Search

Background: Obstructive sleep apnea (OSA) is frequently associated with increased incidence and mortality of pulmonary hypertension (PH). The immune response contributes to pulmonary artery remodeling and OSA-related diseases. The immunologic factors linked to OSA-induced PH are not well understood. STAT6 is crucial in the signaling pathway that modulates immune response. However, the status of phosphorylated STAT6 (p-STAT6) in an OSA-induced PH mouse model remains largely unexplored. Methods: Chronic intermittent hypoxia (CIH) plays a crucial role in the progression of OSA. This study utilized a in vivo CIH model to examine the role of STAT6 in CIH-induced PH. Results: CIH mice exhibited pulmonary artery remodeling and pulmonary hypertension, indicated by increased right ventricular systolic pressure (RVSP), higher right ventricular to left ventricular plus septum (RV/LV + S) ratios, and significant morphological alterations compared to normoxic (Nor) mice. Increased p-STAT6 in the lungs and elevated p-STAT6 + IL-4 + producing T cells in CIH mice. STAT6 deficiency (STAT6-/-) improved PH and PA remodeling in CIH-induced PH mouse models.STAT6 deficiency impaired the T helper 2 (Th2) immune response, affecting IL-4 and IL-13 secretion. IL-4, rather than IL-13, activated STAT6 in human pulmonary artery smooth muscle cells (hPASMCs). STAT6 knockdown decreased the proliferation in IL-4 treated hPASMCs. Conclusion: These findings exhibit the critical role of STAT6 in the pathogenesis of CIH induced PH by regulating Th2 immune response.STAT6 could be a significant therapeutic target for OSA-related PH. [ABSTRACT FROM AUTHOR]

Purpose: The NAB2::STAT6 fusion is predominantly associated with solitary fibrous tumors (SFTs) and is utilized in diagnosing SFTs through nuclear STAT6 protein overexpression. Recent studies expanded the phenotypic spectrum of NAB2::STAT6 rearranged neoplasms, including adamantinoma-like and teratocarcinosarcoma-like phenotypes. We report a case of a NAB2::STAT6 rearranged epithelial tumor exhibiting sebaceous differentiation in the parotid gland. Methods: Fine-needle aspiration (FNA), histopathology, immunohistochemistry, and molecular studies of this case were described. Results: Fine-needle aspiration (FNA) revealed atypical basaloid cells, suggesting primary salivary gland carcinoma or metastasis. Histological examination showed basaloid-squamous cells with a monomorphic appearance containing foci of sebaceous differentiation, expressing pancytokeratin, p40, and androgen receptor, while CD34 staining was negative. Molecular studies identified a NAB2::STAT6 fusion, along with an AKT1 mutation. Conclusion: This case further expands the phenotypic spectrum of NAB2::STAT6 rearranged neoplasms and emphasizes comprehensive histopathological and molecular analysis in challenging head and neck tumors. It suggests STAT6 immunohistochemistry as a potential screening tool for head and neck tumors resembling sebaceous carcinoma, myoepithelial tumors, or GLI1-altered neoplasms. [ABSTRACT FROM AUTHOR]

Introduction: Solitary fibrous tumor (SFT) represents an uncommon mesenchymal neoplasm affecting primarily the extremities and deep soft tissues with, overall, benign but locally aggressive biologic behavior and an underlying pathognomonic NAB2::STAT6 fusion. Intraosseous SFTs are infrequent, and involvement of the jawbones is exceedingly rare. Case presentation: A 54-year-old woman presented with an asymptomatic, well-demarcated, multilocular radiolucency of the left posterior mandible featuring focally irregular borders, root resorption and lingual cortex perforation. The lesion had shown progressive growth over a 6-year period. Microscopically, a proliferation of predominantly ovoid and spindle-shaped cells with indistinct cell membrane borders, elongated, plump or tapered, hyperchromatic nuclei, and lightly eosinophilic cytoplasm was noted. Marked cytologic atypia, pleomorphism and mitoses were absent. A secondary population of epithelioid cells exhibiting ovoid or elongated vesicular nuclei, and abundant, pale eosinophilic or vacuolated cytoplasm was also present. The supporting stroma was densely fibrous with areas of marked hyalinization and variably-sized, ramifying, thin-walled vessels. By immunohistochemistry, lesional cells were strongly and diffusely positive for STAT6 and CD99, and focally immunoreactive for MDM2 and SATB2. Ki-67 was expressed in less than 5% of lesional cells, while most interspersed epithelioid cells were positive for the histiocyte marker, CD163. Molecular analysis disclosed a NAB2::STAT6 fusion confirming the diagnosis of SFT. The patient underwent segmental mandibulectomy. Conclusions: Herein, we report the first case of primary intraosseous SFT of the mandible with complete documentation of its characteristic immunohistochemical and molecular features. Diagnosis of such unusual presentations may be further complicated by the challenging histomorphologic diversity of SFT. [ABSTRACT FROM AUTHOR]

In vitro induced T regulatory cells (iTregs) are promising for addressing inflammation-driven diseases. However, current protocols for the generation and expansion of iTregs fail to induce extensive demethylation of the Treg-specific demethylated region (TSDR) within the FOXP3 gene, recognized as the master regulator for regulatory T cells (Tregs). This deficiency results in the rapid loss of Foxp3 expression and an unstable regulatory phenotype. Nevertheless, inhibition of STAT6 signaling effectively stabilizes Foxp3 expression in iTregs. Thus, this study aimed to develop a protocol combining epigenetic editing with STAT6 deficiency to improve iTregs' ability to maintain stable suppressive function and a functional phenotype. Our findings demonstrate that the combination of STAT6 deficiency (STAT6-/-) with targeted demethylation of the TSDR using a CRISPR-TET1 tool leads to extensive demethylation of FOXP3-TSDR. Demethylation in STAT6-/- iTregs was associated with enhanced expression of Foxp3 and suppressive markers such as CTLA-4, PD-1, IL-10, and TGF-β. Furthermore, the edited STAT6-/- iTregs exhibited an increased capacity to suppress CD8+ and CD4+ lymphocytes and could more efficiently impair Th1-signature gene expression compared to conventional iTregs. In conclusion, the deactivation of STAT6 and TSDR-targeted demethylation via CRISPR-TET1 is sufficient to induce iTregs with heightened stability and increased suppressive capacity, offering potential applications against inflammatory and autoimmune diseases. [ABSTRACT FROM AUTHOR]

Regulatory T (Treg) cells are crucial for maintaining immune tolerance by suppressing response to self-antigens and harmless antigens to prevent autoimmune diseases and uncontrolled immune responses. Therefore, using Treg cells is considered a therapeutic strategy treating inflammatory diseases. Based on their origin, Treg cells are classified into thymus-derived, peripherally induced, and in vitro induced Treg cells. Our group discovered a novel Treg cell subset, namely, Treg-of-B (Treg/B) cells, generated by culturing CD4+CD25− T cells with B cells, including Peyer's patch B cells, splenic B cells and peritoneal B1a cells, for 3 days. Treg/B cells express CD44, OX40 (CD134), cytotoxic T-lymphocyte-associated antigen-4 (CD152), glucocorticoid-induced tumor necrosis factor receptor family-related protein (CD357), interleukin-10 receptor, lymphocyte activation gene-3 (CD223), inducible co-stimulator (CD278), programmed-death 1 (CD279), tumor necrosis factor receptor II, and high levels of IL-10, but not forkhead box protein P3, similar to type 1 Treg (Tr1) cells. However, unlike Tr1 cells, Treg/B cells do not express CD103, CD226, and latency-associated peptide. Treg/B cells have been applied for the treatment of some murine models of inflammatory diseases, including allergic asthma, inflammatory bowel disease, collagen-induced arthritis, gout, psoriasis and primary biliary cholangitis. This review summarizes the current knowledge of Treg/B cells. [ABSTRACT FROM AUTHOR]

Background: Solitary fibrous tumor (SFT) is a rare mesenchymal lesion that has a wide anatomic distribution. However, this lesion rarely occurs in the oral or maxillofacial region. Methods: A retrospective review was performed to evaluate the clinical symptoms, radiological images, pathology and immunohistochemistry results of 9 patients with SFTs treated between January 2015 to April 2024 in our institute. Surgical tumor resection was administered to all patients. Follow-up for these patients spanned until the conclusion of April 2024. Results: The series contained 3 males and 6 females, with the mean age 50.6 years (range: 25 to 73 years). The tumors were distributed at six different sites, including the tongue, submandibular region, cheek, sublingual gland, mandible, and hard palate. Clinically, the mass grew gradually and usually without obvious clinical symptoms. On imaging examination, the boundaries of all the tumors were clear, except for one patient with a mandibular tumor. Surgical excision was performed in all patients. Histological characteristics and positive immunostaining for STAT6, CD99, CD34 and Bcl-2 were the most important criteria for a final diagnosis. All tumors were positive for CD34 and Bcl-2. Only one tumor was negative for STAT6. While CD99 was negative in one case and weakly positive in two cases. All patients had no local recurrence during the follow-up period ranging from 1 to 100 months (mean 41.4 months). Conclusions: Benign SFTs occurring in the oral and maxillofacial region are rare, and surgery is the primary treatment for this tumor. It usually presents as a distinctly bordered heterogeneous mass on imaging. The tumors can compress surrounding bone tissue leading to bone resorption, and in rare cases, it may exhibit invasive resorption. SFTs should be included in the differential diagnosis of lesions in the oral and maxillofacial region. [ABSTRACT FROM AUTHOR]

Clinical studies have demonstrated that IL-4, a type 2 cytokine, plays an important role in the pathogenesis of chronic rhinosinusitis and eosinophilic asthma. However, the direct effect of IL-4 on eosinophils remains unclear. We aimed to elucidate the inflammatory effects of IL-4 on the functions of human eosinophils. A multiomics analysis comprising transcriptomics, proteomics, lipidomics, quantitative RT-PCR, and flow cytometry was performed by using blood eosinophils from healthy subjects stimulated with IL-4, IL-5, or a combination thereof. Transcriptomic and proteomic analyses revealed that both IL-4 and IL-5 upregulate the expression of γ-gultamyl transferase 5, a fatty acid–metabolizing enzyme that converts leukotriene C 4 into leukotriene D 4. In addition, IL-4 specifically upregulates the expression of IL-1 receptor-like 1 (IL1RL1), a receptor for IL-33 and transglutaminase-2. Additional transcriptomic analysis of cells stimulated with IL-13 revealed altered gene expression profiles, characterized by the upregulation of γ-gultamyl transferase 5, transglutaminase-2, and IL1RL1. The IL-13–induced changes were not totally different from the IL-4–induced changes. Lipidomic analysis revealed that IL-5 and IL-4 additively increased the extracellular release of leukotriene D 4. In vitro experiments revealed that STAT6 and IL-4 receptor-α control the expression of these molecules in the presence of IL-4 and IL-13. Analysis of eosinophils derived from patients with allergic disorders indicated the involvement of IL-4 and IL-13 at the inflamed sites. IL-4 induces the proallergic phenotype of IL1RL1high eosinophils, with prominent cysteinyl leukotriene metabolism via STAT6. These cellular changes represent potential therapeutic targets for chronic rhinosinusitis and eosinophilic asthma. [ABSTRACT FROM AUTHOR]

Abstract Background Solitary fibrous tumor (SFT) is a rare mesenchymal lesion that has a wide anatomic distribution. However, this lesion rarely occurs in the oral or maxillofacial region. Methods A retrospective review was performed to evaluate the clinical symptoms, radiological images, pathology and immunohistochemistry results of 9 patients with SFTs treated between January 2015 to April 2024 in our institute. Surgical tumor resection was administered to all patients. Follow-up for these patients spanned until the conclusion of April 2024. Results The series contained 3 males and 6 females, with the mean age 50.6 years (range: 25 to 73 years). The tumors were distributed at six different sites, including the tongue, submandibular region, cheek, sublingual gland, mandible, and hard palate. Clinically, the mass grew gradually and usually without obvious clinical symptoms. On imaging examination, the boundaries of all the tumors were clear, except for one patient with a mandibular tumor. Surgical excision was performed in all patients. Histological characteristics and positive immunostaining for STAT6, CD99, CD34 and Bcl-2 were the most important criteria for a final diagnosis. All tumors were positive for CD34 and Bcl-2. Only one tumor was negative for STAT6. While CD99 was negative in one case and weakly positive in two cases. All patients had no local recurrence during the follow-up period ranging from 1 to 100 months (mean 41.4 months). Conclusions Benign SFTs occurring in the oral and maxillofacial region are rare, and surgery is the primary treatment for this tumor. It usually presents as a distinctly bordered heterogeneous mass on imaging. The tumors can compress surrounding bone tissue leading to bone resorption, and in rare cases, it may exhibit invasive resorption. SFTs should be included in the differential diagnosis of lesions in the oral and maxillofacial region.

Copyright of Hungarian Medical Journal / Orvosi Hetilap is the property of Akademiai Kiado and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Solitary fibrous tumor (SFT) is a fibroblastic tumor with malignant potential that is underpinned by a recurrent inv12(q13q13)-derived NAB2::STAT6 fusion. Breast and axilla are uncommon locations for this entity. Methods: Records of two academic institutions were electronically searched for breast and axillary SFTs. Clinical and pathologic data were reviewed. Literature review for breast or axillary SFTs was performed. Present study and previously reported tumors were stratified using five SFT risk models: original and modified Demicco metastatic risk, Salas local recurrence risk, Salas metastatic risk, and Thompson local recurrence risk. Results: Five patients with breast or axillary SFT were identified. Median age was 49 years, and median follow-up (available for four patients) was 82 months. Three patients showed no evidence of disease, and one developed recurrence. Literature review identified 58 patients with breast or axillary SFT. Median age was 54 years, and median follow-up (available for 35 patients) was 24 months. Thirty-one patients showed no evidence of disease, three developed recurrence, and one developed metastasis. Original and modified Demicco models and Thompson model showed the highest sensitivity; original and modified Demicco models and Salas metastatic risk model demonstrated the highest specificity. Kaplan–Meier models were used to assess recurrence-free probability (RFP). Original and modified Demicco models predicted RFP when stratified by "low risk" and "moderate/intermediate and high risk" tumor, though sample size was small. Conclusions: While many SFTs of breast and axilla remain indolent, a subset may develop recurrence and rarely metastasize. The modified Demicco risk model demonstrated optimal performance characteristics. [ABSTRACT FROM AUTHOR]

The JAK/STAT signaling pathway plays a key role in cytokine signaling and is involved in development, immunity, and tumorigenesis for nearly any cell. At first glance, the JAK/STAT signaling pathway appears to be straightforward. However, on closer examination, the factors influencing the JAK/STAT signaling activity, such as cytokine diversity, receptor profile, overlapping JAK and STAT specificity among non-redundant functions of the JAK/STAT complexes, positive regulators (e.g., cooperating transcription factors), and negative regulators (e.g., SOCS, PIAS, PTP), demonstrate the complexity of the pathways architecture, which can be quickly disturbed by mutations. The JAK/STAT signaling pathway has been, and still is, subject of basic research and offers an enormous potential for the development of new methods of personalized medicine and thus the translation of basic molecular research into clinical practice beyond the use of JAK inhibitors. Gain-of-function and loss-of-function mutations in the three immunologically particularly relevant signal transducers STAT1, STAT3, and STAT6 as well as JAK1 and JAK3 present themselves through individual phenotypic clinical pictures. The established, traditional paradigm of loss-of-function mutations leading to immunodeficiency and gain-of-function mutation leading to autoimmunity breaks down and a more differentiated picture of disease patterns evolve. This review is intended to provide an overview of these specific syndromes from a clinical perspective and to summarize current findings on pathomechanism, symptoms, immunological features, and therapeutic options of STAT1, STAT3, STAT6, JAK1, and JAK3 loss-of-function and gain-of-function diseases.

Background: A key factor underlying the failure of Chimeric Antigen Receptor-T Cell (CAR-T) therapy in ovarian cancer (OC) is the presence of an immunosuppressive tumor microenvironment, which is intricately linked to M2 polarization among tumor-infiltrating macrophages. P2X7 receptor has been previously documented as expressed within these macrophages and its correlation with M2 polarization is evident. This investigation scrutinizes whether silencing of P2X7 receptor within macrophages could lead to augmented anti-tumor potency of CAR-T. Method: Human peripheral blood mononuclear cells were artificially differentiated into macrophages or M2 macrophage in vitro. After silencing P2X7 receptor and/or overexpressing STAT6 within macrophages, the M1 and M2 markers were evaluated via flow cytometry, ELISA, and qRT-PCR. Additionally, the phosphorylation level of STAT6 was monitored by western blot. We engineered CAR-T cells targeting the non-functional P2X7 (nfP2X7) receptor, and co-cultured them with macrophages silencing P2X7 receptor along with OC cells. The anti-tumor effect of these CAR-T cells was assessed through evaluating OC cell viability, lactate dehydrogenase release, and IFN-γ levels. Result: P2X7 receptor silencing promotes M1 macrophage marker expression (CD86, TNF-α, IL-6, IL-1β), diminishes M2 macrophage marker expression (CD206 and IL-10) and suppresses STAT6 phosphorylation, whereas STAT6 overexpression reverses these phenomena. Furthermore, M2 macrophage suppresses the toxic effect of CAR-T cells on OC cells, while silencing the P2X7 receptor nullifies the immunosuppressive effect of M2 macrophages on CAR-T cells. Conclusion: Silencing P2X7 receptor can reverse M2 macrophage polarization by suppressing STAT6 activation, thereby enhancing the anti-tumor efficacy of CAR-T cells targeting nfP2X7 receptor in OC cell lines.

Abstract Background Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal tumor that mostly involves the pleura and infrequently involves extra-pleural sites. De novo SFT of the kidney is uncommon, and malignant SFT is extremely rare. Case presentation We report a case of a 51-year-old man with a large malignant SFT in the left kidney. Pathological examination confirmed the diagnosis of SFT based on typical morphology, nuclear STAT6 expression, and NAB2-STAT6 gene fusion. The malignant subtype was determined by a large tumor size (≥ 15 cm) and high mitotic counts (8/10 high-power fields). KRAS mutation was identified by DNA sequencing. Insulin-like growth factor 2 (IGF2) was diffusely and strongly expressed in tumor cells, however, hypoglycemia was not observed. Hyperglycemia and high adrenocorticotropic hormone (ACTH) concentration were observed one month after surgery. Hormone measurements revealed normal blood cortisol and aldosterone levels, and increased urinary free cortisol level. A pituitary microadenoma was identified using brain magnetic resonance imaging, which may be responsible for the promotion of hyperglycemia. Conclusions We report a case of renal malignant SFT with a KRAS mutation, which was previously unreported in SFT and may be associated with its malignant behavior. Additionally, we emphasize that malignant SFT commonly causes severe hypoglycemia due to the production of IGF2. However, this effect may be masked by the presence of other lesions that promote hyperglycemia. Therefore, when encountering a malignant SFT with diffuse and strong IGF2 expression and without hypoglycemia, other lesions promoting hyperglycemia need to be ruled out.

Abstract Background Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) are distinct hematological malignancies of B-cell origin that share many biological, molecular, and clinical characteristics. In particular, the JAK/STAT signaling pathway is a driver of tumor development due to multiple recurrent mutations, particularly in STAT6. Furthermore, the XPO1 gene that encodes exportin 1 (XPO1) shows a frequent point mutation (E571K) resulting in an altered export of hundreds of cargo proteins, which may impact the success of future therapies in PMBL and cHL. Therefore, targeted therapies have been envisioned for these signaling pathways and mutations. Methods To identify novel molecular targets that could overcome the treatment resistance that occurs in PMBL and cHL patients, we have explored the efficacy of a first-in-class HSP110 inhibitor (iHSP110-33) alone and in combination with selinexor, a XPO1 specific inhibitor, both in vitro and in vivo. Results We show that iHSP110-33 decreased the survival of several PMBL and cHL cell lines and the size of tumor xenografts. We demonstrate that HSP110 is a cargo of XPO1wt as well as of XPO1E571K. Using immunoprecipitation, proximity ligation, thermophoresis and kinase assays, we showed that HSP110 directly interacts with STAT6 and favors its phosphorylation. The combination of iHSP110-33 and selinexor induces a synergistic reduction of STAT6 phosphorylation and of lymphoma cell growth in vitro and in vivo. In biopsies from PMBL patients, we show a correlation between HSP110 and STAT6 phosphorylation levels. Conclusions These findings suggest that HSP110 could be proposed as a novel target in PMBL and cHL therapy.

Objective To explore the effect and mechanism of berberine combined with curcumin on atherosclerosis (AS) by mediating M1 macrophages polarization. Methods M1-type macrophages were obtained from mouse mononuclear macrophages (RAW264.7) induced by lipopolysaccharide (LPS, 100 ng/mL) and interferon (IFN)-γ (20 ng/mL). A cell model was established. The cells were divided into a control group, model group, berberine group, curcumin group and berberine plus curcumin group. Concentrations of berberine and curcumin were detected by CCK-8 assay. The expression levels of M1-type macrophage markers iNOS, TNF-α, CXCL9 and p-STAT6/STAT6 in macrophage supernatant were detected by ELISA. Levels of iNOS, TNF-α and CXCL9 mRNA were detected by RT-PCR. Levels of iNOS, STAT6 and p-STAT6 proteins in each group were detected by Western blot. After down-regulation of STAT6 level by siRNA technology, expression of p-STAT6 protein was detected by Western blot. Expression levels of iNOS, TNF-α, CXCL9 and p-STAT6 were detected by ELISA. Results In the polarization of M1 macrophages induced by LPS and IFN-γ, berberine (25 μmol/L) and curcumin (20 μmol/L) were the best concentrations as compared with other drug concentration groups, and neither alone nor combined use could significantly inhibit the viability of RAW264.7 cells (P < 0.05). As compared with the normal group, iNOS, TNF-α and CXCL9 mRNA and protein levels were increased in the model group, while P-STAT6/STAT6 levels were decreased, with statistical differences (P < 0.05). As compared with the model group, iNOS, TNF-α and CXCL9 mRNA and protein levels in the berberine group, curcumin group, and berberine plus curcumin group were decreased, while P-STAT6 /STAT6 levels were increased, and the changes were more obvious in berberine plus curcumin group, with statistical difference (P < 0.05). After transfection of STAT6 siRNA in M1 macrophages in the berberine plus curcumin group, P-STAT6 levels were down-regulated, while expressions of iNOS, TNF-α and CXCL9 were up-regulated, with statistical differences (P < 0.05). Conclusions Both berberine and curcumin can inhibit the activity of M1-type macrophages and reduce inflammatory response. The action of berberine combined with curcumin is more advantageous than that of either drug alone, which may be the main mechanism of action through activation of STAT6. [ABSTRACT FROM AUTHOR]

Background: Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal tumor that mostly involves the pleura and infrequently involves extra-pleural sites. De novo SFT of the kidney is uncommon, and malignant SFT is extremely rare. Case presentation: We report a case of a 51-year-old man with a large malignant SFT in the left kidney. Pathological examination confirmed the diagnosis of SFT based on typical morphology, nuclear STAT6 expression, and NAB2-STAT6 gene fusion. The malignant subtype was determined by a large tumor size (≥ 15 cm) and high mitotic counts (8/10 high-power fields). KRAS mutation was identified by DNA sequencing. Insulin-like growth factor 2 (IGF2) was diffusely and strongly expressed in tumor cells, however, hypoglycemia was not observed. Hyperglycemia and high adrenocorticotropic hormone (ACTH) concentration were observed one month after surgery. Hormone measurements revealed normal blood cortisol and aldosterone levels, and increased urinary free cortisol level. A pituitary microadenoma was identified using brain magnetic resonance imaging, which may be responsible for the promotion of hyperglycemia. Conclusions: We report a case of renal malignant SFT with a KRAS mutation, which was previously unreported in SFT and may be associated with its malignant behavior. Additionally, we emphasize that malignant SFT commonly causes severe hypoglycemia due to the production of IGF2. However, this effect may be masked by the presence of other lesions that promote hyperglycemia. Therefore, when encountering a malignant SFT with diffuse and strong IGF2 expression and without hypoglycemia, other lesions promoting hyperglycemia need to be ruled out. [ABSTRACT FROM AUTHOR]

Co‐evolutionary adaptation of hookworms with their mammalian hosts has been selected for immunoregulatory excretory/secretory (E/S) products. However, it is not known whether, or if so, how host immunological status impacts the secreted profile of hematophagous adult worms. This study interrogated the impact of host Signal transducer and activator of transcription 6 (STAT6) expression during the experimental evolution of hookworms through the sequential passage of the life cycle in either STAT6 deficient or WT C57BL/6 mice. Proteomic analysis of E/S products by LC–MS showed increased abundance of 15 proteins, including myosin‐3, related to muscle function, and aconitate hydratase, related to iron homeostasis. However, most E/S proteins (174 of 337 unique identities) were decreased, including those in the Ancylostoma‐secreted protein (ASP) category, and metallopeptidases. Several identified proteins are established immune‐modulators such as fatty acid‐binding protein homologue, cystatin, and acetylcholinesterase. Enrichment analysis of InterPro functional categories showed down‐regulation of Cysteine‐rich secretory proteins, Antigen 5, and Pathogenesis‐related 1 proteins (CAP), Astacin‐like metallopeptidase, Glycoside hydrolase, and Transthyretin‐like protein groups in STAT6 KO‐adapted worms. Taken together, these data indicate that in an environment lacking Type 2 immunity, hookworms alter their secretome by reducing immune evasion proteins‐ and increasing locomotor‐ and feeding‐associated proteins. [ABSTRACT FROM AUTHOR]

Solitary Fibrous Tumor (SFT) rarely manifests within the thyroid gland, an organ predominantly associated with epithelial carcinomas. This case report explores the clinical narrative of a 70-year-old patient presenting with a sizable SFT localized in the left lobe of the thyroid, posing diagnostic challenges uncommon in thyroid nodules. The report delves into the clinical history, radiological findings, pathological assessments, and therapeutic interventions, contributing to the limited literature on thyroidal SFTs. The patient's ultrasound revealed a substantial thyroid mass causing tracheal and vascular displacement, categorized as TIRADS 3. Fine needle aspiration indicated mesenchymal origin, prompting further investigation. Contrast-enhanced computed tomography depicted a well-defined lesion with varied enhancement, compressing surrounding structures. Histopathology confirmed a spindle cell proliferation, prompting immunohistochemistry revealing CD34, STAT6, and Bcl-2 positivity, aligning with SFT characteristics. The rarity of thyroidal SFTs poses diagnostic challenges, necessitating reliance on immunohistochemistry for accurate differentiation from other spindle cell neoplasms. Radiological investigations, including ultrasound and magnetic resonance imaging, contribute to preoperative planning. The case underscores the importance of meticulous pathological examination, emphasizing the utility of immunohistochemistry in confirming SFT diagnosis. The report enhances understanding among clinicians, pathologists, and researchers, guiding improved diagnostic accuracy and tailored treatment strategies for future occurrences of thyroidal SFTs. [ABSTRACT FROM AUTHOR]

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm known to occur at various soft tissue and visceral locations. Kidney is a rarely reported site for these tumors. Most of the SFTs described in the kidney exhibit a classical CD34-positive patternless spindle cell histology. Focal round cell morphology is seldom reported. Herein, we describe a 48-year-old male patient with renal SFT. This tumor had pure round cell morphology with a CD34−/STAT6+ immunophenotype. Fluorescent in situ hybridization and a multiplexed sequencing assay performed on an Illumina® HiSeq 4000 platform revealed NAB2 and STAT6 gene rearrangement. Renal tumors with round cell morphology are diagnostically challenging and SFT is not often considered in the differential diagnosis of a round cell tumor of the kidney. Moreover, a CD34-negative profile can be rather confounding while diagnosing such lesions. In such scenarios, a strong nuclear STAT6 immunostaining is extremely helpful in clinching the diagnosis. SFT should always be considered in the differential diagnosis of round cell tumors of the kidney due to significant diagnostic and therapeutic implications. [ABSTRACT FROM AUTHOR]

Background: SERPINB2, a biomarker of Type‐2 (T2) inflammatory processes, has been described in the context of asthma. Chronic rhinosinusitis with nasal polyps (CRSwNP) is also correlated with T2 inflammation and elevated 15LO1 induced by IL‐4/13 in nasal epithelial cells. The aim of this study was to evaluate the expression and location of SERPINB2 in nasal epithelial cells (NECs) and determine whether SERPINB2 regulates 15LO1 and downstream T2 markers in NECs via STAT6 signalling. Methods: SERPINB2 gene expression in bulk and single‐cell RNAseq database was analysed by bioinformatics analysis. SERPINB2, 15LO1 and other T2 markers were evaluated from CRSwNP and HCs NECs. The colocalization of SERPINB2 and 15LO1 was evaluated by immunofluorescence. Fresh NECs were cultured at an air‐liquid interface with or without IL‐13, SERPINB2 Dicer‐substrate short interfering RNAs (DsiRNAs) transfection, exogenous SERPINB2, 15‐HETE recombinant protein and pSTAT6 inhibitors. 15LO1, 15‐HETE and downstream T2 markers were analysed by qRT‐PCR, western blot and ELISA. Results: SERPINB2 expression was increased in eosinophilic nasal polyps compared with that in noneosinophilic nasal polyps and control tissues and positively correlated with 15LO1 and other downstream T2 markers. SERPINB2 was predominantly expressed by epithelial cells in NP tissue and was colocalized with 15LO1. In primary NECs in vitro, SERPINB2 expression was induced by IL‐13. Knockdown or overexpression SERPINB2 decreased or enhanced expression of 15LO1 and 15‐HETE in NECs, respectively, in a STAT6‐dependent manner. SERPINB2 siRNA also inhibited the expression of the 15LO1 downstream genes, such as CCL26, POSTN and NOS2. STAT6 inhibition similarly decreased SERPINB2‐induced 15LO1. Conclusions: SERPINB2 is increased in NP epithelial cells of eosinophilic CRSwNP (eCRSwNP) and contributes to T2 inflammation via STAT6 signalling. SERPINB2 could be considered a novel therapeutic target for eCRSwNP. [ABSTRACT FROM AUTHOR]

Background: Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) are distinct hematological malignancies of B-cell origin that share many biological, molecular, and clinical characteristics. In particular, the JAK/STAT signaling pathway is a driver of tumor development due to multiple recurrent mutations, particularly in STAT6. Furthermore, the XPO1 gene that encodes exportin 1 (XPO1) shows a frequent point mutation (E571K) resulting in an altered export of hundreds of cargo proteins, which may impact the success of future therapies in PMBL and cHL. Therefore, targeted therapies have been envisioned for these signaling pathways and mutations. Methods: To identify novel molecular targets that could overcome the treatment resistance that occurs in PMBL and cHL patients, we have explored the efficacy of a first-in-class HSP110 inhibitor (iHSP110-33) alone and in combination with selinexor, a XPO1 specific inhibitor, both in vitro and in vivo. Results: We show that iHSP110-33 decreased the survival of several PMBL and cHL cell lines and the size of tumor xenografts. We demonstrate that HSP110 is a cargo of XPO1wt as well as of XPO1E571K. Using immunoprecipitation, proximity ligation, thermophoresis and kinase assays, we showed that HSP110 directly interacts with STAT6 and favors its phosphorylation. The combination of iHSP110-33 and selinexor induces a synergistic reduction of STAT6 phosphorylation and of lymphoma cell growth in vitro and in vivo. In biopsies from PMBL patients, we show a correlation between HSP110 and STAT6 phosphorylation levels. Conclusions: These findings suggest that HSP110 could be proposed as a novel target in PMBL and cHL therapy. [ABSTRACT FROM AUTHOR]

Macrophage polarization is closely associated with the inflammatory processes involved in the development and chemoresistance of colorectal cancer (CRC). M2 macrophages, the predominant subtype of tumor-associated macrophages (TAMs) in a wide variety of malignancies, have been demonstrated to promote the resistance of CRC to multiple chemotherapeutic drugs, such as 5-fluorouracil (5-FU). In our study, we investigated the potential of 23-Hydroxybetulinic Acid (23-HBA), a significant active component of Pulsatilla chinensis (P. chinensis), to inhibit the polarization of M2 macrophages induced by IL-4. Our results showed that 23-HBA reduced the expression of M2 specific marker CD206, while downregulating the mRNA levels of M2 related genes (CD206, Arg1, IL-10, and CCL2). Additionally, 23-HBA effectively attenuated the inhibitory effects of the conditioned medium from M2 macrophages on apoptosis in colorectal cancer SW480 cells. Mechanistically, 23-HBA prevented the phosphorylation and nuclear translocation of the STAT6 protein, resulting in the inhibition of IL-10 release in M2 macrophages. Moreover, it interfered with the activation of the IL-10/STAT3/Bcl-2 signaling pathway in SW480 cells, ultimately reducing M2 macrophage-induced resistance to 5-FU. Importantly, depleting STAT6 expression in macrophages abolished the suppressive effect of 23-HBA on M2 macrophage polarization, while also eliminating its ability to decrease M2 macrophage-induced 5-FU resistance in cancer cells. Furthermore, 23-HBA significantly diminished the proportion of M2 macrophages in the tumor tissues of colorectal cancer mice, simultaneously enhancing the anti-cancer efficacy of 5-FU. The findings presented in this study highlight the capacity of 23-HBA to inhibit M2 macrophage polarization, a process that contributes to reduced 5-FU resistance in colorectal cancer. [ABSTRACT FROM AUTHOR]

Objective(s): Colorectal cancer (CRC) remains a major health concern worldwide due to its high incidence, mortality rate, and resistance to conventional treatments. The discovery of new targets for cancer therapy is essential to improve the survival of CRC patients. Here, this study aims to present a finding that identifies the STAT6 oncogene as a potent therapeutic target for CRC.Materials and Methods: HT-29 CRC cells were transfected with STAT6 siRNA and treated with 5-fluorouracil (5-FU) alone and combined. Then, to evaluate cellular proliferation and apoptosis percentage, MTT assay and annexin V/PI staining were carried out, respectively. Moreover, the migration ability of HT-29 cells was followed using a wound-healing assay, and a colony formation assay was performed to explore cell stemness features. Gene expression was quantified via qRT-PCR. Afterward, functional enrichment analysis was used to learn in-depth about the STAT6 co-expressed genes and the pathways to which they belong.Results: Our study shows that silencing STAT6 with small interfering RNA (siRNA) enhances the chemosensitivity of CRC cells to 5-FU, a commonly used chemotherapy drug, by inducing apoptosis, reducing proliferation, and inhibiting metastasis. These results suggest that combining 5-FU with STAT6-siRNA could provide a promising strategy for CRC treatment.Conclusion: Our study sheds light on the potential of STAT6 as a druggable target for CRC cancers, the findings offer hope for more effective treatments for CRC patients, especially those with advanced stages that are resistant to conventional therapies.

Abstract Circular RNAs (circRNAs) play important roles in gastric cancer progression but the regulatory role of circRNAs in controlling macrophage function remains elusive. Exosomes serve as cargo for circRNAs and play a crucial role as mediators in facilitating communication between cancer cells and the tumor microenvironment. In this study, we found that circATP8A1, a previously unreported circular RNA, is highly expressed in both gastric cancer tissues and exosomes derived from plasma. Increased circATP8A1 was associated with advanced TNM stage and worse prognosis in patients with gastric cancer. We showed that the circATP8A1 knockdown significantly inhibited gastric cancer proliferation and invasion in vitro and in vivo. Functionally, exosome circATP8A1 induced the M2 polarization of macrophages through the STAT6 pathway instead of the STAT3 pathway. Mechanistically, circATP8A1 was shown to activate the STAT6 pathway through competitive binding to miR-1-3p, as confirmed by Fluorescence In Situ Hybridization (FISH), RNA immunoprecipitation, RNA pulldown, and Luciferase reporter assays. The reversal of circATP8A1-induced STAT6 pathway activation and macrophage polarization was observed upon blocking miR-1-3p. Macrophages treated with exosomes from gastric cancer cells overexpressing circATP8A1 were able to promote gastric cancer migration, while knockdown of circATP8A1 reversed these effects in vivo. In summary, exosome-derived circATP8A1 from gastric cancer cells induce macrophages M2 polarization via the circATP8A1/miR-1-3p/STAT6 axis, and tumor progression. Our results highlight circATP8A1 as a potential prognostic biomarker and therapeutic target in gastric cancer.

Objective(s): Colorectal cancer (CRC) remains a major health concern worldwide due to its high incidence, mortality rate, and resistance to conventional treatments. The discovery of new targets for cancer therapy is essential to improve the survival of CRC patients. Here, this study aims to present a finding that identifies the STAT6 oncogene as a potent therapeutic target for CRC. Materials and Methods: HT-29 CRC cells were transfected with STAT6 siRNA and treated with 5-fluorouracil (5-FU) alone and combined. Then, to evaluate cellular proliferation and apoptosis percentage, MTT assay and annexin V/PI staining were carried out, respectively. Moreover, the migration ability of HT-29 cells was followed using a wound-healing assay, and a colony formation assay was performed to explore cell stemness features. Gene expression was quantified via qRT-PCR. Afterward, functional enrichment analysis was used to learn in-depth about the STAT6 co-expressed genes and the pathways to which they belong. Results: Our study shows that silencing STAT6 with small interfering RNA (siRNA) enhances the chemosensitivity of CRC cells to 5-FU, a commonly used chemotherapy drug, by inducing apoptosis, reducing proliferation, and inhibiting metastasis. These results suggest that combining 5-FU with STAT6-siRNA could provide a promising strategy for CRC treatment. Conclusion: Our study sheds light on the potential of STAT6 as a druggable target for CRC cancers, the findings offer hope for more effective treatments for CRC patients, especially those with advanced stages that are resistant to conventional therapies. [ABSTRACT FROM AUTHOR]

Proton pump inhibitors (PPIs) are the first-line drug for eosinophilic esophagitis (EoE), although it is estimated that there is a lack of histological remission in 50% of patients. This research aimed to identify pharmacogenetic biomarkers predictive of PPI effectiveness and to study their association with disease features. Peak eosinophil count (PEC) and the endoscopic reference score (EREFS) were determined before and after an eight-week PPI course in 28 EoE patients. The impact of the signal transducer and activator of transcription 6 (STAT6), CYP2C19, CYP3A4, CYP3A5, and ABCB1 genetic variations on baseline PEC and EREFS, their reduction and histological response, and on EoE symptoms and comorbidities was analyzed. PEC reduction was higher in omeprazole-treated patients (92.5%) compared to other PPIs (57.9%, p = 0.003). STAT6 rs12368672 (g.18453G>C) G/G genotype showed higher baseline PEC values compared to G/C and C/C genotypes (83.2 vs. 52.9, p = 0.027). EREFS reduction in STAT6 rs12368672 G/G and G/C genotypes was higher than in the C/C genotype (36.7% vs. −75.0% p = 0.011). However, significance was lost after Bonferroni correction. Heartburn incidence was higher in STAT6 rs167769 (g.27148G>A) G/G patients compared to G/A (54.55% vs. 11.77%, p = 0.030). STAT6 rs12368672G>C and rs167769G>A variants might have a relevant impact on EoE status and PPI response. Further research is warranted to clarify the clinical relevance of these variants. [ABSTRACT FROM AUTHOR]

Solitary fibrous tumour (SFT) is a mesenchymal neoplasm with variable behaviour, very rarely involving the genitourinary (GU) tract. Most reported cases correspond to isolated case reports. STAT6 immunohistochemistry is a more recent and reliable diagnostic marker. The pathology database of two tertiary institutes was searched for SFTs involving the GU tract. STAT6 strong diffuse nuclear staining confirmed the diagnosis in all four cases, and the NAB2::STAT6 fusion was demonstrated by NGS in one case. Two cases were diagnosed in needle biopsy, one involving the prostate and the other involving the seminal vesicle. One case corresponded to a pelvic mass inseparable from and infiltrating the prostate and bladder. The remainder represented an exceedingly rare involvement of the spermatic cord. Involvement by a SFT should be considered in the differential diagnosis of spindle cell lesions involving GU organs. STAT6 strong diffuse nuclear staining is an important ancillary tool, particularly in a biopsy. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) play important roles in gastric cancer progression but the regulatory role of circRNAs in controlling macrophage function remains elusive. Exosomes serve as cargo for circRNAs and play a crucial role as mediators in facilitating communication between cancer cells and the tumor microenvironment. In this study, we found that circATP8A1, a previously unreported circular RNA, is highly expressed in both gastric cancer tissues and exosomes derived from plasma. Increased circATP8A1 was associated with advanced TNM stage and worse prognosis in patients with gastric cancer. We showed that the circATP8A1 knockdown significantly inhibited gastric cancer proliferation and invasion in vitro and in vivo. Functionally, exosome circATP8A1 induced the M2 polarization of macrophages through the STAT6 pathway instead of the STAT3 pathway. Mechanistically, circATP8A1 was shown to activate the STAT6 pathway through competitive binding to miR-1-3p, as confirmed by Fluorescence In Situ Hybridization (FISH), RNA immunoprecipitation, RNA pulldown, and Luciferase reporter assays. The reversal of circATP8A1-induced STAT6 pathway activation and macrophage polarization was observed upon blocking miR-1-3p. Macrophages treated with exosomes from gastric cancer cells overexpressing circATP8A1 were able to promote gastric cancer migration, while knockdown of circATP8A1 reversed these effects in vivo. In summary, exosome-derived circATP8A1 from gastric cancer cells induce macrophages M2 polarization via the circATP8A1/miR-1-3p/STAT6 axis, and tumor progression. Our results highlight circATP8A1 as a potential prognostic biomarker and therapeutic target in gastric cancer. [ABSTRACT FROM AUTHOR]

Diffuse large B-cell lymphoma (DLBCL) relapses in approximately 40% of patients following frontline therapy. We reported that STAT6D419 mutations are enriched in relapsed/refractory DLBCL (rrDLBCL) samples, suggesting that JAK/STAT signaling plays a role in therapeutic resistance. We hypothesized that STAT6D419 mutations can improve DLBCL cell survival by reprogramming the microenvironment to sustain STAT6 activation. Thus, we investigated the role of STAT6D419 mutations on DLBCL cell growth and its microenvironment. We found that phospho-STAT6D419N was retained in the nucleus longer than phospho-STAT6WT following IL-4 stimulation, and STAT6D419N recognized a more restricted DNA-consensus sequence than STAT6WT. Upon IL-4 induction, STAT6D419N expression led to a higher magnitude of gene expression changes, but in a more selective list of gene targets compared with STATWT. The most significantly expressed genes induced by STAT6D419N were those implicated in survival, proliferation, migration, and chemotaxis, in particular CCL17. This chemokine, also known as TARC, attracts helper T-cells to the tumor microenvironment, especially in Hodgkin's lymphoma. To this end, in DLBCL, phospho-STAT6+ rrDLBCL cells had a greater proportion of infiltrating CD4+ T-cells than phospho-STAT6− tumors. Our findings suggest that STAT6D419 mutations in DLBCL lead to cell autonomous changes, enhanced signaling, and altered composition of the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Background: Solitary fibrous tumors (SFT) are the rare mesenchymal tumors originally described in the pleura. SFT of breast is even rarer and to the best of our knowledge about 35 cases are reported to date, including only six malignant SFT cases. Case presentation: We report a case of a 52-year-old lady with a large left breast mass involving all the quadrants. The tumor was diagnosed as malignant SFT in a core needle biopsy which was later confirmed on the resection specimen. Conclusion: Herein, we describe the approach and importance of optimal utilization of immunohistochemistry for diagnosing such rare tumors of the breast, particularly, when clinical presentation, radiology and fine needle aspiration cytology are incongruous. [ABSTRACT FROM AUTHOR]

Abstract Atopic dermatitis (AD) is a common skin disease involving important immune mechanisms. There is an unmet need for a treatment for this condition. Herein, we focused on elucidating the role of Bi2-xMnxO3 nanospheres (BM) in alleviating skin inflammation in AD-like C57BL/6 mice. The BM was fabricated via sacrificial templates and its biosafety was systematically evaluated. The BM was applied topically to skin lesions of AD-like C57BL/6 mice. The phenotypic and histological changes in the skin were examined carefully. The responses of barrier proteins, inflammatory cytokines and cells to BM were evaluated in HaCaT cells and AD mouse models. The data demonstrated that BM treatment alleviated the AD phenotypes and decreased the level of inflammatory factors, while increasing the expression of the barrier proteins filaggrin/involucrin in the skin. BM effectively reduced the expression of phosphorylated STAT6, which in turn reduced the expression of GATA3, and further decreased the differentiation ratio of Th2 cells, thereby reducing the expression of IL-4. In conclusion, topical drug therapy with BM provides a safe and effective treatment modality for AD by reducing IL-4 and increasing barrier proteins. Graphical Abstract

Abstract Various allergic diseases such as atopic dermatitis (AD), allergic rhinitis, and asthma are considered incurable conditions that have yet to be fully conquered. Paedoksan (PDS), an herbal preparation consisting of 14 medicines, displays effective anti-inflammatory and anti-allergic properties, yet its underlying molecular mechanism is unknown. This study aims to uncover PDS’s mechanism for treating allergic diseases and suggest its therapeutic potential. Through a network pharmacological prediction, its impact on signal transducer and activator of transcription 6 (STAT6) regulation, a sub-mechanism of interleukin 4 (IL-4), a major inflammatory cytokine involved in degranulation and allergy, was investigated in RBL-2H3 cells and an atopic mouse model. PDS inhibits immunoglobulin E (IgE)-induced degranulation and STAT6 phosphorylation evoked by IL-4 in granulocytes. The downregulation of phospho-STAT6 and thymic stromal lymphopoietin (TSLP) by PDS was confirmed in 2,4-dinitrochlorobenzene (DNCB)-induced mouse skin. The results demonstrate that PDS exhibited remarkable effects on degranulation and STAT6 phosphorylation in RBL-2H3 cells, as well as in an atopic mouse model. Furthermore, the main active components from PDS based on chromatographic analysis showed good accordance with PDS’s effects on RBL-2H3 cells. In summary, these findings collectively suggest that PDS holds the potential to effectively suppress inflammatory and allergic reactions by obstructing the target IL-4 protein and its downstream effects, as elucidated through a network pharmacological analysis.

Abstract Th9 cells play a crucial role in parasite immunity. The development of Th9 cells is facilitated by several cytokines. Key transcription factors, such as STAT6, STAT5, and PU.1, are known to enhance IL-9 expression during the Th9 immune response. NF-κB-mediated transduction pathways participate in the induction of IL-9. In a previous study, we unveiled a unique ribosomal protein derived from Haemonchus contortus excretory-secretory proteins (HcESPs) that interact with host Th9 cells. In the present study, the effects of the Haemonchus contortus ribosomal protein L6 domain DE-containing protein (HcL6) on IL-9 secretion, Th9 differentiation, and IL-9 transcription were assessed by employing ELISA, flow cytometry, and qPCR methodologies. The observations revealed the transcriptional upregulation of several key genes within the Th9 immune response pathway. Moreover, silencing STAT6, PU.1, and NF-κB was found to attenuate the Th9 immune response. In this study, we unveiled the Th9 immune response-inducing capabilities of HcL6 and elucidated some of its underlying mechanisms. These findings suggest that HcL6 is an immunostimulatory antigen capable of inducing the Th9 immune response. These insights could prove instrumental in identifying potential candidate antigens for the development of immunoprophylactic strategies against H. contortus infections.

Sepsis-induced muscle weakness is a debilitating consequence of prolonged critical illness, often associated with a poor prognosis. While recent research has shown that STAT6 functions as an inhibitor of myogenesis, its role in sepsis-induced muscle weakness remains unclear. In this study, we hypothesized that inhibiting STAT6 could attenuate sepsis-induced muscle atrophy and weakness, and we explored the underlying mechanisms. Leveraging a microarray dataset from sepsis patients, we identified significant enrichment of genes related to muscle function, ferroptosis, and the p53 signalling pathway in muscle tissue from sepsis patients. Using a murine sepsis model induced by cecum ligation and puncture (CLP), we explore the multifaceted role of STAT6 inhibition. Our findings demonstrate that STAT6 inhibition effectively attenuates muscle atrophy, enhances grip strength, preserves mitochondrial integrity, and modulates ferroptosis in septic mice. Additionally, we identify elevated levels of CHI3L1 in septic muscle tissue, which are significantly reduced by STAT6 inhibition. In-depth analysis of primary muscle satellite cells reveals that CHI3L1 overexpression is associated with increased expression of key regulators of satellite cell myogenicity, while negatively impacting cell viability. Silencing CHI3L1 expression mitigates satellite cell injury and loss, highlighting its pivotal role in sepsis-induced muscle damage. In summary, this study unveils the potential of STAT6 as a therapeutic target for mitigating sepsis-induced muscle atrophy and weakness. Our findings underscore the regulation of mitochondrial dysfunction, ferroptosis, and CHI3L1-mediated satellite cell damage by STAT6, offering promising avenues for therapeutic intervention in the management of sepsis-induced muscle weakness.

Tumor-associated macrophages (TAMs) are critical in the tumor microenvironment (TME) of hepatocellular carcinoma (HCC). Major vault protein (MVP) mediates multidrug resistance, cell growth and development, and viral immunity. However, the relationship between MVP and TAMs polarization has not been clarified in HCC. We found that MVP significantly increased M2-TAMs infiltration levels in tumor tissues of HCC patients. MVP promoted HCC proliferation, metastasis, and invasion by regulating M2 polarization in vivo and in vitro. Mechanistically, MVP associated with signal transducer and activator of transcription 6 (STAT6) and enhanced STAT6 phosphorylation. STAT6 translocated from the cytosol to the nucleus and regulated M2 macrophage-associated gene transcription. These findings suggest that MVP modulates the macrophage M2 transcriptional program, revealing its potential role in the TAMs of TME. [ABSTRACT FROM AUTHOR]

The signal transducer and activator of transcription (STAT) family of proteins has been demonstrated to perform pivotal roles downstream of a myriad of cytokines, particularly those that control immune cell production and function. This is highlighted by both gain-of-function (GOF) and loss-of-function (LOF) mutations being implicated in various diseases impacting cells of the immune system. These mutations are typically inherited, although somatic GOF mutations are commonly observed in certain immune cell malignancies. This review details the growing appreciation of STAT proteins as a key node linking immunodeficiency, autoimmunity and cancer. [ABSTRACT FROM AUTHOR]

Airway epithelial cells contribute to a variety of lung diseases including allergic asthma, where IL‐4 and IL‐13 promote activation of the transcription factor STAT6. This leads to goblet cell hyperplasia and the secretion of effector molecules by epithelial cells. However, the specific effect of activated STAT6 in lung epithelial cells is only partially understood. Here, we created a mouse strain to selectively investigate the role of constitutively active STAT6 in Club cells, a subpopulation of airway epithelial cells. CCSP‐Cre_STAT6vt mice and bronchiolar organoids derived from these show an enhanced expression of the chitinase‐like protein Chil4 (Ym2) and resistin‐like molecules (Relm‐α, ‐β, ‐γ). In addition, goblet cells of these mice spontaneously secrete mucus into the bronchi. However, the activated epithelium resulted neither in impaired lung function nor conferred a protective effect against the migrating helminth Nippostrongylus brasiliensis. Moreover, CCSP‐Cre_STAT6vt mice showed similar allergic airway inflammation induced by live conidia of the fungus Aspergillus fumigatus and similar recovery after influenza A virus infection compared to control mice. Together these results highlight that STAT6 signaling in Club cells induces the secretion of Relm proteins and mucus without impairing lung function, but this is not sufficient to confer protection against helminth or viral infections. [ABSTRACT FROM AUTHOR]

Our previous study had demonstrated that Runx1 promoted LPS-induced macrophage inflammatory response, however, the role of Runx1 in M2 macrophage polarization still remains largely unknown. This study was conducted to investigate the role of Runx1 in IL-4/IL-13-induced M2 macrophage polarization and its potential regulatory mechanism. We found that exposure of macrophages to IL-4/IL-13 induced a remarkable increasement in Runx1 expression level. Specifically, we established genetically modified mice lacking Runx1 in myeloid cells, including macrophages. RNA-Seq was performed to identify differentially expressed genes (DEGs) between Runx1 knockout and WT control bone marrow-derived macrophages (BMDMs). We identified 686 DEGs, including many genes which were highly expressed in M2 macrophage. In addition, bioinformatics analysis indicated that these DEGs were significantly enriched in extracellular matrix-related processes. Moreover, RT-qPCR analysis showed that there was an obvious upregulation in the relative expression levels of M2 marker genes, including Arg1, Ym1, Fizz1, CD71, Mmp9, and Tgm2, in Runx1 knockout macrophages, as compared to WT controls. Consistently, similar results were obtained in the protein and enzymatic activity levels of Arg1. Finally, we found that the STAT6 phosphorylation level was significantly enhanced in Runx1 knockout macrophages, and the STAT6 inhibitor AS1517499 partly reduced the upregulated effect of Runx1 deficiency on the M2 macrophage polarization. Taken together, Runx1 deficiency facilitates IL-4/IL-13-induced M2 macrophage polarization through enhancing STAT6 phosphorylation. [ABSTRACT FROM AUTHOR]

Objective and design: Kidney stones commonly occur with a 50% recurrence rate within 5 years, and can elevate the risk of chronic kidney disease. Macrophage-to-myofibroblast transition (MMT) is a newly discovered mechanism that leads to progressive fibrosis in different forms of kidney disease. In this study, we aimed to investigate the role of MMT in renal fibrosis in glyoxylate-induced kidney stone mice and the mechanism by which signal transducer and activator of transcription 6 (STAT6) regulates MMT. Methods: We collected non-functioning kidneys from patients with stones, established glyoxylate-induced calcium oxalate stone mice model and treated AS1517499 every other day in the treatment group, and constructed a STAT6-knockout RAW264.7 cell line. We first screened the enrichment pathway of the model by transcriptome sequencing; detected renal injury and fibrosis by hematoxylin eosin staining, Von Kossa staining and Sirius red staining; detected MMT levels by multiplexed immunofluorescence and flow cytometry; and verified the binding site of STAT6 at the PPARα promoter by chromatin immunoprecipitation. Fatty acid oxidation (FAO) and fibrosis-related genes were detected by western blot and real-time quantitative polymerase chain reaction. Results: In this study, we found that FAO was downregulated, macrophages converted to myofibroblasts, and STAT6 expression was elevated in stone patients and glyoxylate-induced kidney stone mice. The promotion of FAO in macrophages attenuated MMT and upregulated fibrosis-related genes induced by calcium oxalate treatment. Further, inhibition of peroxisome proliferator-activated receptor-α (PPARα) eliminated the effect of STAT6 deletion on FAO and fibrosis-associated protein expression. Pharmacological inhibition of STAT6 also prevented the development of renal injury, lipid accumulation, MMT, and renal fibrosis. Mechanistically, STAT6 transcriptionally represses PPARα and FAO through cis-inducible elements located in the promoter region of the gene, thereby promoting MMT and renal fibrosis. Conclusions: These findings establish a role for STAT6 in kidney stone injury-induced renal fibrosis, and suggest that STAT6 may be a therapeutic target for progressive renal fibrosis in patients with nephrolithiasis. [ABSTRACT FROM AUTHOR]

Copyright of Die Pathologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)