Senescence of T cells is strongly linked to organismal aging through two interconnected processes: chronic low-grade inflammation and reduced immune surveillance of senescent cells. T cells are particularly vulnerable to thymic involution, hematopoietic stem cell aging, repeated homeostatic proliferation, chronic antigenic stimulation, and metabolic and mitochondrial dysfunction. As a result, aged T cells may lose their capacity to combat infection and eliminate senescent cells, while also contributing to inflammaging through the production of inflammatory cytokines. Recent preclinical studies in murine models have demonstrated that modulation of T-cell immunosenescence can ameliorate age-related diseases. These approaches include PD-1/PD-L1 blockade, senolytic chimeric antigen receptor T (CAR-T) cells, and CXCL4/platelet factor 4 (PF4). In addition, early-stage human clinical studies of caloric restriction, low-dose mTOR inhibition, thymic regeneration, and mesenchymal stromal/stem cell (MSC) therapy suggest that interventions targeting immunosenescence may provide health benefits. Moreover, in murine models of Alzheimer's disease, T cells infiltrating the brain may exert either disease-promoting or protective effects depending on the disease stage, highlighting an important point of intersection between T-cell-mediated immunosenescence and brain aging. This review summarizes the basic concepts of immunosenescence, the molecular basis of immune surveillance of senescent cells, age-associated T-cell subsets, their links to brain aging, and interventional strategies aimed at clinical translation, with particular emphasis on T-cell biology and the transcriptional regulatory network driven by NR4a.

Bond-selective vibrational imaging techniques, such as Raman spectroscopy, are opening up many applications that were previously considered impossible or inaccessible by other means, such as fluorescence imaging. In particular, vibrational microscopy offers unique advantages, such as the ability to perform highly multiplexed, label-free imaging. Indeed, recent advances in optical and chemical technologies have made it possible to image biological phenomena at the cellular level with high sensitivity, high resolution, and high specificity. Applications of vibrational microscopy both in biological research and in medicine, including the detection of pathological lesions, are expanding rapidly. Here, we provide a general overview of Raman microscopy, and we review recent progress in cutting-edge applications, including label-free imaging and the development of small Raman tags, Raman probes enabling highly sensitive ultra-multiplexed observation, and functional Raman probes.

BackgroundOcular affections are serious damage to the ocular tissue that results in impaired vision or blindness. Cell-based therapies are a potentially effective therapeutic technique that entails using stem-like precursor cells to induce differentiation of specific cell types and implanting the cells to improve vision in the affected tissue area.MethodsNumerous clinical trials were started to investigate the potential benefits of stem cells for treating ocular affections, based on several encouraging findings from the preclinical research. Following our review, data were collected from various databases, “Google Scholar, Springer, Elsevier, Egyptian Knowledge Bank, ProQuest, and PubMed” using different keywords such as corneal ulcer, retinopathy, glaucoma, ocular regeneration, and stem cells to investigate the various methods for regeneration of ocular affections. The data were obtained and analyzed.ResultsThis review includes tables that show all types of stem cells that were used to treat ocular diseases, such as mesenchymal stem cells (MSCs), hematopoietic stem cells, neural stem cells, embryonic stem cells, and induced pluripotent stem cells. The several characteristics of MSCs that aid in the restoration and regeneration of injured ocular tissue are outlined in this paper, along with their potential applications in the management of ocular degenerative diseases, as determined by physical, histological, immunohistochemical, and biochemical evaluations. Finally, our review highlights the most effective regenerative strategies that assist in rapid ocular regeneration in a variety of animal models, including mice, rats, rabbits, and goats.ConclusionWith the promising results of multiple preclinical studies, stem cell therapy is still a great choice for treating ocular degenerative illnesses. To improve the clinical outcomes, co-transplantation of two or more cell types may be a possibility for future treatment alternatives.

Ca2+ signals play a crucial role in maintaining cardiovascular homeostasis, including regulation of the heartbeat, blood pressure, and adaptation to changes in the external environment. Conversely, abnormal Ca2+ signaling is often involved in the onset and progression of cardiovascular diseases, such as cardiac hypertrophy, heart failure, arteriosclerosis, and hypertension. In excitable cells, such as cardiac myocytes and vascular smooth muscle cells (VSMCs), membrane depolarization, and the subsequent elevation of cytosolic Ca2+ concentration ([Ca2+]cyt) via voltage-dependent Ca2+ channels (VDCCs) cause muscle contraction, which is known as excitation–contraction coupling (E-C coupling). Elevated [Ca2+]cyt can also activate Ca2+-dependent enzymes, in some cases leading to changes in gene expression patterns and contributing to long-term cellular responses. This mechanism is referred to as excitation-transcription coupling (E-T coupling), and it is involved in both the adaptive and pathological responses of the cardiovascular system to chronic stimulation. Specific intracellular regions, known as Ca2+ microdomains, exhibit localized increases in [Ca2+]cyt. Such localized Ca2+ signaling is now known to be one of the molecular mechanisms controlling the diversity of Ca2+ responses. These Ca2+ microdomains are often formed by complexes consisting of Ca2+ channels and downstream Ca2+-dependent enzymes localized by scaffolding proteins. This review outlines some of the molecular mechanisms and roles of Ca2+ microdomain-based E-T coupling in cardiac myocytes and VSMCs. First, we discuss the major molecular components that are essential for functional Ca2+ microdomains. For example, VDCC (CaV1.2 channel), ryanodine receptor (RyR), Ca2+-dependent enzymes (Ca2+/CaM-dependent kinase [CaMK], calcineurin [CaN], and calpain), and scaffolding proteins (A-kinase anchoring proteins [AKAPs], caveolin, and junctophilin). Next, we discuss the roles of Ca2+ microdomain-based E-T coupling in physiological and pathophysiological remodeling in cardiac myocytes and vascular smooth muscle cells.

BackgroundAging-associated dysbiosis leads to chronic inflammation and the development of a range of aging-related diseases. The gut microbiota crosstalks with the host by providing lipid metabolites and modulating metabolic functions. However, the precise mechanism by which the gut microbiota regulates aging is unknown. The objective of this study was to examine the impact of the gut microbiota on the transcriptome and lipidome associated with aging in mouse liver.MethodsRNA-sequencing was conducted on the livers of young and aged male and female-specific pathogen-free (SPF) and germ-free (GF) mice to comprehensively analyze transcriptomic alterations with aging. We also reanalyzed our previously reported results on aging-associated changes in the hepatic lipidome to investigate the gut microbiota-dependent hepatic lipidome signatures associated with aging.ResultsIn contrast to the findings in male mice, the changes in hepatic transcriptome associated with aging were attenuated in female GF mice compared with those in SPF mice. In particular, the gene sets associated with inflammatory signatures (i.e., inflammation and tissue remodeling) were found to be suppressed in female GF mice. The ChIP-Atlas database predicted that transcription factors associated with sex differences may be involved in the gene signature of aged female GF mice. Significant differences in the lipid profile were observed between aged SPF and GF female mice, including in bile acids, sterol sulfates, lysophospholipids, oxidized triacylglycerols, vitamin D, and phytoceramides. Moreover, notable alterations were identified in the quality of phospholipids and sphingolipids. Integrated transcriptomic and lipidomic analysis identified candidate enzymes responsible for the change of lipid profiles in aged female mice.ConclusionsThe findings of this study offer new insights into the molecular mechanisms through which the gut microbiota regulates aging-related phenotypes such as inflammation in the liver, possibly through modulating lipid metabolism in a sex-dependent manner.

Spatial transcriptomics is a cutting-edge technology that analyzes gene expression at the cellular level within tissues while integrating spatial location information. This concept, which combines high-plex RNA sequencing with spatial data, emerged in the early 2010s. Spatial transcriptomics has rapidly expanded with the development of technologies such as in situ hybridization, in situ sequencing, in situ spatial barcoding, and microdissection-based methods. Each technique offers advanced mapping resolution and precise spatial assessments at the single-cell level. Over the past decade, the use of spatial transcriptomics on clinical samples has enabled researchers to identify gene expressions in specific diseased foci, significantly enhancing our understanding of cellular interactions and disease processes. In the field of rheumatology, the complex and elusive pathophysiology of diseases such as rheumatoid arthritis, systemic lupus erythematosus, and Sjögren’s syndrome remains a challenge for personalized treatment. Spatial transcriptomics provides insights into how different cell populations interact within disease foci, such as the synovial tissue, kidneys, and salivary glands. This review summarizes the development of spatial transcriptomics and current insights into the pathophysiology of autoimmune rheumatic diseases, focusing on immune cell distribution and cellular interactions within tissues. We also explore the potential of spatial transcriptomics from a clinical perspective and discuss the possibilities for translating this technology to the bedside.

BackgroundExtracellular vesicles (EVs) hold the potential for elucidating the pathogenesis of amyotrophic lateral sclerosis (ALS) and serve as biomarkers. Notably, the comparative and longitudinal alterations in the protein profiles of EVs in serum (sEVs) and cerebrospinal fluid (CSF; cEVs) of sporadic ALS (SALS) patients remain uncharted. Ropinirole hydrochloride (ROPI; dopamine D2 receptor [D2R] agonist), a new anti-ALS drug candidate identified through induced pluripotent stem cell (iPSC)-based drug discovery, has been suggested to inhibit ALS disease progression in the Ropinirole Hydrochloride Remedy for Amyotrophic Lateral Sclerosis (ROPALS) trial, but its mechanism of action is not well understood. Therefore, we tried to reveal longitudinal changes with disease progression and the effects of ROPI on protein profiles of EVs.MethodsWe collected serum and CSF at fixed intervals from ten controls and from 20 SALS patients participating in the ROPALS trial. Comprehensive proteomic analysis of EVs, extracted from these samples, was conducted using liquid chromatography/mass spectrometer (LC/MS). Furthermore, we generated iPSC-derived astrocytes (iPasts) and performed RNA sequencing on astrocytes with or without ROPI treatment.ResultsThe findings revealed notable disparities yet high congruity in sEVs and cEVs protein profiles concerning disease status, time and ROPI administration. In SALS, both sEVs and cEVs presented elevated levels of inflammation-related proteins but reduced levels associated with unfolded protein response (UPR). These results mirrored the longitudinal changes after disease onset and correlated with the revised ALS Functional Rating Scale (ALSFRS-R) at sampling time, suggesting a link to the onset and progression of SALS. ROPI appeared to counteract these changes, attenuating inflammation-related protein levels and boosting those tied to UPR in SALS, proposing an anti-ALS impact on EV protein profiles. Reverse translational research using iPasts indicated that these changes may partly reflect the DRD2-dependent neuroinflammatory inhibitory effects of ROPI. We have also identified biomarkers that predict diagnosis and disease progression by machine learning-driven biomarker search.ConclusionsDespite the limited sample size, this study pioneers in reporting time-series proteomic alterations in serum and CSF EVs from SALS patients, offering comprehensive insights into SALS pathogenesis, ROPI-induced changes, and potential prognostic and diagnostic biomarkers.

BackgroundCurrent strategies that target cytokines (e.g., tumor necrosis factor (TNF)-α), or signaling molecules (e.g., Janus kinase (JAK)) have advanced the management for allergies and autoimmune diseases. Nevertheless, the molecular mechanism that underpins its clinical efficacy have largely remained elusive, especially in the local tissue environment. Here, we aimed to identify the genetic, epigenetic, and immunological targets of JAK inhibitors (JAKis), focusing on their effects on synovial fibroblasts (SFs), the major local effectors associated with destructive joint inflammation in rheumatoid arthritis (RA).MethodsSFs were activated by cytokines related to inflammation in RA, and were treated with three types of JAKis or a TNF-α inhibitor (TNFi). Dynamic changes in transcriptome and chromatin accessibility were profiled across samples to identify drug targets. Furthermore, the putative targets were validated using luciferase assays and clustered regularly interspaced short palindromic repeat (CRISPR)-based genome editing. ResultsWe found that both JAKis and the TNFi targeted the inflammatory module including IL6. Conversely, specific gene signatures that were preferentially inhibited by either of the drug classes were identified. Strikingly, RA risk enhancers for CD40 and TRAF1 were distinctively regulated by JAKis and the TNFi. We performed luciferase assays and CRISPR-based genome editing, and successfully fine-mapped the single causal variants in these loci, rs6074022-CD40 and rs7021049-TRAF1.ConclusionsJAKis and the TNFi had a direct impact on different RA risk enhancers, and we identified nucleotide-resolution targets for both drugs. Distinctive targets of clinically effective drugs could be useful for tailoring the application of these drugs and future design of more efficient treatment strategies.

Immune cell trafficking, an essential mechanism for maintaining immunological homeostasis and mounting effective responses to infections, operates under a stringent regulatory framework. Recent advances have shed light on the perturbation of cell migration patterns, highlighting how such disturbances can propagate inflammatory diseases from their origin to distal organs. This review collates and discusses current evidence that demonstrates atypical communication between the gut and skin, which are conventionally viewed as distinct immunological spheres, in the milieu of inflammation. We focus on the aberrant, reciprocal translocation of immune cells along the gut-skin axis as a pivotal factor linking intestinal and dermatological inflammatory conditions. Recognizing that the translation of these findings into clinical practices is nascent, we suggest that therapeutic strategies aimed at modulating the axis may offer substantial benefits in mitigating the widespread impact of inflammatory diseases.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease characterized by retarded alveolarization. Tenascin-C (TN-C), an extracellular matrix glycoprotein and soluble molecule, is involved in tissue morphogenesis. In the present study, we demonstrated that the level of TN-C in lung tissues was greater in a mouse model of BPD induced by 85% oxygen. TN-C deficiency, however, impaired alveolarization in the hyperoxia-induced BPD model. In contrast, a functional TN-C blocking antibody ameliorated alveolar dysplasia in BPD-like mice. Mechanistically, hyperoxia increased the soluble TN-C (sTN-C) released from respiratory epithelial cells. On one hand, low-dose sTN-C promoted lung epithelial cell proliferation and migration, which was mediated by ICAM-1. On the other hand, high-dose sTN-C hindered the proliferation and migration of epithelial cells. Overall, this study revealed that TN-C plays a dual role in lung alveolarization and that TN-C may be a target in BPD therapy.