Type 1 diabetes (T1D) is characterized by the autoimmune destruction of insulin-producing β-cells in the pancreas. Regulatory T cells (Tregs) are essential for maintaining immune tolerance, but they manifest impaired functionality, particularly within the pancreatic microenvironment, during T1D development. This review aimed to discuss Treg biology including the developmental trajectory, phenotypic heterogeneity, and suppressive function, by which we sought to emphasize their compromised role in T1D pathogenesis associated with genetic/epigenetic factors along with impaired cytokine signaling. The unique chemokine receptor expression signature, migratory capacity, and metabolic adaptation of pancreatic Tregs are highlighted, alongside insights from single-cell studies. The evolution of Treg-based immunotherapies is explored, with emphasis on genetically engineered Tregs (EngTregs), which are designed for the stable ectopic expression of FoxP3 and antigen-specific receptors, such as T cell receptors (TCR) or chimeric antigen receptors (CAR). It also highlights advancements in genome-editing and delivery technologies, along with rationally designed combination strategies incorporated into multifunctional cellular products. Despite encouraging preclinical results, significant challenges persist in clinical translation. Overall, this review synthesizes existing knowledge and outlines future directions in Treg biology and immunotherapy, underscoring the potential of next-generation Treg therapy to achieve durable immune tolerance in T1D.

MicroRNAs are key regulators of metabolic homeostasis, yet their role in obesity-associated dysfunction remains incompletely understood. Here, we identify miR-432 as a driver of systemic metabolic dysregulation. Serum microRNAs profiling revealed a positive correlation between miR-432 expression and obesity/type 2 diabetes mellitus. Functionally, adipose-specific miR-432 exacerbated HFD-induced obesity and insulin resistance. Similarly, hepatic-specific miR-432 aggravated hepatic steatosis and systemic glucose dysregulation, while skeletal muscle-specific miR-432 disrupted glucose homeostasis without affecting body composition. Mechanistically, miR-432 disrupted insulin sensitivity by inhibiting the PIK3R3/AKT pathway and perturbed lipid homeostasis by suppressing the PIK3R3/PPARα axis. Notably, obesity-induced miR-432 upregulation was predominantly localized in adipocytes and driven by the CDK5-PPARγ axis. Furthermore, adipocyte-derived exosomal miR-432 was identified as a mediator of systemic metabolic dysfunction, facilitating inter-tissue crosstalk in obesity. Collectively, our data demonstrate that miR-432 exacerbates obesity-induced dysregulation of glucose and lipid metabolism.

ABSTRACT:High-salt diet (HSD) has emerged as a prevalent environmental factor that exacerbates chronic inflammation and insulin resistance in obesity-associated type 2 diabetes (T2D) by modulating macrophage polarization, metabolic reprogramming, and epigenetic imprinting. Current evidence demonstrates that HSD activates p38/mitogen-activated protein kinase (MAPK), nuclear factor kappa-B (NF-κB), and NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling pathways, by which it drives macrophage polarization toward a proinflammatory M1 phenotype while inducing a glycolysis-dominant metabolic shift, thereby establishing a persistent "metabolic memory". Moreover, HSD orchestrates metabolic memory in macrophages through coordinated epigenetic machinery, including histone modifications (Trimethylation of histone H3 at lysine 4 [H3K4me3] and Acetylation of histone H3 at lysine 27 [H3K27ac]), DNA methylation, and noncoding RNAs (e.g., long non-coding RNA MALAT1 and miR-155), leading to sustained inflammatory phenotypes. In multiple metabolic organs (e.g., adipose tissue, liver, pancreas, and gut), the HSD-macrophage axis aggravates systemic insulin resistance through shared proinflammatory signaling and other tissue-specific mechanisms. Most importantly, therapeutic strategies targeting the NLRP3 inflammasome, metabolic pathways, and epigenetic alterations offer novel approaches for managing metabolic inflammation. Future investigations are encouraged to leverage lineage tracing, single-cell sequencing, and spatial multi-omics technologies to advance the development of precision medicine for macrophage-associated metabolic disorders.

BackgroundPulmonary fibrosis (PF) is an irreversible and lethal lung disease characterized by progressive scarring lacking safe and effective treatment options. Recent studies have underscored the role of macrophage polarization in fibrotic progression, yet the role of kynurenine (Kyn), a metabolite of tryptophan (Trp), in macrophages during PF progression remains elusive.MethodsLiquid Chromatography-tandem Mass Spectrometry (LC-MS) analysis was used to detect tryptophan metabolism changes in the serum of PF patients and control subjects. Macrophage-specific Ido1 or Ahr deletion mice was utilized to explored the role of Kyn in the bleomycin-induced fibrotic mouse model and ChIP sequence was employed to elucidate the mechanism by which Kyn inhibits pro-fibrotic macrophage activation.ResultsWe identified Kyn, Trp levels and Kyn/Trp ratio (KTR) were notably elevated in the serum of patients with different types of PF and these alterations were inversely correlated with lung function. Although such elevation might appear pathogenic, our functional studies demonstrate that Kyn exerts protective effects in PF, akin to brain natriuretic peptide in heart failure. Macrophage-specific deletion of Ido1 or aryl hydrocarbon receptor (AhR, the receptor of Kyn) exacerbated bleomycin-induced PF, while exogenous Kyn supplementation mitigated disease severity. Mechanistically, Kyn bound to the AhR, facilitating its nuclear translocation, where it promoted Slc39a10 transcription to increase the intracellular levels of zinc ion, thereby inhibiting profibrotic macrophage differentiation. Intriguingly, pirfenidone was noted with high potency to suppress Kyn production and our studies demonstrated that administration of Kyn along with pirfenidone effectively enhanced the therapeutic efficacy against PF.ConclusionsIn summary, these findings reveal a previously unrecognized Kyn-AhR-SLC39A10-Zn2+ signaling axis that governs macrophage polarization in PF, and unveiled the importance of Trp metabolism in PF pathogenesis, which could be novel therapeutic strategies against PF.

Introduction and Objective: Type 1 diabetes (T1D) is an autoimmune disease in which Treg dysfunction contributes to immune imbalance. While lactate-driven lactylation shows context-dependent immunomodulatory effects, its role in Treg regulation in T1D remains unclear. Here, we attempt to investigate the role of lactate in T1D and explore therapeutic strategies targeting gut microbiota-derived lactate. Methods: Effects of lactate were assessed in human cohorts and mouse models. Single-cell and bulk transcriptomics, lactylation proteomics, ChIP-seq, and lactylation-deficient Creb1 K136R knock-in mice were used for mechanistic studies. Gut microbiota-derived lactate intervention was evaluated in a clinical trial. Results: Circulating L-lactate levels were reduced in patients with T1D and positively associated with C-peptide while inversely correlated with glycemia. In NOD mice, lactate exerted dose-dependent effects, with low-dose lactate reducing diabetes incidence and autoimmune pathology, whereas excessive lactate accelerated disease progression. Single-cell sequencing identified a lactate-induced effector Treg subset (Lac-Treg). Mechanistically, CREB1 lactylation at Lys136 restrained canonical CREB1 activity and reprogrammed a Bcl6-centered transcriptional program to sustain Treg function, whereas its loss promoted pro-inflammatory CD4+ T cell skewing and accelerated T1D. Finally, Lacticaseibacillus paracasei was reduced in the gut microbiota of T1D patients, and clinical trial data showed that its oral supplementation was associated with increased lactate levels, improved C-peptide secretion, and better glycemic control. Conclusion: To summarize, lactate exerts dose-dependent immunoregulatory effects in T1D via a lactate-CREB1 lactylation-BCL6 axis that controls Treg function and immune tolerance, shaping disease progression. Restoring systemic lactate levels via modulation of gut microbiota reshapes immunometabolic balance and represents a promising therapeutic strategy for T1D. Disclosure Y. Liu: None. F. Sun: None. C. Wang: None. Funding Noncommunicable Chronic Diseases?National Science and Technology Major Project (2024ZD0531400, 2023ZD0507302), the National Key R&D Program of China (2022YFA0806101), the National Natural Science Foundation of China (81920108009, 82130023, 82570968, 82200923), the Research and Innovative Team Project for Scientific Breakthroughs at Shanxi Bethune Hospital (2024AOXIANG03), the Continuous Funding Program for High?Level Research Achievements at Shanxi Bethune Hospital (2024GSPYJ10 and 2024GSPYJ13) and the IGP Funding from QBRI, Hamad Bin Khalifa University

BACKGROUND:Hypoxic pulmonary hypertension (HPH) is a representative vascular remodeling disease with a poor prognosis. Previous findings from our study have implicated the NICD4 (Notch4 intracellular domain) in pulmonary artery smooth muscle cells (PASMCs) in the pathogenesis of HPH. However, the underlying regulatory mechanisms remain unclear. In this study, we aimed to elucidate the potential regulatory mechanism of NICD4 in HPH. METHODS:Using coimmunoprecipitation combined with mass spectrometry, we identified USP8 (ubiquitin-specific peptidase 8) as a novel binding protein of NICD4 in PASMCs. The functional role of USP8 was investigated in vivo using smooth muscle cell-specific Usp8 knockout (Usp8Acta2-/-) mice and in vitro using primarily cultured PASMCs, alongside pharmacological inhibition with DUB-IN-2 (deubiquitinase-inhibitor-2). RESULTS:USP8 was significantly upregulated in lung tissues from patients with HPH due to interstitial lung disease or chronic obstructive pulmonary disease, HPH rodent models, as well as in hypoxic PASMCs. Usp8 deficiency in Acta2-positive mice (Usp8Acta2-/-) or pharmacological inhibition of USP8 by DUB-IN-2 markedly attenuated HPH development. In vitro, USP8 knockdown suppressed hypoxia-induced PASMC proliferation, migration, and apoptosis resistance by modulating the NICD4-MAPK pathway. Mechanistically, USP8 was bound directly to NICD4 to maintain its stability by removing the K48-linked ubiquitin chain on NICD4 at lysine 1760, thus preventing proteasomal degradation. Furthermore, USP8 can be transcriptionally upregulated by CSL/NICD4 under hypoxia, forming a NICD4/USP8-positive feedback loop. CONCLUSIONS:Our study unveils a critical NICD4/USP8-positive feedback loop that drives HPH pathogenesis, highlighting the importance of ubiquitination in pulmonary vascular remodeling. Targeted disruption of this loop represents a promising therapeutic strategy for HPH.

Loss of immune homeostasis in Type 1 diabetes (T1D) leads to a dysregulated and autoreactive immune response that destroys pancreatic β cells, causing absolute insulin deficiency. Nevertheless, current strategies for restoring immune homeostasis remain limited. Inspired by our earlier research, we leveraged the single-cell RNA sequencing data from T1D patients, and unexpectedly found that STAT1 overrepresentation is much more prominent in dendritic cells (DCs) rather in CD4 T cells. Subsequently, we repurposed the clinically-applied STAT1 inhibitor fludarabine in T1D setting. To resolve the underlying mechanism, we employed a multipronged approach in animal studies, incorporating FACS, RNA-seq, ChIP-qPCR, Co-IP/MS, CESTA, TEM, Seahorse assay and Conditional gene knockout model. Furthermore, we investigated the significance of our data in human autoimmune diabetes. Other than directly targeting CD4+ effector T cells, fludarabine also elevated regulatory T cell (Treg) frequency, and therefore, its administration markedly alleviated T1D pathogenesis. Interestingly, fludarabine did not show a direct effect on Treg cells but indirectly fosters Treg program via inducing tolerogenic DCs (tolDCs). The fludarabine-reprogrammed tolDCs are featured by the metabolic shift towards mitochondrial oxidative respiration and exert protective effects on the adoptive transfer studies. Since the emergence of tolDCs could not be fully explained by STAT1 itself, we further explored whether fludarabine alters the STAT1 interactome. Notably, fludarabine binds to STAT1 and disrupts its interaction with the aryl hydrocarbon receptor (AhR), thereby facilitating AhR nuclear translocation. Activated AhR transcriptionally upregulated the expression of anti-inflammatory, anti-ferroptotic, and mitochondrial respiration genes to uphold the tolerogenic DC phenotype. Our findings identified that fludarabine could be a promising immunometabolic therapeutic candidate to restore immune tolerance, which may be a viable approach against T1D in clinical settings.

Objective:To explore the significance of modeled CA-125 elimination rate constant (KELIM) in predicting satisfactory cytoreduction at interval debulking surgery (IDS), survival prognosis, and platinum-based chemosensitivity in patients with advanced ovarian cancer treated with neoadjuvant chemotherapy followed by interval debulking surgery (NACT-IDS). Methods:The clinical information and follow-up data of 70 patients with advanced ovarian cancer who underwent NACT-IDS in the Department of Gynecology of Dalian Central Hospital from January 2010 to June 2023 were retrospectively analyzed. The KELIM for each patient during neoadjuvant chemotherapy was calculated using the online calculation tool (https://www.biomarker-kinetics.org/CA-125-neo), and its predictive value for IDS surgical outcome, prognosis, and platinum-resistant recurrence (PRR) was analyzed. Results:A total of 70 patients met the inclusion criteria. The median follow-up time was 32 (range 6-116) months. KELIM was an independent factor for predicting satisfactory debulking at IDS. Patients with higher KELIM had a higher probability of achieving satisfactory debulking (1.40 vs. 0.61, P < 0.05). KELIM and IDS surgical outcomes were independent influencing factors for progression-free survival (PFS) and overall survival (OS). The median PFS and OS in patients with KELIM ≥1 were significantly higher than those in patients with KELIM <1 (26 months vs. 18 months, P < 0.05; 39 vs. 28 months, P < 0.05). KELIM ≥1 is an independent protective factor for subsequent recurrence of platinum resistance in patients with NACT-IDS. The median KELIM value of the platinum-sensitive recurrent group was significantly higher than that of the PRR group (1.30 vs. 0.73, P < 0.05). For patients with high KELIM, the risk of PRR is low even if IDS cytoreductive surgery is not satisfactory. Conclusions:KELIM is an important parameter to consider when performing IDS. The KELIM and IDS outcomes are independent predictors of the prognosis and PRR risk of patients with NACT-IDS. Even if cytoreduction is unsatisfactory, patients with high KELIM still have a lower risk of subsequent recurrence of platinum resistance.

Extensive research has underscored the pivotal role of DNA methylation in the development of various diseases, including osteoarthritis (OA). DNA methylation is regulated by methylation writers, readers, and erasers. As a crucial methylation reader, methyl-CpG-binding domain2 (MBD2) has been implicated in modulating the occurrence and progression of multiple inflammatory diseases. This study aims to investigate whether MBD2 contributes to the pathogenesis of OA through its regulation of DNA methylation. Our study confirmed that MBD2 was increased in OA cartilage tissues from humans as well as mice with destabilization of the medial meniscus, despite a reduction in its nuclear import. Specific knockout of Mbd2 in cartilage exacerbated cartilage degradation and accelerated OA progression. Mechanistically, RNA sequencing studies demonstrated that the deletion of MBD2 induced ferroptosis in chondrocytes. Subsequent CUT&Tag and reduced representation bisulfite sequencing analyses revealed that MBD2 binds to the Steap3 promoter region and modulates its methylation state in chondrocytes. STEAP3 catalyzes the reduction of ferric iron (Fe3+) to ferrous iron (Fe2+), contributing to the induction of ferroptosis. The administration of a ferroptosis inhibitor and adeno-associated virus-mediated Steap3 knockdown alleviated OA induced by MBD2 deletion. Adeno-associated virus-mediated overexpression of Mbd2 partially mitigated destabilization of the medial meniscus-induced OA. Our findings provide evidence linking DNA methylation readers to OA development, and targeting MBD2 may offer a promising therapeutic strategy for OA treatment.

SUMOylation is an evolutionary conserved regulatory mechanism, in which Ubc9 is the only E2 conjugating enzyme. Previous studies demonstrated that SUMOylation is involved in multiple biological processes, but its role in dendritic cells (DCs) remains to be fully addressed. Herein in this report, we found that DCs deficient in Ubc9 protected mice from dextran sulfate sodium (DSS)-induced colitis, as evidenced by the ameliorated weight loss, colon length, and disrupted colon structure. Mechanistically, Ubc9 mediated SUMOylation of RBPJ, by which it stabilized RBPJ from ubiquitin-mediated degradation to enhance its transcriptional activity, while Ciita, a critical transcription factor, is a direct target downstream of RBPJ, which forms an enhanceosome complex to transcribe the expression of MHC II genes. Therefore, loss of Ubc9 abolished RBPJ SUMOylation, which was coupled with reduced Ciita transcription, thereby attenuating the expression of MHC class II genes. As a consequence of defective MHC II expression, Ubc9-/- DCs were featured by the impaired capability to process antigen and to prime effector CD4+ T cells, thereby protecting mice from DSS-induced colitis. Together, our results shed novel insight into the understanding of SUMOylation in the regulation of DC functions in pathological conditions.

Background Postmenopausal osteoporosis (PMOP) is characterized by exacerbated bone resorption and inadequate bone formation, with macrophage-driven inflammation playing a key role. However, how immunometabolic reprogramming of macrophages modulates osteoblast fate remains unknown.Methods Using integrated single-cell and bulk transcriptomics, we identified a hypermetabolic macrophage subpopulation in PMOP marrow reliant on HIF-1α-glycolysis. We pharmacologically disrupted this axis with the HDAC inhibitor valproic acid (VPA) and validated its function using the HIF-1α stabilizer DMOG. The paracrine effects on osteoblasts were assessed via conditioned medium, focusing on ferroptosis and differentiation. Therapeutic efficacy was tested in ovariectomized rats.Results VPA upregulated HIF1AN, enhancing its binding to HIF-1α and promoting its degradation. This suppressed glycolytic flux and M1 polarization, reducing IL-6 secretion. The altered secretome protected osteoblasts from ferroptosis by inhibiting the IL-6/p-STAT3/HIF-1α/TFRC axis and rebalancing GPX4/ACSL4. Osteogenic differentiation was restored. In OVX rats, VPA improved bone mass and microstructure, effects abolished by DMOG.Conclusion We unveil a macrophage-centric immunometabolic checkpoint that is linked to osteoblast ferroptosis via IL-6/STAT3 signaling. Targeting this HIF-1α-glycolysis axis, exemplified by VPA, represents a novel therapeutic strategy for PMOP.

The study aimed to characterize the regional histological architecture, collagen type I/III composition, and biomechanical properties of human dura mater to provide insights for the biomimetic design of dural repair substitutes. Dura from nine formalin-fixed cadavers were harvested from four anatomical regions: the cranial calvaria, skull base, cervical enlargement, and lumbosacral enlargement. Histological architecture and collagen type I/III composition were assessed using H&E and picrosirius red staining; elastic fibers were visualized with aldehyde fuchsin staining. Collagen type I/III contents were quantified by LC-MS/MS. Mechanical properties, including thickness, ultimate tensile strength, elastic modulus, elongation at break, and toughness, were determined by uniaxial tensile testing. Prototype patches were fabricated using a collagen type I/III blend and mechanically compared against those made from type I collagen alone using uniaxial tensile testing. Cranial dura exhibited four to five interwoven collagen lamellae, whereas spinal dura comprised three predominantly longitudinal layers. Low levels of collagen III were detected in both cranial and spinal dura. Cranial samples were dominated by collagen I with lower collagen III/I ratio, whereas spinal dura showed a relatively higher collagen III/I ratio, mainly attributable to lower collagen I content rather than an increase in absolute collagen III content. Elastic fibers were sparse in cranial dura, least abundant at the skull base, and most abundant in the lumbosacral region. Tensile tests showed that spinal dura had higher elastic modulus than the calvaria. The lumbosacral region exhibited greater tensile strength, elongation at break, and toughness than the calvaria, and higher tensile strength than the skull base. Correlation analyses suggested regional collagen subtype ratio and elastic fiber abundance were associated with elastic modulus. In the preliminary proof-of-concept tensile comparison, patches incorporating 20% type III collagen exhibited increased elongation at break and higher ultimate tensile strength than type I collagen-only control patches. Human dura mater displays pronounced site-dependent structure-composition-mechanics relationships. Regional variations in architecture, collagen type I/III ratio and elastin abundance help explain the distinct mechanical characteristics in cranial and spinal dura. The findings provide a basis for the design of biomimetic dural graft to improve repair outcomes.

Exosomes have emerged as important resources in skin regenerative medicine. However, only a limited number of studies have demonstrated the anti-aging effects of progenitor cell-derived exosomes. In addition, the development of novel effective progenitor cell-based therapies is crucial for the treatment of skin aging. In this study, the viability and proliferation of human adipose-derived progenitor cells (APCs) from young (18-25 years) and old (60-67 years) donors were compared. Exosomes derived from young (yAPC-Exos) and old (oAPC-Exos) APCs were collected and characterized, and their effects on senescent human dermal fibroblasts (HDFs), as well as the underlying molecular mechanisms, were investigated. The proliferation capacity of aged APCs was significantly reduced. Both yAPC-Exos and oAPC-Exos promoted HUVEC migration and tube formation, as well as HDF migration. Exosome treatment decreased intracellular reactive oxygen species levels and alleviated aging-associated phenotypes in senescent HDFs. These effects occurred primarily through p21 and p53 downregulation and SIRT1 upregulation. Notably, yAPC-Exos exerted more pronounced anti-senescent effects than oAPC-Exos. Taken together, yAPC-Exos may represent an effective therapeutic strategy for aging-related skin pathologies and cosmetic applications.

Adipose tissue serves as a crucial energy storage and metabolic organ in the human body. With the surging of elderly population in China comes significant challenges in preventing and managing age-associated diseases, while adipose tissue aging represents one of the pivotal initiating events for multi-organ senescence. To address these challenges, the Aging China Biomarkers Consortium (ABC) has established an expert consensus on biomarkers of adipose tissue aging by digesting literature and collecting insights from scientists and clinicians. This consensus provides a comprehensive evaluation of the key changes and characteristics, as well as biomarkers related to adipose tissue aging and proposes a systematic framework categorizing these biomarkers into functional, structural and humoral dimensions. Within each dimension, the ABC recommends clinically and empirically validated biomarkers and parameters for assessing both physiological and pathological changes in adipose tissue during aging, which aims to establish a foundation for future prediction, diagnosis, early warning and treatment for adipose tissue aging and its related diseases, with the ultimate goal of improving adipose tissue health and promoting healthy aging in elderly populations both in China and worldwide.

Suppressing immune responses promotes allograft survival but also favours tumour progression and recurrence. Selectively suppressing allograft rejection while maintaining or even enhancing antitumor immunity is challenging. Here, we show loss of allograft-related rejection in mice deficient in Setdb1, an H3K9 methyltransferase, while antitumor immunity remains intact. RNA sequencing shows that Setdb1-deficiency does not affect T-cell activation or cytokine production but induces an increase in Treg-cell-associated gene expression. Depletion of Treg cells impairs graft acceptance in Setdb1-deficient mice, indicating that the Treg cells promote allograft survival. Surprisingly, Treg cell-specific Setdb1 deficiency does not prolong allograft survival, suggesting that Setdb1 may function prior to Foxp3 induction. Using single-cell RNA sequencing, we find that Setdb1 deficiency induces a new Treg population in the thymus. This subset of Treg cells expresses less IL-1R2 and IL-18R1. Mechanistically, during Treg cell induction, Setdb1 is recruited by transcription factor ATF and altered histone methylation. Our data thus define Setdb1 in T cells as a hub for Treg cell differentiation, in the absence of which suppressing allograft rejection is uncoupled from maintaining antitumor immunity.

BACKGROUND:The enteric nervous system (ENS), which arises from enteric neural crest cells (ENCCs), plays important roles in many aspects of gastrointestinal tract function, including motility, secretions, blood flow and hormone release. Defects in ENS development could lead to a broad range of disorders, including Hirschsprung's disease (HSCR), which is characterized by missing nerve cells in the distal segment of the colon. Here, we identify EMB as an evolutionarily conserved regulator of ENS development. METHODS:We first examined EMB expression in human and mouse intestines using scRNA-seq data and immunofluorescence staining. To investigate its role in ENS development, we constructed Emb-knockout zebrafish and mouse models. To explore the underlying mechanisms, we focused on ENCCs and analyzed their proliferation and migration using migration assays in explant guts and organoid cultures. Finally, we assessed rare EMB variants in a cohort of HSCR patients. RESULTS:In zebrafish, loss of emb leads to a decrease number of enteric neurons and impaired intestinal transit ability. In mice, knockout of Emb causes HSCR-like phenotypes and defects. In vitro experiments, including explant mouse gut and organoid cultures, show that EMB is required for both the proliferation and migration of ENCCs. Mechanistically, EMB binds to and recruits the phosphatase complex PP2A to the cellular membrane to facilitate the activation of PI3K-AKT pathway, thereby promoting ENCCs development. Indeed, application of PI3K or AKT agonists partially restores the ENS developmental defects in zebrafish emb mutants. Furthermore, rare variants of EMB may potentially contribute to the pathology of HSCR in humans. CONCLUSIONS:EMB is required for ENS development by regulating the proliferation and migration of the ENCCs. Mechanistically, EMB recruits PP2A to the cell membrane, reducing cytoplasmic dephosphorylation activity and promoting the activation of the PI3K signaling pathway.

Macrophages, an essential component of the innate immune system, exhibit remarkable plasticity and functional heterogeneity governed by the intricate transcriptional regulatory networks. Activating transcription factors (ATFs) have recently been recognized to modulate multiple signaling pathways, including the MAPK cascades, endoplasmic reticulum stress response and NF‑κB signaling, thereby regulating macrophage biological processes such as inflammatory response, glucose‑lipid metabolism, cellular stress adaptation, autophagy‑apoptosis balance and senescence. By integrating stress signals and metabolic cues, ATF family members construct a sophisticated regulatory network implicated in the pathogenesis of infectious and inflammatory diseases, metabolic disorders, malignancies and neurodegenerative diseases. Therefore, targeted modulations of ATFs or their associated pathways are considered to be capable of precisely regulating macrophage anti‑inflammatory function, metabolic activity and tissue repair capacity in disease settings. Recent technological advances, such as specific targeted delivery systems and gene‑editing strategies, offer promising avenues for the spatiotemporal ATF‑targeting interventions in macrophages, which is critical for improving therapeutic efficacy and safety. The present review systematically summarized recent advances in the understanding of ATF‑mediated regulation of macrophage development, survival, migration, phagocytosis, activation/cytokine secretion, along with polarization and metabolic reprogramming. It also elucidated the pathophysiological implications of these regulatory mechanisms and critically evaluated the clinical feasibility of ATF‑targeted therapeutic interventions.

Systemic lupus erythematosus (SLE) is characterized by the overproduction of autoantibodies, and B cells are considered to be the primary cells involved in the development of SLE. Studies have shown that DNA damage responses play a role in B cell activity in SLE. However, the exact role of DNA damage-induced transcript 3 (DDIT3) in humoral immune response and SLE pathogenesis remains unknown. We observed increased expression of DDIT3 in B cells of SLE patients and this expression was positively correlated with disease activity. In DDIT3-knockout mice, we observed disturbances in B cell development and differentiation, inhibition of B cell activation, and BCR signaling. In addition, DDIT3 deficiency leads to a reduction in T-cell-dependent humoral immune responses. Mechanistically, we found that DDIT3 promotes the transcription and expression of Itgad, which enhances PI3K signaling and B cell activation. Finally, we found that DDIT3 deficiency attenuated lupus autoimmunity and reduced germinal center responses. In conclusion, our study reveals for the first time the role of DDIT3 in adaptive immune responses, especially in B cell homeostasis, B cell activation, BCR signaling, and B cell function. These findings provide a new potential target for therapeutic intervention in SLE.

Systemic lupus erythematosus (SLE) is a typical autoimmune disease characterized by the overproduction of autoantibodies and type I interferon, which damages its own tissues, causing multiple organ damage. B cells are thought to play a major role in the pathogenesis of SLE. As a DNA methylation reader, Methyl-CpG-binding domain protein 2 (MBD2) has been extensively studied in the contexts of innate immunity, adaptive immunity, and autoimmune diseases. However, its specific role in B cells and SLE remains unexamined. Herein, we found that MBD2 was highly expressed in B cells of SLE patients and positively correlated with disease activity. Knockout of MBD2 in B cells disturbed B-cell differentiation, dampened B-cell activation, B-cell receptor (BCR) signaling, and T-cell-dependent humoral immune responses in mice. What's more, MBD2 deficiency effectively attenuated lupus-like symptoms, reduced the germinal center responses, and decreased anti-dsDNA antibodies in lupus model mice. Mechanistically, MBD2 selectively bound to the methylated CpG of Lef-1 induced by IFN-α, inhibiting the transcription and expression of Lef-1, which repressed Pten transcription and expression, thereby promoting PI3K-Akt-mTOR signaling. This study first demonstrated the role of MBD2 in the pathogenesis of SLE and provided a new target for SLE.