DUSP1/MKP-1 regulates proliferation and apoptosis in keratinocytes through the ERK/Elk-1/Egr-1 signaling pathway

The EGR1-Artemin Axis in Keratinocytes Enhances the Innervation of Epidermal Sensory Neurons during Skin Inflammation Induced by House Dust Mite Extract from Dermatophagoidesfarinae

Epidermal hyperinnervation is a critical feature of pruritus during skin inflammation. However, the mechanisms underlying epidermal hyperinnervation are unclear. This study investigates the role of the transcription factor EGR1 in epidermal innervation by utilizing wild-type (Egr1+/+) and Egr1-null (Egr1‒/‒) mice topically applied Dermatophagoides farinae extract from dust mite. Our findings revealed that Egr1‒/‒ mice exhibited reduced scratching behaviors and decreased density of epidermal innervation compared with Egr1+/+ mice. Furthermore, we identified artemin, a neurotrophic factor, as an EGR1 target responsible for Dermatophagoides farinae extract-induced hyperinnervation. It has been demonstrated that Dermatophagoides farinae extract stimulates toll-like receptors in keratinocytes. To elucidate the cellular mechanism, we stimulated keratinocytes with Pam3CSK4, a toll-like receptor 1/2 ligand. Pam3CSK4 triggered a toll-like receptor 1/2-mediated signaling cascade involving IRAK4, IκB kinase, MAPKs, ELK1, EGR1, and artemin, leading to increased neurite outgrowth and neuronal migration. In addition, increased expression of EGR1 and artemin was observed in the skin tissues of patients with atopic dermatitis. These findings highlight the significance of the EGR1-artemin axis in keratinocytes, promoting the process of epidermal innervation and suggesting it as a potential therapeutic target for alleviating itch and pain associated with house dust mite-induced skin inflammation.

Granzyme K mediates IL-23-dependent inflammation and keratinocyte proliferation in psoriasis

Psoriasis is an inflammatory disease with systemic manifestations that most commonly presents as itchy, erythematous, scaly plaques on extensor surfaces. Activation of the IL-23/IL-17 pro-inflammatory signaling pathway is a hallmark of psoriasis and its inhibition is key to clinical management. Granzyme K (GzmK) is an immune cell-secreted serine protease elevated in inflammatory and proliferative skin conditions. In the present study, human psoriasis lesions exhibited elevated GzmK levels compared to non-lesional psoriasis and healthy control skin. In an established murine model of imiquimod (IMQ)-induced psoriasis, genetic loss of GzmK significantly reduced disease severity, as determined by delayed plaque formation, decreased erythema and desquamation, reduced epidermal thickness, and inflammatory infiltrate. Molecular characterization in vitro revealed that GzmK contributed to macrophage secretion of IL-23 as well as PAR-1-dependent keratinocyte proliferation. These findings demonstrate that GzmK enhances IL-23-driven inflammation as well as keratinocyte proliferation to exacerbate psoriasis severity.

Effect of in vivo culture conditions on the proliferation and differentiation of rat adipose-derived stromal cells

Adipose-derived stromal cells (ADSCs) are promising stem cell sources for tissue engineering and cell-based therapy. However, long-term in vitro expansion of ADSCs impedes stemness maintenance, which is partly attributed to deprivation of their original microenvironment. Incompetent cells limit the therapeutic effects of ADSC-based clinical strategies. Therefore, reconstructing a more physiologically and physically relevant niche is an ideal strategy to address this issue and therefore facilitates the extensive application of ADSCs. Here, we transplanted separated ADSCs into local subcutaneous adipose tissues of nude mice as an in vivo cell culture model. We found that transplanted ADSCs maintained their primitive morphology and showed improved proliferation and delayed senescence compared to those of cells cultured in an incubator. Significantly increased expression of stemness-related markers and multilineage differentiation abilities were further observed in in vivo cultured ADSCs. Finally, sequencing revealed that genes whose expression differed between ADSCs obtained under in vivo and in vitro conditions were mainly located in the extracellular matrix and extracellular space and that these genes participate in regulating transcription and protein synthesis. Moreover, we found that an Egr1 signaling pathway might exert a crucial impact on controlling stemness properties. Our findings might collectively pave the way for ADSC-based applications.

Natural Product-Derived Compounds Targeting Keratinocytes and Molecular Pathways in Psoriasis Therapeutics

Psoriasis is a chronic autoimmune inflammatory skin disorder that affects approximately 2-3% of the global population due to significant genetic predisposition. It is characterized by an uncontrolled growth and differentiation of keratinocytes, leading to the formation of scaly erythematous plaques. Psoriasis extends beyond dermatological manifestations to impact joints and nails and is often associated with systemic disorders. Although traditional treatments provide relief, their use is limited by potential side effects and the chronic nature of the disease. This review aims to discuss the therapeutic potential of keratinocyte-targeting natural products in psoriasis and highlight their efficacy and safety in comparison with conventional treatments. This review comprehensively examines psoriasis pathogenesis within keratinocytes and the various related signaling pathways (such as JAK-STAT and NF-κB) and cytokines. It presents molecular targets such as high-mobility group box-1 (HMGB1), dual-specificity phosphatase-1 (DUSP1), and the aryl hydrocarbon receptor (AhR) for treating psoriasis. It evaluates the ability of natural compounds such as luteolin, piperine, and glycyrrhizin to modulate psoriasis-related pathways. Finally, it offers insights into alternative and sustainable treatment options with fewer side effects.

Down-regulation of MKP-1 in hippocampus protects against stress-induced depression-like behaviors and neuroinflammation

Chronic stress is the primary environmental risk factor for major depressive disorder (MDD), and there is compelling evidence that neuroinflammation is the major pathomechanism linking chronic stress to MDD. Mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) is a negative regulator of MAPK signaling pathways involved in cellular stress responses, survival, and neuroinflammation. We examined the possible contributions of MKP-1 to stress-induced MDD by comparing depression-like behaviors (anhedonia, motor retardation, behavioral despair), neuroinflammatory marker expression, and MAPK signaling pathways among rats exposed to chronic unpredictable mild stress (CUMS), overexpressing MKP-1 in the hippocampus, and CUMS-exposed rats underexpressing MKP-1 in the hippocampus. Rats exposed to CUMS exhibited MKP-1 overexpression, greater numbers of activated microglia, and enhanced expressions of neuroinflammatory markers (interleukin [IL]-6, [IL]-1β, tumor necrosis factor [TNF]-ɑ, and decreased phosphorylation levels of ERK and p38 in the hippocampus as well as anhedonia in the sucrose preference test, motor retardation in the open field, and greater immobility (despair) in the forced swimming tests. These signs of neuroinflammation and depression-like behaviors and phosphorylation levels of ERK and p38 were also observed in rats overexpressing MKP-1 without CUMS exposure, while CUMS-induced neuroinflammation, microglial activation, phosphorylation levels of ERK and p38, and depression-like behaviors were significantly reversed by MKP-1 knockdown. Moreover, MKP-1 knockdown promoted the activation of the MAPK isoform ERK, implying that the antidepressant-like effects of MKP-1 knockdown may be mediated by the ERK pathway disinhibition. These findings suggested that hippocampal MKP-1 is an essential regulator of stress-induced neuroinflammation and a promising target for antidepressant development.

RORα is required for expansion and memory maintenance of ILC1s via a lymph node-liver axis

Type 1 innate lymphoid cells (ILC1s) possess adaptive immune features, which confer antigen-specific memory responses against haptens and viruses. However, the transcriptional regulation of memory ILC1 responses is currently not known. We show that retinoic acid receptor-related orphan receptor alpha (RORα) has high expression in memory ILC1s in murine contact hypersensitivity (CHS) models. RORα deficiency diminishes ILC1-mediated CHS responses significantly but has no effect on memory T cell-mediated CHS responses. During sensitization, RORα promotes sensitized-ILC1 expansion by suppressing expression of cell-cycle repressors in draining lymph nodes. RORα programs gene-expression patterns related to cell survival and is required for the long-term maintenance of memory ILC1s in the liver. Our findings reveal RORα to be a key transcriptional factor for sensitized-ILC1 expansion and long-term maintenance of memory ILC1s.

DUSP1 mRNA modulation during porcine circovirus type 2 and porcine reproductive and respiratory syndrome virus co-infection regulates viruses replication

The effects of porcine circovirus type 2b (PCV2b) and porcine reproductive and respiratory syndrome virus (PRRSV) co-infection in epithelial cells of the swine respiratory tract is unknown. In the present study, the newborn pig trachea cell line NPTr-CD163, which is permissive to both viruses, was persistently infected with PCV2b and then with PRRSV. Viral replication, cell viability, cytokines' mRNA expression, and modulation of cellular genes expression were evaluated in infected cells. In NPTr-CD163 co-infection model, PCV2b replication was enhanced while PRRSV replication was suppressed. Cell viability was significantly decreased during PCV2b single infection and co-infection compared to mock-infected and PRRSV single infected cells. However, no difference was observed in cell viability between PCV2b and PCV2b/PRRSV infected cells. The IL6, IL8 and IL10 mRNA expression was significantly higher in co-infected cells compared to PCV2b and PRRSV single infected cells. Moreover, the IFN-α/β expression was significantly reduced in co-infected cells compared to PCV2b infected cells whereas it remained higher compared to PRRSV infected cells. The differential gene expression analysis revealed that the mRNA expression level of the cellular gene DUSP1 was significantly higher in all PRRSV infection models compared to PCV2b single infected cells. Knockdown of DUSP1 expression in co-infected cells significantly reduced PCV2b replication, suggesting a role for DUSP1 in PCV2b/PRRSV pathogenesis.

DUSP2 affects bladder cancer prognosis by down-regulating MEK/ERK and P38 MAPK signaling pathways through PTPN7

BACKGROUND

As one of the leading causes of cancer death worldwide, bladder cancer (BCa) ranks 12th in incidence rate. Dual Specific Phosphatase 2 (DUSP2) is a member of the bispecific protein phosphatase subfamily. DUSP2 is closely related to the prognosis of cancer, but the role of DUSP2 in bladder cancer is still unclear. This study aims to explore how DUSP2 affects the prognosis of bladder cancer and clarify the important mechanism in bladder cancer.

METHODS

Bioinformatics and experiments have detected the anti-tumor effect of DUSP2. Construct a DUSP2 overexpression cell model, and then use protein blotting experiments to verify the efficiency of transfection. The effects of DUSP2 on proliferation, metastasis, apoptosis, epithelial mesenchymal transition (EMT) and immune invasion of bladder cancer cells were detected in vitro or in vivo. In addition, the mechanism of DUSP2 regulating MEK/ERK through PTPN7 pathway and P38 MAPK inhibiting the progression of bladder cancer was also discussed.

RESULTS

The expression of DUSP2 was down regulated in bladder cancer samples and cell lines. The overexpression of DUSP2 inhibits the proliferation, metastasis and immune microenvironment of bladder cancer cells. In addition, we confirmed that DUSP2 regulates MEK/ERK and P38 MAPK through PTPN7 pathway to inhibit the progression of bladder cancer.

CONCLUSION

DUSP2 inhibits the progression of bladder cancer by regulating PTPN7. These results suggest that DUSP2/PTPN7/MEK/ERK pathway may become a new therapeutic target for bladder cancer.

Signaling pathways and targeted therapies for psoriasis

Psoriasis is a common, chronic, and inflammatory skin disease with a high burden on individuals, health systems, and society worldwide. With the immunological pathologies and pathogenesis of psoriasis becoming gradually revealed, the therapeutic approaches for this disease have gained revolutionary progress. Nevertheless, the mechanisms of less common forms of psoriasis remain elusive. Furthermore, severe adverse effects and the recurrence of disease upon treatment cessation should be noted and addressed during the treatment, which, however, has been rarely explored with the integration of preliminary findings. Therefore, it is crucial to have a comprehensive understanding of the mechanisms behind psoriasis pathogenesis, which might offer new insights for research and lead to more substantive progress in therapeutic approaches and expand clinical options for psoriasis treatment. In this review, we looked to briefly introduce the epidemiology, clinical subtypes, pathophysiology, and comorbidities of psoriasis and systematically discuss the signaling pathways involving extracellular cytokines and intracellular transmission, as well as the cross-talk between them. In the discussion, we also paid more attention to the potential metabolic and epigenetic mechanisms of psoriasis and the molecular mechanistic cascades related to its comorbidities. This review also outlined current treatment for psoriasis, especially targeted therapies and novel therapeutic strategies, as well as the potential mechanism of disease recurrence.

A Comprehensive Bioinformatics Approach to Identify Molecular Signatures and Key Pathways for the Huntington Disease

Huntington disease (HD) is a degenerative brain disease caused by the expansion of CAG (cytosine-adenine-guanine) repeats, which is inherited as a dominant trait and progressively worsens over time possessing threat. Although HD is monogenetic, the specific pathophysiology and biomarkers are yet unknown specifically, also, complex to diagnose at an early stage, and identification is restricted in accuracy and precision. This study combined bioinformatics analysis and network-based system biology approaches to discover the biomarker, pathways, and drug targets related to molecular mechanism of HD etiology. The gene expression profile data sets GSE64810 and GSE95343 were analyzed to predict the molecular markers in HD where 162 mutual differentially expressed genes (DEGs) were detected. Ten hub genes among them (DUSP1, NKX2-5, GLI1, KLF4, SCNN1B, NPHS1, SGK2, PITX2, S100A4, and MSX1) were identified from protein-protein interaction (PPI) network which were mostly expressed as down-regulated. Following that, transcription factors (TFs)-DEGs interactions (FOXC1, GATA2, etc), TF-microRNA (miRNA) interactions (hsa-miR-340, hsa-miR-34a, etc), protein-drug interactions, and disorders associated with DEGs were predicted. Furthermore, we used gene set enrichment analysis (GSEA) to emphasize relevant gene ontology terms (eg, TF activity, sequence-specific DNA binding) linked to DEGs in HD. Disease interactions revealed the diseases that are linked to HD, and the prospective small drug molecules like cytarabine and arsenite was predicted against HD. This study reveals molecular biomarkers at the RNA and protein levels that may be beneficial to improve the understanding of molecular mechanisms, early diagnosis, as well as prospective pharmacologic targets for designing beneficial HD treatment.

Low let-7d microRNA levels in chick embryos enhance innate immunity against Mycoplasma gallisepticum by suppressing the mitogen-activated protein kinase pathway

Chick embryos are a valuable model for studying immunity and vaccines. Therefore, it is crucial to investigate the molecular mechanism of the Mycoplasma gallisepticum (MG)-induced immune response in chick embryos for the prevention and control of MG. In this study, we screened for downregulated let-7d microRNA in MG-infected chicken embryonic lungs to explore its involvement in the innate immune mechanism against MG. Here, we demonstrated that low levels of let-7d are a protective mechanism for chicken embryo primary type II pneumocytes (CP-II) in the presence of MG. Specifically, we found that depressed levels of let-7 in CP-II cells reduced the adhesion capacity of MG. This suppressive effect was achieved through the activated mitogen-activated protein kinase phosphatase 1 (MKP1) target gene and the inactivated mitogen-activated protein kinase (MAPK) pathway. Furthermore, MG-induced hyperinflammation and cell death were both alleviated by downregulation of let-7d. In conclusion, chick embryos protect themselves against MG infection through the innate immune molecule let-7d, which may result from its function as an inhibitor of the MAPK pathway to effectively mitigate MG adhesion, the inflammatory response and cell apoptosis. This study may provide new insight into the development of vaccines against MG.

Methylprednisolone Promotes Mycobacterium smegmatis Survival in Macrophages through NF-κB/DUSP1 Pathway

Background: Mycobacterium tuberculosis (M. tuberculosis) is the causative agent of tuberculosis. As an important component of host immunity, macrophages are not only the first line of defense against M. tuberculosis but also the parasitic site of M. tuberculosis in the host. Glucocorticoids can cause immunosuppression, which is considered to be one of the major risk factors for active tuberculosis, but the mechanism is unclear. Objective: To study the effect of methylprednisolone on the proliferation of mycobacteria in macrophages and try to find key molecules of this phenomenon. Methods: The macrophage line RAW264.7 infected by M. smegmatis was treated with methylprednisolone, and the intracellular bacterial CFU, Reactive Oxygen Species (ROS), cytokine secretion, autophagy, and apoptosis were measured. After the cells were treated with NF-κB inhibitor BAY 11-7082 and DUSP1 inhibitor BCI, respectively, the intracellular bacterial CFU, ROS, IL-6, and TNF-α secretion were detected. Results: After treatment with methylprednisolone, the CFU of intracellular bacteria increased, the level of ROS decreased, and the secretion of IL-6 and TNF-α decreased in infected macrophages. After BAY 11-7082 treatment, the CFU of M. smegmatis in macrophages increased, and the level of ROS production and the secretion of IL-6 by macrophages decreased. Transcriptome high-throughput sequencing and bioinformatics analysis suggested that DUSP1 was the key molecule in the above phenomenon. Western blot analysis confirmed that the expression level of DUSP1 was increased in the infected macrophages treated with methylprednisolone and BAY 11-7082, respectively. After BCI treatment, the level of ROS produced by infected macrophages increased, and the secretion of IL-6 increased. After the treatment of BCI combined with methylprednisolone or BAY 11-7082, the level of ROS produced and the secretion of IL-6 by macrophages were increased. Conclusion: methylprednisolone promotes the proliferation of mycobacteria in macrophages by suppressing cellular ROS production and IL-6 secretion through down-regulating NF-κB and up-regulating DUSP1 expression. BCI, an inhibitor of DUSP1, can reduce the level of DUSP1 in the infected macrophages and inhibit the proliferation of intracellular mycobacteria by promoting cellular ROS production and IL-6 secretion. Therefore, BCI may become a new molecule for host-directed therapy of tuberculosis, as well as a new strategy for the prevention of tuberculosis when treated with glucocorticoids.

DUSP1 mediates BCG induced apoptosis and inflammatory response in THP-1 cells via MAPKs/NF-κB signaling pathway

Tuberculosis (TB) is a zoonotic infectious disease caused by Mycobacterium tuberculosis (Mtb). Apoptosis and necrosis caused by the interaction between the host and the pathogen, as well as the host's inflammatory response, play an important role in the pathogenesis of TB. Dual-specificity phosphatase 1 (DUSP1) plays a vital role in regulating the host immune responses. However, the role of DUSP1 in the regulation of THP-1 macrophage apoptosis induced by attenuated Mycobacterium bovis Bacillus Calmette-Guérin (BCG) infection remains unclear. In the present study, we report that infection with BCG significantly induces macrophage apoptosis and induces the production of DUSP1, TNF-α and IL-1β. DUSP1 knockdown significantly inhibited BCG-induced macrophage apoptosis and activation of MAPKs/NF-κB signaling pathway. In addition, DUSP1 knockdown suppressed BCG-induced inflammation in vivo. Taken together, this study demonstrates that DUSP1, as a regulator of MAPKs/NF-κB signaling pathway, plays a novel role in BCG-induced macrophage apoptosis and inflammatory response.

Exosomal let-7f-5p derived from mineralized osteoblasts promotes the angiogenesis of endothelial cells via the DUSP1/Erk1/2 signaling pathway

Blood vessel formation is the prerequisite for the survival and growth of tissue-engineered bone. Mineralized osteoblasts (MOBs) have been shown to regulate angiogenesis through the secretion of exosomes containing various pro-angiogenic factors. However, whether the mineralized osteoblast-derived exosomes (MOB-Exos) containing let-7f-5p can regulate the angiogenesis of endothelial cells (ECs) is still unknown. In this study, the angiogenic capabilities of ECs respectively treated with MOB-Exos, let-7f-5p mimicked MOB-Exos (miR mimic group), and let-7f-5p inhibited MOB-Exos (miR inhibitor group) were compared through in vitro and in vivo studies. Moreover, the potential mechanism of MOB-Exo let-7f-5p regulating angiogenesis was explored by verifying the role of the Erk1/2 signaling pathway and target gene DUSP1. The results showed that MOB-Exos could significantly promote the angiogenesis of ECs, which could be enhanced by mimicked exosomal let-7f-5p and attenuated by inhibited exosomal let-7f-5p. Let-7f-5p could suppress the luciferase activity of wide-type DUSP1, and the mutation of DUSP1 could abrogate the repressive ability of let-7f-5p. Furthermore, the expression of DUSP1 exhibited a reversed trend to that of pErk1/2. The expression of pErk1/2 was significantly higher in the miR mimic group and lower in the miR inhibitor group than that in the MOB-Exos group, while inhibition of pErk1/2 could partly impair the angiogenic capabilities of ECs. In conclusion, we concluded that exosomal let-7f-5p derived from MOBs could promote the angiogenesis of ECs via activating the DUSP1/Erk1/2 signaling pathway, which might be a promising target for promoting the angiogenesis of tissue-engineered bone.

Comprehensive ceRNA network for MACF1 regulates osteoblast proliferation

BACKGROUND

Previous studies have shown that microtubule actin crosslinking factor 1 (MACF1) can regulate osteoblast proliferation and differentiation through non-coding RNA (ncRNA) in bone-forming osteoblasts. However, the role of MACF1 in targeting the competing endogenous RNA (ceRNA) network to regulate osteoblast differentiation remains poorly understood. Here, we profiled messenger RNA (mRNA), microRNA (miRNA), and long ncRNA (lncRNA) expression in MACF1 knockdown MC3TC‑E1 pre‑osteoblast cells.

RESULTS

In total, 547 lncRNAs, 107 miRNAs, and 376 mRNAs were differentially expressed. Significantly altered lncRNAs, miRNAs, and mRNAs were primarily found on chromosome 2. A lncRNA-miRNA-mRNA network was constructed using a bioinformatics computational approach. The network indicated that mir-7063 and mir-7646 were the most potent ncRNA regulators and mef2c was the most potent target gene. Pathway enrichment analysis showed that the fluid shear stress and atherosclerosis, p53 signaling, and focal adhesion pathways were highly enriched and contributed to osteoblast proliferation. Importantly, the fluid shear stress and atherosclerosis pathway was co-regulated by lncRNAs and miRNAs. In this pathway, Dusp1 was regulated by AK079370, while Arhgef2 was regulated by mir-5101. Furthermore, Map3k5 was regulated by AK154638 and mir-466q simultaneously. AK003142 and mir-3082-5p as well as Ak141402 and mir-446 m-3p were identified as interacting pairs that regulate target genes.

CONCLUSION

This study revealed the global expression profile of ceRNAs involved in the differentiation of MC3TC‑E1 osteoblasts induced by MACF1 deletion. These results indicate that loss of MACF1 activates a comprehensive ceRNA network to regulate osteoblast proliferation.

Effect of miR-101 on the Proliferation and Apoptosis of Goat Hair Follicle Stem Cells

The Yangtze River Delta white goat is a rare goat species capable of producing high-quality brush hair. Dual specificity protein phosphatase 1 (DUSP1) may play a role in the formation of high-quality brush hair, as evidenced by our previous research. We investigated the potential mechanisms that regulate the proliferation and apoptosis of goat hair follicle stem cells. We particularly focused on the relationship between DUSP1 and miR-101, which directly targets DUSP1, predicted and screened through bioinformatics websites. Then, fluorescence assays, flow cytometry, RT-qPCR, and Western blotting were used to investigate the effects of miR-101 on the proliferation and apoptosis of hair follicle stem cells. We found that miR-101 overexpression significantly decreased (p < 0.01) apoptosis and promoted the proliferation of hair follicle stem cells. Furthermore, the overexpression of miR-101 increased (p < 0.05) the mRNA and protein expression levels of the proliferation-related gene (PCNA) and anti-apoptotic gene (Bcl-2), and it decreased (p < 0.05) the mRNA and protein expression levels of the apoptotic gene (Bax). In conclusion, miR-101 can promote the proliferation of and inhibit the apoptosis of hair follicle stem cells by targeting DUSP1, which provides a theoretical basis for further elucidating the molecular mechanism that regulates the production of high-quality brush hair of Yangtze River Delta white goats.

Bone Marrow Mesenchymal Stem Cells (BMSCs)-Exosome Inhibits Epithelial Ovarian Cancer (EOC) Cell Proliferative Ability Through Regulating Mitogen-Activated Protein Kinase (MKP)-1 and Mitogen-Activated Protein Kinases (MAPK)/Extracellular-Signal-Regulated Kinase (ERK) Signal Pathway

The BMSCs-exosome plays a role in regulating tumor micro-environment so as to affect tumor cell biological behaviors. However, whether it affects the biological characteristics of epithelial ovarian cancer (EOC) cells remains unclear. Our study aimed to discuss whether BMSCs-exosome affects EOC cell proliferative ability. BMSCs cells were cultivated to isolate exosome which was used to treat EOC cells at different concentrations (25, 50, and 100 μmol/L) followed by measuring cell proliferation by CCK-8, cell invasion and migration by Transwell, MKP-1and MAPK/ERK protein level by Western Blot. BMSCs-exosome showed positive expression of CD9, CD63 and CD81 and negative CD116 and CD19. It could significantly inhibit EOC cell proliferation, invasion and migration in a dose-dependent manner along with reduced expression of MAPK/ERK. In conclusion, BMSCs-exosome inhibits EOC cell biological behaviors possibly through regulation of MKP-1 and MAPK/ERK signal pathway, indicating that it might be used as a novel approach for treating EOC.

Genome-scale screening in a rat haploid system identifies Thop1 as a modulator of pluripotency exit

OBJECTIVES

The rats are crucial animal models for the basic medical researches. Rat embryonic stem cells (ESCs), which are widely studied, can self-renew and exhibit pluripotency in long-term culture, but the mechanism underlying how they exit pluripotency remains obscure. To investigate the key modulators on pluripotency exiting in rat ESCs, we perform genome-wide screening using a unique rat haploid system.

MATERIALS AND METHODS

Rat haploid ESCs (haESCs) enable advances in the discovery of unknown functional genes owing to their homozygous and pluripotent characteristics. REX1 is a sensitive marker for the naïve pluripotency that is often utilized to monitor pluripotency exit, thus rat haESCs carrying a Rex1-GFP reporter are used for genetic screening. Genome-wide mutations are introduced into the genomes of rat Rex1-GFP haESCs via piggyBac transposon, and differentiation-retarded mutants are obtained after random differentiation selection. The exact mutations are elucidated by high-throughput sequencing and bioinformatic analysis. The role of candidate mutation is validated in rat ESCs by knockout and overexpression experiments, and the phosphorylation of ERK1/2 (p-ERK1/2) is determined by western blotting.

RESULTS

High-throughput sequencing analysis reveals numerous insertions related to various pathways affecting random differentiation. Thereafter, deletion of Thop1 (one candidate gene in the screened list) arrests the differentiation of rat ESCs by inhibiting the p-ERK1/2, whereas overexpression of Thop1 promotes rat ESCs to exit from pluripotency.

CONCLUSIONS

Our findings provide an ideal tool to study functional genomics in rats: a homozygous haploid system carrying a pluripotency reporter that facilitates robust discovery of the mechanisms involved in the self-renewal or pluripotency of rat ESCs.

The tumor suppressor MIR139 is silenced by POLR2M to promote AML oncogenesis

MIR139 is a tumor suppressor and is commonly silenced in acute myeloid leukemia (AML). However, the tumor-suppressing activities of miR-139 and molecular mechanisms of MIR139-silencing remain largely unknown. Here, we studied the poorly prognostic MLL-AF9 fusion protein-expressing AML. We show that MLL-AF9 expression in hematopoietic precursors caused epigenetic silencing of MIR139, whereas overexpression of MIR139 inhibited in vitro and in vivo AML outgrowth. We identified novel miR-139 targets that mediate the tumor-suppressing activities of miR-139 in MLL-AF9 AML. We revealed that two enhancer regions control MIR139 expression and found that the polycomb repressive complex 2 (PRC2) downstream of MLL-AF9 epigenetically silenced MIR139 in AML. Finally, a genome-wide CRISPR-Cas9 knockout screen revealed RNA Polymerase 2 Subunit M (POLR2M) as a novel MIR139-regulatory factor. Our findings elucidate the molecular control of tumor suppressor MIR139 and reveal a role for POLR2M in the MIR139-silencing mechanism, downstream of MLL-AF9 and PRC2 in AML. In addition, we confirmed these findings in human AML cell lines with different oncogenic aberrations, suggesting that this is a more common oncogenic mechanism in AML. Our results may pave the way for new targeted therapy in AML.

MiR-34a-3p suppresses pulmonary vascular proliferation in acute pulmonary embolism rat by targeting DUSP1

BACKGROUND

Acute pulmonary embolism (APE) is a prevalent reason of cardiovascular morbidity and mortality. Recent studies have underscored the positive effects of microRNAs (miRNAs) on many diseases. The present study aimed to identify the critical miRNA with differential expressions and explore its role in APE.

METHODS

The critical miRNA with its target gene was screened by bioinformatics analysis. Their binding relationship was analyzed by TargetScan, Dual-luciferase reporter and RNA pull-down assays. A rat model of APE was established by self-blood coagulum. Human pulmonary artery smooth muscle cells (PASMCs) were exposed to platelet-derived growth factor (PDGF-BB) for excessive proliferation, and transfected with miR-34a-3p mimic. Mean pulmonary arterial pressure (mPAP) of rat was measured, and the pulmonary tissues were used for the pathological observation by Hematoxylin-Eosin (H&E) staining. Cell viability and proliferation were detected by Cell Counting Kit-8 (CCK-8) and EdU assays. The expressions of miR-34a-3p with its target genes (including dual-specificity phosphatase-1 (DUSP1)), neuron-derived orphan receptor-1 (NOR-1) and proliferating cell nuclear antigen (PCNA) were determined by quantitative reverse transcription polymerase chain reaction (RT-qPCR) or/and Western blot.

RESULTS

MiR-34a-3p expression was down-regulated in APE patients, which attenuated the increment of mPAP and thickening of the pulmonary arterial walls in APE rats, accompanied with regulation of NOR-1 and PCNA levels. MiR-34a-3p suppressed DUSP1 expression by directly binding to its 3'-untranslated region (UTR), and attenuated cell viability, proliferation, and the expressions of NOR-1 and PCNA in PDGF-BB-induced PASMCs by inhibiting DUSP1 expression.

CONCLUSION

Up-regulated miR-34a-3p negatively regulates DUSP1 expression to inhibit PASMC proliferation, which, thus, may act on APE treatment by negatively regulating pulmonary vascular proliferation.

Glucose-regulated protein 78 modulates cell growth, epithelial-mesenchymal transition, and oxidative stress in the hyperplastic prostate

Benign prostatic hyperplasia (BPH) is a chronic condition which mainly affects elderly males. Existing scientific evidences have not completely revealed the pathogenesis of BPH. Glucose-regulated protein 78 (GRP78) is a member of the heat shock protein 70 superfamily, which serves as an important regulator in many diseases. This study aims at elucidating the role of GRP78 in the BPH process. Human prostate tissues, cultured human prostate cell lines (BPH-1 and WPMY-1) and clinical data from BPH patients were utilized. The expression and localization of GRP78 were determined with quantitative real time PCR (qRT-PCR), Western blotting and immunofluorescence staining. GRP78 knockdown and overexpression cell models were created with GRP78 siRNA and GRP78 plasmid transfection. With these models, cell viability, apoptosis rate, as well as marker levels for epithelial-mesenchymal transition (EMT) and oxidative stress (OS) were detected by CCK8 assay, flow cytometry analysis and Western blotting respectively. AKT/mTOR and MAPK/ERK pathways were also evaluated. Results showed GRP78 was localized in the epithelium and stroma of the prostate, with higher expression in BPH tissues. There was no significant difference in GRP78 expression between BPH-1 and WPMY-1 cell lines. In addition, GRP78 knockdown (KD) slowed cell growth and induced apoptosis, without effects on the cell cycle stage of both cell lines. Lack of GRP78 affected expression levels of markers for EMT and OS. Consistently, overexpression of GRP78 completely reversed all effects of knocking down GRP78. We further found that GRP78 modulated cell growth and OS via AKT/mTOR signaling, rather than the MAPK/ERK pathway. Overall, our novel data demonstrates that GRP78 plays a significant role in the development of BPH and suggests that GRP78 might be rediscovered as a new target for treatment of BPH.

Advances in the pathogenesis of psoriasis: from keratinocyte perspective

Psoriasis is a complex long-lasting inflammatory skin disease with high prevalence and associated comorbidity. It is characterized by epidermal hyperplasia and dermal infiltration of immune cells. Here, we review the role of keratinocytes in the pathogenesis of psoriasis, focusing on factors relevant to genetics, cytokines and receptors, metabolism, cell signaling, transcription factors, non-coding RNAs, antimicrobial peptides, and proteins with other different functions. The critical role of keratinocytes in initiating and maintaining the inflammatory state suggests the great significance of targeting keratinocytes for the treatment of psoriasis.

Zinc antagonizes common carp (Cyprinus carpio) intestinal arsenic poisoning through PI3K/AKT/mTOR signaling cascade and MAPK pathway

Arsenic (As) pollution is a serious and longstanding problem, which has obvious threaten to aquatic organisms. The study aimed to explore the mitigation effect of natural antioxidant zinc (Zn) on As toxicity in the foregut and midgut of common carp (Cyprinus carpio L.), and in-depth disclose related signal cascade. Carps were treated with Zn²⁺ (1 mg/L) and/or As³⁺ (2.83 mg/L) for a period of 30 days. Under As exposure, the foregut and midgut showed obvious burst of reactive oxygen species (ROS) and breakdown of antioxidant system. What followed is the activation of the endogenous and exogenous apoptotic pathways, and the rise of autophagy level prompted by the increase in LC3 II and the down-regulation of p62. Mitochondrial swelling, cristae fragmentation and autophagosomes were observed under the electron microscope, which also means the occurrence of apoptosis and autophagy. In addition, As induced the activation of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK) and the inhibition of extracellular signal-related kinase (ERK) in MAPK signaling, and up-regulated the level of autophagy through the inhibition of the phosphatidylinositol 3 kinase (PI3K)/AKT/ mammalian target of rapamycin (mTOR) signaling cascade. However, Zn supplementation has clearly reversed the above phenomenon, and it basically has no effect on foregut and midgut. In conclusion, this study shows that Zn can alleviate the damage caused by subchronic As exposure, which provides a reference for the use of Zn preparations in aquaculture.

Single-Cell Analysis Reveals Major Histocompatibility Complex II‒Expressing Keratinocytes in Pressure Ulcers with Worse Healing Outcomes

Pressure ulcer (PU) is a chronic wound often seen in patients with spinal cord injury and other bed-bound individuals, particularly in the elderly population. Despite its association with high mortality, the pathophysiology of PU remains poorly understood. In this study, we compared single-cell transcriptomic profiles of human epidermal cells from PU wound edges with those from uninjured skin and acute wounds in healthy donors. We identified significant shifts in the cell composition and gene expression patterns in PU. In particular, we found that major histocompatibility complex class II‒expressing keratinocytes were enriched in patients with worse healing outcomes. Furthermore, we showed that the IFN-γ in PU-derived wound fluid could induce major histocompatibility complex II expression in keratinocytes and that these wound fluid‒treated keratinocytes inhibited autologous T-cell activation. In line with this observation, we found that T cells from PUs enriched with major histocompatibility complex II⁺ keratinocytes produced fewer inflammatory cytokines. Overall, our study provides a high-resolution molecular map of human PU compared with that of acute wounds and intact skin, providing insights into PU pathology and the future development of tailored wound therapy.

Sortilin regulates keratinocyte proliferation and apoptosis through the PI3K-AKT signaling pathway

Sortilin is found to regulate proliferation and death of different cells, while its role in regulating keratinocyte proliferation and apoptosis is still unknown. In this study, we found that sortilin levels significantly increased in psoriasis patients, and sortilin suppression eliminated the proliferation of HaCaT cells induced by M5 cocktail solution and enhanced the levels of cleaved caspase 3 protein and the Bax/Bcl-2 ratio; however, levels of p-PI3K and p-AKT were decreased. In addition, sortilin silencing remitted the characteristic changes associated with psoriasis-like skin lesions. In summary, suppressed sortilin expression helped inhibit keratinocyte proliferation in HaCaT cells by inactivating PI3K/AKT signaling, which provides a new target for the therapy of psoriasis.

Studies on the anti-psoriasis effects and its mechanism of a dual JAK2/FLT3 inhibitor flonoltinib maleate

Psoriasis is a chronic, inflammatory autoimmune disease mediated by T cells, and characterized with abnormal proliferation and differentiation of keratinocytes, and inflammatory infiltration. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway has been identified to play essential roles in mediating various of biological processes, and is closely related to autoimmune diseases. Dendritic cells (DCs) are important antigen presenting cells and play an important regulatory role in T cells. The proliferation, differentiation and function of DCs are regulated by JAK and FMS-like tyrosine kinase 3 (FLT3) signal pathways. Flonoltinib maleate (FM), a high selectivity dual JAK2/FLT3 inhibitor with IC50 values of 0.8 nM and 15 nM for JAK2 and FLT3, respectively, was developed by our laboratory. Moreover, FM was a potent JAK2 inhibitor with 863-fold and 696-fold selectivity over JAK1 and JAK3, respectively. In this study, the anti-psoriasis activity of FM was evaluated both in vitro and in vivo. FM effectively inhibited the proliferation of HaCaT, the inflammatory keratinocyte induced by M5 and markedly suppressed the generation and differentiation of DCs from bone marrow (BM), and inhibited the expression of FLT3 in DCs in vitro. FM effectively inhibited the ear thickening and improved the pathological changes of the ear in interleukin (IL)-23-induced psoriasis-like acanthosis mouse model. Further in keratin 14-vascular endothelial growth factor (K14-VEGF) transgenic homozygous mice model, FM could obviously improve the psoriatic symptom and pathological changes, significantly inhibit the generations of Th1 and Th17 cells in the spleen, and the accumulations of DCs in the ears. FM could also significantly reduce the expression of various inflammatory factors both in C57BL/6 and K14-VEGF mice ears, and the serum of K14-VEGF mice. Mechanism revealed that FM effectively suppressed the phosphorylation of JAK2, STAT3 and STAT5 in inflammatory keratinocytes and the mice ears of C57BL/6 and K14-VEGF, as well as the phosphorylation of FLT3 in K14-VEGF mice ears. In conclusion, FM plays an excellent anti-psoriasis activity, including inhibiting keratinocyte proliferation and regulating inflammatory response through inhibiting JAK2 and FLT3 signaling pathway.

RNA sequencing and bioinformatics analysis of human lens epithelial cells in age-related cataract

Background

Age-related cataract (ARC) is the main cause of blindness in older individuals but its specific pathogenic mechanism is unclear. This study aimed to identify differentially expressed genes (DEGs) associated with ARC and to improve our understanding of the disease mechanism.

Methods

Anterior capsule samples of the human lens were collected from ARC patients and healthy controls and used for RNA sequencing to detect DEGs. Identified DEGs underwent bioinformatics analyses, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Subsequently, reverse transcription quantitative RT-qPCR was used to validate the different expression levels of selected genes.

Results

A total of 698 up-regulated DEGs and 414 down-regulated DEGs were identified in ARC patients compared with controls by transcriptome analysis. Through GO and KEGG bioinformatics analysis, the functions of significantly DEGs and their possible molecular mechanisms were determined. Sequencing results were verified by RT-qPCR as being accurate and reliable.

Conclusions

This study identified several genes associated with ARC, which improves our knowledge of the disease mechanism.

Targeting the MDSCs of Tumors In Situ With Inhibitors of the MAPK Signaling Pathway to Promote Tumor Regression

Myeloid-derived suppressor cells (MDSCs) are one of the major components of the tumor microenvironment. Evidence has shown differences in the functions and fates of MDSCs in the tumor tissue and the periphery. However, the exact mechanism that regulates MDSC function has not been completely clarified. In this study, we performed RNA sequencing of MDSCs derived from the spleen and tumor. Based on the results of our RNA-seq analysis, mitogen-activated protein kinases (MAPK) were significantly increased in tumor polymorphonuclear MDSCs (PMN-MDSCs) and monocytic MDSCs (M-MDSCs). Subsequently, 3 major MAPK pathways, including extracellular signal-regulated protein kinases (ERK), p38 and c-Jun NH2-terminal kinases (JNK), were studied to analyze the role of MAPKs in MDSCs. The ERK 1/2 inhibitor SCH772984 and the JNK inhibitor SP600125 significantly increased the apoptosis of both PMN-MDSCs and M-MDSCs in vitro. In addition, SCH772984 exerted a strong effect on inhibiting tumor growth. The flow cytometry analysis showed significant increases in the ratio of M1:M2 tumor-associated macrophages, meanwhile the number of CD4⁺, CD8⁺, CD4⁺CD69⁺ and CD8⁺CD69⁺ lymphocytes were increased after SCH772984 treatment. Our findings established the effect of MAPKs on the tumor microenvironment via MDSCs and may facilitate the development of new antitumor strategies.

Symbiotic Bacterium-Derived Organic Acids Protect Delia antiqua Larvae from Entomopathogenic Fungal Infection

Colonization resistance, i.e., the protective effects of associated microbiota for the animal host against pathogen infection, has been studied widely over the last 100 years. However, few molecules mediating colonization resistance have been identified. In the symbiosis formed by Delia antiqua and its associated microbes, six bacteria protect larvae from infection with the entomopathogen Beauveria bassiana, providing an ideal model to investigate the chemical mechanism for colonization resistance. Subsequently using this symbiotic system, we first compared effects of the six bacterial species, and one control bacterium (Klebsiella oxytoca) that showed no antifungal effects, on B. bassiana and its infection of D. antiqua Second, metabolomic profiles of the six bacteria and K. oxytoca were compared to identify candidate metabolites that may prevent infection. Third, the concentrations of candidate metabolites in situ from axenic and nonaxenic larvae were determined. Finally, effects of artificial metabolite cocktails on B. bassiana and its infection of D. antiqua larvae were determined. Results showed that compared to K. oxytoca, the six bacteria produced a metabolite cocktail showing inhibitory effects on conidial germination, mycelial growth of B. bassiana, and fungal infection. Our work revealed novel molecules that mediate colonization resistance, which could help in developing chemical mechanisms of colonization resistance. Moreover, this work may aid in discovery and expansion of new bioactive antibiotics, promoting development of prophylactic and therapeutic approaches for treating infectious diseases.IMPORTANCE The protection of associated microbiota for their animal hosts against pathogen infection has been studied widely over the last 100 years. However, how those microbes protect the animal host remains unclear. In former studies, body surface microbes of one insect, Delia antiqua, protected the insect larvae from infection with the entomopathogen Beauveria bassiana By comparing the metabolites produced by microbes that protect the insect and microbes that cannot protect the insect, the question of how the microbes protect the insect is answered. It turns out that body surface bacteria produce a metabolite cocktail that inhibits colonization of B. bassiana and consequently protects the insect. This work reveals novel molecules with antifungal activity, which may aid in discovery and expansion of new prophylactic and therapeutic natural chemicals for treating infectious diseases.

Citrus sudachi Peel Extract Suppresses Cell Proliferation and Promotes the Differentiation of Keratinocytes through Inhibition of the EGFR-ERK Signaling Pathway

Citrus sudachi is a well-known fruit in Tokushima Prefecture, Japan, and its peels are rich in phytochemicals, including phenolic compounds. Although it is expected that the extract of the C. sudachi peel elicits various beneficial physiological activities, the effect on the skin has not been investigated. In this study, we report that the aqueous extract from the peel of C. sudachi suppresses cell proliferation of the immortalized human keratinocyte cell line, HaCaT, and primary normal human epidermal keratinocytes. The extract of C. sudachi peel suppressed epidermal growth factor (EGF)-induced EGF receptor activation and tumor necrosis factor (TNF)-α-induced extracellular regulated kinase (ERK) 1/2 activation, which suggests that the extract exerts its inhibitory effect through inhibition of both the EGF receptor (EGFR) and its downstream molecules. Additionally, the extract of C. sudachi peel potentiated calcium-induced keratinocyte differentiation. These results suggest that the extract of C. sudachi peel may have beneficial effects against skin diseases that are characterized by hyperproliferation of epidermal keratinocytes, such as those seen in psoriasis and in cutaneous squamous cell carcinoma.

The Effect of Cyclosporine A on Dermal Fibroblast Cell - Transcriptomic Analysis of Inflammatory Response Pathway

BACKGROUND

The first immunosuppressive drug - cyclosporine A (CsA) has many unquestioned merits in maintaining organ transplants in patients, as well as, in the treatment of many inflammatory diseases, also associated with cutaneous manifestations. The main task of this drug is to suppress the inflammatory response at the sites of action, which is not well known.

OBJECTIVE

The objective of this study was to evaluate the influence of CsA in therapeutic concentration on the expression of genes associated with the inflammatory response pathway in normal human dermal fibroblasts (NHDF; CC-2511), and this study attempted to determine the mechanism of its action.

METHODS

The cytotoxicity MTT test was performed. The expression of the inflammatory response pathway genes was determined using HG-U133A_2.0 oligonucleotide microarrays. Statistical analysis was performed by GeneSpring 13.0 software using the PL-Grid platform.

RESULTS

Among the 5,300 mRNA, only 573 were changed significantly in response to CsA compared to the control fibroblasts (P≤0.05). CsA inhibited the expression of most genes associated with the inflammatory response in NHDFs. There were only 19 genes with a fold change (FC) lower than -2.0, among which EGR1, FOS, PBK, CDK1 and TOP2A had the lowest expression, as did CXCL2 which can directly impact inflammation. Furthermore, ZNF451 was strongly induced, and COL1A1, COL3A1, IL33, TNFRSFs were weakly up-regulated (FC lower than 2.0).

CONCLUSION

The CsA in therapeutic concentration influences the genes linked to the inflammatory response (in the transcriptional level) in human dermal fibroblasts. The findings suggest that the potential mechanism of CsA action in this concentration and on these genes can be associated with a profibrotic and proapoptotic, and genotoxic effects.

Dual-specificity phosphatase 1 regulates cell cycle progression and apoptosis in cumulus cells by affecting mitochondrial function, oxidative stress, and autophagy

Dual-specificity phosphatase 1 ( DUSP1) is differentially expressed in cumulus cells of different physiological states, but its specific function and mechanism of action remain unclear. In this study, we explored the effects of DUSP1 expression inhibition on cell cycle progression, proliferation, apoptosis, and lactate and cholesterol levels in cumulus cells and examined reactive oxygen species levels, mitochondrial function, autophagy, and the expression of key cytokine genes. The results showed that inhibition of DUSP1 in cumulus cells caused abnormal cell cycle progression, increased cell proliferation, decreased apoptosis rates, increased cholesterol synthesis and lactic acid content, and increased cell expansion. The main reason for these effects was that inhibition of DUSP1 reduced ROS accumulation, increased glutathione level and mitochondrial membrane potential, and reduced autophagy levels in cells. These results indicate that DUSP1 limits the biological function of bovine cumulus cells under normal physiological conditions and will greatly contribute to further explorations of the physiological functions of cumulus cells and the interactions of the cumulus-oocyte complex.

Role of Dual-Specificity Phosphatase 1 in Glucocorticoid-Driven Anti-inflammatory Responses

Glucocorticoids (GCs) potently inhibit pro-inflammatory responses and are widely used for the treatment of inflammatory diseases, such as allergies, autoimmune disorders, and asthma. Dual-specificity phosphatase 1 (DUSP1), also known as mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1), exerts its effects by dephosphorylation of MAPKs, i.e., extracellular-signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). Endogenous DUSP1 expression is tightly regulated at multiple levels, involving both transcriptional and post-transcriptional mechanisms. DUSP1 has emerged as a central mediator in the resolution of inflammation, and upregulation of DUSP1 by GCs has been suggested to be a key mechanism of GC actions. In this review, we discuss the impact of DUSP1 on the efficacy of GC-mediated suppression of inflammation and address the underlying mechanisms.