The Mitogen-Activated Protein Kinase (MAPK) Pathway: Role in Immune Evasion by Trypanosomatids

Ceramide synthase 6 impacts T-cell allogeneic response and graft-versus-host disease through regulating N-RAS/ERK pathway

Allogeneic hematopoietic cell transplantation (allo-HCT) is an effective immunotherapy for various hematologic malignances, predominantly through potent graft-versus-leukemia (GVL) effect. However, the mortality after allo-HCT is because of relapse of primary malignancy and followed by graft-vs-host-disease (GVHD) as a major cause of transplant-related mortality. Hence, strategies to limit GVHD while preserving the GVL effect are highly desirable. Ceramide, which serves a central role in sphingolipid metabolism, is generated by ceramide synthases (CerS1–6). In this study, we found that genetic or pharmacologic targeting of CerS6 prevented and reversed chronic GVHD (cGVHD). Furthermore, specific inhibition of CerS6 with ST1072 significantly ameliorated acute GVHD (aGVHD) while preserving the GVL effect, which differed from FTY720 that attenuated aGVHD but impaired GVL activity. At the cellular level, blockade of CerS6 restrained donor T cells from migrating into GVHD target organs and preferentially reduced activation of donor CD4 T cells. At the molecular level, CerS6 was required for optimal TCR signaling, CD3/PKCθ co-localization, and subsequent N-RAS activation and ERK signaling, especially on CD4⁺ T cells. The current study provides rationale and means for targeting CerS6 to control GVHD and leukemia relapse, which would enhance the efficacy of allo-HCT as an immunotherapy for hematologic malignancies in the clinic.

Can Neuropeptide S Be an Indicator for Assessing Anxiety in Psychiatric Disorders?

Neuropeptide S (NPS) is a neuropeptide primarily produced within three brainstem regions including locus coeruleus, trigeminal nerve nucleus, and lateral parabrachial nucleus. NPS is involved in the central regulation of stress, fear, and cognitive integration. NPS is a mediator of behavior, seeking food, and the proliferation of new adipocytes in the setting of obesity. So far, current research of NPS is only limited to animal models; data regarding its functions in humans is still scarce. Animal studies showed that anxiety and appetite might be suppressed by the action of NPS. The discovery of this neuromodulator peptide is effective considering its strong anxiolytic action, which has the potential to be an interesting therapeutic option in treating neuropsychiatric disorders. In this article, we aimed to analyze the pharmaceutical properties of NPS as well as its influence on several neurophysiological aspects-modulation of behavior, association with obesity, as well as its potential application in rehabilitation and treatment of psychiatric disorders.

The Molecular Mechanism of Hepatic Lipid Metabolism Disorder Caused by NaAsO2 through Regulating the ERK/PPAR Signaling Pathway

Chronic arsenic exposure is a risk factor for human fatty liver disease, and the ERK signaling pathway plays an important role in the regulation of liver lipid metabolism. However, whether ERK plays a role in the progression of arsenic-induced liver lipid metabolism disorder and the specific mechanism remain unclear. Here, by constructing a rat model of liver lipid metabolism disorder induced by chronic arsenic exposure, we demonstrated that ERK might regulate arsenic-induced liver lipid metabolism disorders through the PPAR signaling pathway. Arsenic could upregulate the expression of PPARγ and CD36 in the rat liver, decrease the expression of PPARα and CPT-1 in the rat liver, increase the organ coefficient of the rat liver, decrease the content of TG in rat serum, and promote fat deposition in the rat liver. In the arsenic-induced rat model of hepatic lipid metabolism disorder, we found that the expression of p-ERK was increased. In order to further explore whether the ERK signaling pathway was involved in arsenic-induced liver lipid metabolism disorder, we exposed L-02 cells to different arsenic concentrations, and the results showed that arsenic significantly increased the expression of P-ERK in L-02 cells in a dose-dependent manner. We further treated L-02 cells with ERK inhibitors and found that the expression of TG, PPARα, and CPT-1 in L-02 cells increased, while the expression of P-ERK, PPARγ, and CD36 decreased. In conclusion, ERK may be involved in arsenic-induced liver lipid metabolism disorder by regulating the PPAR signaling pathway. These findings are expected to provide a new targeting strategy for arsenic-induced liver lipid metabolism disorder.

The Complex Biology of the Obesity-Induced, Metastasis-Promoting Tumor Microenvironment in Breast Cancer

Breast cancer is one of the most prevalent cancers in women contributing to cancer-related death in the advanced world. Apart from the menopausal status, the trigger for developing breast cancer may vary widely from race to lifestyle factors. Epidemiological studies refer to obesity-associated metabolic changes as a critical risk factor behind the progression of breast cancer. The plethora of signals arising due to obesity-induced changes in adipocytes present in breast tumor microenvironment, significantly affect the behavior of adjacent breast cells. Adipocytes from white adipose tissue are currently recognized as an active endocrine organ secreting different bioactive compounds. However, due to excess energy intake and increased fat accumulation, there are morphological followed by secretory changes in adipocytes, which make the breast microenvironment proinflammatory. This proinflammatory milieu not only increases the risk of breast cancer development through hormone conversion, but it also plays a role in breast cancer progression through the activation of effector proteins responsible for the biological phenomenon of metastasis. The aim of this review is to present a comprehensive picture of the complex biology of obesity-induced changes in white adipocytes and demonstrate the relationship between obesity and breast cancer progression to metastasis.

Bioprospecting of microalgae metabolites against cytokine storm syndrome during COVID-19

In viral respiratory infections, disrupted pathophysiological outcomes have been attributed to hyper-activated and unresolved inflammation responses of the immune system. Integration between available drugs and natural therapeutics have reported benefits in relieving inflammation-related physiological outcomes and microalgae may be a feasible source from which to draw from against future coronavirus-infections. Microalgae represent a large and diverse source of chemically functional compounds such as carotenoids and lipids that possess various bioactivities, including anti-inflammatory properties. Therefore in this paper, some implicated pathways causing inflammation in viral respiratory infections are discussed and juxtaposed along with available research done on several microalgal metabolites. Additionally, the therapeutic properties of some known anti-inflammatory, antioxidant and immunomodulating compounds sourced from microalgae are reported for added clarity.

Transcriptomic Profile of Canine DH82 Macrophages Infected by Leishmania infantum Promastigotes with Different Virulence Behavior

Zoonotic visceral leishmaniosis caused by Leishmania infantum is an endemic disease in the Mediterranean Basin affecting mainly humans and dogs, the main reservoir. The leishmaniosis outbreak declared in the Community of Madrid (Spain) led to a significant increase in human disease incidence without enhancing canine leishmaniosis prevalence, suggesting a better adaptation of the outbreak's isolates by other host species. One of the isolates obtained in the focus, IPER/ES/2012/BOS1FL1 (BOS1FL1), has previously demonstrated a different phenotype than the reference strain MCAN/ES/1996/BCN150 (BCN150), characterized by a lower infectivity when interacting with canine macrophages. Nevertheless, not enough changes in the cell defensive response were found to support their different behavior. Thus, we decided to investigate the molecular mechanisms involved in the interaction of both parasites with DH82 canine macrophages by studying their transcriptomic profiles developed after infection using RNA sequencing. The results showed a common regulation induced by both parasites in the phosphoinositide-3-kinase-protein kinase B/Akt and NOD-like receptor signaling pathways. However, other pathways, such as phagocytosis and signal transduction, including tumor necrosis factor, mitogen-activated kinases and nuclear factor-κB, were only regulated after infection with BOS1FL1. These differences could contribute to the reduced infection ability of the outbreak isolates in canine cells. Our results open a new avenue to investigate the true role of adaptation of L. infantum isolates in their interaction with their different hosts.

Temporary Shutdown of ERK1/2 Phosphorylation Is Associated With Activation of Adaptive Immune Cell Responses and Disease Progression During Leishmania amazonensis Infection in BALB/c Mice

Leishmania spp. infection outcomes are dependent on both host and parasite factors. Manipulation of host signaling pathways involved in the generation of immune responses is thought to be one of the most common mechanisms used by parasites for persistence within the host. Considering the diversity of pathologies caused by different Leishmania spp., it is plausible that significant differences may exist in the mechanisms of host cell manipulation by each parasite species, which may have implications when developing new vaccine or treatment strategies. Here we show that in L. braziliensis-infection in BALB/c mice, a model of resistance, activation of ERK1/2 coincides with the peak of inflammatory responses and resolution of tissue parasitism. In contrast, in the susceptibility model of L. amazonensis-infection, an early silent phase of infection is observed, detected solely by quantification of parasite loads. At this early stage, only basal levels of P-ERK1/2 are observed. Later, after a brief shutdown of ERK1/2 phosphorylation, disease progression is observed and is associated with increased inflammation, lesion size and tissue parasitism. Moreover, the short-term down-regulation of ERK1/2 activation affected significantly downstream inflammatory pathways and adaptive T cell responses. Administration of U0126, a MEK/ERK inhibitor, confirmed this phenomenon, since bigger lesions and higher parasite loads were seen in infected mice that received U0126. To investigate how kinetics of ERK1/2 activation could affect the disease progression, U0126 was administered to L. amazonensis-infected animals earlier than the P-ERK1/2 switch off time-point. This intervention resulted in anticipation of the same effects on inflammatory responses and susceptibility phenotype seen in the natural course of infection. Additionally, in vitro inhibition of ERK1/2 affected the phagocytosis of L. amazonensis by BMDMs. Collectively, our findings reveal distinct temporal patterns of activation of inflammatory responses in L. braziliensis and L. amazonensis in the same animal background and a pivotal role for a brief and specific shutdown of ERK1/2 activation at late stages of L. amazonensis infection. Since activation of inflammatory responses is a crucial aspect for the control of infectious processes, these findings may be important for the search of new and specific strategies of vaccines and treatment for tegumentary leishmaniasis.

Glytabastan B, a coumestan isolated from Glycine tabacina, alleviated synovial inflammation, osteoclastogenesis and collagen-induced arthritis through inhibiting MAPK and PI3K/AKT pathways

The roots of Glycine tabacina are used to treat rheumatoid arthritis (RA) and joint infection in folk medicine. Glytabastan B (GlyB), a newly reported coumestan isolated from this species, was found to significantly attenuate IL-1β-induced inflammation in SW982 human synovial cells at 3 and 6 μM, as evidenced by the decreased levels of pro-inflammatory mediators and matrix metalloproteinases (MMPs). GlyB also suppressed RANKL-induced osteoclastogenesis, decreased the expression of osteoclastogenic markers (NFATc1, CTSK, MMP-9) and osteoclast-mediated bone resorption. Further, GlyB administration (12.5 and 25 mg/kg) significantly inhibited inflammation, osteoclast formation and disease progression in collagen-induced arthritis (CIA) mice. Integration of network pharmacology, quantitative phosphoproteomic and experimental pharmacology results revealed that these beneficial actions were closely associated with the blockade of GlyB on the activation of MAPK, PI3K/AKT and their downstream signals including NF-κB and GSK3β/NFATc1. Drug affinity responsive target stability (DARTS) assay, cellular thermal shift (CETSA) assay and molecular docking analysis confirmed that there were direct interactions between GlyB and its target proteins ERK2, JNK1 and class Ⅰ PI3K catalytic subunit p110 (α, β, δ and γ), which significantly contributed to the inhibition of activation of MAPK and PI3K/AKT pathways. In conclusion, these results strongly suggest GlyB is a promising multiple-target candidate for the development of agents for the prevention and treatment of RA.

Roles of Therapeutic Bioactive Compounds in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is due to poor prognosis and lack of availability of effective treatment. Novel therapeutic strategies will be the fine tuning of intracellular ROS signaling to effectively deprive cells of ROS-induced tumor-promoting events. This review discusses the generation of ROS, the major signaling their modulation in therapeutics. We explore some of the major pathways involved in HCC, which include the VEGF, MAPK/ERK, mTOR, FGF, and Ser/Thr kinase pathways. In this review, we study cornerstone on natural bioactive compounds with their effect on hepatocarcinomas. Furthermore, we focus on oxidative stress and FDA-approved signaling pathway inhibitors, along with chemotherapy and radiotherapy enhancers which with early evidence of success. While more in vivo testing is required to confirm the findings presented here, our findings will aid future nonclinical, preclinical, and clinical studies with these compounds, as well as inspire medicinal chemistry scientists to conduct appropriate research on this promising natural compound and their derivatives.

Associations of Polymorphisms Localized in the 3'UTR Regions of the KRAS, NRAS, MAPK1 Genes with Laryngeal Squamous Cell Carcinoma

Background: Genetic variations, localized in the 3′ untranslated region (UTR) in mitogen-activated protein kinase (MAPK) pathway-related genes, may alter the transcription and impact the pathogenesis of laryngeal squamous cell carcinoma (LSCC). The present study investigated the associations of single-nucleotide polymorphisms (SNP), localized in the 3′UTR) of the KRAS, NRAS, and MAPK1 genes with LSCC risk and clinicopathological features. Methods: Genomic DNA and clinical data were collected from 327 adult men with LSCC. The control group was formed from 333 healthy men. Genotyping of the SNPs was performed using TaqMan SNP genotyping assays. Five KRAS, NRAS, and MAPK1 polymorphisms were analyzed. All studied genotypes were in Hardy–Weinberg equilibrium and had the same allele distribution as the 1000 Genomes project Phase 3 dataset for the European population. Results: Significant associations of the studied SNPs with reduced LSCC risk were observed between NRAS rs14804 major genotype CC. Significant associations of the studied SNPs with clinicopathologic variables were also observed between NRAS rs14804 minor T allele and advanced tumor stage and positive lymph node status. SNP of MAPK1 rs9340 was associated with distant metastasis. Moreover, haplotype analysis of two KRAS SNPs rs712 and rs7973450 revealed that TG haplotype was associated with positive lymph node status in LSCC patients. Conclusions: According to the present study, 3′UTR SNP in the NRAS and MAPK1 genes may contribute to the identifications of patients at higher risk of LSCC lymph node and distant metastasis development.

Pterostilbene Attenuates Particulate Matter-Induced Oxidative Stress, Inflammation and Aging in Keratinocytes

Particulate matter (PM) is the main indicator of air pollutants, and it may increase the level of reactive oxygen species (ROS) in keratinocytes, leading to skin inflammation, aging, and decreased moisturizing ability. Pterostilbene (PTS) is a dimethylated analog of resveratrol that has antioxidant effects. However, the molecular mechanisms of PTS in preventing PM-induced keratinocyte inflammation and aging have not been investigated yet. Therefore, we used PM-induced human keratinocytes to investigate the protective mechanisms of PTS. The results showed that 20 μM PTS had no toxicity to HaCaT keratinocytes and significantly reduced PM-induced intracellular ROS production. In addition, nuclear translocation of the aryl hydrocarbon receptor (AHR) was inhibited by PTS, leading to reduced expression of its downstream CYP1A1. PTS further inhibited PM-induced MAPKs, inflammation (COX-2), and aging (MMP-9) protein cascades, and rescued moisturizing (AQP-3) protein expression. We analyzed the PTS content in cells at different time points and compared the concentration required for PTS to inhibit the target proteins. Finally, we used the skin penetration assay to show that the PTS essence mainly exists in the epidermal layer and did not enter the system circulation. In conclusion, PTS could protect HaCaT keratinocytes from PM-induced damage and has the potential to become a cosmetic ingredient.

Comparison Study of Cytotoxicity of Bare and Functionalized Zinc Oxide Nanoparticles

In this paper, a study of the cytotoxicity of bare and functionalized zinc oxide nanoparticles (ZnO NPs) is presented. The functionalized ZnO NPs were obtained by various types of biological methods including microbiological (intra- and extracellular with Lactobacillus paracasei strain), phytochemical (Medicago sativa plant extract) and biochemical (ovalbumin from egg white protein) synthesis. As a control, the bare ZnO NPs gained by chemical synthesis (commercially available) were tested. The cytotoxicity was measured through the use of (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) dye as well as lactate dehydrogenase (LDH) assays against murine fibroblast L929 and Caco-2 cell lines. As a complementary method, scanning electron microscopy (SEM) was performed to assess the morphology of the tested cells after treatment with ZnO NPs. The microscopic data confirmed the occurrence of apoptotic blebbing and loss of membrane permeability after the administration of all ZnO NPs. The reactive oxygen species (ROS) concentration during the cell lines’ exposure to ZnO NPs was measured fluorometrically. Additionally, the photocatalytic degradation of methylene blue (MB) dye in the different light conditions, as well as the antioxidant activity of bare and functionalized ZnO NPs, is also reported. The addition of all types of tested ZnO NPs to methylene blue resulted in enhanced rates of photo-degradation in the presence of both types of irradiation, but the application of UV light resulted in higher photocatalytic activity of ZnO NPs. Furthermore, bare (chemically synthetized) NPs have been recognized as the strongest photocatalysts. In the context of the obtained results, a mechanism underlying the toxicity of bio-ZnO NPs, including (a) the generation of reactive oxygen species and (b) the induction of apoptosis, is proposed.

Regulation of Jun and Fos AP-1 transcription factors by JNK MAPKs signaling cascade in areca nut extract treated KB cells

The edible endosperm of Areca catechu is recognized as a potent carcinogenic agent either consumed alone or in combination with tobacco. Habitual chewing of areca nut leads to orally potential malignant disorders which are highly effective in malignant transformation and thereby lead to oral carcinogenesis. Human buccal epithelial KB carcinoma cells were used as an experimental cell system to inspect the mechanistic act of aqueous extract of areca nut on biochemical status and their implications on transcriptional activation of cancer signaling cascade that could possibly trigger numerous oncogenic players and finally decides the cells fate. Extract treated cells showed reduced viability with altered balance between oxidants and antioxidants which lead to redox status and which is known to distort various biological processes within the cell system. Results of RT-PCR demonstrated decreased expression of BCl2, cell cycle regulators along with Activator Protein -1 (AP-1) components. While Bax, p16 and p21 mRNAs showed increased expression in extract treated KB cells. Likewise, the translational levels of proliferation cell nuclear antigen (PCNA), tumor suppressor p53, retinoblastoma (Rb) and cyclin dependent kinase 4 (CDK4) were decreased along with AP-1 subunits (c-Jun/c-Fos) with increased protein levels of p21 in extract treated KB cells. Further, the downstream activation and regulation of AP-1 transcription factors could be through stress activated c-Jun - N terminal Kinase (JNK) Mitogen Activated Protein Kinases (MAPKs) which downregulated both Jun and Fos mRNA transcripts in areca nut extract exposed KB cells. Thus, outcome of the study provides insights into mechanistic path of pathogenesis of areca related disorders. Further, it could aid in designing new therapeutic modalities that specific targets these oncogenic players and help in disease management.

Effective Targeting of Raf-1 and Its Associated Autophagy by Novel Extracted Peptide for Treating Breast Cancer Cells

Breast cancer is one of the most common causes of death in women worldwide and has harmful influence on their psychological state during therapy. Multikinase inhibitors have become effective drugs for treating a variety of cancer diseases such as breast cancer. A purified short peptide (H-P) was isolated from the natural honey and tested for its potential regulatory role in breast cancer cells compared with the effectiveness of the anticancer drug, Sorafenib (SOR), using MCF-7, EFM-19, and MCF-10A cell lines. Furthermore, we investigated the direct connection between Raf-1 activation and cellular autophagy as potential targets of SOR and H-P extract using RNA interference. Interestingly, the treatment with H-P showed competitive regulation of phosphorylated Raf-1, MEK1/2, and matched autophagy-related LC3B without any detectable toxic effects in the non-tumorigenic epithelial cells. Unlike SOR, the regulation of Raf-1 protein and autophagic machinery by the novel H-P extract showed neglected levels of the released proinflammatory cytokine. This regulation of cytokine secretion by H-P resulted in decreasing the expression level of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) in treated cells. Moreover, the transfection of MCF-7 cells with small interference RNA (siRNA) antagonist Raf-1 expression markedly reduced the expression of LC3B, while it increased the expression of NF-kB1 and NF-kB2, indicating the potential cross-link between Raf-1, autophagy, and NF-kB effector. Collectively, these findings suggest that H-P-mediated Raf-1, MEK1/2, LC3B, and NF-kB provide a novel and efficacious multikinase inhibitor for treating breast cancer without detectable cytotoxic effects.

Liver X Receptor as a Possible Drug Target for Blood-Brain Barrier Integrity

Purpose: blood-brain barrier (BBB) is made of specialized cells that are responsible for the selective passage of substances directed to the brain. The integrated BBB is essential for precise controlling of the different substances passage as well as protecting the brain from various damages. In this article, we attempted to explain the role of liver X receptor (LXR) in maintaining BBB integrity as a possible drug target.

Methods: In this study, various databases, including PubMed, Google Scholar, and Scopus were searched using the following keywords: blood-brain barrier, BBB, liver X receptor, and LXR until July, 2020. Additionally, contents close to the subject of our study were surveyed.

Results: LXR is a receptor the roles of which in various diseases have been investigated. LXR can affect maintaining BBB by affecting various ways such as ATP-binding cassette transporter A1 (ABCA1), matrix metalloproteinase-9 (MMP9), insulin-like growth factor 1 (IGF1), nuclear factor-kappa B (NF-κB) signaling, mitogen-activated protein kinase (MAPK), tight junction molecules, both signal transducer and activator of transcription 1 (STAT1), Wnt/β-catenin Signaling, transforming growth factor beta (TGF-β) signaling, and expressions of Smad 2/3 and Snail.

Conclusion: LXR could possibly be used either as a target for drug delivery to brain tissue or as a target for maintaining the BBB integrity in different diseases; thereby the drug will be conducted to tissues, other than the brain. If it is verified that only LXRα is necessary for protecting BBB, some specific LXRα ligands must be found and then used in medication.

Circulating miR-146a as a possible candidate biomarker in the indeterminate phase of Chagas disease

BACKGROUND

Chagas disease is considered important and presents intense inflammatory and fibrotic processes induced by the perpetuation of the parasite in the affected tissues and organs. Therefore, it is necessary to inquire about the host defense and attack mechanisms to have a more detailed knowledge about Chagas disease. MicroRNAs are found in blood, tissues and extracellular vesicles. These small regulators of gene expression are involved in physiological and pathological processes in both mammals and parasites. Several microRNAs have deregulated expression in chagasic heart disease, although little is known about their extracellular expression. Our main objective was to evaluate the involvement of miR-21, miR-146a and miR-155 in several samples from mice infected with the TcI Ninoa strain from the acute and indeterminate phases. We also explored a potential functional association of the selected microRNAs using STRING software. This software identified 23 pathways associated with Trypanosoma cruzi infection. In addition, eleven genes were identified through bioinformatics analysis, and we found that SMAD family member 5 was downregulated in both phases. This gene serves as a mediator in the TGF-β signaling pathway. Thus, forty female mice of the CD1 strain were distributed into 4 groups and the expression levels of miR-21, miR-146a and miR-155 were measured in samples of heart tissue, total plasma and plasma extracellular vesicles by quantitative real-time polymerase chain reaction.

RESULTS

Overexpression of miR-21, miR-146a and miR-155 was observed in heart and plasma in both phases. Moreover, in extracellular vesicles miR-21 and miR-146a were also overexpressed in the acute phase, whereas in the indeterminate chronic phase we found only miR-146a up-regulated.

CONCLUSIONS

The expression of inflammatory microRNAs miR-21, miR-146a and miR-155 were up-regulated in each of the samples from acutely and chronically infected mice. The relevant finding was that miR-146a was up-regulated in each sample in both phases; therefore, this miRNA could be a possible candidate biomarker in Chagas disease.

Trastuzumab Mechanism of Action; 20 Years of Research to Unravel a Dilemma

Trastuzumab as a first HER2-targeted therapy for the treatment of HER2-positive breast cancer patients was introduced in 1998. Although trastuzumab has opened a new avenue to treat patients with HER2-positive breast cancer and other types of cancer, some patients are not responsive or become resistant to this treatment. So far, several mechanisms have been suggested for the mode of action of trastuzumab; however, the findings regarding these mechanisms are controversial. In this review, we aimed to provide a detailed insight into the various mechanisms of action of trastuzumab.

Post-translational modifications: Regulators of neurodegenerative proteinopathies

One of the hallmark features in the neurodegenerative disorders (NDDs) is the accumulation of aggregated and/or non-functional protein in the cellular milieu. Post-translational modifications (PTMs) are an essential regulator of non-functional protein aggregation in the pathogenesis of NDDs. Any alteration in the post-translational mechanism and the protein quality control system, for instance, molecular chaperone, ubiquitin-proteasome system, autophagy-lysosomal degradation pathway, enhances the accumulation of misfolded protein, which causes neuronal dysfunction. Post-translational modification plays many roles in protein turnover rate, accumulation of aggregate and can also help in the degradation of disease-causing toxic metabolites. PTMs such as acetylation, glycosylation, phosphorylation, ubiquitination, palmitoylation, SUMOylation, nitration, oxidation, and many others regulate protein homeostasis, which includes protein structure, functions and aggregation propensity. Different studies demonstrated the involvement of PTMs in the regulation of signaling cascades such as PI3K/Akt/GSK3β, MAPK cascade, AMPK pathway, and Wnt signaling pathway in the pathogenesis of NDDs. Further, mounting evidence suggests that targeting different PTMs with small chemical molecules, which acts as an inhibitor or activator, reverse misfolded protein accumulation and thus enhances the neuroprotection. Herein, we briefly discuss the protein aggregation and various domain structures of different proteins involved in the NDDs, indicating critical amino acid residues where PTMs occur. We also describe the implementation and involvement of various PTMs on signaling cascade and cellular processes in NDDs. Lastly, we implement our current understanding of the therapeutic importance of PTMs in neurodegeneration, along with emerging techniques targeting various PTMs.

Ethanol Extract of Maclura tricuspidata Fruit Protects SH-SY5Y Neuroblastoma Cells against H2O2-Induced Oxidative Damage via Inhibiting MAPK and NF-κB Signaling

Free radical generation and oxidative stress push forward an immense influence on the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Maclura tricuspidata fruit (MT) contains many biologically active substances, including compounds with antioxidant properties. The current study aimed to investigate the neuroprotective effects of MT fruit on hydrogen peroxide (H₂O₂)-induced neurotoxicity in SH-SY5Y cells. SH-SY5Y cells were pretreated with MT, and cell damage was induced by H₂O₂. First, the chemical composition and free radical scavenging properties of MT were analyzed. MT attenuated oxidative stress-induced damage in cells based on the assessment of cell viability. The H₂O₂-induced toxicity caused by ROS production and lactate dehydrogenase (LDH) release was ameliorated by MT pretreatment. MT also promoted an increase in the expression of genes encoding the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). MT pretreatment was associated with an increase in the expression of neuronal genes downregulated by H₂O₂. Mechanistically, MT dramatically suppressed H₂O₂-induced Bcl-2 downregulation, Bax upregulation, apoptotic factor caspase-3 activation, Mitogen-activated protein kinase (MAPK) (JNK, ERK, and p38), and Nuclear factor-κB (NF-κB) activation, thereby preventing H₂O₂-induced neurotoxicity. These results indicate that MT has protective effects against H₂O₂-induced oxidative damage in SH-SY5Y cells and can be used to prevent and protect against neurodegeneration.

Hypoxic Jumbo Squid Activate Neuronal Apoptosis but Not MAPK or Antioxidant Enzymes during Oxidative Stress

AbstractThe limitations that hypoxia imparts on mitochondrial oxygen supply are circumvented by the activation of anaerobic metabolism and prosurvival mechanisms in hypoxia-tolerant animals. To deal with the hypoxia that jumbo squid (Dosidicus gigas) experience in the ocean's depth, they depress their metabolic rate by up to 52% relative to normoxic conditions. This is coupled with molecular reorganization to facilitate their daily descents into the ocean's oxygen minimum zone, where they face not only low oxygen levels but also higher pressures and colder frigid waters. Our current study explores the tissue-specific hypoxia responses of three central processes: (1) antioxidant enzymes responsible for defending against oxidative stress, (2) early apoptotic machinery that signals the activation of cell death, and (3) mitogen-activated protein kinases (MAPKs) that act as central regulators of numerous cellular processes. Luminex xMAP technology was used to assess protein levels and phosphorylation states under normoxic and hypoxic conditions in brains, branchial hearts, and mantle muscles. Hypoxic brains were found to activate apoptosis via upregulation of phospho-p38, phospho-p53, activated caspase 8, and activated caspase 9, whereas branchial hearts were the only tissue to show an increase in antioxidant enzyme levels. Hypoxic muscles seemed the least affected by hypoxia. Our results suggest that hypoxic squid do not undergo large dynamic changes in the phosphorylation states of key apoptotic and central MAPK factors, except for brains, suggesting that these mechanisms are involved in squid hypometabolic responses.

Leishmania donovani Secretory Mevalonate Kinase Regulates Host Immune Response and Facilitates Phagocytosis

Leishmania secretes over 151 proteins during in vitro cultivation. Cellular functions of one such novel protein: mevalonate kinase is discussed here; signifying its importance in Leishmania infection.

Visceral Leishmaniasis is a persistent infection, caused by Leishmania donovani in Indian subcontinent. This persistence is partly due to phagocytosis and evasion of host immune response. The underlying mechanism involves secretory proteins of Leishmania parasite; however, related studies are meagre. We have identified a novel secretory Leishmania donovani glycoprotein, Mevalonate kinase (MVK), and shown its importance in parasite internalization and immuno-modulation. In our studies, MVK was found to be secreted maximum after 1 h temperature stress at 37°C. Its secretion was increased by 6.5-fold in phagolysosome-like condition (pH ~5.5, 37°C) than at pH ~7.4 and 25°C. Treatment with MVK modulated host immune system by inducing interleukin-10 and interleukin-4 secretion, suppressing host’s ability to kill the parasite. Peripheral blood mononuclear cell (PBMC)-derived macrophages infected with mevalonate kinase-overexpressing parasites showed an increase in intracellular parasite burden in comparison to infection with vector control parasites. Mechanism behind the increase in phagocytosis and immunosuppression was found to be phosphorylation of mitogen-activated protein (MAP) kinase pathway protein, Extracellular signal-regulated kinases-1/2, and actin scaffold protein, cortactin. Thus, we conclude that Leishmania donovani Mevalonate kinase aids in parasite engulfment and subvert the immune system by interfering with signal transduction pathways in host cells, which causes suppression of the protective response and facilitates their persistence in the host. Our work elucidates the involvement of Leishmania in the process of phagocytosis which is thought to be dependent largely on macrophages and contributes towards better understanding of host pathogen interactions.

Caryocar coriaceum Wittm. fruit extracts as Leishmania inhibitors: in-vitro and in-silico approaches

Leishmaniasis is a group of neglected diseases caused by parasites of the Leishmania genus. The treatment of Leishmaniasis represents a great challenge, because the available drugs present high toxicity and none of them is fully effective. Caryocar is a botanical genus rich in phenolic compounds, which leaves extracts have already been described by its antileishmanial action. Thus, we investigated the effect of pulp and peel extracts of the Caryocar coriaceum fruit on promastigote and amastigote forms of Leishmania amazonensis. Both extracts had antipromastigote effect after 24, 48, and 72 h, and this effect was by apoptosis-like process induction, with reactive oxygen species (ROS) production, damage to the mitochondria and plasma membrane, and phosphatidylserine exposure. Knowing that the fruit extracts did not alter the viability of macrophages, we observed that the treatment reduced the infection of these cells. Thereafter, in the in vitro infection context, the extracts showed antioxidant proprieties, by reducing NO, ROS, and MDA levels. Besides, both peel and pulp extracts up-regulated Nrf2/HO-1/Ferritin expression and increase the total iron-bound in infected macrophages, which culminates in a depletion of available iron for L. amazonensis replication. In silico, the molecular modeling experiments showed that the three flavonoids presented in the C. coriaceum extracts can act as synergistic inhibitors of Leishmania proteins, and compete for the active site. Also, there is a preference for rutin at the active site due to its greater interaction binding strength.

Comparative phosphoproteomic analysis unravels MAPK1 regulated phosphoproteins in Leishmania donovani

Mitogen Activated Protein Kinase1 (MAPK1) of Leishmania donovani functions as key regulators of various cellular activities, which seem to be imperative for parasite survival, infectivity, drug resistance and post-translational modification of chaperones/co-chaperones. However, very less is known about LdMAPK1 target proteins. With recent advancements in proteomics, we aimed to identify phosphoproteins which were differentially expressed in LdMAPK1 overexpressing (Dd8++/++) and single replacement mutants (Dd8+/) as compared to wild type (Dd8+/+) parasites, utilizing LC-MS/MS approach. An in-depth label-free phospoproteomic analysis revealed that modulation of LdMAPK1 expression significantly modulates expression levels of miscellaneous phosphoproteins which may act as its targets/substrates. Out of 1974 quantified phosphoproteins in parasite, 140 were significantly differentially expressed in MAPK1 overexpressing and single replacement mutants. These differentially expressed phosphoproteins are majorly associated with metabolism, signal transduction, replication, transcription, translation, transporters and cytoskeleton/motor proteins, hence suggested that MAPK1 may act in concert to modulate global biological processes. The study further implicated possible role of LdMAPK1 in regulation and management of stress machinery in parasite through post translational modifications. Precisely, comparative phosphoproteomics study has elucidated significant role of LdMAPK1 in regulating various pathways contributing in parasite biology with relevance to future drug development. SIGNIFICANCE: MAPKinase1, the downstream kinase of MAPK signal transduction pathway, has drawn much attention as potential therapeutic drug target due to their indispensable role in survival and infectivity of Leishmania donovani. However, limited information is available about its downstream effector proteins/signaling networks. Utilizing label free LC-MS/MS analysis, phosphoproteome of LdMAPK1 over-expressing (Dd8++/++) and LdMAPK1 single replacement mutants (Dd8+/-) with wild type (Dd8+/+) parasites was compared and identified 140 LdMAPK1 modulated phosphoproteins, mainly involved in pathways like signal transduction, metabolism, transcriptional, translational, post-translational modification and regulation of heat shock proteins. Interestingly, LdMAPK1 interacts directly with only six phosphoproteins i.e. casein kinase, casein kinase II, HSP83/HSP90, LACK, protein kinase and serine/threonine protein kinase. Thus, the study elucidates significant role of LdMAPK1 in Leishmania biology which may drive drug-discovery efforts against visceral leishmaniasis.

Anticancer Mechanism of Curcumin on Human Glioblastoma

Glioblastoma (GBM) is the most malignant brain tumor and accounts for most adult brain tumors. Current available treatment options for GBM are multimodal, which include surgical resection, radiation, and chemotherapy. Despite the significant advances in diagnostic and therapeutic approaches, GBM remains largely resistant to treatment, with a poor median survival rate between 12 and 18 months. With increasing drug resistance, the introduction of phytochemicals into current GBM treatment has become a potential strategy to combat GBM. Phytochemicals possess multifarious bioactivities with multitarget sites and comparatively marginal toxicity. Among them, curcumin is the most studied compound described as a potential anticancer agent due to its multi-targeted signaling/molecular pathways properties. Curcumin possesses the ability to modulate the core pathways involved in GBM cell proliferation, apoptosis, cell cycle arrest, autophagy, paraptosis, oxidative stress, and tumor cell motility. This review discusses curcumin’s anticancer mechanism through modulation of Rb, p53, MAPK, P13K/Akt, JAK/STAT, Shh, and NF-κB pathways, which are commonly involved and dysregulated in preclinical and clinical GBM models. In addition, limitation issues such as bioavailability, pharmacokinetics perspectives strategies, and clinical trials were discussed.

Metabolic Profile Reveals the Immunosuppressive Mechanisms of Methionyl-Methionine in Lipopolysaccharide-Induced Inflammation in Bovine Mammary Epithelial Cell

Our previous transcriptomic study found that methionyl-methionine (Met-Met) exerts an anti-inflammatory effect in the bovine mammary epithelial cell (MAC-T) at a molecular level. However, evidence of whether the metabolic production of Met-Met confers protection was scarce. To investigate the inflammatory response and metabolite changes of Met-Met in lipopolysaccharide (LPS)-induced inflammation of MAC-T, mass spectrometry-based metabolomics and qPCR were conducted. The increased levels of IL-8, TNF-α, AP-1, and MCP-1 were reduced by pretreating with 2 mM Met-Met after LPS exposure. Metabolomics profiling analysis demonstrated that LPS induced significant alteration of metabolites, including decreased tryptophan, phenylalanine, and histidine levels and increased palmitic acid and stearic acid levels as well as purine metabolism disorder, whereas Met-Met reversed these changes significantly. Pathways analysis revealed that overlapping metabolites were mainly enriched in the cysteine and methionine metabolism, fatty acids biosynthesis, and purines degradation. Correlation networks showed that the metabolic profile was significantly altered under the conditions of inflammation and Met-Met treatment. Collectively, Met-Met might relieve MAC-T cell inflammation via hydrolysate methionine, which further changes the processes of amino acid, purine, and fatty acid metabolism.

Mixed signals - how Trypanosoma cruzi exploits host-cell communication and signaling to establish infection

Chagas disease (American trypanosomiasis) is a 'neglected' pathology that affects millions of people worldwide, mainly in Latin America. Trypanosoma cruzi, the causative agent, is an obligate intracellular parasite with a complex and diverse biology that infects several mammalian species, including humans. Because of genetic variability among strains and the presence of four biochemically and morphologically distinct parasite forms, the outcome of T. cruzi infection varies considerably depending on host cell type and parasite strain. During the initial contact, cellular communication is established by host-recognition-mediated responses, followed by parasite adherence and penetration. For this purpose, T. cruzi expresses a variety of proteins that modify the host cell, enabling it to safely reach the cytoplasm. After entry into the host cell, T. cruzi forms a transitory structure termed 'parasitophorous vacuole' (PV), followed by its cytoplasmic replication and differentiation after PV rupture, and subsequent invasion of other cells. The success of infection, maintenance and survival inside host cells is facilitated by the ability of T. cruzi to subvert various host signaling mechanisms. We focus in this Review on the various mechanisms that induce host cytoskeletal rearrangements, activation of autophagy-related proteins and crosstalk among major immune response regulators, as well as recent studies on the JAK-STAT pathway.

A gene co-association network regulating gut microbial communities in a Duroc pig population

BACKGROUND

Analyses of gut microbiome composition in livestock species have shown its potential to contribute to the regulation of complex phenotypes. However, little is known about the host genetic control over the gut microbial communities. In pigs, previous studies are based on classical "single-gene-single-trait" approaches and have evaluated the role of host genome controlling gut prokaryote and eukaryote communities separately.

RESULTS

In order to determine the ability of the host genome to control the diversity and composition of microbial communities in healthy pigs, we undertook genome-wide association studies (GWAS) for 39 microbial phenotypes that included 2 diversity indexes, and the relative abundance of 31 bacterial and six commensal protist genera in 390 pigs genotyped for 70 K SNPs. The GWAS results were processed through a 3-step analytical pipeline comprised of (1) association weight matrix; (2) regulatory impact factor; and (3) partial correlation and information theory. The inferred gene regulatory network comprised 3561 genes (within a 5 kb distance from a relevant SNP-P < 0.05) and 738,913 connections (SNP-to-SNP co-associations). Our findings highlight the complexity and polygenic nature of the pig gut microbial ecosystem. Prominent within the network were 5 regulators, PRDM15, STAT1, ssc-mir-371, SOX9 and RUNX2 which gathered 942, 607, 588, 284 and 273 connections, respectively. PRDM15 modulates the transcription of upstream regulators of WNT and MAPK-ERK signaling to safeguard naive pluripotency and regulates the production of Th1- and Th2-type immune response. The signal transducer STAT1 has long been associated with immune processes and was recently identified as a potential regulator of vaccine response to porcine reproductive and respiratory syndrome. The list of regulators was enriched for immune-related pathways, and the list of predicted targets includes candidate genes previously reported as associated with microbiota profile in pigs, mice and human, such as SLIT3, SLC39A8, NOS1, IL1R2, DAB1, TOX3, SPP1, THSD7B, ELF2, PIANP, A2ML1, and IFNAR1. Moreover, we show the existence of host-genetic variants jointly associated with the relative abundance of butyrate producer bacteria and host performance.

CONCLUSIONS

Taken together, our results identified regulators, candidate genes, and mechanisms linked with microbiome modulation by the host. They further highlight the value of the proposed analytical pipeline to exploit pleiotropy and the crosstalk between bacteria and protists as significant contributors to host-microbiome interactions and identify genetic markers and candidate genes that can be incorporated in breeding program to improve host-performance and microbial traits. Video Abstract.

Brucein D modulates MAPK signaling cascade to exert multi-faceted anti-neoplastic actions against breast cancer cells

Breast cancer is a prominent type of malignancy among women with a high rate of mortality. A number of previous studies have demonstrated the anticancer potential of brucein D (BD), a quassinoid extracted from Brucea javanica, against the cancers of the pancreas, bone, and liver. We investigated the impact of BD on apoptotic as well on mitogen-activated protein kinase (MAPK) signaling cascades in breast cancer cells. The effect of BD on p38 MAPK and JNK signaling pathways and its downstream functions was deciphered in both MDA-MB-231 and MCF-7 cell lines. We noted that BD decreased the viability of breast cancer cells without affecting the growth of healthy mammary epithelial cells (MCF-10A). Flow cytometric analysis revealed that BD can increase sub-G1 cells and enhanced annexin-V-PI stained cells. The apoptogenic impact of BD was further substantiated by cleavage of procaspase-3/8 and downregulation of antiapoptotic proteins (Bcl-xL, XIAP, and survivin). Furthermore, BD also downmodulated the migratory ability, and chemokine triggered invasion of breast cancer cells. Interestingly, the pharmacological inhibition of p38 MAPK and JNK kinases abrogated the observed anticancer actions of BD. Overall, the data indicated that BD can induce substantial apoptosis and interfere with cellular invasion by modulating MAPK signaling pathway in breast cancer cells.

Withanolides from Withania somnifera as an immunity booster and their therapeutic options against COVID-19

Traditionally, Withania somnifera is widely used as an immune booster, anti-viral, and for multiple medicinal purposes. The present study investigated the withanolides as an immune booster and anti-viral agents against the coronavirus-19. Withanolides from Withania somnifera were retrieved from the open-source database, their targets were predicted using DIGEP-Pred, and the protein-protein interaction was evaluated. The drug-likeness score and intestinal absorptivity of each compound were also predicted. The network of compounds, proteins, and modulated pathways was constructed using Cytoscape, and docking was performed using autodock4.0, and selected protein-ligand complexes were subjected to 100 ns Molecular Dynamics simulations. The molecular dynamics trajectories were subjected to free energy calculation by the MM-GBSA method. Withanolide_Q was predicted to modulate the highest number of proteins, showed human intestinal absorption, and was predicted for the highest drug-likeness score. Similarly, combined network interaction identified Withanolide_Q to target the highest number of proteins; RAC1 was majorly targeted, and fluid shear stress and atherosclerosis associated pathway were chiefly regulated. Similarly, Withanolide_D and Withanolide_G were predicted to have a better binding affinity with PLpro, Withanolide_M with 3CLpro, and Withanolide_M with spike protein based on binding energy and number of hydrogen bond interactions. MD studies suggested Withanoside_I with the highest binding free energy (ΔG_bind-31.56 kcal/mol) as the most promising inhibitor. Among multiple withanolides from W. somnifera, Withanolide_D, Withanolide_G, Withanolide_M, and Withanolide_Q were predicted as the lead hits based on drug-likeness score, modulated proteins, and docking score to boost the immune system and inhibit the COVID-19 infection, which could primarily act against COVID-19. HighlightsWithanolides are immunity boosters.Withanolides are a group of bio-actives with potential anti-viral properties.Withanolide_G, Withanolide_I, and Withanolide_M from Withania somnifera showed the highest binding affinity with PLpro, 3CLpro, and spike protein, respectively.Withanolides from Withania somnifera holds promising anti-viral efficacy against COVID-19.Communicated by Vsevolod Makeev.

Posttranslational modifications as therapeutic targets for intestinal disorders

A variety of biological processes are regulated by posttranslational modifications. Posttranslational modifications including phosphorylation, ubiquitination, glycosylation, and proteolytic cleavage, control diverse physiological functions in the gastrointestinal tract. Therefore, a better understanding of their implications in intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, celiac disease, and colorectal cancer would provide a basis for the identification of novel biomarkers as well as attractive therapeutic targets. Posttranslational modifications can be common denominators, as well as distinct biomarkers, characterizing pathological differences of various intestinal diseases. This review provides experimental evidence that identifies changes in posttranslational modifications from patient samples, primary cells, or cell lines in intestinal disorders, and a summary of carefully selected information on the use of pharmacological modulators of protein modifications as therapeutic options.

Thymoquinone in autoimmune diseases: Therapeutic potential and molecular mechanisms

Autoimmune diseases (AUDs) are a multifactorial disease, among which rheumatoid arthritis, systemic lupus erythematosus and multiple sclerosis are more prevalent. Several anti-inflammatory, biologics, and AUD-modifying drugs are found effective against them, but their repeated use are associated with various adverse effects. In this review article, we have focused on the regulation of inflammatory molecules, molecular signaling pathways, immune cells, and epigenetics by natural product thymoquinone on AUDs. Studies indicate that thymoquinone can regulate inflammatory molecules including interferons, interleukins, tumor necrosis factor-α (TNF-α), oxidative stress, regulatory T cells, and various signaling pathways such as nuclear factor kappa beta (NF-κβ), janus kinase/signal transduction and activator of transcription (JAK-STAT), mitogen-activated protein kinase (MAPK) at the molecular level and epigenetic alteration. As these molecules and signaling pathways with defective immune function play an important role in AUD development, controlling these molecules and deregulated molecular mechanism is a significant feature of AUD therapeutics. Interestingly thymoquinone is reported to possess all these potential. This article reviewed the deregulated mechanism of AUDs, and the action of thymoquinone on inflammatory molecules, immune cells, signaling pathways, and epigenetic machinery. Thymoquinone can be regarded as a potential drug candidate for AUD treatment.

Hidden in plain sight: The effects of BCG vaccination in the COVID-19 pandemic

To investigate the relationship between Bacille Calmette‐Guérin (BCG) vaccination and SARS‐CoV‐2 by a bioinformatics approach, two datasets for the SARS‐CoV‐2 infection group and BCG‐vaccinated group were downloaded. Differentially Expressed Genes were identified. Gene ontology and pathways were functionally enriched, and networking was constructed in NetworkAnalyst. Lastly, the correlation between post‐BCG vaccination and COVID‐19 transcriptome signatures was established. A total of 161 DEGs (113 upregulated DEGs and 48 downregulated genes) were identified in the SARS‐CoV‐2 group. In the pathway enrichment analysis, a cross‐reference of upregulated Kyoto Encyclopedia of Genes and Genomes pathways in SARS‐CoV‐2 with downregulated counterparts in the BCG‐vaccinated group, resulted in the intersection of 45 common pathways, accounting for 86.5% of SARS‐CoV‐2 upregulated pathways. Of these intersecting pathways, a vast majority were immune and inflammatory pathways with top significance in interleukin‐17, tumor necrosis factor, NOD‐like receptors, and nuclear factor‐κB signaling pathways. Given the inverse relationship of the specific differentially expressed gene pathways highlighted in our results, the BCG‐vaccine may play a protective role against COVID‐19 by mounting a nonspecific immunological response and further investigation of this relationship is warranted.

Network pharmacology of AYUSH recommended immune-boosting medicinal plants against COVID-19

The Ministry of AYUSH recommended the use of a decoction of the mixture of Ocimum tenuiflorum, Cinnamomum verum, Piper nigrum, Zingiber officinale, and Vitis vinifera as a preventive measure by boosting the immunity against the severity of infection caused by a novel coronavirus (COVID-19). The present study aimed to identify the probable modulated pathways by the combined action of AYUSH recommended herbal tea and golden milk formulation as an immune booster against COVID-19. Reported phytoconstituents of all the medicinal plants were retrieved from the ChEBI database, and their targets were predicted using DIGEP-Pred. STRING database and Cytoscape were used to predict the protein–protein interaction and construct the network, respectively. Likewise, MolSoft and admet SAR2.0 were used to predict the druglikeness score and ADMET profile of phytoconstituents. The study identified the modulation of HIF-1, p53, PI3K-Akt, MAPK, cAMP, Ras, Wnt, NF-kappa B, IL-17, TNF, and cGMP-PKG signaling pathways to boost the immune system. Further, multiple pathways were also identified which are involved in the regulation of pathogenesis of the multiple infections and non-infectious diseases due to the lower immune system. Results indicated that the recommended herbal formulation not only modulated the pathways involved in boosting the immunity but also modulated the multiple pathways that are contributing to the progression of multiple disease pathogenesis which would add the beneficial effect in the co-morbid patients of hypertension and diabetes. The study provides the scientific documentation of the role of the Ayurvedic formulation to combat COVID-19.

Hispolon: A natural polyphenol and emerging cancer killer by multiple cellular signaling pathways

Nature as an infinite treasure of chemotypes and pharmacophores will continue to play an imperative role in the drug discovery. Natural products (NPs) such as plant and fungal metabolites have emerged as leads in drug discovery during recent years due to their efficacy, safety and selectivity. The current review summarizes natural sources as well as pharmacological potential of hispolon which is a major constituent of traditional medicinal mushroom Phellinus linteus. The study aims to update the scientific community about recent developments of hispolon in the arena of natural drugs by providing insights into its present status in therapeutic pursuits. Hispolon, a polyphenol has been reported to possess anticancer, antidiabetic, antioxidant, antiviral and anti-inflammatory activities. It fights against cancer via induction of apoptosis, halting cell cycle and inhibition of metastasis by targeting various cellular signaling pathways including PI3K/Akt, MAPK and NF-κB. The current review proposes that hispolon provides a novel opportunity for pharmacological applications and its styrylpyrone carbon skeleton might serve as an attractive scaffold for drug development. However, future researches are recommended to assess bioavailability, toxicological limits, pharmacokinetic and pharmacodynamic profiles of hispolon, in order to establish its potential as a potent multi-targeted drug in the near future.

Quercetin as an Agent for Protecting the Bone: A Review of the Current Evidence

Quercetin is a flavonoid abundantly found in fruits and vegetables. It possesses a wide spectrum of biological activities, thus suggesting a role in disease prevention and health promotion. The present review aimed to uncover the bone-sparing effects of quercetin and its mechanism of action. Animal studies have found that the action of quercetin on bone is largely protective, with a small number of studies reporting negative outcomes. Quercetin was shown to inhibit RANKL-mediated osteoclastogenesis, osteoblast apoptosis, oxidative stress and inflammatory response while promoting osteogenesis, angiogenesis, antioxidant expression, adipocyte apoptosis and osteoclast apoptosis. The possible underlying mechanisms involved are regulation of Wnt, NF-κB, Nrf2, SMAD-dependent, and intrinsic and extrinsic apoptotic pathways. On the other hand, quercetin was shown to exert complex and competing actions on the MAPK signalling pathway to orchestrate bone metabolism, resulting in both stimulatory and inhibitory effects on bone in parallel. The overall interaction is believed to result in a positive effect on bone. Considering the important contributions of quercetin in regulating bone homeostasis, it may be considered an economical and promising agent for improving bone health. The documented preclinical findings await further validation from human clinical trials.

MicroRNA expression profile analysis of skin immune response in crucian carp (Carassius auratus) infected by Aeromonas hydrophila

MicroRNAs (miRNAs) are non-coding RNA molecules that regulate gene expression in fish, but its regulatory mechanism of the skin mucosal immune response remains poorly understood. In order to investigate the immunological role of miRNAs, three sRNA libraries (mSC, mST1, mST2) from skin samples of crucian carp (Carassiusauratus) infected with Aeromonas hydrophila at three time points (0, 6 and 12 hpi) were constructed and examined using Illumina Hiseq 2000 platform. All of the identified miRNA, rRNA and tRNA were 69444 (13.39%), 29550 (5.70%) and 10704 (2.06%) in skin, respectively. At 6 and 12 hpi, 829 and 856 miRNAs were differentially expressed, respectively. Among these DEMs, 53 known and 10 novel miRNAs were all significantly differentially expressed during early infection (p < 0.01). GO and KEGG enrichment analyses revealed that 118111 target-genes were primarily involved in cellular process, metabolic process, biological regulation and stress response, such as antigen processing and presentation, complement and coagulation cascades, phagosome, MAPK, TLR, NF-κB and JAK-STAT signaling pathways. These results will help to elucidate the mechanism of miRNAs involved in the skin mucosal immune response of crucian carp against Aeromonas hydrophila infection.

Genomic Study of Babesia bovis Infection Level and Its Association With Tick Count in Hereford and Braford Cattle

Bovine babesiosis is a tick-borne disease caused by intraerythrocytic protozoa and leads to substantial economic losses for the livestock industry throughout the world. Babesia bovis is considered the most pathogenic species, which causes bovine babesiosis in Brazil. Genomic data could be used to evaluate the viability of improving resistance against B. bovis infection level (IB) through genomic selection, and, for that, knowledge of genetic parameters is needed. Furthermore, genome-wide association studies (GWAS) could be conducted to provide a better understanding of the genetic basis of the host response to B. bovis infection. No previous work in quantitative genetics of B. bovis infection was found. Thus, the objective of this study was to estimate the genetic correlation between IB and tick count (TC), evaluate predictive ability and applicability of genomic selection, and perform GWAS in Hereford and Braford cattle. The single-step genomic best linear unbiased prediction method was used, which allows the estimation of both breeding values and marker effects. Standard phenotyping was conducted for both traits. IB quantifications from the blood of 1,858 animals were carried using quantitative PCR assays. For TC, one to three subsequent tick counts were performed by manually counting adult female ticks on one side of each animal's body that was naturally exposed to ticks. Animals were genotyped using the Illumina BovineSNP50 panel. The posterior mean of IB heritability, estimated by the Bayesian animal model in a bivariate analysis, was low (0.10), and the estimations of genetic correlation between IB and TC were also low (0.15). The cross-validation genomic prediction accuracy for IB ranged from 0.18 to 0.35 and from 0.29 to 0.32 using k-means and random clustering, respectively, suggesting that genomic predictions could be used as a tool to improve genetics for IB, especially if a larger training population is developed. The top 10 single nucleotide polymorphisms from the GWAS explained 5.04% of total genetic variance for IB, which were located on chromosomes 1, 2, 5, 6, 12, 17, 18, 16, 24, and 26. Some candidate genes participate in immunity system pathways indicating that those genes are involved in resistance to B. bovis in cattle. Although the genetic correlation between IB and TC was weak, some candidate genes for IB were also reported in tick infestation studies, and they were also involved in biological resistance processes. This study contributes to improving genetic knowledge regarding infection by B. bovis in cattle.

Comparative Analysis of the Secretome and Interactome of Trypanosoma cruzi and Trypanosoma rangeli Reveals Species Specific Immune Response Modulating Proteins

Chagas disease, a zoonosis caused by the flagellate protozoan Trypanosoma cruzi, is a chronic and systemic parasitic infection that affects ~5–7 million people worldwide, mainly in Latin America. Chagas disease is an emerging public health problem due to the lack of vaccines and effective treatments. According to recent studies, several T. cruzi secreted proteins interact with the human host during cell invasion. Moreover, some comparative studies with T. rangeli, which is non-pathogenic in humans, have been performed to identify proteins directly involved in the pathogenesis of the disease. In this study, we present an integrated analysis of canonical putative secreted proteins (PSPs) from both species. Additionally, we propose an interactome with human host and gene family clusters, and a phylogenetic inference of a selected protein. In total, we identified 322 exclusively PSPs in T. cruzi and 202 in T. rangeli. Among the PSPs identified in T. cruzi, we found several trans-sialidases, mucins, MASPs, proteins with phospholipase 2 domains (PLA2-like), and proteins with Hsp70 domains (Hsp70-like) which have been previously characterized and demonstrated to be related to T. cruzi virulence. PSPs found in T. rangeli were related to protozoan metabolism, specifically carboxylases and phosphatases. Furthermore, we also identified PSPs that may interact with the human immune system, including heat shock and MASP proteins, but in a lower number compared to T. cruzi. Interestingly, we describe a hypothetical hybrid interactome of PSPs which reveals that T. cruzi secreted molecules may be down-regulating IL-17 whilst T. rangeli may enhance the production of IL-15. These results will pave the way for a better understanding of the pathophysiology of Chagas disease and may ultimately lead to the identification of molecular targets, such as key PSPs, that could be used to minimize the health outcomes of Chagas disease by modulating the immune response triggered by T. cruzi infection.

Discovery of the possible mechanisms in kouyanqing granule for treatment of oral ulcers based on network pharmacology

Background

Oral ulcer diseases are complex inflammatory diseases caused by multi-factors, which severely impact patient quality of life. Kouyanqing Granule (KYQG) has been used to treat inflammatory diseases of the mouth and throat, including recurrent aphthous stomatitis (RAS), traumatic ulcers, oral leukoplakia and so on. However, the underlying molecular mechanisms of KYQG in treating these diseases are still unclear. We aimed to explore the possible mechanisms in KYQG for the treatment of oral ulcers.

Methods

An innovative network pharmacology method was established by incorporating targets searching and fishing, network analysis, and silico validation to discover the pharmacological mechanisms of action of KYQG for the treatment of oral ulcers. Then, we verified the reliability of this method by an animal experiment.

Results

Our data indicated that a total of 47 key targets were screened, which mainly involved in three function modules including the inhibition of inflammation, the regulation of immunological response, and the suppression of oxidative stress. The implementation of these functions relies on the complex multi-pathways network, especially TNF signaling pathway and HIF-1 signaling pathway. The results of the experimental verification indicated that KYQG significantly inhibited the serum levels of cyclooxygenase-2 (COX2), matrix metalloproteinase 9 (MMP9) and tumor necrosis factor-alpha (TNF-α) in rats with oral ulcer.

Conclusion

KYQG exhibited the therapeutic effects on oral ulcers probably by inhibiting inflammation, regulating immunological response, and suppressing oxidative stress through a complex multi-pathways network. Particularly, TNF signaling pathway and HIF-1 signaling pathway may play crucial roles in the protection of KYQG against oral ulcers. This work not only offers a method for understanding the functional mechanisms of KYQG for treating oral ulcer diseases from a multi-scale perspective but also may provide an efficient way for research and development of complex composition formula.

Food-derived bioactive compounds with anti-aging potential for nutricosmetic and cosmeceutical products

Besides providing essential nutrients for humans, food contains bioactive compounds that exert diverse biological activities such as anti-microbial, anti-cancerogenic, anti-viral, anti-inflammatory and antioxidant. The cosmetic industry is interested in natural bioactive compounds for their use in nutricosmetic and cosmeceutical products. These products aimed to reduce skin aging, inflammation or provide photoprotection against UV radiation. As a result, nutricosmetics and cosmeceuticals are becoming innovative self-care products in the beauty market. These products contain phytochemicals as active compounds obtained from fruits, vegetables, legumes, medicinal herbs and plants with anti-aging potential. This review summarizes the information within the last 5 years related to bioactive compounds present in fruits, vegetables, herbs and spices commonly used for human consumption. Their antioxidant and biological potential for modulating molecular markers involved in the aging process, as well as their mechanism of action. Diverse natural foods and their byproducts could be used as a source of bioactive compounds for developing cosmeceutical and nutricosmetic products.

Peanut skin polyphenols inhibit toxicity induced by advanced glycation end-products in RAW264.7 macrophages

This is the first work to use a polyphenolic fraction derived from peanut skin to attenuate the toxicity induced by advanced glycation-end products (AGEs) in RAW264.7 macrophages. The RAW264.7 cells were stimulated by AGEs using the bovine serum albumin-fructose (BSA-FRU), bovine serum albumin-methylglyoxal (BSA-MGO) and arginine-methylglyoxal (ARG-MGO) models. The AGEs increased considerably the levels of reactive oxygen species and the gene expression of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide. Twenty-eight polyphenols, including catechin, phenolic acids, and resveratrol were annotated in peanut skin extract (PSE) with the use of ultra-performance liquid chromatography coupled to quadrupole time of flight mass spectrometry (UPLC-QTOF/MS^E) and to the UNIFI Scientific Information System. The administration of PSE at 100 and 150 μg/mL significantly inhibited oxidative stress, by suppressing the production of reactive oxygen species up to 70% and reducing the production of nitric oxide, IL-6 and TNF-α up to 1.7-, 10- and 107-fold, respectively.

Probiotic inhibits oral carcinogenesis: A systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to investigate the effects if probiotics can inhibit oral carcinogenesis.

DESIGN

PubMed, Web of Science, Scopus, and PLOS databases were searched up to February 2020 to identify randomised controlled trials that fulfilled the eligibility criteria. Joanna Briggs Institute (JBI) Critical Appraisal Tool was used for quality assessment of articles. This review was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA-P) 2015 protocol guidelines.

RESULT

The initial search retrieved 774 articles. Of these, only five articles were included in the qualitative synthesis. Two out of the five papers were further analysed for quantitative synthesis in meta-analysis. The majority of the included studies were found to be of "moderate quality". The qualitative synthesis found four probiotics that exhibited potential therapeutic effects in oral carcinogenesis, includingAcetobacter syzygii, AJ2, Lactobacillus plantarum, and Lactobacillus salivarius REN. Among them, the application of L. salivarius REN resulted in a 95 % lower risk for developing oral cancer (p < 0.05).

CONCLUSION

It is known that probiotics have the potential to inhibit oral carcinogenesis, thus supporting the hypothesis of the study. The ability of L. salivarius REN to inhibit the development of oral cancer suggested that this bacterium can be a potential inhibitory agent against oral carcinogenesis.

Zinc Oxide Nanoparticles Induce Ferroptotic Neuronal Cell Death in vitro and in vivo

Purpose

Zinc oxide nanoparticles (ZnONPs) are one of the most important nanomaterials that are widely used in the food, cosmetic and medical industries. Humans are often exposed to ZnONPs via inhalation, and they may reach the brain where neurotoxic effects could occur via systemic distribution. However, the mechanisms underlying how ZnONPs produce neurotoxic effects in the brain remain unclear. In this study, we aimed to investigate the novel mechanism involved in ZnONPs-induced neurotoxicity.

Methods and Results

We demonstrated for the first time that pulmonary exposure to ZnONPs by intratracheal instillation could trigger ferroptosis, a new form of cell death, in the neuronal cells of mouse cerebral cortex. A similar phenomenon was also observed in cultured neuron-like PC-12 cell line. By using a specific inhibitor of ferroptosis ferrostatin-1 (Fer-1), our results showed that inhibition of ferroptosis by Fer-1 could significantly alleviate the ZnONPs-induced neuronal cell death both in vivo and in vitro. Mechanistic investigation revealed that ZnONPs selectively activated the JNK pathway and thus resulted in the ferroptotic phenotypes, JNK inhibitor SP600125 could reverse lipid peroxidation upregulation and ferroptotic cell death induced by ZnONPs in PC-12 cells.

Conclusion

Taken together, this study not only demonstrates that pulmonary exposure of ZnONPs can induce JNK-involved ferroptotic cell death in mouse cortex and PC-12 cells, but also provides a clue that inhibition of ferroptosis by specific agents or drugs may serve as a feasible approach for reducing the untreatable neurotoxicity induced by ZnONPs.

Current and Future molecular mechanism in Inflammation and Arthritis

Inflammation is an immune response of the human body but excessive inflammation is taken as a major factor in the development of many diseases including autoimmune disorders, cancer and nerve disorders etc. In this regards the need is to suppress the inflammatory response. Suppression of extra or imperfect inflammatory response is not a big deal provided there is an exact knowledge of particular target in the body. Recent advancements in Pharmacological aspect made the therapy with improved outcomes in number of patients. Anticytokine therapy might be one of the important and novel approaches for inflammation and Arthritis. This can be achieved only when we go through the pathophysiology of expression and identification of mediators. Let's take an example of cytokine like interleukins (IL), chemokines, interferons (INF), tumor necrosis factors (TNF-α), growth factors, and colony stimulating factors) release pathway which is a major signalling protein in inflammatory response. In the present study we have reviewed the recent pharmacological therapeutic advancement, inflammatory mediators, receptors, and major signalling pathways. Such information will not only provide the idea about the mechanism of action of Pharmaceuticals and molecular targets but also it provides a new aspect for drug designing and new corrective approaches in existing clinical medicines. This study will be a source of good information for the researchers working in the area of drug designing and molecular Pharmacology especially in anti-inflammatory and anti arthritic medicines for target based therapy.

Slight temperature changes cause rapid transcriptomic responses in Trypanosoma cruzi metacyclic trypomastigotes

Background

Severe changes in temperature can affect the behavior and ecology of some infectious agents. Trypanosoma cruzi is a protozoan that causes Chagas disease. This parasite has high genetic variability and can be divided into six discrete typing units (DTUs). Trypanosoma cruzi also has a complex life-cycle, which includes the process of metacyclogenesis when non-infective epimastigote forms are differentiated into infective metacyclic trypomastigotes (MT). Studies in triatomines have shown that changes in temperature also affect the number and viability of MT.

Methods

The objective of this study was to evaluate how temperature affects the transcriptional profiles of T. cruzi I and II (TcI and TcII) MT by exposing parasites to two temperatures (27 °C and 28 °C) and comparing those to normal culture conditions at 26 °C. Subsequently, RNA-seq was conducted and differentially expressed genes were quantified and associated to metabolic pathways.

Results

A statistically significant difference was observed in the number of MT between the temperatures evaluated and the control, TcII DTU was not strongly affected to exposure to high temperatures compared to TcI. Similar results were found when we analyzed gene expression in this DTU, with the greatest number of differentially expressed genes being observed at 28 °C, which could indicate a dysregulation of different signaling pathways under this temperature. Chromosome analysis indicated that chromosome 1 harbored the highest number of changes for both DTUs for all thermal treatments. Finally, gene ontology (GO) analyses showed a decrease in the coding RNAs involved in the regulation of processes related to the metabolism of lipids and carbohydrates, the evasion of oxidative stress, and proteolysis and phosphorylation processes, and a decrease in RNAs coding to ribosomal proteins in TcI and TcII, along with an increase in the expression of surface metalloprotease GP63 in TcII.

Conclusions

Slight temperature shifts lead to increased cell death of metacyclic trypomastigotes because of the deregulation of gene expression of different processes essential for the TcI and TcII DTUs of T. cruzi.

Anti-Inflammatory Drugs as Anticancer Agents

Inflammation is strictly associated with cancer and plays a key role in tumor development and progression. Several epidemiological studies have demonstrated that inflammation can predispose to tumors, therefore targeting inflammation and the molecules involved in the inflammatory process could represent a good strategy for cancer prevention and therapy. In the past, several clinical studies have demonstrated that many anti-inflammatory agents, including non-steroidal anti-inflammatory drugs (NSAIDs), are able to interfere with the tumor microenvironment by reducing cell migration and increasing apoptosis and chemo-sensitivity. This review focuses on the link between inflammation and cancer by describing the anti-inflammatory agents used in cancer therapy, and their mechanisms of action, emphasizing the use of novel anti-inflammatory agents with significant anticancer activity.

The Skeletal-Protecting Action and Mechanisms of Action for Mood-Stabilizing Drug Lithium Chloride: Current Evidence and Future Potential Research Areas

Lithium, the lightest natural-occurring alkali metal with an atomic number of three, stabilizes the mood to prevent episodes of acute manic and depression. Multiple lines of evidence point to lithium as an anti-suicidal, anti-viral, anti-cancer, immunomodulatory, neuroprotective and osteoprotective agent. This review article provides a comprehensive review of studies investigating the bone-enhancing effects of lithium and its possible underlying molecular mechanisms. Most of the animal experimental studies reported the beneficial effects of lithium in defective bones but not in healthy bones. In humans, the effects of lithium on bones remain heterogeneous. Mechanistically, lithium promotes osteoblastic activities by activating canonical Wingless (Wnt)/beta (β)-catenin, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) and bone morphogenetic protein-2 (BMP-2) transduction pathways but suppresses osteoclastic activities by inhibiting the receptor activator of nuclear factor-kappa B (RANK)/receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) system, nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and calcium signaling cascades. In conclusion, lithium confers protection to the skeleton but its clinical utility awaits further validation from human clinical trials.

The spinal microglial IL-10/β-endorphin pathway accounts for cinobufagin-induced mechanical antiallodynia in bone cancer pain following activation of α7-nicotinic acetylcholine receptors

Background

Cinobufagin is the major bufadienolide of Bufonis venenum (Chansu), which has been traditionally used for the treatment of chronic pain especially cancer pain. The current study aimed to evaluate its antinociceptive effects in bone cancer pain and explore the underlying mechanisms.

Methods

Rat bone cancer model was used in this study. The withdrawal threshold evoked by stimulation of the hindpaw was determined using a 2290 CE electrical von Frey hair. The β-endorphin and IL-10 levels were measured in the spinal cord and cultured primary microglia, astrocytes, and neurons.

Results

Cinobufagin, given intrathecally, dose-dependently attenuated mechanical allodynia in bone cancer pain rats, with the projected E_max of 90% MPE and ED₅₀ of 6.4 μg. Intrathecal cinobufagin also stimulated the gene and protein expression of IL-10 and β-endorphin (but not dynorphin A) in the spinal cords of bone cancer pain rats. In addition, treatment with cinobufagin in cultured primary spinal microglia but not astrocytes or neurons stimulated the mRNA and protein expression of IL-10 and β-endorphin, which was prevented by the pretreatment with the IL-10 antibody but not β-endorphin antiserum. Furthermore, spinal cinobufagin-induced mechanical antiallodynia was inhibited by the pretreatment with intrathecal injection of the microglial inhibitor minocycline, IL-10 antibody, β-endorphin antiserum and specific μ-opioid receptor antagonist CTAP. Lastly, cinobufagin- and the specific α-7 nicotinic acetylcholine receptor (α7-nAChR) agonist PHA-543613-induced microglial gene expression of IL-10/β-endorphin and mechanical antiallodynia in bone cancer pain were blocked by the pretreatment with the specific α7-nAChR antagonist methyllycaconitine.

Conclusions

Our results illustrate that cinobufagin produces mechanical antiallodynia in bone cancer pain through spinal microglial expression of IL-10 and subsequent β-endorphin following activation of α7-nAChRs. Our results also highlight the broad significance of the recently uncovered spinal microglial IL-10/β-endorphin pathway in antinociception.

Identification and Classification of Differentially Expressed Genes and Network Meta-Analysis Reveals Potential Molecular Signatures Associated With Tuberculosis

Tuberculosis (TB) is one of deadly transmissible disease that causes death worldwide; however, only 10% of people infected with Mycobacteriumtuberculosis develop disease, indicating that host genetic factors may play key role in determining susceptibility to TB disease. In this way, the analysis of gene expression profiling of TB infected individuals can give us a snapshot of actively expressed genes and transcripts under various conditions. In the present study, we have analyzed microarray data set and compared the gene expression profiles of patients with different datasets of healthy control, latent infection, and active TB. We observed the transition of genes from normal condition to different stages of the TB and identified and annotated those genes/pathways/processes that have important roles in TB disease during its cyclic interventions in the human body. We identified 488 genes that were differentially expressed at various stages of TB and allocated to pathways and gene set enrichment analysis. These pathways as well as GSEA’s importance were evaluated according to the number of DEGs presents in both. In addition, we studied the gene regulatory networks that may help to further understand the molecular mechanism of immune response against the TB infection and provide us a new angle for future biomarker and therapeutic targets. In this study, we identified 26 leading hubs which are deeply rooted from top to bottom in the gene regulatory network and work as the backbone of the network. These leading hubs contains 31 key regulator genes, of which 14 genes were up-regulated and 17 genes were down-regulated. The proposed approach is based on gene-expression profiling, and network analysis approaches predict some unknown TB-associated genes, which can be considered (or can be tested) as reliable candidates for further (in vivo/in vitro) studies.

Knockout of SlMAPK3 enhances tolerance to heat stress involving ROS homeostasis in tomato plants

BACKGROUND

High temperature is a major environmental stress that limits plant growth and agriculture productivity. Mitogen-activated protein kinases (MAPKs) are highly conserved serine and threonine protein kinases that participate in response to diverse environmental stresses in plants. A total of 16 putative SlMAPK genes are identified in tomato, and SlMAPK3 is one of the most extensively studied SlMAPKs. However, the role of SlMAPK3 in response to heat stress is not clearly understood in tomato plants. In this study, we performed functional analysis of SlMAPK3 for its possible role in response to heat stress.

RESULTS

qRT-PCR analyses revealed that SlMAPK3 relative expression was depressed by heat stress. Here, wild-type (WT) tomato plants and CRISPR/Cas9-mediated slmapk3 mutant lines (L8 and L13) were used to investigate the function of SlMAPK3 in response to heat stress. Compared with WT plants, slmapk3 mutants exhibited less severe wilting and less membrane damage, showed lower reactive oxygen species (ROS) contents, and presented higher both activities and transcript levels of antioxidant enzymes, as well as elevated expressions of genes encoding heat stress transcription factors (HSFs) and heat shock proteins (HSPs).

CONCLUSIONS

CRISPR/Cas9-mediated slmapk3 mutants exhibited more tolerance to heat stress than WT plants, suggesting that SlMAPK3 was a negative regulator of thermotolerance. Moreover, antioxidant enzymes and HSPs/HSFs genes expression were involved in SlMAPK3-mediated heat stress response in tomato plants.