P38 Mitogen-activated Protein Kinase Signaling Research Articles

Role of apigenin in high glucose-induced retinal microvascular endothelial cell dysfunction via regulating NOX4/p38 MAPK pathway in vitro.

To investigate the retinoprotective role of Apigenin (Api) against high glucose (HG)-induced human retinal microvascular endothelial cells (HRMECs), and to explore its regulatory mechanism. HRMECs were stimulated by HG for 48h to establish the in vitro cell model. Different concentrations of Api (2.5, 5, and 10 µmol/L) were applied for treatment. Cell counting kit-8 (CCK-8), Transwell, and tube formation assays were performed to examine the effects of Api on the viability, migration, and angiogenesis in HG-induced HRMECs. Vascular permeability was evaluated by Evans blue dye. The inflammatory cytokines and oxidative stress-related factors were measured using their commercial kits. Protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) and p38 mitogen-activated protein kinase (MAPK) was measured by Western blot. Api prevented HG-induced HRMECs viability, migration, angiogenesis, and vascular permeability in a concentration-dependent manner. Meanwhile, Api also concentration-dependently inhibited inflammation and oxidative stress in HRMECs exposed to HG. In addition, HG caused an elevated expression of NOX4, which was retarded by Api treatment. HG stimulation facilitated the activation of p38 MAPK signaling in HRMECs, and Api could weaken this activation partly via downregulating NOX4 expression. Furthermore, overexpression of NOX4 or activation of p38 MAPK signaling greatly weakened the protective role of Api against HG-stimulated HRMECs. Api might exert a beneficial role in HG-stimulated HRMECs through regulating NOX4/p38 MAPK pathway.

The inhibition of p38 MAPK blocked inflammation to restore the functions of rat meibomian gland epithelial cells

Meibomian glands (MGs) are vital for ocular surface health. However, the roles of inflammation in the progression of meibomian gland dysfunction (MGD) are largely unknown. In this study, the roles of the inflammation factor interleukin-1β (IL-1β) via the p38 mitogen-activated protein kinases (MAPK) signaling pathway on rat meibomian gland epithelial cells (RMGECs) were explored. Eyelids from adult rat mice at 2 months and 2 years of age were stained with specific antibodies against IL-1β to identify inflammation levels. RMGECs were exposed to IL-1β and/or SB203580, a specific inhibitor of p38 MAPK signaling pathway, for 3 days. Cell proliferation, keratinization, lipid accumulation, and matrix metalloproteinases 9 (MMP9) expression were evaluated by MTT assay, polymerase chain reaction (PCR), immunofluorescence staining, apoptosis assay, lipid staining, and Western blot analyses. We found that IL-1β was significantly higher in the terminal ducts of MGs in rats with age-related MGD than in young rats. IL-1β inhibited cell proliferation, suppressed lipid accumulation and peroxisome proliferator activator receptor γ (PPARγ) expression, and promoted apoptosis while activating the p38 MAPK signaling pathway. Cytokeratin 1 (CK1), a marker for complete keratinization, and MMP9 in RMGECs were also up-regulated by IL-1β. SB203580 effectively diminished the effects of IL-1β on differentiation, keratinization, and MMP9 expression by blocking IL-1β-induced p38 MAPK activation, although it also inhibited cell proliferation. The inhibition of the p38 MAPK signaling pathway blocked IL-1β-induced differentiation reduction, hyperkeratinization, and MMP9 overexpression of RMGECs, which provides a potential therapy for MGD.

The ubiquitination status of the glucagon receptor determines signal bias

The pancreatic hormone glucagon activates the glucagon receptor (GCGR), a class B seven-transmembrane G protein-coupled receptor that couples to the stimulatory heterotrimeric G protein and provokes PKA-dependent signaling cascades vital to hepatic glucose metabolism and islet insulin secretion. Glucagon-stimulation also initiates recruitment of the endocytic adaptors, βarrestin1 and βarrestin2, which regulate desensitization and internalization of the GCGR. Unlike many other G protein-coupled receptors, the GCGR expressed at the plasma membrane is constitutively ubiquitinated and upon agonist-activation, internalized GCGRs are deubiquitinated at early endosomes and recycled via Rab4-containing vesicles. Herein we report a novel link between the ubiquitination status and signal transduction mechanism of the GCGR. In the deubiquitinated state, coupling of the GCGR to Gs is diminished, while binding to βarrestin is enhanced with signaling biased to a βarrestin1-dependent p38 mitogen activated protein kinase (MAPK) pathway. This ubiquitin-dependent signaling bias arises through the modification of lysine333 (K333) on the cytoplasmic face of transmembrane helix V. Compared with the GCGR-WT, the mutant GCGR-K333R has impaired ubiquitination, diminished G protein coupling, and PKA signaling but unimpaired potentiation of glucose-stimulated-insulin secretion in response to agonist-stimulation, which involves p38 MAPK signaling. Both WT and GCGR-K333R promote the formation of glucagon-induced βarrestin1-dependent p38 signaling scaffold that requires canonical upstream MAPK-Kinase3, but is independent of Gs, Gi, and βarrestin2. Thus, ubiquitination/deubiquitination at K333 in the GCGR defines the activation of distinct transducers with the potential to influence various facets of glucagon signaling in health and disease.

Osteomodulin contributes to keloid development by regulating p38 MAPK signaling.

A keloid is a classic fibrotic skin disease characterized by excessive deposition of extracellular matrix (ECM). Osteomodulin (OMD) is a heterologous protein that is a part of osteoadherin and plays a role in modulating ECM deposition. In this study, we investigated the effects of OMD on ECM synthesis and the tumor-like phenotype of keloid fibroblasts. We enrolled 10 patients with keloids and 10 age- and sex-matched healthy individuals, whose keloid or normal skin tissues were collected during surgery. Real-time quantitative polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemical staining were performed to analyze OMD expression in skin tissues. Cell transfection, CCK-8 assay, EdU staining, Transwell assay, qRT-PCR, western blotting, and immunofluorescence were performed to study the effects of OMD on primary keloid-derived fibroblasts (KFs). OMD exhibited greater expression in human keloid specimens than in normal skin tissues. Consistently, higher expression of OMD was observed in KFs, compared to that in normal fibroblasts. Silencing OMD expression in transforming growth factor (TGF)-β1-treated KFs inhibited cell proliferation and migration, as well as collagen and fibronectin expression; however, overexpression of OMD had the opposite effect. p38 mitogen-activated protein kinase (MAPK) was activated in keloid tissues but not in normal skin. OMD was positively correlated with p38 MAPK activation. Adding SB203580, p38 MAPK inhibitor, significantly reversed the effects of OMD on the regulation of KF phenotype. The high expression of OMD may contribute to hyperproliferation of KFs, their migration, and excess ECM synthesis in KFs via regulation of the p38 MAPK signaling pathway.

Involvement of matrix metalloproteinase 1 and urokinase-type plasminogen activator in the PKCα-p38 MAPK pathway-mediated progression of human liver cancer cells.

Our previous studies have shown that the plasminogen activator (PA) and matrix metalloproteinases (MMPs) proteinase systems were highly expressed in highly malignant liver cancer cells and regulated by PKCα. This study investigates whether the PKCα regulation of PA and MMPs systems is conducted through p38 mitogen-activated protein kinase (MAPK) signaling and the pathway is responsible for promoting cell progression. We found that the expressions of p38 MAPK in both highly malignant HA22T/VGH and SK-Hep-1 liver cancer cells were higher than that in other lower malignancy liver cancer cells. Since PKCα activates p38 MAPK in progression of liver cancer, we suspected the PKCα/p38 MAPK signaling pathway to be involved in the regulation of MMPs and PA systems. When SK-Hep-1 cells were treated with SB203580 or DN-p38, only MMP-1 and u-PA mRNA expressions decreased. The p38 MAPK inhibition also decreased the cell migration and invasion. In addition, the mRNA decay assays showed that the higher expressions of MMP-1 and u-PA mRNA in SK-Hep-1 cells were due to the alteration of mRNA stability by p38 MAPK inhibition. Zymography of SK-Hep-1 cells treated with siPKCα vector also showed the decrease of the activity of MMP-1 and u-PA and confirmed changes in mRNA level. Furthermore, only the transfection of MKK6 to the siPKCα-treated SK-Hep-1 stable clone cell restored the attenuation of MMP-1 and u-PA expressions. The treatment of SK-Hep-1 cells with either inhibitor of MMP-1 or u-PA reduced migration, and the reduction was enhanced with both inhibitors. In addition, tumorigenesis was also reduced with both inhibitors. These data suggest a novel finding that MMP-1 and u-PA are critical components in PKCα/MKK6/p38 MAPK signaling pathway which mediates liver cancer cell progression, and that the targeting of both genes may be a viable approach in liver cancer treatment.

SPRED2 promotes autophagy and attenuates inflammatory response in IL-1β induced osteoarthritis chondrocytes via regulating the p38 MAPK signaling pathway

Osteoarthritis (OA) is an age-related degenerative disease primarily characterized by articular cartilage degeneration. Many inflammatory mediators are upregulated in OA patients. Mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways play a role in the regulation of inflammatory response. Autophagy appears to exhibit a protective mechanism, and alleviate the symptoms of OA in rats. Dysregulation of SPRED2 is associated with various diseases involving inflammatory response. However, the role of SPRED2 in OA development remains to be investigated. The present work demonstrated that SPRED2 promoted autophagy and attenuated inflammatory response in IL-1β induced osteoarthritis chondrocytes via regulating the p38 MAPK signaling pathway. SPRED2 was downregulated in human knee cartilage tissues of OA patients and in IL-1β-induced chondrocytes. SPRED2 enhanced chondrocyte proliferation and prevented cell apoptosis induced by IL-1β. SPRED2 prevented IL-1β-induced chondrocytes autophagy and inflammatory response in chondrocytes. SPRED2 inhibited the activation of p38 MAPK signaling pathway and ameliorated OA injury of cartilage. Thus, SPRED2 promoted autophagy and inhibited inflammatory response by regulation of p38 MAPK signaling pathway in vivo.

A review of cytokine-based pathophysiology of Long COVID symptoms.

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production. In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release. Chronic low-grade inflammation leads to dysregulated brain microglia with an exaggerated release of central cytokines, producing neuroinflammation. Immunothrombosis linked to chronic inflammation with microclot formation leads to decreased tissue perfusion and ischemia. Intermittent fatigue, Post Exertional Malaise (PEM), CNS symptoms with "brain fog," arthralgias, paresthesias, dysautonomia, and GI and ophthalmic problems can consequently arise as result of the elevated peripheral and central cytokines. There are abundant similarities between symptoms in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). DNA polymorphisms and viral-induced epigenetic changes to cytokine gene expression may lead to chronic inflammation in Long COVID patients, predisposing some to develop autoimmunity, which may be the gateway to ME/CFS.

Regorafenib induces NOX5-mediated endoplasmic reticulum stress and potentiates the anti-tumor activity of cisplatin in non-small cell lung cancer cells

Lung cancer is one of the most commonly diagnosed cancers worldwide. Although cisplatin-based chemotherapy regimens serve a pivotal role in non-small cell lung cancer (NSCLC) treatment, drug resistance and serious side effects limited its further clinical application. Regorafenib, a small-molecule multi-kinase inhibitor, was demonstrated to have promising anti-tumor activity in various solid tumors. In the present study, we found that regorafenib markedly enhanced cisplatin-induced cytotoxicity in lung cancer cells by activating reactive oxygen species (ROS)-mediated endoplasmic reticulum stress (ER Stress), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways. Regorafenib increased ROS generation by promoting NADPH oxidase 5 (NOX5) expression, and knocking down NOX5 attenuated ROS-mediated cytotoxicity of regorafenib in lung cancer cells. Additionally, mice xenograft model validated that synergistic anti-tumor effects of combined treatment with regorafenib and cisplatin. Our results suggested that combination therapy with regorafenib and cisplatin may serve as a potential therapeutic strategy for some NSCLC patients.

White-spotted flower chafer (Protaetia brevitarsis) ameliorates inflammatory responses in LPS-stimulated RAW 264.7 macrophages

White-spotted flower chafer (Protaetia brevitarsis) is an edible insect andP. brevitarsis larvae are used in traditional Oriental medicine. However, the molecular mechanisms behind the anti-inflammatory action ofP. brevitarsis larvae are unknown. We investigated the effects ofP. brevitarsis larvae ethanol extract (PBLE) on the inflammatory response as well as the molecular mechanisms underpinning this effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. PBLE effectively inhibited the synthesis of nitric oxide (NO) through inducible NO synthase (iNOS) and cyclooxygenase 2 protein expression and 20 μM PBLE suppressed the expression of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-8, at a dose of. Further investigation of the mechanisms revealed that PBLE attenuated phosphorylation of nuclear factor kappa B (NF-κB) inhibitor alpha (IκB-α) and NF-κB p65 and interfered selectively with extracellular signal-regulated kinase (ERK)1/2 and p38 phosphorylation. These findings provide the first molecular basis that PBLE could be a potential candidate for attenuating proinflammatory NO induction via selective inhibition of the NF-κB, ERK, and p38 mitogen-activated protein kinase signalling pathways. It is necessary to verify the anti-inflammatory action of PBLE and to ascertain the related mechanisms, both inin vivo models and in clinical studies, to enable the application of PBLE as a potential therapeutic agent for inflammatory diseases.

Cardamonin as a p38 MAPK Signaling Pathway Activator Inhibits Human Coronavirus OC43 Infection in Human Lung Cells.

A natural chalcone, cardamonin (2',4'-dihydroxy-6'-methoxychalcone; CDN) was isolated from the seeds of Alpinia katsumadai Hayata, which has been traditionally used to treat stomach aches. CDN has been reported to possess various pharmacological properties, including anticancer and anti-inflammatory effects. This study evaluated the antiviral activity of CDN against human coronavirus HCoV-OC43 and determined the mode of action in HCoV-OC43-infected human lung cell lines (MRC-5 and A549 cells). CDN significantly inhibited HCoV-OC43-induced cytopathic effects with an IC50 of 3.62 μM and a CC50 of >50 μM, resulting in a selectivity index of >13.81. CDN treatment reduced the level of viral RNA and the expression of spike and nucleocapsid proteins in HCoV-OC43-infected cells as determine through qRT-PCR and Western blot analysis. Additionally, the activation of p38 mitogen-activated protein kinase (MAPK) by anisomycin decreased viral protein expression, whereas an inhibitor of p38 MAPK signaling, SB202190, increased viral protein expression. CDN also amplified and extended the p38 MAPK signaling pathway in HCoV-OC43-infected cells. In conclusion, CDN inhibited HCoV-OC43 infection by activating the p38 MAPK signaling pathway and has potential as a therapeutic agent against human coronavirus.

Roles of p38 MAPK signalling in intervertebral disc degeneration.

Intervertebral disc degeneration (IVDD) is a common degenerative disease mediated by multiple factors. Because of its complex aetiology and pathology, no specific molecular mechanisms have yet been identified and no definitive treatments are currently available for IVDD. p38 mitogen-activated protein kinase (MAPK) signalling, part of the serine and threonine (Ser/Thr) protein kinases family, is associated with the progression of IVDD, by mediating the inflammatory response, increasing extracellular matrix (ECM) degradation, promoting cell apoptosis and senescence and suppressing cell proliferation and autophagy. Meanwhile, the inhibition of p38 MAPK signalling has a significant effect on IVDD treatment. In this review, we first summarize the regulation of p38 MAPK signalling and then highlight the changes in the expression of p38 MAPK signalling and their impact on pathological process of IVDD. Moreover, we discuss the current applications and future prospects of p38 MAPK as a therapeutic target for IVDD treatment.

P38 Mitogen-Activated Protein Kinase Signaling Enhances Reovirus Replication by Facilitating Efficient Virus Entry, Capsid Uncoating, and Postuncoating Steps.

Mammalian orthoreovirus serotype 3 Dearing is an oncolytic virus currently undergoing multiple clinical trials as a potential cancer therapy. Previous clinical trials have emphasized the importance of prescreening patients for prognostic markers to improve therapeutic success. However, only generic cancer markers such as epidermal growth factor receptor (EGFR), Hras, Kras, Nras, Braf, and p53 are currently utilized, with limited benefit in predicting therapeutic efficacy. This study aimed to investigate the role of p38 mitogen-activated protein kinase (MAPK) signaling during reovirus infection. Using a panel of specific p38 MAPK inhibitors and an inactive inhibitor analogue, p38 MAPK signaling was found to be essential for establishment of reovirus infection by enhancing reovirus endocytosis, facilitating efficient reovirus uncoating at the endo-lysosomal stage, and augmenting postuncoating replication steps. Using a broad panel of human breast cancer cell lines, susceptibility to reovirus infection corresponded with virus binding and uncoating efficiency, which strongly correlated with status of the p38β isoform. Together, results suggest p38β isoform as a potential prognostic marker for early stages of reovirus infection that are crucial to successful reovirus infection. IMPORTANCE The use of Pelareorep (mammalian orthoreovirus) as a therapy for metastatic breast cancer has shown promising results in recent clinical trials. However, the selection of prognostic markers to stratify patients has had limited success due to the fact that these markers are upstream receptors and signaling pathways that are present in a high percentage of cancers. This study demonstrates that the mechanism of action of p38 MAPK signaling plays a key role in establishment of reovirus infection at both early entry and late replication steps. Using a panel of breast cancer cell lines, we found that the expression levels of the MAPK11 (p38β) isoform are a strong determinant of reovirus uncoating and infection establishment. Our findings suggest that selecting prognostic markers that target key steps in reovirus replication may improve patient stratification during oncolytic reovirus therapy.

ZFP36L1 Promotes Gastric Cancer Progression via Regulating JNK and p38 MAPK Signaling Pathways.

The RNA-binding protein Zinc Finger Protein 36 like 1(ZFP36L1) plays an important role in regulating the AU-rich elements (AREs) in the 3' untranslated region (3' UTR) of mRNAs, indicating a potential link between its expression and cancers. However, the role and mechanism of ZFP36L1 in gastric cancer (GC) are unclear. This study aimed to explore the role and mechanism of ZFP36L1 in gastric cancer. GC tissue samples and matched normal gastric tissues were collected, and the ZFP36L1 expression in these samples was evaluated by immunohistochemistry analysis. GC cells with different differentiation were selected for in vitro experiments. The ZFP36L1 expression in GC cells was examined by quantitative real-time polymerase chain reaction (qRTPCR) and Western blot analysis. The viability and invasiveness of GC cells were assayed by 5- Ethynyl-2-deoxyuridine (EdU) and Transwell assays, respectively. Western blot assay was used to detect the expression of epithelial-to-mesenchymal transition (EMT) related proteins and proteins of the c-Jun N-terminal kinase (JNK) and p38 Mitogen-Activated Protein Kinase (MAPK) signaling pathways. ZFP36L1 is overexpressed in GC tissues. Patients with high ZFP36L1 expression have a poor prognosis. Moreover, ZFP36L1 is overexpressed in the cell lines with a high degree of malignancy. ZFP36L1 increases cell proliferation, invasion, and migration in vitro. Furthermore, ZFP36L1 induces EMT. The JNK inhibitor and p38 inhibitor alone or in combination affect the biological function of GC cells. Furthermore, ZFP36L1 promotes GC progression by inhibiting JNK and p38 MAPK signaling pathways. RNA-binding protein ZFP36L1 exerts a role in the occurrence of gastric cancer by the regulation of the JNK and p38 MAPK signaling pathways. The combination of inhibitors of the JNK and p38 MAPK signaling pathways could be a novel treatment strategy for gastric cancer.

Effect of p38 inhibitor on the proliferation of chicken muscle stem cells and differentiation into muscle and fat

Inhibiting the p38 mitogen-activated protein kinase (MAPK) signaling pathway delays differentiation and increases proliferation of muscle stem cells in most species. Here, we aimed to investigate the effect of p38 inhibitor (p38i) treatment on the proliferation and differentiation of chicken muscle stem cells. Chicken muscle stem cells were collected from the muscle tissues of Hy-line Brown chicken embryos at embryonic day 18, then isolated by the preplating method. Cells were cultured for 4 days in growth medium supplemented with dimethyl sulfoxide or 1, 10, 20 μM of p38i, then subcultured for up to 4 passages. Differentiation was induced for 3 days with differentiation medium. Each treatment was replicated 3 times. The proliferation and mRNA expression of paired box 7 gene and myogenic factor 5 gene, as well as the mRNA expression of myogenic differentiation marker gene myogenin were significantly higher in p38i-treated cultures than in control (p<0.05), but immunofluorescence staining and mRNA expression of myosin heavy chain (MHC) were not significantly different between the two groups. Oil red O staining of accumulated lipid droplets in differentiated cell cultures revealed a higher lipid density in p38i-treated cultures than in control; however, the expression of the adipogenic marker gene peroxisome proliferator activated receptor gamma was not significantly different between the two groups. p38 inhibition in chicken muscle stem cells improves cell proliferation, but the effects on myogenic differentiation and lipid accumulation require additional analysis. Further studies are needed on the chicken p38-MAPK pathway to understand the muscle and fat development mechanism.

Protective effect of urotensin II receptor antagonist urantide and exercise training on doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) has a wide antitumor spectrum, but its adverse cardiotoxicity may lead to heart failure. Urotensin II (UII) is the most potent vasoconstrictor in mammals. It plays a role by activating the UII receptor (UT), the orphan G protein-coupled receptor (GPR14), collectively referred to as the UII/UT system. In the new version of "Chinese expert consensus on cardiac rehabilitation of chronic heart failure," it is pointed out that exercise rehabilitation is the cornerstone of cardiac rehabilitation. In this study, in vitro and in vivo assessments were performed using DOX-treated H9C2 cells and rats. It was found that the UT antagonist Urantide and exercise training improved DOX-induced cardiac insufficiency, reduced DOX-induced cardiomyocyte apoptosis, improved the structural disorder of myocardial fibers, and inhibited DOX-induced myocardial fibrosis. Further studies showed that Urantide alleviated DOX-induced cardiotoxicity by downregulating the expression levels of the p38 mitogen-activated protein kinase signaling pathway.

Von Willebrand factor: from figurant to main character in the scene of inflammation

von Willebrand factor: from figurant to main character in the scene of inflammation

Advances in research on the relationship between thymoquinone and pancreatic cancer.

Pancreatic cancer has one of the worst prognoses among the most common cancers in the world. Its characteristics include a high rate of metastasis and chemotherapeutic resistance, which present major challenges to the medical community. The potential anticancer effects of thymoquinone (TQ), which is the main bioactive compound of the black seeds of the Nigella sativa plant, have recently received widespread attention for their potential use in treating pancreatic cancer. TQ can inhibit cell proliferation, promote cancer cell apoptosis, inhibit cell invasion and metastasis, enhance chemotherapeutic sensitivity, inhibit angiogenesis, and exert anti-inflammatory effects. These anticancer effects predominantly involve the nuclear factor (NF)-κB, phosphoinositide 3 kinase (PI3K)/Akt, Notch, transforming growth factor (TGF)-β, c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) signaling pathways as well as the regulation of the cell cycle, matrix metallopeptidase (MMP)-9 expression, and pyruvate kinase isozyme type M2 (PKM2) activity. TQ regulates the occurrence and development of pancreatic cancer at multiple levels and through multiple targets that communicate with each other. In this review, we summarize and discuss the analogs and carriers of TQ that have been developed in recent years. Given its multilevel anticancer effects, TQ may become a new therapeutic drug for treating pancreatic cancer in the future. This review presents a brief introduction to the research that has been conducted on TQ in relation to pancreatic cancer to provide a theoretical basis for future studies on the topic.

Cationic phosphorus dendron nanomicelles deliver microRNA mimics and microRNA inhibitors for enhanced anti-inflammatory therapy of acute lung injury.

The development of efficient nanomedicines to repress the repolarization of M1 phenotype macrophages and therefore inhibit pro-inflammatory cytokine overexpression for anti-inflammatory therapy is still a challenging task. We report here an original gene delivery nanoplatform based on pyrrolidinium-modified amphiphilic generation 1 phosphorus dendron (C12G1) nanomicelles with a rigid phosphorous dendron structure. The nanomicelles display higher gene delivery efficiency than the counterpart materials of pyrrolidinium-modified G1 phosphorus dendrimers, and meanwhile exhibit excellent cytocompatibility. The C12G1 nanomicelles can be employed to co-deliver the miRNA-146a mimic (miR-146a mimic) and miRNA-429 inhibitor (miR-429i) to inhibit the Toll-like receptor-4 signaling pathway and p38 mitogen-activated protein kinase signaling pathway, respectively, thus causing repression of M1 phenotype alveolar macrophage polarization. The developed C12G1/miR-mixture polyplexes enable efficient therapy of lipopolysaccharide-activated alveolar macrophages in vitro and an acute lung injury mouse model in vivo. The generated cationic phosphorus dendron nanomicelles may hold promising potential for anti-inflammatory gene therapy of other inflammatory diseases.

IFI6 Downregulation Reverses Oxaliplatin Resistance of Colorectal Cancer Cells by Activating the ROS-Induced p38MAPK Signaling Pathway

Oxaliplatin (OXA) is a usual chemotherapeutic agent applied in the colorectal cancer (CRC) clinical treatment. Interferon-alpha inducible protein 6 (IFI6) has been proved to promote proliferation and suppress apoptosis in several tumor cells, while the impacts of IFI6 on OXA resistance in CRC still need exploration. HCT116 and SW620 cells were used as the parental to obtain OXA-resistant cells. The influence of IFI6 on OXA sensitivity, cell proliferation and apoptosis were evaluated by overexpression or knockdown IFI6 in cells. In this work, we found that the level of IFI6 was significantly enhanced in HCT116/OXA and SW620/OXA cells as compared to the parental cells. Overexpression of IFI6 decreased the sensitivity of HCT116 and SW620 cells to OXA. However, knockdown of IFI6 enhanced the sensitivity of HCT116/OXA and SW620/OXA cells to OXA. And upregulated IFI6 promoted the proliferation and repressed apoptosis in HCT116 cells, while suppressed IFI6 markedly reduced proliferation and increased apoptosis in HCT116/OXA cells. Additionally, IFI6 suppressed the phosphorylation level of p38, and silenced IFI6 enhanced it. The addition of the p38 kinase inhibitor, SB203580, alleviated the decreased cell proliferation and increased apoptosis in HCT116/OXA cells. Suppressed IFI6 enhanced the reactive oxygen species (ROS) level in HCT116/OXA cells, and blockade of ROS with N-acetyl-L-cysteine (NAC) decreased the enhancement level of ROS and the phosphorylation level of the p38, which was induced by IFI6 down-regulation. We, therefore, implied that suppressed IFI6 reverses OXA-resistance of CRC cells via promoting the ROS-induced p38 mitogen-activated protein kinase (MAPK) signaling pathway.

Peptide RL-QN15 promotes wound healing of diabetic foot ulcers through p38 mitogen-activated protein kinase and smad3/miR-4482-3p/vascular endothelial growth factor B axis.

Wound management of diabetic foot ulcers (DFUs) is a complex and challenging task, and existing strategies fail to meet clinical needs. Therefore, it is important to develop novel drug candidates and discover new therapeutic targets. However, reports on peptides as molecular probes for resolving issues related to DFUs remain rare. This study utilized peptide RL-QN15 as an exogenous molecular probe to investigate the underlying mechanism of endogenous non-coding RNA in DFU wound healing. The aim was to generate novel insights for the clinical management of DFUs and identify potential drug targets. We investigated the wound-healing efficiency of peptide RL-QN15 under diabetic conditions using in vitro and in vivo experimental models. RNA sequencing, in vitro transfection, quantitative real-time polymerase chain reaction, western blotting, dual luciferase reporter gene detection, in vitro cell scratches, and cell proliferation and migration assays were performed to explore the potential mechanism underlying the promoting effects of RL-QN15 on DFU repair. Peptide RL-QN15 enhanced the migration and proliferation of human immortalized keratinocytes (HaCaT cells) in a high-glucose environment and accelerated wound healing in a DFU rat model. Based on results from RNA sequencing, we defined a new microRNA (miR-4482-3p) related to the promotion of wound healing. The bioactivity of miR-4482-3p was verified by inhibiting and overexpressing miR-4482-3p. Inhibition of miR-4482-3p enhanced the migration and proliferation ability of HaCaT cells as well as the expression of vascular endothelial growth factor B (VEGFB). RL-QN15 also promoted the migration and proliferation ability of HaCaT cells, and VEGFB expression was mediated via inhibition of miR-4482-3p expression by the p38 mitogen-activated protein kinase (p38MAPK) and smad3 signaling pathways. RL-QN15 is an effective molecule for the treatment of DFUs, with the underlying mechanism related to the inhibition of miR-4482-3p expression via the p38MAPK and smad3 signaling pathways, ultimately promoting re-epithelialization, angiogenesis and wound healing. This study provides a theoretical basis for the clinical application of RL-QN15 as a molecular probe in promoting DFU wound healing.