Betulinic acid protects against ovarian impairment by decreasing F-2 toxin-induced oxidative stress and inflammation associated with the downregulation of p38 expression in mice

F-2 toxin is an estrogenic mycotoxin that causes reproductive disorders in animals.Betulinic acid(BA)is a natural pentacyclic lupane-structure triterpenoid that has diverse pharmacological activities.In this study,the antioxidative and anti-inflammatory effects of BA and its underlying mechanism are explored in F-2 toxin-triggered mouse ovarian damage.We found that BA alleviated the F-2 toxin-induced ovarian impairment by stimulating follicle growth,reducing inflammatory cell infiltration,repairing damaged mitochondria and endoplasmic reticulum.Simultaneously,BA not only reversed F-2 toxin-induced reduction of follicle stimulating hormone(FSH)and luteinizing hormone(LH)levels in the serum,but also restrained the protein expression of the estrogen receptors a(ERa)and ERβ.Moreover,BA restored the balance of F-2 toxin-induced ovarian redox system disorders.Subsequently,we found that 0.25 mg/kg BA played an anti-inflammatory role in the F-2 toxin-induced ovarian impairment by decreasing interleukin-1β(IL-1β).IL-6,and tumor necrosis factor-α(TNF-α)mRNA expression,as well as inhibiting p38 protein expression.These data demonstrated that BA exerts its protective effect on F-2 toxin-induced ovarian oxidative impairment and inflammation by inhibiting p38 expression,which implies a natural product-based medicine to ameliorate F-2 toxin-caused female reproductive toxicity and provides a detoxifying method for food contaminated by mycotoxin.

To investigate the effects of butylphthalide on reducing neuronal apoptosis in rats with cerebral infarction by inhibiting the JNK/P38 MAPK signaling pathway

Objective:To investigate the effects of butylphthalide on reducing neuronal apoptosis in rats with cerebral infarction by inhibiting the JNK/P38 MAPK signaling pathway.Methods:Forty-eight SD male rats were divided into DZ group(control group),CI group(model group)and NBP group(butylphthalide group).Rats in CI group and NBP group were used to establish cerebral infarction models.NBP group used NBP.The solution(80 mg/(kg?d))was administered orally,and the remaining two groups were administered with the same volume of peanut oil.After 14 consecutive days of treatment,the Zea Longa score was used to evaluate the neurological function of DZ,CI and NBP rats.Scoring,TTC staining was used to observe the cerebral infarction volume of rats in DZ group,CI group and NBP group,HE staining was used to observe the pathological morphology of brain tissue in DZ group,CI group and NBP group.Neuronal apoptosis,Western blot was used to detect the expression of p-JNK and p-p38MAPK in brain tissues of DZ group,CI group and NBP group.Results:The neurological function of the rats in the CI group was higher than that in the DZ group,and the difference was statistically significant(P<0.05).The neurological function score of the rats in the NBP group was reduced compared with the CI group,and the difference was statistically significant(P<0.05).The cerebral infarction volume in the group was 35.56%higher than that in the DZ group,and the difference was statistically significant(P<0.05).The minor infarct volume in the NBP group was 21.59%,which was less than that in the CI group,and the difference was statistically significant(P<0.05).Nerve cells are neatly sorted,with a large number.The gap between blood vessels and interstitial tissue in the CI group is enlarged,the cells are severely contracted,and the neuron structure is incomplete.Compared with the CI group,the NBP group has reduced neuron contraction and increased number;The dead nerve cells were brown.The apoptosis rate of nerve cells in the CI group was 79.65%higher than that in the DZ group was 5.82%.The difference was statistically significant(P<0.05).The nerve cell apoptosis rate in the NBP group was 30.23%.Compared with CI group,the difference was statistically significant(P<0.05);Western blot results showed that p-JNK and p-p38MAPK protein expression in CI group was higher than that in DZ group,and the difference was statistically significant(P<0.05).The levels of p-JNK and p-p38MAPK proteins in the NBP group were lower than those in the CI group.There was statistically significant(P<0.05).Conclusion:Butylphthalide can improve neurological damage,reduce apoptotic nerve cells,and reduce infarct volume in rats with cerebral infarction,which is related to the inhibition of JNK/P38 MAPK pathway expression.

Promotion effect of FOXCUT as a microRNA sponge for miR-24-3p on progression in triple-negative breast cancer through the p38 MAPK signaling pathway

Background:Triple-negative breast cancer(TNBC)is a type of highly invasive breast cancer with a poor prognosis.According to new research,long noncoding RNAs(lncRNAs)play a significant role in the progression of cancer.Although the role of lncRNAs in breast cancer has been well reported,few studies have focused on TNBC.This study aimed to explore the biological function and clinical significance of forkhead box C1 promoter upstream transcript(FOXCUT)in triple-negative breast cancer.Methods:Based on a bioinformatic analysis of the cancer genome atlas(TCGA)database,we detected that the lncRNA FOXCUT was overexpressed in TNBC tissues,which was further validated in an external cohort of tissues from the General Surgery Department of the First Affiliated Hospital of Nanjing Medical University.The functions of FOXCUT in proliferation,migration,and invasion were detected in vitro or in vivo.Luciferase assays and RNA immunoprecipitation(RIP)were performed to reveal that FOXCUT acted as a competitive endogenous RNA(ceRNA)for the microRNA miR-24-3p and consequently inhibited the degradation of p38.Results:lncRNA FOXCUT was markedly highly expressed in breast cancer,which was associated with poor prognosis in some cases.Knockdown of FOXCUT significantly inhibited cancer growth and metastasis in vitro or in vivo.Mechanistically,FOXCUT competitively bounded to miR-24-3p to prevent the degradation of p38,which might act as an oncogene in breast cancer.Conclusion:Collectively,this research revealed a novel FOXCUT/miR-24-3p/p38 axis that affected breast cancer progression and suggested that the lncRNA FOXCUT could be a diagnostic marker and therapeutic target for breast cancer.

Mannitol inhibits the proliferation of neural stem cell by a p38 mitogen-activated protein kinase-dependent signaling pathway

Purpose:Mannitol is one of the first-line drugs for reducing cerebral edema through increasing the extracellular osmotic pressure.However,long-term administration of mannitol in the treatment of cerebral edema triggers damage to neurons and astrocytes.Given that neural stem cell(NSC)is a subpopulation of main regenerative cells in the central nervous system after injury,the effect of mannitol on NSC is still elusive.The present study aims to elucidate the role of mannitol in NSC proliferation.Methods:C57 mice were derived from the animal house of Zunyi Medical University.A total of 15 pregnant mice were employed for the purpose of isolating NSCs in this investigation.Initially,mouse primary NSCs were isolated from the embryonic cortex of mice and subsequently identified through immunofluorescence staining.In order to investigate the impact of mannitol on NSC proliferation,both cell counting kit-8 assays and neurospheres formation assays were conducted.Thein vitro effects of mannitol were examined at various doses and time points.In order to elucidate the role of Aquaporin 4(AQP4)in the suppressive effect of mannitol on NSC proliferation,various assays including reverse transcription polymerase chain reaction,western blotting,and immunocytochemistry were conducted on control and mannitol-treated groups.Additionally,the phosphorylated p38(p-p38)was examined to explore the potential mechanism underlying the inhibitory effect of mannitol on NSC proliferation.Finally,to further confirm the involvement of the p38 mitogen-activated protein kinase-dependent(MAPK)signaling pathway in the observed inhibition of NSC proliferation by mannitol,SB203580 was employed.All data were analyzed using SPSS 20.0 software(SPSS,Inc.,Chicago,IL).The statistical analysis among multiple comparisons was performed using one-way analysis of variance(ANOVA),followed by Turkey’’s post hoc test in case of the data following a normal distribution using a Shapiro-Wilk normality test.Comparisons between 2 groups were determined using Student’s t-test,if the data exhibited a normal distribution using a Shapiro-Wilk normality test.Meanwhile,data were shown as median and interquartile range and analyzed using the Mann-WhitneyU test,if the data failed the normality test.A p<0.05 was considered as significant difference.Results:Primary NSC were isolated from the mice,and the characteristics were identified using immunostaining analysis.Thereafter,the results indicated that mannitol held the capability of inhibiting NSC proliferation in a dose-dependent and time-dependent manner using cell counting kit-8,neurospheres formation,and immunostaining of Nestin and Ki67 assays.During the process of mannitol suppressing NSC proliferation,the expression of AQP4 mRNA and protein was downregulated,while the gene expression of p-p38 was elevated by reverse transcription polymerase chain reaction,immunostaining,and western blotting assays.Subsequently,the administration of SB203580,one of the p38 MAPK signaling pathway inhibitors,partially abrogated this inhibitory effect resulting from mannitol,supporting the fact that the p38 MAPK signaling pathway participated in curbing NSC proliferation induced by mannitol.Conclusions:Mannitol inhibits NSC proliferation through downregulating AQP4,while upregulating the expression of p-p38 MAPK.

ANTI-OXIDATIVE MECHANISMS OF PRAVASTATIN PREVENTING AORTIC ATHEROSCLEROSIS IN apoE KNOCKOUT MICE:ROLE OF p38 MAPK PATHWAY

Objective To determine whether pravastatin exerts anti-oxidative effects on preventing aortic＂ atherosclerosis via modulating p38 MAPK pathway. Methods Male 8-week-old apoE^-/- mice fed a diet containing 1.25% cholesterol （wt/wt） were divided into pravastatin group administered with pravastatin （80 mg. kg ^-1· d^-1 ） and atherosclerosis group administered with PBS; and male 8-week-old C57BL/6J mice fed a normal diet were as control group （ n = 12 ）. In thoracoabdominal aortas of mice, levels of Malondialdehyde （ MDA ） and activities of superoxide dismutase （ SOD ） were measured and expression of phosphorylated p38 MAPK （ p-p38 MAPK） and phosphorylated signal transducer and activator of transcr（ption 1 （pSTAT1） were examined by Western blotting. Results After eight weeks, atherosclerosis in aortic root was significantly prevented by pravastatin. In aortic atherosclerosis lesion, the level of MDA was significantly reduced; adversely the activity, of SOD was increased. Expressions of p-p38 MAPK and pSTAT1 were significantly decreased in aortic atherosclerosis lesion. Conclusion Our results suggests that anti-oxidative mechanisms of pravastatin preventing aortic atherosclerosis may partially depend on modulating p38 MAPK signal pathway.

Skeletal muscle myogenesis is regulated by G protein-coupled receptor kinase 2

G protein-coupled receptor kinase 2 （GRK2） is an important serine/threonine-kinase regulating different membrane receptors and intraceUular proteins. Attenuation of Drosophila Gprk2 in embryos or adult flies induced a defective differentiation of somatic muscles, loss of fibers, and a flightless phenotype. In vertebrates, GRK2 hemizygous mice contained less but more hypertrophied skeletal muscle fibers than wild-type littermates. In C2C12 myoblasts, overexpression of a GRK2 kinase-deficient mutant （K220R） caused precocious differentiation of ceUs into immature myotubes, which were wider in size and contained more fused nuclei, while GRK2 overexpression blunted differentiation. Moreover, p38MAPK and Akt pathways were activated at an earlier stage and to a greater extent in K220R-expressing cells or upon kinase downregulation, while the activation of both kinases was impaired in GRK2-overexpressing cells. The impaired differentiation and fewer fusion events promoted by enhanced GRK2 levels were recapitulated by a p38MAPK mutant, which was able to mimic the inhibitory phosphorylation of p38MAPK by GRK2, whereas the blunted differentiation observed in GRK2-expressing clones was rescued in the presence of a constitutively active upstream stimulator of the p38MAPK pathway. These results suggest that balanced GRK2 function is necessary for a timely and complete myogenic process.

Polysaccharides from Agrocybe cylindracea residue alleviate type 2-diabetes-induced liver and colon injuries by p38 MAPK signaling pathway

In this experiment,we investigated the possible mechanism of polysaccharides from Agrocybe cylindracea residue (PACR) on ameliorating the type-2-diabetes-induced liver and colon injuries.Animal experiments have proved that PACR could reduce the oxidative damage and inflammatory response.Meanwhile,the PACR could restore lipid levels,decrease the level of liver and colon lesions in injured mice,and finally play a role in protecting liver and colon.The results showed that PACR could be used as a supplement to decrease blood glucose and relieve T2DM and reduce oxidative stress and inflammatory response by inhibiting the activation of p38 MAPK signaling pathway.

The p38/MAPK pathway as a therapeutic target to prevent therapeutic escape of breast cancer stem cells

Cancer stem cells(CSCs)play an important role in metastasis development,tumor recurrence,and treatment resistance,and are essential for the eradication of cancer.Currently,therapies fail to eradicate CSCs due to their therapeutic stress-induced cellular escape,which leads to enhanced aggressive behaviors compared with CSCs that have never been treated.However,the underlying mechanisms regulating the therapeutic escape remain unknown.To this end,we established a model to isolate the therapeutic escaped CSCs(TSCSCs)from breast CSCs and performed the transcription profile to reveal the mechanism.Mechanistically,we demonstrated that the behavior of therapeutic escape was regulated through the p38/MAPK signaling pathway,resulting in TSCSCs exhibiting enhanced motility and metastasis.Notably,blocking the p38/MAPK signaling pathway effectively reduced motility and metastasis ability both in vitro and in vivo,which were further supported by downregulated motility-related genes and epithelial-mesenchymal transition(EMT)-related proteins vimentin and N-cadherin.The obtained findings reveal the p38/MAPK pathway as a potential therapeutic target for TSCSCs and would provide profound implications for cancer therapy.

Effects of PGC-1αoverexpression on the myogenic response during skeletal muscle regeneration

The ability of skeletal muscle to regenerate from injury is crucial for locomotion,metabolic health,and quality of life.Peroxisome proliferator-activated receptor-γcoactivator-1α(PGC1A)is a transcriptional coactivator required for mitochondrial biogenesis.Increased mitochondrial biogenesis is associated with improved muscle cell differentiation,however PGC1A's role in skeletal muscle regeneration following damage requires further investigation.The purpose of this study was to investigate the role of skeletal muscle-specific PGC1A overexpression during regeneration following damage.22 C57BL/6J(WT)and 26 PGC1A muscle transgenic(A1)mice were injected with either phosphate-buffered saline(PBS,uninjured control)or Bupivacaine(MAR,injured)into their tibialis anterior(TA)muscle to induce skeletal muscle damage.TA muscles were extracted 3-or 28-days postinjury and analyzed for markers of regenerative myogenesis and protein turnover.Pgc1a mRNA was~10–20 fold greater in A1 mice.Markers of protein synthesis,AKT and 4EBP1,displayed decreases in A1 mice compared to WT at both timepoints indicating a decreased protein synthetic response.Myod mRNA was~75%lower compared to WT 3 days post-injection.WT mice exhibited decreased cross-sectional area of the TA muscle at 28 days post-injection with bupivacaine compared to all other groups.PGC1A overexpression modifies the myogenic response during regeneration.

The functional analysis of transiently upregulated miR-101 suggests a “braking” regulatory mechanism during myogenesis

Skeletal muscle differentiation is a highly coordinated process that involves many cellular signaling pathways and microRNAs(miRNAs).A group of muscle-specific miRNAs has been reported to promote myogenesis by suppressing key signaling pathways for cell growth.However,the functional role and regulatory mechanism of most non-muscle-specific miRNAs with stage-specific changes during differentiation are largely unclear.Here,we describe the functional characterization of miR-101a/b,a pair of non-muscle-specific miRNAs that show the largest change among a group of transiently upregulated miRNAs during myogenesis in C2C12 cells.The overexpression of miR-101a/b inhibits myoblast differentiation by suppressing the p38/MAPK,Interferon Gamma,and Wnt pathways and enhancing the C/EBP pathway.Mef2a,a key protein in the p38/MAPK pathway,was identified as a direct target of miR-101a/b.Interestingly,we found that the long non-coding RNA(lncRNA)Malat1,which promotes muscle differentiation,interacts with miR-101a/b,and this interaction competes with Mef2a mRNA to relieve the inhibition of the p38/MAPK pathway during myogenesis.These results uncovered a“braking”role in differentiation of transiently upregulated miRNAs and provided new insights into the competing endogenous RNA(ceRNA)regulatory mechanism in myoblast differentiation and myogenesis.