[Analysis of vocal fold movement characteristics in patients with laryngeal neurogenic injury].

Objective:To analyze the characteristics of vocal fold movement and glottic closure in patients with laryngeal neurogenic injury. Methods:A total of 185 patients with vocal fold paralysis diagnosed by laryngeal electromyography as neurogenic damage to cricothyroid muscle, thyreoarytenoid muscle and posterior cricoarytenoid muscle were enrolled, they were divided into unilateral vocal fold paralysis group and bilateral vocal fold paralysis group, respectively, and superior laryngeal paralysis group, recurrent laryngeal nerve paralysis group and vagal nerve paralysis group according to nerve injury. The characteristics of vocal fold movement and glottic closure were analyzed under strobe laryngoscope. The qualitative evaluation of vocal fold movement was fixed vocal fold, reduced vocal fold movement and normal vocal fold movement, and the qualitative evaluation of glottic closure was glottic closure and glottic imperfection. The results were analyzed statistically. Results:The proportion of normal, reduced and fixed vocal fold motion in bilateral vocal fold paralysis group was significantly different from that in unilateral vocal fold paralysis group（P<0.05）, the composition of normal and reduced vocal fold motion in bilateral vocal fold paralysis group（47.70%） was significantly greater than that in unilateral vocal fold paralysis group（12.27%）. There was no significant difference between the proportion of glottic closure and glottic imperfecta in bilateral vocal fold paralysis group and unilateral vocal fold paralysis group（P<0.05）. The proportion of decreased vocal fold motion in superior laryngeal nerve paralysis group（50.00%） was higher than that in recurrent laryngeal nerve paralysis group（9.32%） and vagal nerve paralysis group（9.00%）. The proportion of decreased and fixed vocal fold motion in superior laryngeal nerve paralysis group, recurrent laryngeal nerve paralysis group and vagal nerve paralysis group was statistically significant（P<0.05）.There was no significant difference in glottic closure among the three groups（P<0.05）. Conclusion:Vocal fold movement characteristics of patients with laryngeal neurogenic injury were mainly vocal fold fixation, or normal or weakened vocal fold movement. There may be missed diagnosis of unilateral vocal fold paralysis in clinical practice. In half of the patients with superior laryngeal nerve palsy, vocal fold movement is characterized by vocal fold fixation.

Serratus Anterior Fascia for Immediate Implant-Based Breast Reconstruction: A Case Series of 65 Patients With Breast Cancer.

OBJECTIVE: After immediate implant-based breast reconstruction (IIBR) after mastectomy, implant exposure or capsular contracture can occur. This study aimed to evaluate IIBR using serratus anterior fascia in patients with breast cancer. METHODS: This retrospective case series study enrolled patients with breast cancer underwent IIBR using the serratus anterior fascia after mastectomy in the Department of Breast Surgery of Fujian Cancer Hospital between January 2021 and December 2022. RESULTS: Sixty-five cases with breast cancer underwent IIBR using serratus anterior fascia were enrolled, with a median age of 39 years (range, 24-57 years) and body mass index of 21.32 kg/m 2 (range, 19-25 kg/m 2 ). The aesthetic outcomes of the reconstructed breasts showed good in 53 cases (81.6%), moderate in 11 cases (16.9%), and poor in 1 case (1.5%) due to offset position. Two cases showed poor wound healing, which improved after repeat suturing and 5 cases developed partial ischemic necrosis of the nipple, which scabbed and healed spontaneously. CONCLUSIONS: Implant-based breast reconstruction using serratus anterior fascia may provide good aesthetic outcomes with few complications.

Exosomes modified with anti-MEK1 siRNA lead to an effective silencing of triple negative breast cancer cells.

Triple negative breast cancer (TNBC) is a highly heterogenous disease not sensitive to endocrine or HER2 therapy and standardized treatment regimens are still missing. Therefore, development of novel TNBC treatment approaches is of utmost relevance. Herein, the potential of MAPK/ERK downregulation by RNAi-based therapeutics in a panel of mesenchymal stem-like TNBC cell lines was uncovered. Our data revealed that suppression of one of the central nodes of this signaling pathway, MEK1, affects proliferation, migration, and invasion of TNBC cells, that may be explained by the reversion of the epithelial-mesenchymal transition phenotype, which is facilitated by the MMP-2/MMP-9 downregulation. Moreover, an exosome-based system was successfully generated for the siRNA loading (iExoMEK1). Our data suggested absence of modification of the physical properties and general integrity of the iExoMEK1 comparatively to the unmodified counterparts. Such exosome-mediated downregulation of MEK1 led to a tumor regression accompanied by a decrease of angiogenesis using the chick chorioallantoic-membrane model. Our results highlight the potential of the targeting of MAPK/ERK cascade as a promising therapeutic approach against TNBC.

KRASG12D inhibition reprograms the microenvironment of early and advanced pancreatic cancer to promote FAS-mediated killing by CD8+ T cells.

The KRASG12D mutation is present in nearly half of pancreatic adenocarcinomas (PDAC). We investigated the effects of inhibiting the KRASG12D mutant protein with MRTX1133, a non-covalent small molecule inhibitor of KRASG12D, on early and advanced PDAC and its influence on the tumor microenvironment. Employing 16 different models of KRASG12D-driven PDAC, we demonstrate that MRTX1133 reverses early PDAC growth, increases intratumoral CD8+ effector T cells, decreases myeloid infiltration, and reprograms cancer-associated fibroblasts. MRTX1133 leads to regression of both established PanINs and advanced PDAC. Regression of advanced PDAC requires CD8+ T cells and immune checkpoint blockade (ICB) synergizes with MRTX1133 to eradicate PDAC and prolong overall survival. Mechanistically, inhibition of KRASG12D in advanced PDAC and human patient derived organoids induces FAS expression in cancer cells and facilitates CD8+ T cell-mediated death. Collectively, this study provides a rationale for a synergistic combination of MRTX1133 with ICB in clinical trials.

The role of total antioxidant capacity and malondialdehyde of seminal plasma in the association between air pollution and sperm quality.

Accumulating evidence has suggested that men exposed to air pollution are associated with decreased sperm quality, and seminal plasma plays a pivotal role in maintaining sperm viability. However, the role of seminal plasma in air pollution related sperm quality decline remain unestablished. In current study, we recruited 524 participants from couples who underwent in vitro fertilization treatment due to female factors at a fertility clinic in China from March to August 2020. Conventional sperm parameters, total antioxidant capacity (T-AOC), malondialdehyde (MDA) and testosterone were measured using semen samples. The six main air pollutants (PM2.5, PM10, NO2, SO2, CO, O3) during four key periods of sperm development (meiotic stage, spermiogenesis stage, epididymal stage and total sperm cycle period) were estimated using inverse distance weighting method. Multiple linear regression models were employed to investigate the exposure-outcome relationships. And we found that PM10 exposures were negatively related to sperm total motility and the exposures of PM2.5 and PM10 were inversely associated with sperm progressive motility during epididymal stage. Furthermore, PM2.5 and PM10 exposures were positively associated with seminal plasma MDA and PM10 was negatively related to seminal plasma T-AOC during epididymal stage. PM2.5, PM10 and CO exposures during total sperm cycle period might relate to increased seminal plasma testosterone. Mediation analysis indicated seminal plasma MDA and T-AOC partially mediated PM10 associated reduction of sperm motility during epididymal stage. Our study suggested MDA and T-AOC of seminal plasma played a role in air pollution associated decline of sperm motility.

Induced regulatory T cells remain suppressive capability on effector T cells and synovial fibroblasts in collagen-induced arthritis.

Rheumatoid arthritis (RA) is a common autoimmune disorder initiated by inflammatory synovitis. Hyperproliferation of destructive synovial fibroblasts (SFs) is one of the pathogenic mechanisms of RA. Abnormalities in regulatory T cells (Tregs) may also play a critical role in this progression. To date, it is unclear whether both natural Tregs (nTregs) and induced Tregs (iTregs) share similar characteristics in RA progression and whether Tregs directly suppress the autoaggressive activities of SFs. In this study, we compared suppressive effects on effector T cells (Teffs) and inflamed SFs between nTregs and iTregs in a collagen-induced arthritis (CIA) model. Our results demonstrated that iTregs but not nTregs maintained a suppressive effect on Teffs after adoptive transfer into CIA mice. Additionally, we discovered that iTregs directly inhibited the destructive activities of CIA-SFs. Thus, this study suggests that administration of the iTreg subset has great potential for treatment of RA in the clinic in the future.

Oncogenic Kras G12D specific non-covalent inhibitor reprograms tumor microenvironment to prevent and reverse early pre-neoplastic pancreatic lesions and in combination with immunotherapy regresses advanced PDAC in a CD8 + T cells dependent manner.

Pancreatic ductal adenocarcinoma (PDAC) is associated with mutations in Kras, a known oncogenic driver of PDAC; and the KRAS G12D mutation is present in nearly half of PDAC patients. Recently, a non-covalent small molecule inhibitor (MRTX1133) was identified with specificity to the Kras G12D mutant protein. Here we explore the impact of Kras G12D inhibition by MRTX1133 on advanced PDAC and its influence on the tumor microenvironment. Employing different orthotopic xenograft and syngeneic tumor models, eight different PDXs, and two different autochthonous genetic models, we demonstrate that MRTX1133 reverses early PDAC growth, increases intratumoral CD8 + effector T cells, decreases myeloid infiltration, and reprograms cancer associated fibroblasts. Autochthonous genetic mouse models treated with MRTX1133 leads to regression of both established PanINs and advanced PDAC. Regression of advanced PDAC requires CD8 + T cells and immune checkpoint blockade therapy (iCBT) synergizes with MRTX1133 to eradicate PDAC and prolong overall survival. Mechanistically, inhibition of mutant Kras in advanced PDAC and human patient derived organoids (PDOs) induces Fas expression in cancer cells and facilitates CD8 + T cell mediated death. These results demonstrate the efficacy of MRTX1133 in different mouse models of PDAC associated with reprogramming of stromal fibroblasts and a dependency on CD8 + T cell mediated tumor clearance. Collectively, this study provides a rationale for a synergistic combination of MRTX1133 with iCBT in clinical trials.

Oncogenic collagen I homotrimers from cancer cells bind to α3ß1 integrin and impact tumor microbiome and immunity to promote pancreatic cancer.

In contrast to normal type I collagen (Col1) heterotrimer (α1/α2/α1) produced by fibroblasts, pancreatic cancer cells specifically produce unique Col1 homotrimer (α1/α1/α1). Col1 homotrimer results from epigenetic suppression of the Col1a2 gene and promotes oncogenic signaling, cancer cell proliferation, tumor organoid formation, and growth via α3ß1 integrin on cancer cells, associated with tumor microbiome enriched in anaerobic Bacteroidales in hypoxic and immunosuppressive tumors. Deletion of Col1 homotrimers increases overall survival of mice with pancreatic ductal adenocarcinoma (PDAC), associated with reprograming of the tumor microbiome with increased microaerophilic Campylobacterales, which can be reversed with broad-spectrum antibiotics. Deletion of Col1 homotrimers enhances T cell infiltration and enables efficacy of anti-PD-1 immunotherapy. This study identifies the functional impact of Col1 homotrimers on tumor microbiome and tumor immunity, implicating Col1 homotrimer-α3ß1 integrin signaling axis as a cancer-specific therapeutic target.

Identification of Functional Heterogeneity of Carcinoma-Associated Fibroblasts with Distinct IL6-Mediated Therapy Resistance in Pancreatic Cancer.

The tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) involves a significant accumulation of fibroblasts as part of the host response to cancer. Using single-cell RNA sequencing, multiplex immunostaining, and several genetic mouse models, we identify carcinoma-associated fibroblasts (CAF) with opposing functions in PDAC progression. Depletion of fibroblast activation protein (FAP)+ CAFs results in increased survival, in contrast to depletion of alpha smooth muscle actin (αSMA)+ CAFs, which leads to decreased survival. Tumor-promoting FAP+ CAFs (TP-CAF) and tumor-restraining αSMA+ CAFs (TR-CAF) differentially regulate cancer-associated pathways and accumulation of regulatory T cells. Improved efficacy of gemcitabine is observed when IL6 is deleted from αSMA+ CAFs but not from FAP+ CAFs using dual-recombinase genetic PDAC models. Improved gemcitabine efficacy due to lack of IL6 synergizes with anti-PD-1 immunotherapy to significantly improve survival of PDAC mice. Our study identifies functional heterogeneity of CAFs in PDAC progression and their different roles in therapy response. SIGNIFICANCE: PDAC is associated with accumulation of dense stroma consisting of fibroblasts and extracellular matrix that regulate tumor progression. Here, we identify two distinct populations of fibroblasts with opposing roles in the progression and immune landscape of PDAC. Our findings demonstrate that fibroblasts are functionally diverse with therapeutic implications. This article is highlighted in the In This Issue feature, p. 1397.

Type-I collagen produced by distinct fibroblast lineages reveals specific function during embryogenesis and Osteogenesis Imperfecta.

Type I collagen (Col1) is the most abundant protein in mammals. Col1 contributes to 90% of the total organic component of bone matrix. However, the precise cellular origin and functional contribution of Col1 in embryogenesis and bone formation remain unknown. Single-cell RNA-sequencing analysis identifies Fap+ cells and Fsp1+ cells as the major contributors of Col1 in the bone. We generate transgenic mouse models to genetically delete Col1 in various cell lineages. Complete, whole-body Col1 deletion leads to failed gastrulation and early embryonic lethality. Specific Col1 deletion in Fap+ cells causes severe skeletal defects, with hemorrhage, edema, and prenatal lethality. Specific Col1 deletion in Fsp1+ cells results in Osteogenesis Imperfecta-like phenotypes in adult mice, with spontaneous fractures and compromised bone healing. This study demonstrates specific contributions of mesenchymal cell lineages to Col1 production in organogenesis, skeletal development, and bone formation/repair, with potential insights into cell-based therapy for patients with Osteogenesis Imperfecta.

Stabilized epithelial phenotype of cancer cells in primary tumors leads to increased colonization of liver metastasis in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is therapeutically recalcitrant and metastatic. Partial epithelial to mesenchymal transition (EMT) is associated with metastasis; however, a causal connection needs further unraveling. Here, we use single-cell RNA sequencing and genetic mouse models to identify the functional roles of partial EMT and epithelial stabilization in PDAC growth and metastasis. A global EMT expression signature identifies ∼50 cancer cell clusters spanning the epithelial-mesenchymal continuum in both human and murine PDACs. The combined genetic suppression of Snail and Twist results in PDAC epithelial stabilization and increased liver metastasis. Genetic deletion of Zeb1 in PDAC cells also leads to liver metastasis associated with cancer cell epithelial stabilization. We demonstrate that epithelial stabilization leads to the enhanced collective migration of cancer cells and modulation of the immune microenvironment, which likely contribute to efficient liver colonization. Our study provides insights into the diverse mechanisms of metastasis in pancreatic cancer and potential therapeutic targets.

Therapeutic targeting of STAT3 with small interference RNAs and antisense oligonucleotides embedded exosomes in liver fibrosis.

Hepatic fibrosis is a wound healing response that results in excessive extracellular matrix (ECM) accumulation in response to chronic hepatic injury. Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor associated with the pathogenesis of liver fibrosis. Though a promising potential therapeutic target, there are no specific drug candidates for STAT3. Exosomes are extracellular vesicles generated by all cell types with a capacity to efficiently enter cells across different biological barriers. Here, we utilize exosomes as delivery conduit to specifically target STAT3 in liver fibrosis. Exosomes derived from clinical grade fibroblast-like mesenchymal stem cells (MSCs) were engineered to carry siRNA or antisense oligonucleotide (ASO) targeting STAT3 (iExosiRNA-STAT3 or iExomASO-STAT3 ). Compared to scrambled siRNA control, siRNA-STAT3, or ASO-STAT3, iExosiRNA-STAT3 or iExomASO-STAT3 showed enhanced STAT3 targeting efficiency. iExosiRNA-STAT3 or iExomASO-STAT3 treatments suppressed STAT3 levels and ECM deposition in established liver fibrosis in mice, and significantly improved liver function. iExomASO-Stat3 restored liver function more efficiently when compared to iExosiRNA-STAT3 . Our results identify a novel anti-fibrotic approach for direct targeting of STAT3 with exosomes with immediate translational potential.

Type I collagen deletion in αSMA+ myofibroblasts augments immune suppression and accelerates progression of pancreatic cancer.

Stromal desmoplastic reaction in pancreatic ductal adenocarcinoma (PDAC) involves significant accumulation of type I collagen (Col1). However, the precise molecular and mechanistic contribution of Col1 in PDAC progression remains unknown. Activated pancreatic stellate cells/αSMA+ myofibroblasts are major contributors of Col1 in the PDAC stroma. We use a dual-recombinase genetic mouse model of spontaneous PDAC to delete Col1 specifically in myofibroblasts. This results in significant reduction of total stromal Col1 content and accelerates the emergence of PanINs and PDAC, decreasing overall survival. Col1 deletion leads to Cxcl5 upregulation in cancer cells via SOX9. Increase in Cxcl5 is associated with recruitment of myeloid-derived suppressor cells and suppression of CD8+ T cells, which can be attenuated with combined targeting of CXCR2 and CCR2 to restrain accelerated PDAC progression in the setting of stromal Col1 deletion. Our results unravel the fundamental role of myofibroblast-derived Co1l in regulating tumor immunity and restraining PDAC progression.

Sperm mtDNA copy number, telomere length, and seminal spermatogenic cells in relation to ambient air pollution: Results of a cross-sectional study in Jing-Jin-Ji region of China.

Evidences on the association of air pollutants and semen quality were limited and mechanism-based biomarkers were sparse. We enrolled 423 men at a fertility clinic in Shijiazhuang, China to evaluate associations between air pollutants and semen quality parameters including the conventional ones, sperm mitochondrial DNA copy number (mtDNAcn), sperm telomere length (STL) and seminal spermatogenic cells. PM2.5, PM10, CO, SO2, NO2 and O3 exposure during lag0-90, lag0-9, lag10-14 and lag70-90 days were evaluated with ordinary Kringing model. The exposure-response correlations were analyzed with multiple linear regression models. CO, PM2.5 and PM10 were adversely associated with conventional semen parameters including sperm count, motility and morphology. Besides, CO was positively associated with seminal primary spermatocyte (lag70-90, 0.49; 0.14, 0.85) and mtDNAcn (lag0-90, 0.37; 0.12, 0.62, lag10-14, 0.31; 0.12, 0.49), negatively associated with STL (lag0-9, -0.30; -0.57, -0.03). PM2.5 was positively associated with mtDNAcn (0.50; 0.24, 0.75 and 0.38; 0.02, 0.75 for lag0-90 and lag70-90) while negatively associated with STL (lag70-90, -0.49; -0.96, -0.01). PM10 and NO2 were positively associated with mtDNAcn. Our findings indicate CO and PM might impair semen quality testicularly and post-testicularly while seminal spermatogenic cell, STL and mtDNAcn change indicate necessity for more attention on these mechanisms.

DIM mitigates the development of experimental autoimmune encephalomyelitis by maintaining the stability and suppressive function of regulatory T cells.

Recent studies have revealed that indoles, dietary ligands of the aryl hydrocarbon receptor (AhR), have immunomodulatory characteristics of balancing the differentiation of regulatory T cells (Tregs) and Th17 cells in multiple autoimmune diseases. In this study, we aimed to investigate the potency of the indole, 3,3'-diindolylmethane (DIM), on the stability and suppressive function of Tregs in experimental autoimmune encephalomyelitis (EAE). Furthermore, we used the AhR antagonist CH223191 to verify that DIM exerts its effects on Tregs through the activation of AhR. We found that DIM treatment significantly alleviated the severity of EAE by maintaining the stability and suppressive function of Tregs instead of facilitating the differentiation of Tregs. Thus, these DIM-treated Tregs might indirectly inhibit the generation of Th17 cells and the production of proinflammatory cytokines. And we confirmed the critical role of AhR in the EAE model. Our study further investigated the mechanisms by which dietary indoles promote Treg activity in the EAE model. DIM may act as a novel therapeutic to restrain autoimmune inflammation in multiple sclerosis.

Induced, but not natural, regulatory T cells retain phenotype and function following exposure to inflamed synovial fibroblasts.

Aberrant number and/or dysfunction of CD4+Foxp3+ Regulatory T cells (Tregs) are associated with the pathogenesis of rheumatoid arthritis (RA). A previous study has demonstrated that thymus-derived, natural Tregs (nTregs) prefer to accumulate in inflamed joints and transdifferentiate to TH17 cells under the stimulation of inflamed synovial fibroblasts (SFs). In this study, we made a head-to-head comparison of both Treg subsets and demonstrated that induced Tregs (iTregs), but not nTregs, retained Foxp3 expression and regulatory function on T effector cells (Teffs) after being primed with inflamed SFs. In addition, iTregs inhibited proliferation, inflammatory cytokine production, migration, and invasion ability of collagen-induced arthritis (CIA)-SFs in vitro and in vivo. Moreover, we noted that iTregs directly targeted inflamed SFs to treat autoimmune arthritis, while nTregs failed to do this. Thus, manipulation of the iTreg subset may have a greater potential for prevention or treatment of patients with RA.

Ambient air pollution exposed during preantral-antral follicle transition stage was sensitive to associate with clinical pregnancy for women receiving IVF.

Maternal exposure to air pollution is associated with poor reproductive outcomes in in vitro fertilization (IVF). However, the susceptible time windows are still not been known clearly. In the present study, we linked the air pollution data with the information of 9001 women receiving 10,467 transfer cycles from August 2014 to August 2019 in The Second Hospital of Hebei Medical University, Shijiazhuang City, China. Maternal exposure was presented as individual average daily concentrations of PM2.5, PM10, NO2, SO2, CO, and O3, which were predicted by spatiotemporal kriging model based on residential addresses. Exposure windows were divided to five periods according to the process of follicular and embryonic development in IVF. Generalized estimating equation model was used to evaluate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for association between clinical pregnancy and interquartile range increased average daily concentrations of pollutants during each exposure period. The increased PM2.5 (adjusted OR = 0.95, 95% CI: 0.90, 0.99), PM10 (adjusted OR = 0.93, 95% CI: 0.89, 0.98), NO2 (adjusted OR = 0.89, 95% CI: 0.85, 0.94), SO2 (OR = 0.94, 95% CI: 0.90, 0.98), CO (adjusted OR = 0.93, 95% CI: 0.89, 0.97) whereas decreased O3 (OR = 1.08, 95% CI: 1.02, 1.14) during the duration from preantral follicles to antral follicles were the strongest association with decreased probability of clinical pregnancy among the five periods. Especially, women aged 20-29 years old were more susceptible in preantral-antral follicle transition stage. Women aged 36-47 years old were more vulnerable during post-oocyte retrieve period. Our results suggested air pollution exposure during preantral-antral follicle transition stage was a note-worthy challenge to conceive among females receiving IVF.

Dural Arteriovenous Fistula Complicated with Cerebral Venous Sinus Thrombosis.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is always confused with dural arteriovenous fistula (DAVF) in clinical practice; however, both of them are very rare cerebral vascular diseases. In this report, we provide one case of DAVF combined with CVST. CASE DESCRIPTION: A 75-year-old woman complained of headache with nausea and vomiting for 4 days. Magnetic resonance venography revealed filling defect in the torcular, left transverse, and sigmoid sinus, which strongly suggested sinus thrombosis. The patient underwent anticoagulation treatment for 9 days. However, the manifestation was not alleviated, magnetic resonance imaging detected the lesion was enlarged, and the midline shifted to the left. Digital subtraction angiography examination detected that one fistula classified as Borden type IA was fed by the left superficial temporal artery and drained into the left transverse and sigmoid sinus. Endovascular embolization with ethylene vinyl alcohol was conducted. CONCLUSIONS: Follow-up at 6 months indicated that the patient recovered without any sequelae.

Differential roles of TNFα-TNFR1 and TNFα-TNFR2 in the differentiation and function of CD4+Foxp3+ induced Treg cells in vitro and in vivo periphery in autoimmune diseases.

Tumor Necrosis Factor (TNF) α is a multifunctional cytokine with pro-inflammatory and anti-inflammatory characteristics. Increasing evidence suggests that thymus-derived, natural regulatory T cells (nTreg) express a remarkably high level of TNF Receptor 2 (TNFR2) and TNFα modulates the number or function of nTreg via TNFR2 in autoimmune diseases. Nonetheless, Treg cells consist of at least nTreg and iTreg that are induced in the periphery or in vitro and two subsets may have different biological characteristics. However, the role of TNF-TNFR signaling in development and function of these iTreg cells is less clear. In this study, we systemically studied the effect of TNFα and its receptor signals on iTreg differentiation, proliferation, and function in vitro and in vivo. We further investigated the expression and requirement of TNFR1 or TNFR2 expression on iTreg by utilizing TNFR1-/- and TNFR2-/- mice. We found that exogenous TNFα facilitated iTreg differentiation and function in vitro. TNFR2 deficiency hampered iTreg differentiation, proliferation, and function, while TNFR1 deficiency decreased the differentiation of inflammatory T cells such as Th1 and Th17 cells but maintained the regulatory capabilities of iTreg both in vitro and in vivo. Using colitis model, we also revealed TNFR2 but not TNFR1 deficiency compromised the iTreg functionality. Interestingly, inflammation affects TNFR expression on nTreg but not iTreg subset. Our results demonstrate that exogenous TNFα may enhance the differentiation and function of iTreg via TNFR2 signaling. The expression of TNFR2 on Treg might be downregulated in some autoimmune diseases, accompanied by an increased level of TNFR1. Thus, TNFR2 agonists or TNFR1-specific antagonists hold a potential promise for clinical application in treating patients with autoimmune diseases.

Role of TNF-TNF Receptor 2 Signal in Regulatory T Cells and Its Therapeutic Implications.

Tumor necrosis factor α (TNFα) is a pleiotropic cytokine which signals through TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2). Emerging evidence has demonstrated that TNFR1 is ubiquitously expressed on almost all cells, while TNFR2 exhibits a limited expression, predominantly on regulatory T cells (Tregs). In addition, the signaling pathway by sTNF via TNFR1 mainly triggers pro-inflammatory pathways, and mTNF binding to TNFR2 usually initiates immune modulation and tissue regeneration. TNFα plays a critical role in upregulation or downregulation of Treg activity. Deficiency in TNFR2 signaling is significant in various autoimmune diseases. An ideal therapeutic strategy for autoimmune diseases would be to selectively block the sTNF/TNFR1 signal through the administration of sTNF inhibitors, or using TNFR1 antagonists while keeping the TNFR2 signaling pathway intact. Another promising strategy would be to rely on TNFR2 agonists which could drive the expansion of Tregs and promote tissue regeneration. Design of these therapeutic strategies targeting the TNFR1 or TNFR2 signaling pathways holds promise for the treatment of diverse inflammatory and degenerative diseases.