Inflammation and regeneration最新文献

Chimeric antigen receptor (CAR)-T cell therapy is now considered a mainstay treatment for certain hematologic malignancies, as evidenced by several products that have gained marketing authorization from regulatory authorities worldwide. Despite the undeniable successes of this treatment in certain blood cancers, its effectiveness in solid tumors remains unsatisfactory. This limited efficacy is attributed to several factors, including low trafficking and poor infiltration of CAR-T cells into the tumor bed, antigen heterogeneity, the risk of on-target off-tumor toxicities, immunosuppressive tumor microenvironment, and intrinsic resistance mechanisms in tumor cells. Advances in gene editing platforms, notably CRISPR/Cas9 and its derivative novel technologies, have created opportunities to overcome the existing hurdles of CAR-T cell therapy in solid tumors. Gene editing can be harnessed to disrupt, correct, activate, repress intended genes, and precisely integrate transgenes at predefined loci. Multiplex genome editing using the CRISPR system enables the simultaneous targeting of multiple genes to induce desired changes in cellular behavior, aiming to improve the efficacy and safety profile of CAR-T cell therapy. This review comprehensively examines how gene editing technology is leveraged to enhance CAR-T cell therapy against solid tumors. In this regard, after an overview of various applications of gene editing in CAR-T cell therapy of solid tumors, clinical trials of genome-edited CAR-T cells in solid tumors are discussed to provide a comprehensive perspective regarding the current state of genome-edited CAR-T cell therapy in solid tumors.

Background: Pulmonary fibrosis (PF) is a severe lung disease characterized by the destruction of lung architecture resulting from chronic epithelial injury. The PF microenvironment induces PF-specific epithelial cells, such as aberrant basaloid cells (ABCs). However, limited experimental models capable of inducing and activating PF-specific epithelial cells hinder the understanding of their roles.

Methods: To address the lack of experimental models, in this study, we developed an ex vivo murine lung-organoid model designed to induce and activate ABCs. The organoids were subjected to bleomycin (BLM) stimulation. Dose-dependent reductions in number and size, structural disorganization, and transcriptomic changes were assessed following stimulation. Single-cell RNA-sequencing (scRNA-seq) analysis was performed to identify ABC subsets. Cell-cell interaction analysis was also conducted.

Results: Following BLM stimulation, the organoids displayed dose-dependent reductions in number and size, along with structural disorganization and transcriptomic changes that were similar to those observed in the in vivo murine fibrosis model. scRNA-seq analysis identified two ABC subsets: Krt5^low Tp63^low Krt17⁺ ABCs_1, found in patients with idiopathic pulmonary fibrosis (IPF), and Krt5^hi Tp63^hi Krt17⁺ ABCs_2, which have been observed in cultured tissues from patients with IPF but not in traditional murine models. BLM stimulation led to the induction of transforming growth factor beta (TGF-β2) expression in ABCs. Cell-cell interaction analysis suggested that BLM-damaged type 2 alveolar epithelial cells (AT2s) enhanced their direct and indirect interactions with ABCs_2 via ephrin-A signaling. In line with this observation, stimulation experiments of BLM-damaged organoids revealed that Ephrin A4 induced ABC cell differentiation-related gene expression changes, whereas Ephrin A3 enhanced epithelial proliferation-related gene expression changes and suppressed fibroblast activation-related gene expression changes.

Conclusions: The developed organoid model serves as a novel platform for studying the roles and responses of PF-specific ABCs. This model may contribute to advancing the understanding of PF pathogenesis and facilitate the development of ABC-targeted therapies.

Osteoarthritis (OA) is a chronic degenerative joint disease that affects more than 200 million people globally. Despite its high prevalence, treatment efficacy remains low, largely due to the complex nature of the disease and the significant variability in response to medication of individual patients. Both genetic and environmental factors play a major role in disease progression and in how patients respond to various therapies, making personalised treatment strategies crucial for effective disease management. In light of these challenges, there is an urgent need for reliable, objective tools that can assess the response of individual patients to different medications. This would allow clinicians to tailor treatments based on a patient's unique genetic and biological profile, improving outcomes and minimizing unnecessary side effects. Here we are presenting a method, where we are differentiating mesenchymal stem cells (MSCs) into the chondrogenic lineage using a 3D organ-on-a-chip approach. Two sources of MSCs, the infrapatellar fat pad and abdominal adipose tissue are compared using targeted gene expression analysis and morphological assessment. In addition, we assessed how gene expression is changed after artificially inflammatory exposure with medications compared to that in untreated cells. We found that both abdominal adipose and infrapatellar fat pad MSCs were capable of differentiating in the chondrogenic direction however exhibited differences in morphology and gene expression status. These findings suggest that the combination of MSCs and the organ-on-a-chip platform could offer a viable alternative to cartilage biopsy for providing deeper insights into individual genetic susceptibilities related to OA and facilitate the development of personalised treatment strategies, paving the way for more effective management of this chronic and often debilitating condition.

Idiopathic inflammatory myopathies (IIM) are a group of autoimmune muscle disorders characterized by muscle weakness caused by muscle tissue inflammation, as well as lung and skin symptoms. Their pathophysiology and exacerbation are primarily associated with the tissue infiltration of immune cells, such as T cells and macrophages, revealing a strong connection with the immune system. Based on the clinical and pathological features of IIMs, polymyositis, which is characterized by CD8 T-cell infiltration around muscle fibers, and dermatomyositis, which is characterized by CD4 T-cell infiltration with complement infiltration around blood vessels, along with distinctive skin symptoms, have been traditionally distinguished. However, recent classifications based on autoantibodies and gene expression have proposed new categories, such as antisynthetase syndrome, clinical amyopathic dermatomyositis, immune-mediated necrotizing myopathy, and inclusion body myositis, resulting in the concept of IIM as a spectrum of diseases including these subtypes. Furthermore, advancements in next-generation sequencing have analyzed single-cell RNA sequencing and spatial transcriptomics using human patient samples, demonstrating the detailed characteristics of immune cell subsets, contributions of new immune cells, and interactions with effector cells in each disease subtype. A variety of IIM mouse models have been developed by activating the immune system through different methods, reflecting distinct myositis classifications within IIM. Recently, polymyositis models have used a humanized immune system, enabling the evaluation of therapeutics across species. This review provides an overview of the latest insights into the immunopathology of IIM and myositis models, reflecting various subtypes, advancing nonbiased and in-depth understanding using omics technologies.

With advancing age, vascular endothelial cells (ECs) exhibit functional decline and reduced angiogenic capacity, adversely affecting muscle homeostasis. Satellite cells (SCs), serving as the primary stem cells in adult skeletal muscle, are responsible for proliferating, differentiating, and repairing damaged tissue post-injury. Notably, ECs regulate skeletal muscle regeneration not only through angiogenesis-mediated oxygen and nutrient supply to injured areas but also via molecular signaling pathways that modulate SC activation, proliferation, and differentiation. Investigating the regulatory mechanisms of ECs on SCs is crucial for understanding muscle regeneration, repair, and therapeutic strategies for related disorders. This review focuses on EC-mediated regulation of SCs during skeletal muscle regeneration, aiming to elucidate their intricate interplay and provide novel perspectives and theoretical frameworks for advancing research in muscle regeneration and muscle-related disease treatment.

Macrophages are highly plastic immune cells that adopt diverse functional states in response to the local microenvironment. The traditional M1/M2 polarization model that has long been used to describe macrophage activation is insufficient to capture the full spectrum of macrophage diversity observed in vivo. Advances in single-cell RNA sequencing (scRNA-seq) have revealed that macrophages exist in a continuum of transcriptional states formed by tissue-specific and disorder-specific cues. This insight has led to the recognition of disorder-specific macrophages, defined as macrophage subpopulations that emerge in response to pathological stimuli and play unique roles in disease progression. These macrophages exhibit distinct transcriptional signatures, epigenetic modifications, and functional properties shaped by their ontogeny and microenvironmental signals, arising from the reprogramming of resident macrophages or the differentiation of bone marrow-derived progenitors. Notable examples include macrophages in chronic infections (e.g., tuberculosis), immunosuppressive tumor-associated macrophages, lipid-associated macrophages in obesity, and disease-associated microglia in neurodegeneration. These subsets exhibit unique regulatory mechanisms, including enhancer remodeling driven by histone H3 lysine 27 acetylation in non-alcoholic steatohepatitis, CCAAT enhancer binding protein α-mediated differentiation in obesity, and Jmjd3-IRF4 axis control in allergic inflammation. Additionally, their function and fate are strongly influenced by their subtissular niche, as evidenced by crown-like structures in adipose tissue, tumor microenvironments, fibrotic lesions, and granulomas, where distinct microenvironmental cues shape macrophage behavior. Furthermore, interindividual heterogeneity in macrophage function, driven by genetic polymorphisms, is increasingly recognized, highlighting the role of host genetic background in disease susceptibility and macrophage-driven pathology. Here, we review the conceptual evolution of the disorder-specific macrophage, tracing its origins from the limited M1/M2 model to its refinement through scRNA-seq-based classification. We summarize the ontogeny, transcriptional regulation, and spatial heterogeneity of these macrophages across various disorders, emphasizing how the subtissular niche dictates functional specialization. Finally, we discuss potential therapeutic strategies targeting disorder-specific macrophage subsets, highlighting the need for integrative multi-omics approaches to refine their classification and functional characterization. Understanding the regulatory networks that govern disorder-specific macrophages will advance our knowledge of macrophage biology while facilitating the development of precision medicine for immune-related disorders.

Tertiary lymphoid structures (TLSs) are ectopic lymphoid aggregates that develop in non-lymphoid organs under pathological conditions of chronic inflammation, such as cancer, autoimmune diseases, chronic infections, organ transplantation, and age-related disorders. TLSs produce various cytokines and chemokines, and orchestrate local adaptive immune responses by serving as sites for antigen presentation. TLSs have attracted significant attention because of their multifaceted roles in various diseases. However, the diversity in cellular composition, development, and maturation of TLSs, depending on the disease context and organ, makes it challenging to fully understand their characteristics. Several basic and clinical studies have demonstrated the clinical and pathophysiological roles of TLSs, revealing both their protective and harmful effects. In cancer, TLSs generally activate anticancer immune responses, leading to the suppression of tumor growth. Additionally, they contribute to host defense against pathogens in infectious diseases. Conversely, they can provide a niche for autoantibody production, exacerbating autoimmune diseases and chronic rejection in transplanted organs. In age-related diseases, they may prolong tissue inflammation and hinder tissue repair. The pathophysiological significance of TLSs has prompted the development of therapeutic strategies that target their formation and maturation. However, their potential systemic immunological effects must be carefully considered. Recent advances in single-cell omics technologies have facilitated a deeper understanding of the diverse cellular components of TLSs and their cell-cell interactions, which may contribute to the development of TLS-specific therapies. The fact that TLSs can only be identified using invasive diagnostic methods remains a barrier to further research. Advances in artificial intelligence-driven pathology diagnostics and improvements in imaging technologies for noninvasive detection are expected to accelerate TLS research. Categorizing various conditions with TLSs as 'TLS-related diseases' could deepen our understanding of TLS pathophysiology and lead to the development of novel therapeutic strategies.

Background: Spiny mice (Acomys sp.) have a unique ability of scarless regeneration. Therefore, the transfer of models used in convenient laboratory mice to study fibrosis could be a prospective approach, enabling the identification of novel antifibrotic therapies.

Methods: In this study, we first applied a model of bleomycin-induced pulmonary fibrosis in Acomys cahirinus (Acomys), using Mus musculus C57BL/6 (Mus) as a control. Changes in lung tissue density were assessed using magnetic resonance imaging (MRI). The severity of fibrosis in lung tissue, as well as the deposition of extracellular matrix components, was assessed by histochemical analysis and morphometry (hematoxylin and eosin, Van Gieson). Data on the content of the main profibrotic proteins of the extracellular matrix, including collagen types I and IV, fibronectin, and fibronectin with EDA domain, were additionally validated by dot blotting. Changes in the number and localization of the main cell types contributing to the development of fibrosis (myofibroblasts, activated stromal cells, epithelium, M2 macrophages, leukocytes) were assessed by immunohistochemical analysis and morphometry. Statistical analysis was performed using GraphPad Prism software. Kruskal-Wallis H-test with the Dunn test and Mann-Whitney test was used for comparison between groups. Differences were considered significant when *p < 0.05.

Results: Our data demonstrate that Acomys can survive high doses of bleomycin, which are sub-lethal and lethal for C57/Bl6 mice strain. In the head-to-head study, we performed an MRI to reveal changes in lung density as well as analyzed the morphology of Mus and Acomys lungs together with the identification of cell types required for fibrotic development. In contrast to Mus, Acomys demonstrated a decrease in respiratory regions upon bleomycin administration, but "classical" signs of fibrosis, such as fibrotic focuses or extracellular matrix accumulation, are detected only in small areas.

Conclusions: The model of bleomycin-induced pulmonary fibrosis in Acomys is valid for the further investigation of possible mechanisms of resistance to damage-induced profibrotic stimuli.

Background: Although abdominal surgeries can be lifesaving, they are often accompanied by the complication of peritoneal adhesion formation. While macrophages contribute to this process, the specific subtypes and underlying mechanisms remain unclear.

Methods: We aimed to identify and investigate the roles of the functional subtypes of macrophages involved in adhesion formation to identify new strategies to combat postoperative peritoneal adhesions. The functional cell types and relevant molecular mechanisms involved in adhesion formation were identified using single-cell RNA sequencing. A human postoperative peritoneal adhesion model derived from appendicitis cases was used to validate the findings. Functional experiments were then conducted using a cecal ligation and puncture mouse model, as well as primary macrophage and mesothelial cell lines.

Results: The findings led to the identification of a macrophage subpopulation characterized by its role in anti-adhesion formation in postoperative peritoneal adhesions. These findings indicate that CD163-positive macrophages accumulate in not only the serous layer of the primary site of postoperative inflammation, but also the tissues adjacent to the adhesion. In addition, CD163 deficiency appears to promote the formation of postoperative adhesions and acute inflammatory responses, and peritoneal CD163-positive macrophages appear to migrate to the postoperative inflammation site, thereby reducing adhesion formation by decreasing PAI-1 secretion from mesothelial cells, enhancing the fibrinolytic system, and ultimately reducing postoperative adhesions.

Conclusions: The present findings clarify the interaction between CD163-positive macrophages and mesothelial cells, which play a crucial role in the formation of postoperative peritoneal adhesions.

Background: CD157 marks a population of tissue-resident vascular endothelial stem cells (VESCs) in mice known for their critical role in homeostatic endothelial cell (EC) turnover and the rapid response to vascular damage in the liver by regeneration. Nevertheless, the mechanism underlying the maintenance and differentiation of postnatal VESCs under both physiological and pathological conditions remains unclear.

Methods: APJ knockout (KO) mice were utilized to explore the role of apelin/APJ signaling in VESC functionality. Flow cytometry, colony-forming unit assays, and in vitro differentiation experiments were conducted to characterize VESC populations. Partial hepatectomy (PHx) was performed to assess vascular regeneration.

Results: APJ deficiency led to an accumulation of VESCs in the liver of adult mice, which displayed enhanced colony-forming capacity but delayed differentiation into mature ECs. APJ KO mice exhibited impaired vascular regeneration following PHx, linked to compromised VESC differentiation. Transcriptomic analysis revealed upregulation of transcription factors EGR1 and EGR2 and downregulation of Ccnd1 in APJ KO VESCs, implicating disrupted cell cycle regulation. Additionally, APJ deletion reduced collagen IV levels, weakening the basement membrane and contributing to the maintenance of VESCs in an undifferentiated state.

Conclusion: APJ signaling is critical for balancing VESC self-renewal and differentiation. APJ deficiency disrupts this balance, leading to impaired vascular regeneration in the liver due to delayed VESC differentiation. This defect is associated with altered transcriptional regulation, favoring a proliferative, undifferentiated state and extracellular matrix changes that weaken structural integrity. These findings highlight the apelin/APJ pathway as a potential therapeutic target to enhance vascular regeneration in regenerative medicine.