infiltration could be visible under the light microscope, and the hepatocytes presented with vacuolar degeneration. In the Cur + Radiation group, the hepatocytes swelled under the microscope, but the pathological changes were alleviated in comparison with the Radiation group. RILD rats with curcumin treatment presented with decreased ALT, AST, ALP, LDH, and maleicdialdehyde (MDA) levels, and elevated TP, superoxide dismutase (SOD), caspase activated DNase (CAD) and glutathione (GSH) levels. Apoptosis and inflammation in rats with RILD were up-regulated, and the NF-κB pathway was activated, but they were reversed after continuously intragastric administration of curcumin for 14 days.ConclusionOur study highlights that curcumin treatment reduces the liver damage caused by radiation through the inhibition of the NF-κB pathway.

Sevoflurane ameliorates adriamycin-induced myocardial injury in rats through the PI3K/Akt/GSK-3β pathway.

The aim of this study was to explore the effects of sevoflurane (SEV) pretreatment on Adriamycin (ADR)-induced myocardial injury through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway. A total of 24 rats weighing 200-250 g were divided into four groups, including: control group (C group), ADR injection group (ADR group), SEV pretreatment group (ADR + SEV group) and inhibitor group (ADR + SEV + LY group). H9c2 cells were cultured in vitro and were divided into control group (C group), ADR treatment group (ADR group), and SEV pretreatment group (ADR + SEV group) and inhibitor group (ADR + SEV + LY group) as well. Next, the content of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) in the serum was detected via Enzyme-Linked Immunosorbent Assay (ELISA). Hematoxylin-eosin (HE) staining assay was performed to determine the severity of myocardial injury. Meanwhile, the apoptosis rate of cells was detected through terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay. Additionally, Western blotting (WB) was employed to measure the protein expression levels of phosphorylated (p)-GSK-3β, p-PI3K, Akt and p-Akt. Compared with C group, ADR significantly increased the content of AST, LDH and CK in the serum (p<0.01), reduced protein expression levels of p-GSK-3β, p-PI3K and p-Akt (p<0.01), increased apoptosis rate (p<0.01), and induced myocardial injury. SEV pretreatment significantly alleviated the effect of ADR, manifested as significantly lowered content of AST, LDH and CK in the serum (p<0.01), distinctly elevated protein expression levels of p-GSK-3β, p-PI3K and p-Akt (p<0.01), notably reduced apoptosis rate (p<0.01), and relieved myocardial injury. LY294002 remarkably inhibited the protective effect of SEV against myocardial injury (p<0.01) CONCLUSIONS: SEV is able to prominently ameliorate ADR-induced myocardial injury by regulating the phosphorylation level of the PI3K/Akt/GSK-3β signaling pathway.

Propofol relieves inflammation in MIRI rats by inhibiting Rho/Rock signaling pathway.

The aim of this study was to investigate the effects of propofol on myocardial ischemia-reperfusion injury (MIRI) and its mechanism by establishing in vivo rat models. Sprague-Dawley rats were selected for the construction of MIRI models in vivo. All rats were divided into three groups, including sham operation group (Sham operation), MIRI group and MIRI + propofol group. At 2 h after reperfusion, myocardial tissues and blood samples were collected from rats. The expression levels of serum lactic dehydrogenase (LDH) and creatine kinase-MB (CK-MB), as well as serum interleukin-6 (IL-6), IL-10 and tumor necrosis factor-α (TNF-α), were measured in each group of rats, respectively. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay was employed to detect the apoptosis of myocardial cells. Additionally, the messenger ribonucleic acid (mRNA) and protein expressions of Ras homolog gene family, member A (RhoA) and Rho-associated coiled-coil-containing protein kinase 2 (Rock2) were determined via quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting, respectively. (1) The expression levels of serum LDH and CK-MB were significantly lower in MIRI + propofol group than those in MIRI group (p<0.05). (2) In comparison with MIRI group, MIRI + propofol group exhibited significantly reduced serum IL-6 and TNF-α levels (p<0.01) and elevated serum IL-10 level (p<0.01). (3) Compared with MIRI group, the apoptosis of myocardial cells was remarkably reduced in MIRI + propofol group after IRI (p<0.05). (4) The mRNA and protein expressions of RhoA and Rock2 were significantly lower in MIRI + propofol group than those in MIRI group (p<0.05). Propofol relieves MIRI and inflammation, reduces the level of oxidative stress and represses I/R-induced myocardial cell apoptosis in MIRI rats by inhibiting the activity of the Rho/Rock signaling pathway.

Downregulation of miR-34a ameliorates inflammatory response and apoptosis induced by renal ischemia-reperfusion by promoting Kruppel-like factor 4 expression.

To explore the influence of micro ribonucleic acid (miR)-34a on renal ischemia-reperfusion by regulating Kruppel-like factor 4 (KLF4). A total of 36 Sprague-Dawley (SD) rats weighing 180-200 g were randomly divided into sham operation group (n=12), model group (n=12), and miR-34a inhibitor group (n=12). Renal ischemia-reperfusion modeling was performed in rats of model group and miR-34a inhibitor group. Those in the sham operation group received the same procedures without ligation. 200 μL of miR-34a inhibitor was pre-injected before modeling in rats of miR-34a inhibitor group. An automatic biochemical analyzer was used to detect serum creatinine and urea nitrogen levels in each group of rats, thus reflecting renal functions. The expressions of B-cell lymphoma 2 (Bcl-2), an apoptotic protein, and KLF4, a transcription factor, were detected via Western blotting. Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) assay was conducted to measure the expression levels of miR-34a and KLF4 in rat renal tissues in each group. Immunohistochemistry was employed to determine the expressions of inflammatory factors tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10). Additionally, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining was utilized to determine the apoptotic rate in rat kidney tissues in each group. Compared with those in the sham operation group, serum creatinine level, urea nitrogen level, expressions of miR-34a, TNF-α and Bcl-2 (p<0.05) increased, while the levels of KLF4 and IL-10 (p<0.05) decreased in the model group. Apoptosis rate was also higher in the model group than the controls. In comparison with the model group, miR-34a inhibitor group had lowered serum creatinine level, urea nitrogen level, expressions of miR-34a, TNF-α and Bcl-2, and apoptotic rate (p<0.05), but raised levels of KLF4 and IL-10 (p<0.05), showing statistically significant differences. Downregulation of miR-34a ameliorates inflammatory response and apoptosis induced by renal ischemia-reperfusion by promoting KLF4 level, thus improving renal functions in rats.

Could high DNA stainability (HDS) be a valuable indicator of sperm nuclear integrity?

BackgroundThe Sperm Chromatin Structure Assay (SCSA®), in addition to identifying the DNA Fragmentation Index (DFI) also identifies High DNA satiability (HDS), supposed to reflect the nuclear compaction of spermatozoa. However, data on what exactly this parameter reveals, its relevance and usefulness are contradictory. In order to shed light on this situation, spermatozoa of a cohort (N = 397) of infertile men were subjected to the SCSA®, TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling) and CMA3 (Chromomycin A3) tests. In a smaller subcohort (N = 100), aniline blue (AB) and toluidine blue (TB) staining were performed in addition. The objective of this study was thus to answer the question of whether HDS is a relevant and reliable parameter to be taken into account?ResultsHDS does not appear to be a reliable indicator of nuclear immaturity because it shows a weak correlation with the CMA3, AB and TB stains. The low correlation of HDS with sperm DNA fragmentation (TUNEL and SCSA®) and DNA condensation (CMA3, AB and TB) tests suggests that these two parameters could be decoupled. Unlike DFI and TUNEL, HDS has not been shown to correlate with classic clinical situations of male infertility (asthenozoospermia, teratozoospermia or astheno-teratozoospermia).ConclusionHDS correlates poorly with most tests that focus specifically on the level of maturity of the sperm nucleus. To our knowledge, this study is the first to compare SCSA®, TUNEL, AB, TB and CMA3 assays on identical samples. It shows the potency, consistency and limitations of each test and the care that must be taken in their interpretation.

ANO1 relieves pressure overload-induced myocardial fibrosis in mice by inhibiting TGF-β/Smad3 signaling pathway.

The aim of this study was to measure the expression of anoctamin 1 (ANO1) in myocardial tissues of mice with pressure overload-induced myocardial fibrosis, and to further investigate the effect of ANO1 on myocardial fibrosis in mice and its mechanism. A total of 40 male C57/B6 mice aged 6-8 weeks old were divided into 2 groups using a random number table, namely sham operation group (Sham group, n=20) and thoracic aortic constriction group (TAC group, n=20). Meanwhile, 20 ANO1 transgenic (TG) mice aged 6-8 weeks old were enrolled for TAC as TAC + ANO1 TG group. At 8 weeks after TAC, ejection fraction (EF%) and fraction shortening (FS%) in each group of mice were detected via echocardiography. Western blotting and immunofluorescence staining assays were conducted to measure the protein expression of ANO1 in myocardial tissues of mice in each group. The pathological changes in myocardial tissues of mice were evaluated through hematoxylin-eosin (H&E) staining. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) assay was performed to measure the messenger ribonucleic acid (mRNA) expression levels of hypertrophy markers atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in myocardial tissues of mice in each group. The deposition of collagen fibers in heart tissues was determined by Masson staining assay. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining assay was carried out to detect the apoptosis of myocardial cells and fibroblasts in heart tissues. Additionally, the protein expressions of oxidative stress markers superoxide dismutase 1 (SOD1) and 4-hydroxynonenal (4-HNE) in myocardial tissues were detected as well. Finally, Western blotting was employed to detect the effect of ANO1 overexpression on the expression of transforming growth factor-β (TGF-β)/Smad3 signaling pathway-related proteins in myocardial tissues of mice. At 8 weeks after TAC, ANO1 expression was overtly reduced in myocardial tissues of mice (p<0.05). Echocardiographic results showed that ANO1 overexpression significantly alleviated TAC-induced cardiac function deterioration in mice (p<0.05). The mRNA expression levels of ANP and BNP in myocardial tissues of TAC + ANO1 TG group were evidently lower than those in TAC group (p<0.05). Meanwhile, myocardial interstitial collagen deposition was significantly ameliorated in TAC + ANO1 TG group compared with TAC group (p<0.05). ANO1 overexpression notably mitigated the apoptosis of myocardial cells and oxidative stress in mice with cardiac pressure overload (p<0.05). Western blotting results further indicated that after overexpression of ANO1, the protein levels of TGF-β and phosphorylated Smad3 (p-Smad3) were significantly inhibited in mice undergoing TAC (p<0.05). In the case of cardiac pressure overload in mice, ANO1 is lowly expressed in myocardial tissues. Meanwhile, its overexpression is able to attenuate pressure overload-induced myocardial fibrosis in mice by repressing the TGF-β/smad3 signaling pathway. All our findings indicate that ANO1 can serve as a potential gene target for the treatment of myocardial fibrosis in the future.

Ulinastatin improves myocardial ischemia-reperfusion injury in rats through endoplasmic reticulum stress-induced apoptosis pathway.

To investigate the protective role of ulinastatin (UTI) on myocardial ischemia-reperfusion (I/R) injury in rats via endoplasmic reticulum stress (ERS)-induced apoptosis pathway. A total of 60 rats were randomly divided into normal group (n=20), myocardial I/R model group (model group, n=20), and myocardial I/R model+UTI treatment group (treatment group, n=20). The myocardial function indicators [creatinine (Scr) and creatine kinase (CK)] were detected. Enzyme-linked immunosorbent assay (ELISA) was performed to measure serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and matrix metalloproteinase-9 (MMP-9). Meanwhile, the contents of reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) in rat left ventricular tissues were determined by ELISA as well. The cardiac function indexes were determined via magnetic resonance imaging (MRI) and echocardiography (ECG). Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining assay was carried out to detect the apoptosis of myocardial tissues. Additionally, the expression levels of endoplasmic reticulum stress and apoptosis genes were measured through quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) assay and Western blotting analysis, respectively. Serum levels of alanine aminotransferase (ALT), CK, and Scr in model group were significantly higher than those in normal group (p<0.05). Besides, rats in model group had significantly lowered SOD, ejection fraction (EF, %), and fractional shortening (FS, %) than those in normal group (p<0.05). In addition, remarkably increased contents of TNF-α, IL-6, MMP-9, MDA, and ROS, as well as higher left ventricular end-diastolic diameter (LVEDd) and left ventricular end-systolic diameter (LVESd) were observed in model group in comparison with normal group (p<0.05). TUNEL staining results revealed that there were more apoptotic cells in model group than that in the other two groups (p<0.05). Expression levels of cysteine aspartic acid-specific protease 12 (Caspase-12) and glucose-regulated protein 78 (GRP78) were evidently higher in model group than those in normal group (p<0.05), while the expression level of B-cell lymphoma 2 (Bcl-2) was clearly lower in model group than that in normal group (p<0.05). UTI treatment partially reversed the above expression changes (p<0.05). UTI has a protective effect against myocardial I/R injury in rats by repressing the occurrence of ERS-induced apoptosis.

Relationship between miR-375 regulating Ndrg2/IL-6/STAT3 signaling pathway and diabetic retinopathy in rats.

To explore the relationship between micro ribonucleic acid (miR)-375 in regulating the N-Myc downstream-regulated gene 2 (Ndrg2)/interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway and diabetic retinopathy (DR) in rats. Thirty Sprague- Dawley rats were randomly divided into Control group (n=10), Model group (n=10), and miR-375 inhibitor group [miR-375 small interfering RNA (siRNA) group, n=10]. The rats in Model group were injected with streptozotocin (STZ) via the tail vein to prepare into rat models of diabetes. The body weight, fasting blood glucose, and retinal barrier permeability of rats in each group were detected. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in rat serum were measured using kits. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay was performed to determine the apoptosis of optic ganglion cells in rat retinal tissues. Additionally, the messenger RNA (mRNA) and protein levels of Ndrg2, IL-6 and STAT3 in rat retinal tissues were detected via reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. Compared with Control group, Model group had reduced body weight of rats, increased blood glucose and retinal permeability of rats, raised serum MDA content, decreased SOD activity, up-regulated apoptotic rate of optic ganglia, and notably elevated mRNA and protein levels of Ndrg2, IL-6 and STAT3 in retinal tissues. Compared with those in Model group, the body weight of rats declined, the blood glucose of rats rose, the retinal permeability of rats was decreased significantly, the serum MDA content was reduced, the SOD activity was raised, the apoptotic rate of optic ganglia was decreased, and the mRNA and protein levels of Ndrg2, IL-6 and STAT3 in retinal tissues were also decreased significantly in miR-375 siRNA group. MiR-375 inhibitors are able to reduce blood glucose, retinal permeability, and optic ganglion apoptosis in rats with DR, and the mechanism of action may be related to the regulation on the Ndrg2/IL-6/STAT3 signaling pathway.

Effect of miR-133 on apoptosis of trophoblasts in human placenta tissues via Rho/ROCK signaling pathway.

The aim of this study was to explore the role of micro ribonucleic acid (miR)-133 in the apoptosis of human placental trophoblasts through the Ras homolog gene family (Rho)/Rho-associated coiled-coil forming protein kinase (ROCK) signaling pathway. The plasma samples were collected from 30 patients with pre-eclampsia (PE) undergoing treatment and 30 healthy subjects (control group) who received physical examination in our hospital. The Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was utilized to measure the expression of miR-133 in PE patients and healthy people. Meanwhile, blood pressure, urine protein content, liver function, and kidney function were detected in patients of both groups as well. Subsequently, the placental trophoblasts were extracted and transfected with inhibitors and miRNA mimics to suppress and overexpress miR-133, respectively. The transfection efficiency was determined by RT-PCR. The levels of interleukin-6 (IL-6), IL-1, and tumor necrosis factor-alpha (TNF-α) were measured in both groups. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay was performed to determine the apoptosis of trophoblasts. Next, the RT-PCR and Western blotting were carried out to detect the expressions of the Rho/ROCK pathway. Furthermore, the influence of miR-133 on the apoptosis of trophoblasts in human placenta tissues through Rho/ROCK was comprehensively observed. In vivo experiments demonstrated that the urinary protein content, miR-133 level, systolic blood pressure, diastolic blood pressure, and liver function and renal function indexes were significantly elevated in pre-eclampsia (PE) patients in comparison with normal subjects (p<0.05). After transfection of mimics and inhibitors, the expression of miR-133 was remarkably up- and down-regulated, respectively. The content of the inflammatory factors in miR-133 mimics group was overtly higher than the other two groups. The TUNEL staining results showed that the number of apoptotic cells significantly increased and decreased in the miR-133 mimics group and miR-133 inhibitors group, respectively. Subsequent experiments indicated that the expressions of apoptosis gene Caspase3, pathway gene, and protein ROCKI were notably up-regulated in miR-133 mimics group. However, they were evidently down-regulated in miR-133 inhibitors group than in the control group. In addition, a consistent trend was observed in the protein expression level. MiR-133 participates in the development and progression of PE through the Rho/ROCK signaling pathway, which may affect the apoptosis of trophoblasts in the placenta tissues.

Morphine alleviates myocardial ischemia/reperfusion injury in rats by inhibiting TLR4/NF-κB signaling pathway.

The aim of this study was to investigate the effect of morphine on myocardial ischemia/reperfusion (I/R) injury in rats and its underlying mechanism, thereby providing a reference for the prevention and treatment of myocardial I/R injury in clinical practice. A total of 60 male Sprague-Dawley (SD) rats were randomly divided into 3 groups, including: Sham group (n=20), I/R group (n=20) and I/R + morphine group (n=20) using a random number table. The left anterior descending coronary artery (LAD) of rat was ligated and re-canalized, and the I/R model was established in rats. Rats in I/R + sevoflurane (SEV) group were pretreated with 2.5% SEV. Infarction area of heart in each group was detected using triphenyltetrazolium chloride (TTC) test. Ejection fraction % (EF%) and fraction shortening % (FS%) were determined by echocardiography. Hematoxylin-eosin (HE) staining assay was performed to detect the morphological changes of cardiac myocardial cells in each group. Meanwhile, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining was adopted to detect the apoptosis of myocardial cells and fibroblasts. In addition, the expression levels of toll-like receptor 4 (TLR4) and p65 in heart samples of rats in each group were measured via immuno-histochemical staining. Finally, the influence of morphine on TLR4/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway was detected using Western blotting. Morphine significantly alleviated I/R-induced cardiac dysfunction in rats, whereas significantly increased EF% and FS% (p<0.05). In addition, morphine evidently inhibited myocardial infarction caused by I/R injury. Meanwhile, it reduced the infarction area from [(59.61±3.41) %] to [(26.67±3.62) %] (p<0.05). The results of HE staining showed that compared with I/R group, I/R + morphine group exhibited remarkably tidier cardiac myofilament, less degradation and necrosis, as well as significantly relieved cellular edema. Immuno-histochemical staining results revealed that morphine overtly reversed decreased expressions of TLR4 and p65 induced by I/R in rats (p<0.05). Furthermore, Western blotting found that morphine significantly inhibited the protein expressions of TLR4 and phosphorylated p65. Morphine clearly alleviates I/R-induced myocardial injury in rats. The possible mechanism may be associated with the inhibition on TLR4/NF-κB signaling pathway.

Melatonin inhibits the inflammation and apoptosis in rats with diabetic retinopathy via MAPK pathway.

To investigate the effect of melatonin on diabetic retinopathy rats through the mitogen-activated protein kinase (MAPK) pathway. A total of 48 Sprague Dawley (SD) rats were randomly divided into normal group (n=12), model group (n=12), melatonin group (n=12), and inhibitor group (n=12). The rats in normal group received no treatment. Those in model group, melatonin group, and inhibitor group were prepared into models of diabetic retinopathy and intraperitoneally injected with normal saline, melatonin, and SB 203580, respectively. After 7 days of intervention, the materials were taken. The expressions of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected through immunohistochemistry. Western blotting was employed to determine the protein expression levels of p38 MAPK, phosphorylated (p)-p38 MAPK, and cysteinyl aspartate specific proteinase-3 (Caspase-3). The messenger ribonucleic acid (mRNA) expression levels of Bax and Bcl-2 were measured via quantitative Polymerase Chain Reaction (qPCR). Enzyme-linked immunosorbent assay (ELISA) was performed to detect the levels of serum interleukin-1β (IL-1β) and IL-18. The apoptosis was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL). Based on immunohistochemistry, model group, melatonin group, and inhibitor group exhibited significantly increased positive expression of Bax but notably decreased positive expression of Bcl-2 in comparison with normal group (p<0.05). Compared with those in model group, the positive expression of Bax was clearly reduced, while the positive expression of Bcl-2 was overtly raised in melatonin group and inhibitor group (p<0.05). The results of Western blotting showed that there was no difference in the protein expression of p38 MAPK among all groups (p>0.05). Compared with normal group, the other three groups had remarkably elevated protein expressions of p-p38 MAPK and Caspase-3 (p<0.05). The protein expressions of p-p38 MAPK and Caspase-3 in melatonin group and inhibitor group were significantly lower than those in model group decreased (p<0.05). QPCR assay revealed that the mRNA expression of Bax was markedly lower in normal group than that in the other three groups, while the mRNA expression of Bcl-2 was significantly higher in normal group than that in the other three groups (p<0.05). Compared with model group, melatonin group, and inhibitory group showed clearly declined mRNA expression level of Bax and notably increased mRNA expression level of Bcl-2 (p<0.05). TUNEL results revealed that the apoptosis rate was remarkably elevated in the other three groups compared with that in normal group (p<0.05). In comparison with model group, melatonin group and inhibitor group exhibited significantly reduced apoptosis rate (p<0.05). Melatonin inhibits the inflammation and apoptosis in rats with diabetic retinopathy by repressing the MAPK pathway.

Effects of dexmedetomidine on sepsis-induced liver injury in rats.

To explore the effect of dexmedetomidine (DEX) on sepsis-induced liver injury in rats and the mechanism of action, providing certain references for the prevention and treatment of sepsis-induced liver injury in clinical practice. A total of 60 male Sprague Dawley (SD) rats were randomly divided into 3 groups, namely sham operation group (Sham group, n=20), sepsis-induced liver injury group [lipopolysaccharides (LPS) group, n=20], and sepsis-induced liver injury + DEX group (LPS + DEX group, n=20) using a random number table. Rat models of sepsis-induced liver injury were established by intraperitoneal injection of LPS (10 mg/kg), and at the same time, DEX was intragastrically injected at a dose of 50 μg/kg. After 24 h, the survival analysis curves of each group of rats were plotted. Meanwhile, the levels of liver function indexes and oxidative stress markers were measured at 12 h in each group of rats. Hematoxylin-eosin (H&E) staining assay was carried out to detect the morphological changes of rat liver cells in each group. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) staining assay was performed to detect the apoptosis level in rat liver tissues in each group. In addition, the expression level of Caspase 3 in three groups of rats was measured through immunohistochemical staining assay. Lastly, the effect of DEX on the protein expression of extracellular signal-regulated kinases 1/2 (ERK1/2) in liver tissues was detected via Western blotting. DEX significantly improved liver dysfunction induced by LPS and raised the 24 h-survival rates of rats (p<0.05). Besides, H&E staining results showed that DEX clearly relieved the pathological damage of rat liver cells caused by LPS. In comparison with LPS group, LPS + DEX group displayed more neatly arranged liver cells, less degradation and necrosis, and evidently attenuated cellular edema. Immunohistochemistry results revealed that DEX significantly reversed the increase in Caspase 3 expression resulting from LPS. The results of the TUNEL staining assay showed that DEX clearly inhibited the apoptosis of rat liver cells induced by LPS. The results of Western blotting revealed that DEX notably reversed the decrease of phosphorylated ERK1/2 (p-ERK1/2) in rat liver tissues compared with LPS group. DEX is able to markedly relieve LPS-induced liver injury in rats and the underlying mechanism may be related to the activation of the ERK1/2 signaling pathway.

LINGO-1 deficiency promotes nerve regeneration through reduction of cell apoptosis, inflammation, and glial scar after spinal cord injury in mice

Leucine-rich repeat and immunoglobulin domain-containing protein 1 (LINGO-1) is a transmembrane protein that negatively regulates neural regeneration in the central nervous system. LINGO-1 expression is up-regulated after central nerve injury, and is accompanied by cell death. Both LINGO-1 and cell death in the injury microenvironment are thought to limit neural regeneration, but the relationship between LINGO-1 and cell death has not been characterized. To investigate whether LINGO-1 deletion improves the spinal cord microenvironment after spinal cord injury (SCI) and contributes to cell survival, we generated LINGO-1 knockout (KO) mice. These mice and wild-type control mice were subjected to spinal cord transection. Fourteen days after spinal cord transection, cell apoptosis, inflammation, glial scar, and growth of nerve fibers were evaluated by immunostaining. The results showed that LINGO-1 KO mice demonstrated a profound reduction in expression of caspase-3, transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL), ionized calcium binding adapter molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and chondroitin sulfate proteoglycans (CSPGs) compared to controls. In contrast, expression of neurofilament (NF) at the SCI site in LINGO-1 KO mice was markedly increased compared to that in wild-type mice. These results suggested that LINGO-1 plays a critical role in the injury microenvironment in processes such as cell death, inflammatory response, and glial scar formation. Importantly, LINGO-1 deletion and a positive microenvironment may exert synergistic effects to promote nerve fiber regeneration. Therefore, inhibition of LINGO-1 may be a therapeutic strategy to promote neural regeneration following SCI.