P38α MAPK Research Articles

Discovery of novel 2,3,5-trisubstituted pyridine analogs as potent inhibitors of IL-1β via modulation of the p38 MAPK signaling pathway.

Interleukin-1β is a central mediator of innate immune responses and inflammation. It plays a key role in a wide variety of pathologies, ranging from autoinflammatory diseases to metabolic syndrome and malignant tumors. It is well established that its inhibition results in a rapid and sustained reduction in disease severity, underlining the importance of having a repertoire of drugs of this class. At present, there are only three interleukin-1β blockers approved in the clinic. All of them are biologics, requiring parenteral administration and resulting in expensive treatments. In an exercise to identify small molecule allosteric inhibitors of MAP kinases, we discovered a series of compounds that block IL-1β release produced as a consequence of a stimulus involved in triggering an inflammatory response. The present study reports the hit-to-lead optimization process that permitted the identification of the compound 13b (AIK3-305) an orally available, potent and selective inhibitor of IL-1β. Furthermore, the study also reports the results of an invivo efficacy study of 13b in a LPS endotoxic shock model in male BALB/c mice, where IL-1β inhibition is monitored in different tissues.

Blunting p38 MAPKα and ERK1/2 activities by empagliflozin enhances the antifibrotic effect of metformin and augments its AMPK-induced NF-κB inactivation in mice intoxicated with carbon tetrachloride

AimMetformin and empagliflozin combined therapy may have complementary effects that go beyond the well-recognized targets of their monotherapy through AMPK activation. Therefore, the current study was designed to investigate for the first time the hepatoprotective effects of such combination therapy in the carbon tetrachloride (CCl4)-induced hepatic fibrosis model in mice. Materials and methodsDetermination of liver enzymes and the liver content of oxidative stress parameters, and hydroxyproline were performed biochemically. ELISA was performed to measure PDGF-BB, TNF-α, TGF-β, TIMP-1, AMPK, p-mTOR, NF-κB P65 binding activity, p38 MAPKα, JNK1/2 and ERK1/2. Real-time qPCR was conducted to determine Col1a1 and α-SMA. In addition, histopathological examination using H&E and Masson's trichrome stain were performed for determination of histopathological changes. Key findingsEmpagliflozin inhibited the activation of p38 MAPK and ERK1/2 and exhibited a weak AMPKα stimulation. On the other hand, metformin exerted a more robust stimulatory action on the AMPKα that was accompanied by a notable decrease in the NF-κB nuclear binding activity and a decline in the p-mTOR levels. Nevertheless, the effect of metformin on MAPK kinases was insignificant. Our results revealed that blunting p38 MAPKα and ERK1/2 activities by empagliflozin enhanced the antifibrotic effect of metformin and augmented its AMPK-induced NF-κB inactivation. SignificanceAs diabetes is one of the most common risk factors for liver fibrosis, the use of antidiabetic drugs is expected to improve therapeutic outcome. Therefore, metformin/empagliflozin combined therapy could be promising in preventing hepatic inflammation and fibrosis via exhibiting complementary effects particularly in diabetic patients.

Moringa oleifera Lam. leaf extract safely inhibits periodontitis by regulating the expression of p38α/MAPK14-OPG/RANKL

Periodontitis is a chronic disease clinically defined by loss of alveolar bone and connective tissue degeneration. Although Moringa oleifera Lam. (MO), a tree belonging to the Moringacea family, is widely used as an anti-inflammatory agent, its effect on periodontitis is still unclear. In this work, the phenol compounds in MO leaf extract (MOL) were identified by UPLC-ESI-MS/MS, and the anti-periodontitis effects and mechanism of MOL were predicted using network pharmacology and molecular docking. Moreover, the cytotoxic, antioxidant, and anti-periodontitis properties of MOL were confirmed in vivo and in vitro. In total, 88 phenolic compounds and 234 potential MOL periodontitis targets were screened, involving 2916 biological processes (BP). The p38α MAPK (MAPK14) pathway and OPG/RANKL complex were predicted to be involved in the process of molecular docking. Furthermore, experimental validation suggested that MOL significantly ameliorated inflammation and reduced alveolar bone resorption. The OPG/RANKL ratio was regulated through the inhibition of MAPK14, and the anti-periodontitis effect was realized by the antioxidant properties of MOL. Hematoxylin and eosin (H&E) staining of rat vital organs and the survival rate of RAW 264.7 cells confirmed the safety of MOL. The present study provides valuable insights into how MOL reduces inflammation and alveolar bone resorption associated with periodontitis. In conclusion, MOL safely inhibits chronic periodontitis highly likely by regulating the expression of p38α/MAPK14-OPG/RANKL. Network pharmacology coupled with experimental validation is an effective way to find new drugs in the future. Data availability statementThe original data presented in the study are included in the article. Further inquiries can be directed to the corresponding authors.

LPA1-mediated PKD2 activation promotes LPA-induced tissue factor expression via the p38α and JNK2 MAPK pathways in smooth muscle cells

Tissue factor (TF) is the principal initiator of blood coagulation and is necessary for thrombosis. We previously reported that lysophosphatidic acid (LPA), a potent bioactive lipid, highly induces TF expression at the transcriptional level in vascular smooth muscle cells. To date, however, the specific role of the LPA receptor is unknown, and the intracellular signaling pathways that lead to LPA induction of TF have been largely undetermined. In the current study, we found that LPA markedly induced protein kinase D (PKD) activation in mouse aortic smooth muscle cells (MASMCs). Small-interfering RNA-mediated knockdown of PKD2 blocked LPA-induced TF expression and activity, indicating that PKD2 is the key intracellular mediator of LPA signaling leading to the expression and cell surface activity of TF. Furthermore, our data reveal a novel finding that PKD2 mediates LPA-induced TF expression via the p38α and JNK2 MAPK signaling pathways, which are accompanied by the PKD-independent MEK1/2-ERK-JNK pathway. To identify the LPA receptor(s) responsible for LPA-induced TF expression, we isolated MASMCs from LPA receptor-knockout mice. Our results demonstrated that SMCs isolated from LPA receptor 1 (LPA1)-deficient mice completely lost responsiveness to LPA stimulation, which mediates induction of TF expression and activation of PKD and p38/JNK MAPK, indicating that LPA1 is responsible for PKD2-mediated activation of JNK2 and p38α. Taken together, our data reveal a new signaling mechanism in which the LPA1-PKD2 axis mediates LPA-induced TF expression via the p38α and JNK2 pathways. This finding provides new insights into LPA signaling, the PKD2 pathway, and the mechanisms of coagulation/atherothrombosis.

Protective effects of rutin against deltamethrin-induced hepatotoxicity and nephrotoxicity in rats via regulation of oxidative stress, inflammation, and apoptosis.

Deltamethrin is a type-II pyrethroid synthetic insecticide that is extensively used for controlling mosquitoes, flies, pests, and insects worldwide. This study was carried out to evaluate the likelihood protective effects of rutin, a natural antioxidant, against deltamethrin-induced liver and kidney toxicities in rats. Hepatotoxicity and nephrotoxicity were evaluated after the rats were treated orally with deltamethrin (1.28 mg/kg b.w.) alone or with rutin (25 and 50 mg/kg b.w.) for 30 days. Deltamethrin administration caused an increase in lipid peroxidation level and a decrease in activities of SOD, CAT, GPx, and GSH levels in the both tissues. Deltamethrin also increased serum ALT, AST, ALP, urea, and creatinine levels, while reduced nephrine levels in rats. In addition, deltamethrin increased the activation of inflammatory and apoptotic pathways by decreasing Bcl-2 and increasing TNF-α, NF-κB, IL-1β, p38α MAPK, COX-2, iNOS, beclin-1, Bax, and caspase-3 protein levels and/or activities. Furthermore, deltamethrin increased mRNA expression levels of PARP-1, VEGF, and immunohistochemical expressions of c-fos in the tissues. Rutin treatment significantly improved all examined parameters and restored the liver and kidney histopathological and immunohistochemical alterations. These findings demonstrate that rutin could be used to ameliorate hepatotoxicity and nephrotoxicity associated with oxidative stress, inflammation, and apoptosis in deltamethrin-induced rats.

Rare Opportunities for Insights Into Serotonergic Contributions to Brain and Bowel Disorders: Studies of the SERT Ala56 Mouse.

Altered structure, expression, and regulation of the presynaptic serotonin (5-HT) transporter (SERT) have been associated with multiple neurobehavioral disorders, including mood disorders, obsessive-compulsive disorder (OCD), and autism spectrum disorder (ASD). Opportunities to investigate mechanistic links supporting these associations were spurred with the identification of multiple, rare human SERT coding variants in a study that established a male-specific linkage of ASD to a linkage marker on chromosome 17 which encompassed the location of the SERT gene (SLC6A4). We have explored the most common of these variants, SERT Ala56, in vitro and in vivo. Results support a tonic elevation of 5-HT transport activity in transfected cells and human lymphoblasts by the variant in vitro that leads to an increased 5-HT clearance rate in vivo when studied in the SERT Ala56 mouse model, along with altered sensitivity to SERT regulatory signaling pathways. Importantly, hyperserotonemia, or an elevated whole blood 5-HT, level, was found in SERT Ala56 mice, reproducing a well-replicated trait observed in a significant fraction of ASD subjects. Additionally, we found multiple biochemical, physiological, and behavioral alterations in the SERT Ala56 mice that can be analogized to those observed in ASD and its medical comorbidities. The similarity of the functional impact of the SERT Ala56 variant to the consequences of p38α MAPK activation, ascribed to the induction of a biased conformation of the transporter toward an outward-facing conformation, has resulted in successful efforts to restore normal behavioral and bowel function via pharmacological and genetic p38α MAPK targeting. Moreover, the ability of the inflammatory cytokine IL-1β to enhance SERT activity via a p38α MAPK-dependent pathway suggests that the SERT Ala56 conformation mimics that of a chronic inflammatory state, supporting findings in ASD of elevated inflammatory cytokine levels. In this report, we review studies of the SERT Ala56 variant, discussing opportunities for continued insight into how chronically altered synaptic 5-HT homeostasis can drive reversible, functional perturbations in 5-HT sensitive pathways in the brain and periphery, and how targeting the SERT regulome, particularly through activating pathways such as those involving IL-1β/p38α MAPK, may be of benefit for neurobehavioral disorders, including ASD.

Active p38α causes macrovesicular fatty liver in mice

One third of the western population suffers from nonalcoholic fatty liver disease (NAFLD), which may ultimately develop into hepatocellular carcinoma (HCC). The molecular event(s) that triggers the disease are not clear. Current understanding, known as the multiple hits model, suggests that NAFLD is a result of diverse events at several tissues (e.g., liver, adipose tissues, and intestine) combined with changes in metabolism and microbiome. In contrast to this prevailing concept, we report that fatty liver could be triggered by a single mutated protein expressed only in the liver. We established a transgenic system that allows temporally controlled activation of the MAP kinase p38α in a tissue-specific manner by induced expression of intrinsically active p38α allele. Here we checked the effect of exclusive activation in the liver. Unexpectedly, induction of p38α alone was sufficient to cause macrovesicular fatty liver. Animals did not become overweight, showing that fatty liver can be imposed solely by a genetic modification in liver per se and can be separated from obesity. Active p38α-induced fatty liver is associated with up-regulation of MUC13, CIDEA, PPARγ, ATF3, and c-jun mRNAs, which are up-regulated in human HCC. Shutting off expression of the p38α mutant resulted in reversal of symptoms. The findings suggest that p38α plays a direct causative role in fatty liver diseases and perhaps in other chronic inflammatory diseases. As p38α activity was induced by point mutations, it could be considered a proto-inflammatory gene (proto-inflammagene).

Cancer-Induced Muscle Wasting Requires p38β MAPK Activation of p300.

Cancer-associated cachexia, characterized by muscle wasting, is a lethal metabolic syndrome without defined etiology or established treatment. We previously found that p300 mediates cancer-induced muscle wasting by activating C/EBPβ, which then upregulates key catabolic genes. However, the signaling mechanism that activates p300 in response to cancer is unknown. Here, we show that upon cancer-induced activation of Toll-like receptor 4 in skeletal muscle, p38β MAPK phosphorylates Ser-12 on p300 to stimulate C/EBPβ acetylation, which is necessary and sufficient to cause muscle wasting. Thus, p38β MAPK is a central mediator and therapeutic target of cancer-induced muscle wasting. In addition, nilotinib, an FDA-approved kinase inhibitor that preferentially binds p38β MAPK, inhibited p300 activation 20-fold more potently than the p38α/β MAPK inhibitor, SB202190, and abrogated cancer cell-induced muscle protein loss in C2C12 myotubes without suppressing p38α MAPK-dependent myogenesis. Systemic administration of nilotinib at a low dose (0.5 mg/kg/day, i.p.) in tumor-bearing mice not only alleviated muscle wasting, but also prolonged survival. Therefore, nilotinib appears to be a promising treatment for human cancer cachexia due to its selective inhibition of p38β MAPK. SIGNIFICANCE: These findings demonstrate that prevention of p38β MAPK-mediated activation of p300 by the FDA-approved kinase inhibitor, nilotinib, ameliorates cancer cachexia, representing a potential therapeutic strategy against this syndrome.

The Roles of Epinephelus coioides miR-122 in SGIV Infection and Replication

In mammals, mature miR-122 is 22 nucleotides long and can be involved in regulating a variety of physiological and biological pathways. In this study, the expression profile and effects of grouper Epinephelus coioides miR-122 response to Singapore grouper iridovirus (SGIV) infection were investigated. The sequences of mature microRNAs (miRNAs) from different organisms are highly conserved, and miR-122 from E. coioides exhibits high similarity to that from mammals and other fish. The expression of miR-122 was up-regulated during SGIV infection. Up-regulation of miR-122 could significantly enhance the cytopathic effects (CPE) induced by SGIV, the transcription levels of viral genes (MCP, VP19, LITAF and ICP18), and viral replication; reduce the expression of inflammatory factors (TNF-a, IL-6, and IL-8), and the activity of AP-1 and NF-κB, and miR-122 can bind the target gene p38α MAPK to regulate the SGIV-induced cell apoptosis and the protease activity of caspase-3. The results indicated that SGIV infection can up-regulate the expression of E. coioides miR-122, and up-regulation of miR-122 can affect the activation of inflammatory factors, the activity of AP-1 and NF-κB, and cell apoptosis to regulate viral replication and proliferation.

Design, crystal structure determination, molecular dynamic simulation and MMGBSA calculations of novel p38-alpha MAPK inhibitors for combating Alzheimer’s disease

The hallmark of the Alzheimer’s disease (AD) is the accumulation of aggregated, misfolded proteins. The cause for this accumulation is increased production of misfolded proteins and impaired clearance of them. Amyloid aggregation and tau hyperphosphorylation are the two proteinopathies which accomplish deprivation of cell and tissue hemostasis during neuropathological process of the AD, as a result of which progressive neuronal degeneration and the loss of cognitive functions. p38 mitogen-activated protein kinase (p38 MAPK) has been implicated in both the events associated with AD: tau protein phosphorylation and inflammation. p38α MAPK pathway is activated by a dual phosphorylation at Thr180 and Tyr182 residues. Clinical and preclinical evidence implicates the stress related kinase p38α MAPK as a potential neurotherapeutic target. Drug design of p38α MAPK inhibitors is mainly focused on small molecules that compete for Adenosine triphosphate in the catalytic site. Here we have carried out the synthesis of phenyl sulfonamide derivatives Sulfo (I) and Sulfo (II). Crystal structures of Sulfo (I) and Sulfo (II) were solved by direct methods using SHELXS-97. Sulfo (I) and Sulfo (II) have Rint values of 0.0283 and 0.0660, respectively, indicating good quality of crystals and investigated their ability against p38α MAPK. Docking studies revealed that the Sulfo (I) had better binding affinity (−62.24 kcal/mol) as compared to Sulfo (II) and cocrystal having binding affinity of −54.61 kcal/mol and −59.84 kcal/mol, respectively. Molecular dynamics simulation studies of Sulfo (I) and cocrystal of p38α MAPK suggest that during the course of 30 ns simulation run, compound Sulfo (I) attained stability, substantiating the consistency of its binding to p38α MAPK compared to cocrystal. Binding free energy analysis suggests that the compound Sulfo (I) is better than the cocrystal. Thus, this study corroborates the therapeutic potential of synthesized Sulfo (I) in combatting AD. Communicated by Ramaswamy H. Sarma

A novel P38α MAPK activator Bruceine A exhibits potent anti-pancreatic cancer activity

Pancreatic cancer remains one of the cancers with the poorest prognosis bearing an overall 5-year survival rate of about 5%. Efficient new chemotherapic drugs are still highly desired. Here, bruceine A, a quassinoid identified from the dried fruits of Brucea javanica (L.) Merr., displayed the most potent anti-proliferation activity against pancreatic cancer in vitro and in vivo. Phosphoproteomic analysis revealed p38α MAPK phosphorylation was involved in bruceine A’s action in MIA PaCa-2 cells. Utilizing fortebio octet system and microscale thermophoresis, we found p38α MAPK had high affinity for bruceine A. Molecular docking and molecular dynamic simulations showed that bruceine A widely bound to residues (Leu171, Ala172, Met179, Thr180, Val183) in P-loop of p38α MAPK. Key determinants of bruceine A binding with P-loop of p38α MAPK were 19-CO, 22-CH3, 32-CH3, and 34-CH3. Taken together, our findings demonstrate that bruceine A binds directly to p38α MAPK, which can be used to probe the role of p38α MAPK phosphorylation in pancreatic cancer progression, and as a novel lead compound for pancreatic cancer therapy.

Nox2 Upregulation and p38α MAPK Activation in Right Ventricular Hypertrophy of Rats Exposed to Long-Term Chronic Intermittent Hypobaric Hypoxia.

One of the consequences of high altitude (hypobaric hypoxia) exposure is the development of right ventricular hypertrophy (RVH). One particular type of exposure is long-term chronic intermittent hypobaric hypoxia (CIH); the molecular alterations in RVH in this particular condition are less known. Studies show an important role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex-induced oxidative stress and protein kinase activation in different models of cardiac hypertrophy. The aim was to determine the oxidative level, NADPH oxidase expression and MAPK activation in rats with RVH induced by CIH. Male Wistar rats were randomly subjected to CIH (2 days hypoxia/2 days normoxia; n = 10) and normoxia (NX; n = 10) for 30 days. Hypoxia was simulated with a hypobaric chamber. Measurements in the RV included the following: hypertrophy, Nox2, Nox4, p22phox, LOX-1 and HIF-1α expression, lipid peroxidation and H2O2 concentration, and p38α and Akt activation. All CIH rats developed RVH and showed an upregulation of LOX-1, Nox2 and p22phox and an increase in lipid peroxidation, HIF-1α stabilization and p38α activation. Rats with long-term CIH-induced RVH clearly showed Nox2, p22phox and LOX-1 upregulation and increased lipid peroxidation, HIF-1α stabilization and p38α activation. Therefore, these molecules may be considered new targets in CIH-induced RVH.

Pulmonary hypertension: reduction of vascular and cardiac remodeling by a new inhibitor of p38-alpha MAPK

Abstract Background Pulmonary arterial hypertension (PAH) is a disease characterized by pulmonary vascular remodeling with subsequent right ventricular (RV) failure. This work investigated the effects of a new p38-alpha mitogen-activated protein kinase (p38-α MAPK) inhibitor, named LASSBio-1824, on PAH model in rats. Methods All experiments were in accordance with the Animal Care and Use Committee at our university (039/19). Male Wistar rats was exposed to hypoxia (10% O2) during 3 weeks plus i.p. injection of an antagonist of vascular endothelial growth factor receptor (SU5416; 20 mg/kg/week) to induce PAH. Control rats were kept in normoxia (21% O2). After 21 days of protocol, echocardiography images confirmed PAH using the pulmonary artery (PA) outflow waveform. After disease onset, animals were randomly divided into three groups: control + vehicle (DMSO), HAP + vehicle and HAP + LASSBio-1824 (50 mg/kg/day). Vehicle and LASSBio-1824 were administered by oral gavage during two weeks. Results Pulmonary acceleration time (PAT; ms) was reduced from 33.2±2.7 (control) to 22.7±1.1 in PAH + vehicle group (p<0.05) and restored to 29.6±1.9 after treatment with LASSBio-1824 (p<0.05). RV afterload was detected in HAP group because of the increase of systolic pressure (mmHg) from 22.2±1.5 (control) to 47.2±3.6 (p<0.05) and reduced to 18.0±2.9 with LASSBio-1824. Medial wall thickness (%) of distal PA (<50 μm) was measured by using immunohistochemistry for alpha smooth muscle actin (α-SMA) which was increased from 62.5±5.6 (control) to 78.0±7.9 in PAH group (p<0.05), but it was significantly reduced to 54.4±2.3 in PAH + LASSBio-1824 group (p<0.05). Vascular reactivity was evaluated comparing the acetylcholine (ACh)-induced maximal relaxation (%) in PA from normal and PAH rats, which was reduced from 67.5±2.1 to 49.63±5.6 (PAH group; p<0.05). Therefore, the treatment with the p38 inhibitor normalized the ACh-induced response to 73.7±4.1%. The immunohistochemistry for c-fos protein, a product of the p38 pathway related to cell proliferation, showed an increased ratio of stained and total myocyte nuclei (%) in PAH animals of 38.0±0.5 compared to normal group of 20.2±4.2. LASSBio-1824 significantly reduced ratio to 24.0±2.3% (p<0.05). PAH increased inflammatory condition because the expression of inducible nitric oxide synthase increased from 0.31±0.01 (control) to 0.57±0.02 and it was recovered by the treatment with LASSBio-1824 to 0.31±0.10 (p<0.05). Conclusion LASSBio-1824, an inhibitor of p38-alpha MAPK represents an important approach for the future treatment of PAH which improves the underlying remodeling and inflammation processes in the cardiopulmonary system. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES; Conselho Nacional de Desenvolvimento Científico e Tecnolόgico - CNPq

Neuroprotective effect of chrysin on isoniazid-induced neurotoxicity via suppression of oxidative stress, inflammation and apoptosis in rats

Isoniazid (INH) is among the most important anti-tuberculosis agents widely prescribed. However, its clinical use is restricted due to its severe side effects associated with neurotoxicity. The aim of the present study was to investigate the neuroprotective effects of chrysin (CR), a natural antioxidant, against INH-induced neurotoxicity in rats. The rats were treated orally with INH (400 mg/kg body weight) alone or with CR (25 and 50 mg/kg body weight) for 7 consecutive days. INH administration significantly increased brain lipid peroxidation and resulted in a significant decrease in antioxidant biomarkers including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH). INH treatment also increased levels of nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), glial fibrillary acidic protein (GFAP) and activities of p38α mitogen-activated protein kinase (p38α MAPK) while decreasing levels of neural cell adhesion molecule (NCAM). Double immunofluorescence expressions of c-Jun N-terminal kinase (JNK) and Bcl-2 associated X protein (Bax) in brain tissues were increased after INH administration. Furthermore, INH increased mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), glutamate-cysteine ligase modifier subunit (Gclm), glutamate cysteine ligase catalytic subunit (Gclc), NF-κB, TNF-α, interleukin-1β (IL-1β), interleukin-6 (IL-6) and GFAP in rat brain tissues. Co-treatment with CR increased anti-oxidant capacity as well as regulated inflammation and apoptosis in brain. Additionally, molecular docking results showed that CR had the potential to interact with the active sites of TNF-α and NFκ-B. In conclusion, CR improved INH-induced brain oxidative damage, inflammation and apoptosis, possibly through their antioxidant properties.

Prostaglandin I2 (PGI2) inhibits Brucella abortus internalization in macrophages via PGI2 receptor signaling, and its analogue affects immune response and disease outcome in mice

To date, the implications of prostaglandin I2 (PGI2), a prominent lipid mediator for modulation of immune responses, has not been clearly understood in Brucella infection. In this study, we found that cyclooxygenase-2 (COX-2) was significantly expressed in both infected bone marrow-derived macrophages (BMMs) and RAW 264.7 cells. Prostaglandin I2 synthase (PTGIS) expression was not significantly changed, and PGI2receptor (PTGIR) expression was downregulated in BMMs but upregulated in RAW 264.7 macrophages at late infection. Here, we presented that PGI2, a COX-derived metabolite, was produced by macrophages during Brucella infection and its production was regulated by COX-2 and IL-10. We suggested that PGI2 and selexipag, a potent PGI2 analogue, inhibited Brucella internalization through IP signaling which led to down-regulation of F-actin polymerization and p38α MAPK activity. Administration with selexipag suppressed immune responses and resulted in a notable reduction in bacterial burden in spleen of Brucella-challenged mice. Taken together, our study is the first to characterize PGI2 synthesis and its effect in evasion strategy of macrophages against Brucella infection.

Silymarin alleviates docetaxel-induced central and peripheral neurotoxicity by reducing oxidative stress, inflammation and apoptosis in rats.

Docetaxel (DTX) is a chemotherapeutic agent used in the treatment of various malignancies but is often associated with central and peripheral neurotoxicity. The aim of this study was to investigate the neuroprotective effect of silymarin (SLM) against DTX-induced central and peripheral neurotoxicities in rats. Rats received 25 and 50mg/kg body weight SLM orally for seven consecutive days after receiving a single injection of 30mg/kg body weight DTX on the first day. SLM significantly decreased brain lipid peroxidation level and ameliorated brain glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in DTX-administered rats. SLM attenuated levels of nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), glial fibrillary acidic protein (GFAP) and activity of p38α mitogen-activated protein kinase (p38α MAPK) whereas caused an increase in levels of neural cell adhesion molecule (NCAM) in the brain and sciatic nerve of DTX-induced rats. In addition, SLM improved the histological structure of the brain and sciatic nerve tissues and decreased the expression of c-Jun N-terminal kinase (JNK) in the sciatic nerve whereas increased cyclic AMP response element binding protein (CREB) expression in the brain induced by DTX. Additionally, SLM markedly up-regulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and B-cell lymphoma-2 (Bcl-2) and downregulated the expression of Bcl-2 associatedXprotein (Bax) in the brain and sciatic nerve tissues of DTX-induced rats. Our results show that SLM can protect DTX-induced brain and sciatic nerve injuries by enhancing the antioxidant defense system and suppressing apoptosis and inflammation.

Targeting of BCR-ABL1 and IRE1α induces synthetic lethality in Philadelphia-positive acute lymphoblastic leukemia.

BCR-ABL1-positive acute lymphoblastic leukemia (ALL) cell survival is dependent on the inositol-requiring enzyme 1 alpha (IRE1α) branch of the unfolded protein response. In the current study, we have focused on exploring the efficacy of a simultaneous pharmacological inhibition of BCR-ABL1 and IRE1α in Philadelphia-positive (Ph+) ALL using tyrosine kinase inhibitor (TKI) nilotinib and the IRE1α inhibitor MKC-8866. The combination of 0.5 µM nilotinib and 30 µM MKC-8866 in Ph+ ALL cell lines led to a synergistic effect on cell viability. To mimic this dual inhibition on a genetic level, pre-B-cells from conditional Xbp1+/fl mice were transduced with a BCR-ABL1 construct and with either tamoxifen-inducible cre or empty vector. Cells showed a significant sensitization to the effect of TKIs after the induction of the heterozygous deletion. Finally, we performed a phosphoproteomic analysis on Ph+ ALL cell lines treated with the combination of nilotinib and MKC-8866 to identify potential targets involved in their synergistic effect. An enhanced activation of p38 mitogen-activated protein kinase α (p38α MAPK) was identified. In line with this findings, p38 MAPK and, another important endoplasmic reticulum-stress-related kinase, c-Jun N-terminal kinase (JNK) were found to mediate the potentiated cytotoxic effect induced by the combination of MKC-8866 and nilotinib since the targeting of p38 MAPK with its specific inhibitor BIRB-796 or JNK with JNK-in-8 hindered the synergistic effect observed upon treatment with nilotinib and MKC-8866. In conclusion, the identified combined action of nilotinib and MKC-8866 might represent a successful therapeutic strategy in high-risk Ph+ ALL.

Morin attenuates acrylamide-induced testicular toxicity in rats by regulating the NF-κB, Bax/Bcl-2 and PI3K/Akt/mTOR signaling pathways

AimAcrylamide (AC) is a carcinogenic substance which is formed during the heating of starchy foods at high temperatures and constitutes an important risk for human health. Therefore, reducing the detrimental effects of AC has become an important research topic. This study was performed to evaluate the protective effect of morin against the testicular toxicity induced by AC in male rats. Materials and methodsTesticular damage was evaluated after the rats were treated orally with AC (38.27 mg/kg body weight) alone or with morin (50 and 100 mg/kg body weight) for 10 consecutive days. Key findingsOur results showed that treatment with morin could significantly decrease MDA level and considerably increase the activity of antioxidant enzymes (SOD, CAT, GPx) and GSH level in the testicular tissue of the AC-treated rats. Morin supplementation also suppressed the activation of inflammatory, apoptotic and autophagic pathways by increasing Bcl-2 and decreasing p38α MAPK, TNF-α, NF-κB, IL-1β, IL-6, COX-2, cytochrome c, Bax, caspase-3, LC3A, LC3B and beclin-1 protein levels. Morin also alleviated the side effects caused by AC by regulating the PI3K/Akt/mTOR signaling pathway. SignificanceCollectively, our results have shown the possible protective mechanism of morin, a potential therapeutic agent for AC-induced testicular toxicity.

Upregulation of miR-133a-3p in the Sciatic Nerve Contributes to Neuropathic Pain Development.

The micro (mi)RNAs expressed in the sciatic nerve of streptozotocin (STZ)-induced diabetic rats were evaluated in terms of their therapeutic potential in patients with diabetic neuropathic pain (DNP). Relative miRNA expression in sciatic nerve with DNP was analyzed using next-generation sequencing and quantitative PCR. Potential downstream targets of miRNAs were predicted using Ingenuity Pathway Analysis and the TargetScan database. In vitro experiments were performed using miR-133a-3p-transfected RSC96 Schwann cells. We performed micro-Western and Western blotting and immunofluorescence analyses to verify the role of miR-133a-3p. In vivo, the association between miR-133a-3p with DNP was analyzed via AAV-miR-133a-3p intraneural (intra-epineural but extrafascicular) injection into the sciatic nerve of normal rats or injection of an miR-133a-3p antagomir into the sciatic nerve of diabetes mellitus (DM) rats. miR-133a-3p mimics transfected into RSC96 Schwann cells increased VEGFR-2, p38α MAPK, TRAF-6, and PIAS3 expression and reduced NFκB p50 and MKP3 expression. In normal rats, AAV-miR-133a-3p delivery via intraneural injection into the sciatic nerve induced mechanical allodynia and p-p38 MAPK activation. In DM rats, miR-133a-3p antagomir administration alleviated DNP and downregulated p-p38 phosphorylation. Overexpression of miR-133a-3p in the sciatic nerve induced such pain. We suggest that miR-133a-3p is a potential therapeutic target for DNP.

Coinhibition of activated p38 MAPKα and mTORC1 potentiates stemness maintenance of HSCs from SR1-expanded human cord blood CD34+ cells via inhibition of senescence.

The stemness of ex vivo expanded hematopoietic stem cells (HSCs) is usually compromised by current methods. To explore the failure mechanism of stemness maintenance of human HSCs, which were expanded from human umbilical cord blood (hUCB) CD34+ cells, by differentiation inhibitor Stem Regenin 1 (SR1), an antagonist of aryl hydrocarbon receptor, we investigated the activity of p38 mitogen‐activated protein kinase α (p38 MAPKα, p38α) and mammalian target of rapamycin complex 1 (mTORC1), and their effect on SR1‐expanded hUCB CD34+ cells. Our results showed that cellular senescence occurred in the SR1‐expanded hUCB CD34+ cells in which p38α and mTORC1 were successively activated. Furthermore, their coinhibition resulted in a further decrease in hUCB CD34+ cell senescence without an effect on apoptosis, promoted the maintenance of expanded phenotypic HSCs without differentiation inhibition, increased the hematopoietic reconstitution ability of multiple lineages, and potentiated the long‐term self‐renewal capability of HSCs from SR1‐expanded hUCB CD34+ cells in NOD/Shi‐scid/IL‐2Rγnull mice. Our mechanistic study revealed that senescence inhibition by our strategy was mainly attributed to downregulation of the splicesome, proteasome formation, and pyrimidine metabolism signaling pathways. These results suggest that coinhibition of activated p38α and mTORC1 potentiates stemness maintenance of HSCs from SR1‐expanded hUCB CD34+ cells via senescence inhibition. Thus, we established a new strategy to maintain the stemness of ex vivo differentiation inhibitor‐expanded human HSCs via coinhibition of multiple independent senescence initiating signal pathways. This senescence inhibition‐induced stemness maintenance of ex vivo expanded HSCs could also have an important role in other HSC expansion systems.