[Knockdown of dual-specificity phosphatase 5 (DUSP5) inhibits BCG-induced inflammatory response in RAW264.7 macrophages via blocking NF-κB signaling pathway].

Objective To explore the regulatory role of dual-specificity phosphatase 5 (DUSP5) in BCG-mediated inflammatory response in mouse RAW264.7 macrophages. Methods Western blot analysis was employed to detect the expression changes of DUSP5 in BCG-infected RAW264.7 macrophages at the period of 0.5, 1, 2, 4, 6, 8, 12 and 24 hours. Intracellular DUSP5 was reduced by small interfering RNA (siRNA) and transfected RAW264.7 macrophages were divided into siRNA-negative control (si-NC) group, DUSP5 knockdown (si-DUSP5) group, si-NC combined BCG infection group, and si-DUSP5 combined BCG infection group. Real-time quantitative PCR was conducted to measure the mRNA expression of interleukin 1ß (IL-1ß), IL-6, tumor necrosis factor α (TNF-α), and IL-10 in cells. ELISA was performed to measure the concentration of the cytokines in cell culture medium. Western blot analysis was performed to detect the expression changes of cellular nuclear factor κB (NF-κB) and phosphorylated NF-κB (p-NF-κB). Results BCG infection upregulated DUSP5 protein expression in RAW264.7 macrophages with the expression of DUSP5 reaching the peak after 4 hours' BCG stimulation. Comparing with si-NC combined BCG infection group, DUSP5 knockdown inhibited the expression and secretion of pro-inflammatory factors IL-1ß, IL-6, and TNF-α, while the expression of the anti-inflammatory factor IL-10 was not affected by DUSP5. Moreover, knockdown of DUSP5 inhibited the phosphorylation of NF-κB in cells. Conclusion DUSP5 knockdown inhibites BCG-mediated macrophage inflammatory response via blocking NF-κB signaling activation.

MicroRNA-671-5p regulates the inflammatory response of periodontal ligament stem cells via the DUSP8/p38 MAPK pathway.

BACKGROUND: MicroRNAs are differentially expressed in periodontitis tissues. They are involved in cellular responses to inflammation and can be used as markers for diagnosing periodontitis. Microarray analysis showed that the expression level of microRNA-671-5p in periodontal tissues of patients with periodontitis was increased. In this study, we investigated the mechanism of action of microRNA-671-5p in human periodontal ligament stem cells (hPDLSCs) under inflammatory conditions. METHODS AND RESULTS: HPDLSCs were treated with lipopolysaccharide (LPS) to establish an inflammation model. The cell survival rate was determined using the cell counting kit-8 (CCK8). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analyses were used to detect the expression of microRNA-671-5p and dual-specificity phosphatase (DUSP) 8 proteins, respectively, Interleukin (IL)-6, IL-1ß, and tumor necrosis factor (TNF)-α were detected using qRT-PCR and Enzyme-linked immunosorbent assay (ELISA). A dual-luciferase reporter system was employed to determine the relationship between micoRNA-671-5p and DUSP8 expression. Activation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway was confirmed using western blot analysis. Following the treatment of hPDLSCs with LPS, the expression levels of microRNA-671-5p in hPDLSCs were increased, cell viability decreased, and the expression of inflammatory factors displayed an increasing trend. MicroRNA-671-5p targets and binds to DUSP8. Silencing microRNA-671-5p or overexpressing DUSP8 can improve cell survival rate and reduce inflammatory responses. When DUSP8 was overexpressed, the expression of p-p38 was reduced. CONCLUSIONS: microRNA-671-5p targets DUSP8/p38 MAPK pathway to regulate LPS-induced proliferation and inflammation in hPDLSCs.

Dual-specificity phosphatase 26 protects against kidney injury caused by ischaemia-reperfusion through restraint of TAK1-JNK/p38-mediated apoptosis and inflammation of renal tubular epithelial cells.

Dual-specificity phosphatase 26 (DUSP26) acts as a pivotal player in the transduction of signalling cascades with its dephosphorylating activity. Currently, DUSP26 attracts extensive attention due to its particular function in several pathological conditions. However, whether DUSP26 plays a role in kidney ischaemia-reperfusion (IR) injury is unknown. Aims of the current work were to explore the relevance of DUSP26 in kidney IR damage. DUSP26 levels were found to be decreased in renal tubular epithelial cells following hypoxia-reoxygenation (HR) and kidney samples subjected to IR treatments. DUSP26-overexpressed renal tubular epithelial cells exhibited protection against HR-caused apoptosis and inflammation, while DUSP26-depleted renal tubular epithelial cells were more sensitive to HR damage. Upregulation of DUSP26 in rat kidneys by infecting adenovirus expressing DUSP26 markedly ameliorated kidney injury caused by IR, while also effectively reducing apoptosis and inflammation. The mechanistic studies showed that the activation of transforming growth factor-ß-activated kinase 1 (TAK1)-JNK/p38 MAPK, contributing to kidney injury under HR or IR conditions, was restrained by increasing DUSP26 expression. Pharmacological restraint of TAK1 markedly diminished DUSP26-depletion-exacebated effects on JNK/p38 activation and HR injury of renal tubular cells. The work reported a renal-protective function of DUSP26, which protects against IR-related kidney damage via the intervention effects on the TAK1-JNK/p38 axis. The findings laid a foundation for understanding the molecular pathogenesis of kidney IR injury and provide a prospective target for treating this condition.

Epithelial cells derived exosomal miR-203a-3p facilitates stromal inflammation of type IIIA chronic prostatitis/chronic pelvic pain syndrome by targeting DUSP5 and increasing MCP-1 generation.

Increased proinflammatory cytokines and infiltration of inflammatory cells in the stroma are important pathological features of type IIIA chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS-A), and the interaction between stromal cells and other cells in the inflammatory microenvironment is closely related to the inflammatory process of CP/CPPS-A. However, the interaction between stromal and epithelial cells remains unclear. In this study, inflammatory prostate epithelial cells (PECs) released miR-203a-3p-rich exosomes and facilitated prostate stromal cells (PSCs) inflammation by upregulating MCP-1 expression. Mechanistically, DUSP5 was identified as a novel target gene of miR-203a-3p and regulated PSCs inflammation through the ERK1/2/MCP-1 signaling pathway. Meanwhile, the effect of exosomes derived from prostatic fluids of CP/CPPS-A patients was consistent with that of exosomes derived from inflammatory PECs. Importantly, we demonstrated that miR-203a-3p antagomirs-loaded exosomes derived from PECs targeted the prostate and alleviated prostatitis by inhibiting the DUSP5-ERK1/2 pathway. Collectively, our findings provide new insights into underlying the interaction between PECs and PSCs in CP/CPPS-A, providing a promising therapeutic strategy for CP/CPPS-A.

Increasing expression of dual-specificity phosphatase 12 mitigates oxygen-glucose deprivation/reoxygenation-induced neuronal apoptosis and inflammation through inactivation of the ASK1-JNK/p38 MAPK pathway.

Dual-specificity phosphatase 12 (DUSP12) is abnormally expressed under various pathological conditions and plays a crucial role in the pathological progression of disorders. However, the role of DUSP12 in cerebral ischaemia/reperfusion injury has not yet been investigated. This study explored the possible link between DUSP12 and cerebral ischaemia/reperfusion injury using an oxygen-glucose deprivation/reoxygenation (OGD/R) model. Marked decreases in DUSP12 levels have been observed in cultured neurons exposed to OGD/R. DUSP12-overexpressed neurons were resistant to OGD/R-induced apoptosis and inflammation, whereas DUSP12-deficient neurons were vulnerable to OGD/R-evoked injuries. Further investigation revealed that DUSP12 overexpression or deficiency affects the phosphorylation of apoptosis signal-regulating kinase 1 (ASK1), c-Jun NH2-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) in neurons under OGD/R conditions. Moreover, blockade of ASK1 diminished the regulatory effect of DUSP12 deficiency on JNK and p38 MAPK activation. In addition, DUSP12-deficiency-elicited effects exacerbating neuronal OGD/R injury were reversed by ASK1 blockade. In summary, DUSP12 protects against neuronal OGD/R injury by reducing apoptosis and inflammation through inactivation of the ASK1-JNK/p38 MAPK pathway. These findings imply a neuroprotective function for DUSP12 in cerebral ischaemia/reperfusion injury.

Peripheral T-cell lymphomas expressing CD30 and CD15 expand the spectrum of anaplastic large cell lymphoma, ALK-negative.

Peripheral T-cell lymphomas (PTCL) are morphologically and biologically heterogeneous and a subset expresses CD30, including anaplastic large cell lymphomas (ALCL) and a minority of PTCL, not otherwise specified (PTCL, NOS). ALCL with ALK translocations (ALCL, ALK+) are readily identified by routine diagnostic methods, but differentiating ALCL without ALK translocation (ALCL, ALK-) and PTCL, NOS expressing CD30 (PTCL CD30+) can be challenging. Furthermore, rare PTCL co-express CD30 and CD15 (PTCL CD30+CD15+); some resemble ALCL, ALK- while others resemble classic Hodgkin lymphoma. To explore the relationship between PTCL CD30+CD15+ and ALCL, ALK-, we analysed 19 cases of PTCL with CD30 expression, previously diagnosed as ALCL, ALK- (nine cases) and PTCL CD30+CD15+ (10 cases) for DUSP22/IRF4 rearrangements, coding RNA expression and selected transcriptome analysis using the NanoString nCounter gene expression analysis platform. Unsupervised clustering showed no clear segregation between ALCL, ALK- and PTCL CD30+CD15+. Three cases previously classified as PTCL CD30+CD15+ showed DUSP22/IRF4 rearrangements, favouring a diagnosis of ALCL, ALK-. Our results suggest that cases previously designated PTCL CD30+CD15+, likely fall within the spectrum of ALCL, ALK-; additionally, a subset of ALCL, ALK- with DUSP22/IRF4 rearrangement expresses CD15, consistent with previous reports and expands the immunophenotypic spectrum of this lymphoma subgroup.

Revealing the Complete Bispecific Phosphatase Genes (DUSPs) across the Genome and Investigating the Expression Patterns of GH_A11G3500 Resistance against Verticillium wilt.

DUSPs, a diverse group of protein phosphatases, play a pivotal role in orchestrating cellular growth and development through intricate signaling pathways. Notably, they actively participate in the MAPK pathway, which governs crucial aspects of plant physiology, including growth regulation, disease resistance, pest resistance, and stress response. DUSP is a key enzyme, and it is the enzyme that limits the rate of cell metabolism. At present, complete understanding of the DUSP gene family in cotton and its specific roles in resistance to Verticillium wilt (VW) remains elusive. To address this knowledge gap, we conducted a comprehensive identification and analysis of four key cotton species: Gossypium arboreum, Gossypium barbadense, Gossypium hirsutum, and Gossypium raimondii. The results revealed the identification of a total of 120 DUSP genes in the four cotton varieties, which were categorized into six subgroups and randomly distributed at both ends of 26 chromosomes, predominantly localized within the nucleus. Our analysis demonstrated that closely related DUSP genes exhibited similarities in terms of the conserved motif composition and gene structure. A promoter analysis performed on the GhDUSP gene promoter revealed the presence of several cis-acting elements, which are associated with abiotic and biotic stress responses, as well as hormone signaling. A tissue expression pattern analysis demonstrated significant variations in GhDUSP gene expression under different stress conditions, with roots exhibiting the highest levels, followed by stems and leaves. In terms of tissue-specific detection, petals, leaves, stems, stamens, and receptacles exhibited higher expression levels of the GhDUSP gene. The gene expression analysis results for GhDUSPs under stress suggest that DUSP genes may have a crucial role in the cotton response to stress in cotton. Through Virus-Induced Gene Silencing (VIGS) experiments, the silencing of the target gene significantly reduced the resistance efficiency of disease-resistant varieties against Verticillium wilt (VW). Consequently, we conclude that GH_A11G3500-mediated bispecific phosphorylated genes may serve as key regulators in the resistance of G. hirsutum to Verticillium wilt (VW). This study presents a comprehensive structure designed to provide an in-depth understanding of the potential biological functions of cotton, providing a strong foundation for further research into molecular breeding and resistance to plant pathogens.

The lincRNA JUNI regulates the stress-dependent induction of c-Jun, cellular migration and survival through the modulation of the DUSP14-JNK axis.

Cancer cells employ adaptive mechanisms to survive various stressors, including genotoxic drugs. Understanding the factors promoting survival is crucial for developing effective treatments. In this study, we unveil a previously unexplored long non-coding RNA, JUNI (JUN-DT, LINC01135), which is upregulated by genotoxic drugs through the activation of stress-activated MAPKs, JNK, and p38 and consequently exerts positive control over the expression of its adjacent gene product c-Jun, a well-known oncoprotein, which transduces signals to multiple transcriptional outputs. JUNI regulates cellular migration and has a crucial role in conferring cellular resistance to chemotherapeutic drugs or UV radiation. Depletion of JUNI markedly increases the sensitivity of cultured cells and spheroids to chemotherapeutic agents. We identified 57 proteins interacting with JUNI. The activity of one of them the MAPK phosphatase and inhibitor, DUSP14, is counteracted by JUNI, thereby, facilitating efficient JNK phosphorylation and c-Jun induction when cells are exposed to UV radiation. The antagonistic interplay with DUSP14 contributes not only to c-Jun induction but also augments the survival of UV-exposed cells. In summary, we introduce JUNI as a novel stress-inducible regulator of c-Jun, positioning it as a potential target for enhancing the sensitivity of cancer cells to chemotherapy.

Impaired malin expression and interaction with partner proteins in Lafora disease.

Lafora disease (LD) is an autosomal recessive myoclonus epilepsy with onset in the teenage years leading to death within a decade of onset. LD is characterized by the overaccumulation of hyperphosphorylated, poorly branched, insoluble, glycogen-like polymers called Lafora bodies. The disease is caused by mutations in either EPM2A, encoding laforin, a dual specificity phosphatase that dephosphorylates glycogen, or EMP2B, encoding malin, an E3-ubiquitin ligase. While glycogen is a widely accepted laforin substrate, substrates for malin have been difficult to identify partly due to the lack of malin antibodies able to detect malin in vivo. Here we describe a mouse model in which the malin gene is modified at the C-terminus to contain the c-myc tag sequence, making an expression of malin-myc readily detectable. Mass spectrometry analyses of immunoprecipitates using c-myc tag antibodies demonstrate that malin interacts with laforin and several glycogen-metabolizing enzymes. To investigate the role of laforin in these interactions we analyzed two additional mouse models: malin-myc/laforin knockout and malin-myc/LaforinCS, where laforin was either absent or the catalytic Cys was genomically mutated to Ser, respectively. The interaction of malin with partner proteins requires laforin but is not dependent on its catalytic activity or the presence of glycogen. Overall, the results demonstrate that laforin and malin form a complex in vivo, which stabilizes malin and enhances interaction with partner proteins to facilitate normal glycogen metabolism. They also provide insights into the development of LD and the rescue of the disease by the catalytically inactive phosphatase.

Gene expression profile of mitogen-activated kinases and microRNAs controlling their expression in HaCaT cell culture treated with lipopolysaccharide A and cyclosporine A.

Studies indicate that mitogen-activated protein kinases (MAPKs) are activated and overexpressed in psoriatic lesions. The aim of the study was to assess changes in the expression pattern of genes encoding MAPKs and microRNA (miRNA) molecules potentially regulating their expression in human adult low-calcium high-temperature (HaCaT) keratinocytes exposed to bacterial lipopolysaccharide A (LPS) and cyclosporine A (CsA). HaCaT cells were treated with 1 µg/mL LPS for 8 h, followed by treatment with 100 ng/mL cyclosporine A for 2, 8, or 24 h. Untreated cells served as controls. The molecular analysis consists of microarray, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay analyses. The statistical analysis of the obtained results was performed using Transcriptome Analysis Console and STATISTICA 13.5 PL with the statistical significance threshold of p < 0.05. Changes in the expression profile of six mRNAs: dual-specificity phosphatase 1 (DUSP1), dual-specificity phosphatase 4 (DUSP4), mitogen-activated protein kinase kinase 2 (MAP2K2), mitogen-activated protein kinase kinase 7 (MAP2K7), mitogen-activated protein kinase kinase kinase 2 (MAP3K2) and mitogen-activated protein kinase 9 (MAPK9) in cell culture exposed to LPS or LPS and the drug compared to the control. We observed that under the LPS and cyclosporine treatment, the expression o/ miR-34a, miR-1275, miR-3188, and miR-382 changed significantly (p < 0.05). We demonstrated a potential relationship between DUSP1 and miR-34a; DUSP4 and miR-34a, miR-382, and miR-3188; MAPK9 and miR-1275, MAP2K7 and mir-200-5p; MAP3K2 and mir-200-5p, which may be the subject of further research in the context of psoriasis.

DUSP22 Ameliorates Endothelial-to-Mesenchymal Transition in HUVECs through Smad2/3 and MAPK Signaling Pathways.

Endothelial-to-mesenchymal transition (EndMT) is the process by which endothelial cells lose their endothelial properties and acquire mesenchymal characteristics. Dual-specific protein phosphatase 22 (DUSP22) inactivates various protein kinases and transcription factors by dephosphorylating serine/threonine residues: hence, it plays a key role in many diseases. The aim of this study was to explore the functional role of DUSP22 in EndMT. In the transforming growth factor-ß-induced EndMT model in human umbilical vein endothelial cells (HUVECs), we observed a downregulation of DUSP22 expression. This DUSP22 deficiency could aggravate EndMT. Conversely, the overexpression of DUSP22 could ameliorate EndMT. We used signaling pathway inhibitors to verify our results and found that DUSP22 could regulate EndMT through the smad2/3 and the mitogen-activated protein kinase (MAPK) signaling pathways. In summary, DUSP22 ameliorates EndMT in HUVECs in vitro through the smad2/3 and MAPK signaling pathways.

miR-147b mediated suppression of DUSP8 promotes lung cancer progression.

Dual-specificity phosphatase 8 (DUSP8) plays an important role as a selective c-Jun N-terminal kinase (JNK) phosphatase in mitogen-activated protein kinase (MAPK) signaling. In this study, we found that DUSP8 is silenced by miR-147b in patients with lung adenocarcinoma (LUAD), which correlates with poor overall survival. Overexpression of DUSP8 resulted in a tumor-suppressive phenotype in vitro and in vivo experimental models, whereas silencing DUSP8 with a siRNA approach abrogated the tumor-suppressive properties. We found that miR-147b is a posttranscriptional regulator of DUSP8 that is highly expressed in patients with LUAD and is associated with lower survival. NanoString analysis revealed that the MAPK signaling pathway is mainly affected by overexpression of miR-147b, leading to increased proliferation and migration and decreased apoptosis in vitro. Moreover, induction of miR-147b promotes tumor progression in vitro and in vivo experimental models. Knockdown of miR-147b restored DUSP8, decreased tumor progression in vitro, and increased apoptosis via JNK phosphorylation. These results suggest that miR-147b plays a key role in regulating MAPK signaling in LUAD. The link between DUSP8 and miR-147b may provide novel approaches for the treatment of lung cancer.

Transcriptomic analysis of Porphyromonas gingivalis-infected head and neck cancer cells: Identification of PLAU as a candidate prognostic biomarker.

Periodontal disease is a risk factor for head and neck squamous cell carcinoma (HNSCC), and Porphyromonas gingivalis, a major periodontal pathogen, has been identified as a specific and potentially independent microbial factor that increases the risk of cancer mortality. Gene expression in HNSCC due to P. gingivalis infection and how changes in gene expression affect the prognosis of HNSCC patients are not clarified. When P. gingivalis was cultured with HNSCC cells, it efficiently adhered to these cells and enhanced their invasive ability. A transcriptome analysis of P. gingivalis -infected HNSCC cells showed that genes related to migration, including CCL20, CITED2, CTGF, C8orf44-SGK3, DUSP10, EGR3, FUZ, HBEGF, IL1B, IL24, JUN, PLAU, PTGS2, P2RY1, SEMA7A, SGK1 and SIX2, were highly up- or down-regulated. The expression of up-regulated genes was examined using the expression data of HNSCC patients obtained from The Cancer Genome Atlas (TCGA) database, and the expression of 5 genes, including PLAU, was found to be higher in cancer tissue than in solid normal tissue. An analysis of protein-protein interactions revealed that these 5 genes formed a dense network. A Cox regression analysis showed that high PLAU expression levels were associated with a poor prognosis in patients with TCGA-HNSCC. Furthermore, the prognostic impact correlated with tumour size and the presence or absence of lymph node metastasis. Collectively, these results suggest the potential of PLAU as a molecular prognostic marker in HNSCC patients. Further in vivo and in vitro studies are needed to verify the findings of this study.

Impact of knockout of dual-specificity protein phosphatase 5 on structural and mechanical properties of rat middle cerebral arteries: implications for vascular aging.

Vascular aging influences hemodynamics, elevating risks for vascular diseases and dementia. We recently demonstrated that knockout (KO) of Dusp5 enhances cerebral and renal hemodynamics and cognitive function. This improvement correlates with elevated pPKC and pERK1/2 levels in the brain and kidneys. Additionally, we observed that Dusp5 KO modulates the passive mechanical properties of cerebral and renal arterioles, associated with increased myogenic tone at low pressure, enhanced distensibility, greater compliance, and reduced stiffness. The present study evaluates the structural and mechanical properties of the middle cerebral artery (MCA) in Dusp5 KO rats. We found that vascular smooth muscle cell layers and the collagen content in the MCA wall are comparable between Dusp5 KO and control rats. The internal elastic lamina in the MCA of Dusp5 KO rats exhibits increased thickness, higher autofluorescence intensity, smaller fenestrae areas, and fewer fenestrations. Despite an enhanced myogenic response and tone of the MCA in Dusp5 KO rats, other passive mechanical properties, such as wall thickness, cross-sectional area, wall-to-lumen ratio, distensibility, incremental elasticity, circumferential wall stress, and elastic modulus, do not significantly differ between strains. These findings suggest that while Dusp5 KO has a limited impact on altering the structural and mechanical properties of MCA, its primary role in ameliorating hemodynamics and cognitive functions is likely attributable to its enzymatic activity on cerebral arterioles. Further research is needed to elucidate the specific enzymatic mechanisms and explore potential clinical applications in the context of vascular aging.

Proteomic Signaling of Dual-Specificity Phosphatase 4 (DUSP4) in Alzheimer's Disease.

DUSP4 is a member of the DUSP (dual-specificity phosphatase) subfamily that is selective to the mitogen-activated protein kinases (MAPK) and has been implicated in a range of biological processes and functions in Alzheimer's disease (AD). In this study, we utilized the stereotactic delivery of adeno-associated virus (AAV)-DUSP4 to overexpress DUSP4 in the dorsal hippocampus of 5xFAD and wildtype (WT) mice, then used mass spectrometry (MS)-based proteomics along with the label-free quantification to profile the proteome and phosphoproteome in the hippocampus. We identified protein expression and phosphorylation patterns modulated in 5xFAD mice and examined the sex-specific impact of DUSP4 overexpression on the 5xFAD proteome/phosphoproteome. In 5xFAD mice, a substantial number of proteins were up- or down-regulated in both male and female mice in comparison to age and sex-matched WT mice, many of which are involved in AD-related biological processes, such as activated immune response or suppressed synaptic activities. Many proteins in pathways, such as immune response were found to be suppressed in response to DUSP4 overexpression in male 5xFAD mice. In contrast, such a shift was absent in female mice. For the phosphoproteome, we detected an array of phosphorylation sites regulated in 5xFAD compared to WT and modulated via DUSP4 overexpression in each sex. Interestingly, 5xFAD- and DUSP4-associated phosphorylation changes occurred in opposite directions. Strikingly, both the 5xFAD- and DUSP4-associated phosphorylation changes were found to be mostly in neurons and play key roles in neuronal processes and synaptic functions. Site-centric pathway analysis revealed that both the 5xFAD- and DUSP4-associated phosphorylation sites were enriched for a number of kinase sets in females but only a limited number of sets of kinases in male mice. Taken together, our results suggest that male and female 5xFAD mice responded to DUSP4 overexpression via shared and sex-specific molecular mechanisms, which might underly similar reductions in amyloid pathology in both sexes while learning deficits were reduced in only females with DUSP4 overexpression. Finally, we validated our findings with the sex-specific AD-associated proteomes in human cohorts and further developed DUSP4-centric proteomic network models and signaling maps for each sex.

The phosphatase DUSP22 inhibits UBR2-mediated K63-ubiquitination and activation of Lck downstream of TCR signalling.

DUSP22 is a dual-specificity phosphatase that inhibits T cell activation by inactivating the kinase Lck. Here we show that the E3 ubiquitin ligase UBR2 is a positive upstream regulator of Lck during T-cell activation. DUSP22 dephosphorylates UBR2 at specific Serine residues, leading to ubiquitin-mediated UBR2 degradation. UBR2 is also modified by the SCF E3 ubiquitin ligase complex via Lys48-linked ubiquitination at multiple Lysine residues. Single-cell RNA sequencing analysis and UBR2 loss of function experiments showed that UBR2 is a positive regulator of proinflammatory cytokine expression. Mechanistically, UBR2 induces Lys63-linked ubiquitination of Lck at Lys99 and Lys276 residues, followed by Lck Tyr394 phosphorylation and activation as part of TCR signalling. Inflammatory phenotypes induced by TCR-triggered Lck activation or knocking out DUSP22, are attenuated by genomic deletion of UBR2. UBR2-Lck interaction and Lck Lys63-linked ubiquitination are induced in the peripheral blood T cells of human SLE patients, which demonstrate the relevance of the UBR2-mediated regulation of inflammation to human pathology. In summary, we show here an important regulatory mechanism of T cell activation, which finetunes the balance between T cell response and aggravated inflammation.

Starch phosphorylation regulates starch granule morphological homogeneity in Arabidopsis thaliana.

Starch granule morphological homogeneity presents a gap in starch research. Transitory starch granules in wild-type plants are discoid, regardless of species. Notably, while the shape of starch granules can differ among mutants, it typically remains homogeneous within a genotype. We found an Arabidopsis thaliana mutant, dpe2sex4, lacking both the cytosolic disproportionating enzyme 2 (DPE2) and glucan phosphatase SEX4, showing an unprecedented bimodal starch granule diameter distribution when grown under a light/dark rhythm. dpe2sex4 contained 2 types of starch granules: large granules and small granules. In contrast to the double starch initiation in wheat (Triticum aestivum) endosperm, where A-type granules are initiated first and B-type granules are initiated later, dpe2sex4 small and large granules developed simultaneously in the same chloroplast. Compared with the large granules, the small granules had more branched amylopectin and less surface starch-phosphate, thus having a more compact structure that may hinder starch synthesis. During plant aging, the small granules barely grew. In in vitro experiments, fewer glucosyl residues were incorporated in small granules. Under continuous light, dpe2sex4 starch granules were morphologically homogeneous. Omitting the dark phase after a 2-wk light/dark cycle by moving plants into continuous light also reduced morphological variance between these 2 types of granules. These data shed light on the impact of starch phosphorylation on starch granule morphology homogeneity.

Dual-specificity phosphatase 5-mediated fatty acid oxidation promotes Mycobacterium bovis BCG -induced inflammatory responses.

Mycobacterium tuberculosis (Mtb) reprograms FAs metabolism of macrophages during infection and affects inflammatory reaction eventually, however, the mechanism remains poorly understood. Here we show that Mycobacterium bovis (BCG) induces DUSP5 expression through TLR2-MAPKs signaling pathway and promotes fatty acid oxidation (FAO). Silencing DUSP5 by adeno-associated virus vector (AAV) ameliorates lung injury and DUSP5 knockdown reduces the expression of IL-1ß, IL-6 and inactivated NF-κB signaling in BCG-infected macrophages. Of note, DUSP5 specific siRNA increases the content of free fatty acids (FFAs) and triglyceride (TG), but represses the expression of FAO associated enzymes such as CPT1A and PPARα, suggesting DUSP5 mediated FAO during BCG infection. Moreover, Inhibiting FAO by pharmacological manner suppresses IL-1ß, IL-6, TNF-α expression and relieves lung damage. Taken together, our data indicates DUSP5 mediates FAO reprogramming and promotes inflammatory response to BCG infection.

DUSP22 suppresses tumor progression by directly dephosphorylating AKT in non-small cell lung cancer.

Protein kinase B (AKT) plays a pivotal in regulating cell migration, proliferation, apoptosis, and survival, making it a prominent target for anticancer therapy. While the kinase activity of AKT has been extensively explored, its dephosphorylation have largely remained uncharted. Herein, we aimed to unravel the molecular mechanisms governing AKT dephosphorylation, with a specific emphasis on dual-specificity phosphatases DUSP22. Our investigation sought to shed light on the potential of DUSP22 as a potential therapeutic target for non-small cell lung cancer (NSCLC). To determine the expression level of DUSP22 in NSCLC cell lines, the gene expression profiling interactive analysis (GEPIA) and Oncomine database were searched. Additionally, the effect of DUSP22 on patient survival was analyzed with Kaplan-Meier database. Antitumor effects of DUSP22 were tested in A549 and H1299 cell lines. Experiments are based on: (1) cell viability determined by the cell counting kit-8 assay and colony-formation assay; (2) cell migratory ability assessed through the scratch assay and the transwell migration assay; (3) the mechanism behind the antitumor effects of DUSP22 dissected with co-immunoprecipitation (Co-IP) and in vitro kinase assays. Our study revealed a significant downregulation of DUSP22 in both NSCLC cell lines and tissues. Meanwhile, survival rate analysis results demonstrated that reduced DUSP22 expression was correlated with poorer overall survival in lung cancer patients. Moreover, DUSP22 exhibited an inhibitory effect on the cell viability and migratory capacity of A549 and H1299 cells. This inhibition was accompanied by the decrease in the phosphorylation of AKT and p38. Mechanistically, the phosphatase domain of DUSP22 interacted with AKT, resulting in the inhibition of AKT phosphorylation. This inhibitory effect was contingent upon the phosphatase activity of DUSP22. These findings provide compelling evidence that DUSP22 directly interacted with AKT, leading to the dephosphorylation of AKT at S473 and T308 residues, ultimately curbing the proliferation and migration of lung cancer cells. Additionally, our results also highlight a preclinical rationale for utilizing DUSP22 as a prognostic marker in NSCLC.

Dual-specificity phosphatase 1 inhibits Singapore grouper iridovirus replication via regulating apoptosis in Epinephelus coioides.

The dual-specificity phosphatase (DUSP) family plays key roles in the maintenance of cellular homeostasis and apoptosis etc. In this study, the DUSP member DUSP1 of Epinephelus coioides was characterized: the length was 2371 bp including 281 bp 5' UTR, 911 bp 3' UTR, and a 1125 bp open reading frame encoding 374 amino acids. E. coioides DUSP1 has two conserved domains, a ROHD and DSPc along with a p38 MAPK phosphorylation site, localized at Ser308. E. coioides DUSP1 mRNA can be detected in all of the tissues examined, and the subcellular localization showed that DUSP1 was mainly distributed in the nucleus. Singapore grouper iridovirus (SGIV) infection could induce the differential expression of E. coioides DUSP1. Overexpression of DUSP1 could inhibit SGIV-induced cytopathic effect (CPE), the expressions of SGIV key genes, and the viral titers. Overexpression of DUSP1 could also regulate SGIV-induced apoptosis, and the expression of apoptosis-related factor caspase 3. The results would be helpful to further study the role of DUSP1 in viral infection.