The matricellular protein SPARC induces inflammatory interferon-response in macrophages during aging

Cysteine depletion triggers adipose tissue thermogenesis and weight loss

Caloric restriction and methionine restriction-driven enhanced lifespan and healthspan induces 'browning' of white adipose tissue, a metabolic response that increases heat production to defend core body temperature. However, how specific dietary amino acids control adipose thermogenesis is unknown. Here, we identified that weight loss induced by caloric restriction in humans reduces thiol-containing sulfur amino acid cysteine in white adipose tissue. Systemic cysteine depletion in mice causes lethal weight loss with increased fat utilization and browning of adipocytes that is rescued upon restoration of cysteine in diet. Mechanistically, cysteine-restriction-induced adipose browning and weight loss requires sympathetic nervous system-derived noradrenaline signalling via β3-adrenergic-receptors that is independent of FGF21 and UCP1. In obese mice, cysteine deprivation induced rapid adipose browning, increased energy expenditure leading to 30% weight loss and reversed metabolic inflammation. These findings establish that cysteine is essential for organismal metabolism as removal of cysteine in the host triggers adipose browning and rapid weight loss.

Redefining macrophage phenotypes after spinal cord injury: An open data approach

Spinal cord injury (SCI) triggers intraspinal inflammation through an influx of blood-derived inflammatory cells such as neutrophils and monocyte-derived macrophages. Macrophages play a complex role in SCI pathophysiology ranging from potentiating secondary injury to facilitating recovery and wound healing. In vitro, macrophages have been classified as having a pro-inflammatory, M1 phenotype, or a regenerative, M2 phenotype. In vivo, however, studies suggest that macrophages exist in a spectrum of phenotypes and can shift from one phenotype to another. Single-cell RNA sequencing (scRNA-seq) allows us to assess immune cell heterogeneity in the spinal cord after injury, and several groups have created publicly available datasets containing valuable data for further exploration. In this study, we compared three different scRNA-seq datasets and analyzed macrophage heterogeneity after SCI based on cell clustering according to gene expression profiles. We analyzed data from 7 days post injury (dpi) in young female mice that received a mid-thoracic SCI contusion. Using the Seurat pipeline, we clustered cells, subsetted macrophages from microglia and other myeloid cells, and identified different macrophage populations. Using SingleR as a cross-dataset cluster comparison tool, we identified similarities in macrophage populations across datasets. To confirm and refine this analysis, we analyzed the top 10 differentially expressed genes for each population in each dataset. Most clusters identified in the SingleR analysis were confirmed to have a unique genetic signature and were consistently present in all datasets analyzed. Taken together, four distinct macrophage populations were consistently identified after SCI at 7 dpi in three datasets from independent research teams. Our identification of biologically conserved macrophage populations after SCI using an unbiased approach highlights the power of data sharing and open data in redefining macrophage heterogeneity.

Suppressing SPARC gene with siRNA exerts therapeutic effects and inhibits MMP-2/9 and ADAMTS1 overexpression in a murine model of ischemia/reperfusion-induced acute kidney injury

Secreted protein acidic and rich in cysteine (SPARC), a collagen-binding matricellular protein, is reported to facilitate inflammation and fibrosis in various tissues including the kidneys. Ischemia/reperfusion (I/R) is a major process of acute kidney injury. To investigate whether SPARC inhibition might attenuate renal I/R injury, we injected small interfering RNA (siRNA) targeting SPARC into male BALB/c mice one day before 45 min of renal ischemia followed by 72 h of reperfusion. Serum creatinine concentration, blood urea nitrogen, histological tubular damage, tubulointerstitial fibrosis, and expression of collagen I and transforming growth factor-β were increased after I/R. Expression of 4-hydroxy-2-nonenal, an oxidative stress marker, and the inflammatory cytokines monocyte chemoattractant protein-1 and tumor necrosis factor-α, were also upregulated in I/R kidneys. Overexpression of SPARC mRNA was observed after I/R, and immunohistochemistry revealed that SPARC was localized mainly in damaged tubuloepithelial cells. Additionally, a disintegrin and metalloproteinase with thrombospondin type 1 motif (ADAMTS1) expression colocalized with SPARC. Injection of siRNA targeting SPARC attenuated renal dysfunction, histological abnormalities, collagen deposition, oxidative stress, and renal inflammation. In addition, SPARC gene knockdown suppressed the I/R-induced increases in ADAMTS1 and matrix metalloproteinase-2/9 expression. In conclusion, I/R-induced SPARC could be a novel therapeutic target against acute kidney injury.

Single-cell RNA sequencing-guided engineering of mitochondrial therapies for intervertebral disc degeneration by regulating mtDNA/SPARC-STING signaling

Intervertebral disc degeneration (IVDD) is a leading cause of discogenic low back pain, contributing significantly to global disability and economic burden. Current treatments provide only short-term pain relief without addressing the underlying pathogenesis. Herein we report engineering of biomimetic therapies for IVDD guided by single-cell RNA-sequencing data from human nucleus pulposus tissues, along with validation using animal models. In-depth analyses revealed the critical role of mitochondrial dysfunction in fibrotic phenotype polarization of nucleus pulposus cells (NPCs) during IVDD progression. Consequently, mitochondrial transplantation was proposed as a novel therapeutic strategy. Transplanted exogeneous mitochondria improved mitochondrial quality control in NPCs under pathological conditions, following endocytosis, separate distribution or fusion with endogenous mitochondria, and transfer to neighboring cells by tunneling nanotubes. Correspondingly, intradiscal mitochondrial transplantation significantly delayed puncture-induced IVDD progression in rats, demonstrating efficacy in maintaining mitochondrial homeostasis and alleviating pathological abnormalities. Furthermore, exogenous mitochondria were engineered with a bioactive, mitochondrial-targeting macromolecule to impart anti-oxidative and anti-inflammatory activities. The obtained multi-bioactive biotherapy exhibited significantly enhanced benefits in IVDD treatment, in terms of reversing IVDD progression and restoring structural integrity through the mtDNA/SPARC-STING signaling pathways. Overall, our engineered mitochondrial therapies hold great promise for treating IVDD and other musculoskeletal diseases linked to mitochondrial dysfunction.

Paricalcitol plus hydroxychloroquine enhances gemcitabine activity and induces mesenchymal to epithelial transition in pancreatic ductal adenocarcinoma: A single cell RNA-seq analysis

Epithelial-mesenchymal transition (EMT) describes a process by which epithelial cells acquire mesenchymal properties associated with increased migration, invasion, and resistance to therapy. In pancreatic ductal adenocarcinoma (PDAC), targeting the molecular and intercellular communication pathways that drive EMT represents a promising therapeutic strategy. Here, we investigate the effects of combined treatment with gemcitabine (G), paricalcitol (P), and hydroxychloroquine (GPH) in KPC-Luc orthotopic mouse models of PDAC, using single-cell RNA sequencing (scRNA-seq), high-dimensional weighted gene co-expression network analysis (hdWGCNA), and cell-cell communication analysis. GPH treatment reduces EMT, which is associated with the downregulation of the essential gene fibronectin (Fn1). Collagen and Fn1 pathways co-expression decreases in GPH-treated KPC-Luc tumors. Cancer-associated fibroblasts (CAFs) appear dominant in collagen signaling, whereas macrophages mediate Fn1 signaling. GPH treatment reduces the expression interaction strength between ligands and receptors (collagen-integrin and Fn1-Cd44 or Fn1-Sdc4) compared to sham, PH, and G. Altogether, this study presents a comprehensive single-cell resolution map of the molecular and cellular mechanisms by which GPH treatment impairs EMT in PDAC, identifying potential therapeutic targets within the fibronectin and collagen signaling axes.

Persistent immune dysregulation and metabolic alterations following SARS-CoV-2 infection

SARS-CoV-2 can cause a variety of post-acute sequelae including Long COVID19 (LC), a complex, multisystem disease characterized by a broad range of symptoms including fatigue, cognitive impairment, and post-exertional malaise. The pathogenesis of LC is incompletely understood. In this study, we performed comprehensive cellular and transcriptional immunometabolic profiling within a cohort that included SARS-CoV-2-naïve controls (NC, N=30) and individuals with prior COVID-19 (~4-months) who fully recovered (RC, N=38) or went on to experience Long COVID symptoms (N=58). Compared to the naïve controls, those with prior COVID-19 demonstrated profound metabolic and immune alterations at the proteomic, cellular, and epigenetic level. Specifically, there was an enrichment in immature monocytes with sustained inflammasome activation and oxidative stress, elevated arachidonic acid levels, decreased tryptophan, and variation in the frequency and phenotype of peripheral T-cells. Those with LC had increased CD8 T-cell senescence and a distinct transcriptional profile within CD4 and CD8 T-cells and monocytes by single cell RNA sequencing. Our findings support a profound and persistent immunometabolic dysfunction that follows SARS-CoV-2 which may form the pathophysiologic substrate for LC. Our findings suggest that trials of therapeutics that help restore immune and metabolic homeostasis may be warranted to prevent, reduce, or resolve LC symptoms.

Kinsenoside alleviates experimental acute pancreatitis by suppressing M1 macrophage polarization via the TLR4/STAT1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Acute pancreatitis (AP) is an inflammatory disease that can progress to systemic immune responses and multi-organ damage in its severe forms. Anoectochilus roxburghii (Wall.) Lindl. (AR), a traditional Chinese medicinal plant, has been reported to exhibit anti-inflammatory, hypoglycemic, hepatoprotective, and analgesic properties. Kinsenoside (KD), the primary bioactive glycoside in AR, is responsible for many of its therapeutic effects. Given its anti-inflammatory and immunomodulatory properties, KD may have the potential to mitigate pancreatic inflammation in AP. However, its protective role in AP has not yet been investigated.

AIM OF THE STUDY

This study aimed to investigate the protective effects of the natural active compound KD against acute pancreatitis (AP) and its associated molecular mechanisms.

MATERIALS AND METHODS

Two AP mouse models were established: one by intraperitoneal injection of caerulein combined with lipopolysaccharide (LPS) and the other by retrograde injection of sodium taurocholate (NaT) into the biliopancreatic duct. KD (2.5, 5, 10 mg/kg) was administered as a pre-treatment 1 h before the induction of AP. The severity of AP was evaluated through histopathological analysis, while macrophage infiltration and phenotypic changes in pancreatic tissues were examined using immunofluorescence staining and flow cytometry. Bone marrow-derived macrophages (BMDMs) were polarized into the M1 phenotype through two distinct methods: stimulation with LPS and interferon-γ (IFNγ) and indirect co-culture with pancreatic acinar cells. Changes in macrophage phenotype after KD supplementation (100, 200, and 400 μM) were analyzed using quantitative Reverse Transcription PCR (qRT-PCR) and flow cytometry. Network pharmacology and transcriptomic sequencing were utilized to identify potential targets and pathways affected by KD, with validation of key signaling pathways performed through qPCR and Western blot analysis.

RESULTS

In two models of AP mice, KD at a high dose (10 mg/kg) significantly alleviated pancreatic damage. It reduced pancreatic edema, necrosis, and inflammatory cell infiltration, with a notable decrease in macrophage infiltration. Furthermore, KD (10 mg/kg) administration significantly reduced serum lipase by 53.62% in the Caerulein + LPS model and 41.14% in the NaT model, as well as amylase by 28.13% and 27.99%, respectively. Additionally, KD (10 mg/kg) administration mitigated systemic inflammation and lung injury during AP. Both in vivo and in vitro experiments demonstrated that KD (400 μM) significantly reduced the proportion of M1 macrophages. Furthermore, KD (400 μM) downregulated the mRNA expression of M1-associated genes, including Nos2, Tnf, Il1b, and Il6, in macrophages stimulated by both LPS + IFNγ and pancreatic acinar cell-conditioned media. Network pharmacology and transcriptomic analyses identified toll-like receptor 4 (TLR4) as a potential target of KD in the context of AP. KD (400 μM) was shown to inhibit the activation of the TLR4/STAT1 signaling pathway in macrophages exposed to inflammatory stimuli.

CONCLUSIONS

KD administration mitigated experimental AP induced by diverse etiologies through the inhibition of M1 macrophage polarization via the TLR4/STAT1 signaling pathway. These findings highlight KD as a promising therapeutic candidate with potential clinical applications in the management of AP.

Association between the atherogenic index of plasma and the systemic immuno-inflammatory index using NHANES data from 2005 to 2018

The atherogenic index of plasma (AIP) is used to evaluate the risk of atherosclerosis, while the systemic immune-inflammation index (SII) measures inflammation. The AIP and SII are indicators used to predict diseases in various areas. This study aims to explore the relationship between AIP and SII. A cross-sectional study design was used to recruit 70,190 participants from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018, excluding AIP missing data, SII missing data, participants under 20 years of age, and participants with missing covariates to eventually include 8163 participants. We used weighted multiple linear regression analysis, trend test, smooth curve fitting and threshold effect analysis to examine the relationship between AIP and SII. Among the 8163 participants included in the study, the mean (± SD) age was 48.412 ± 16.842 years. The mean SII (± SD) for all participants was 519.910 ± 316.974. In a model adjusted for all covariates (Model 3), AIP showed a significant positive correlation with SII [β (95% CI) 32.497 (5.425, 59.569), P = 0.021]. The smooth curve fitting results of AIP and SII are an "inverted U-shape" non-linear relationship, and the inflection point is at AIP = 0.82. This positive association between AIP and SII was found only in females and participants under 50. Specifically, for females, the positive correlation between AIP and SII was linear [β (95% CI) 80.791 (44.625, 116.958); P < 0.001]. In participants under 50, the positive correlation between AIP and SII was [β (95% CI) 34.198 (3.087, 65.310); P = 0.034], and there was also an "inverted U-shape" non-linear relationship with an inflection point of AIP = 0.549. For participants aged 20-50 years and males, the smooth curve showed a "down-flat-down" non-linear relationship. There is a significant positive correlation between AIP and SII. A positive association between AIP and SII was observed exclusively in females and among participants under 50. Furthermore, AIP and SII demonstrated a nonlinear relationship that resembles an "inverted U-shape". These findings offer new insights into the prevention, treatment, and management of cardiovascular disease. However, further comprehensive cohort studies are necessary to validate the relationship between AIP and SII.

SPARC: a key mediator of apoptosis in human umbilical vein endothelial cells and its role in hypertension mechanism

Hypertensionis a leading global health issue associated with high mortality and severe complications. Understanding its molecular mechanisms is essential for identifying novel therapeutic targets. Secreted protein acidic and rich in cysteine (SPARC) is associated with cell migration, disease pathophysiology, and inflammation; however, its role in hypertension remains under investigation. This study investigates the role of SPARC in hypertension, focusing on its impact on endothelial dysfunction.Using the GSE75815 dataset from the GEO database, we identified 71 differentially expressed genes (DEGs) associated with hypertension. Pathway analyses and protein-protein interaction networks constructed through the STRING database highlighted six hub genes, with further evaluation based on Comparative Toxicogenomics Database (CTD) scores. Immune cell profiling via ImmuCellAI revealed an increase in naive B cells, positively correlating with hub gene expression.Experimental validation in human umbilical vein endothelial cells (HUVECs) treated with angiotensin II demonstrated that SPARC downregulation reduced apoptosis and BAX expression. Silencing SPARC enhanced endothelial cell proliferation, migration, and nitric oxide production, counteracting angiotensin II-induced damage. Notably, angiotensin II upregulated SPARC secretion, suggesting its critical role in mediating endothelial dysfunction.These findings establish SPARC as a key contributor to the molecular pathways underlying hypertension. Targeting SPARC may represent a novel therapeutic strategy to mitigate endothelial dysfunction and improve outcomes for hypertensive patients.Our findings highlight SPARC as a key player in the molecular pathways of hypertension. Modulating SPARC expression may offer a promising therapeutic strategy to counteract endothelial dysfunction and improve outcomes in hypertensive patients.

Targeting Delivery of Dexamethasone to Inflamed Joints by Albumin-Binding Peptide Modified Liposomes for Rheumatoid Arthritis Therapy

Introduction

Delivering the anti-inflammatory dexamethasone in nanoformulations is important for reducing off-target effects when treating rheumatoid arthritis. Nanoformulations can be targeted to sites of inflammation by modifying the nanoparticles with albumin before administration, but such particles can be unstable in vivo.

Methods

Here, we have developed and validated an alternative targeting in which dexamethasone-loaded liposomes were modified with a 46-residue peptide called "albumin-binding domain", such that the liposomes would adsorb endogenous albumin after administration.

Results

The resulting liposomes were small (90 nm diameter) and uniformly dispersed, and both X-ray diffraction and differential scanning calorimetry confirmed efficient dexamethasone encapsulation. Functionalizing the liposomes with albumin-binding peptide strongly increased not only their binding to albumin in vitro but also their uptake by RAW264.7 cells in culture. After injection into rats with adjuvant-induced arthritis, the liposomes accumulated and persisted at sites of inflammation, effectively inhibiting joint swelling and reducing the level of the inflammatory factors TNF-α and IL-1β in joints. The liposomes decorated with the albumin-binding peptide did not display obvious hepatotoxicity and did not reduce red and white blood cells number.

Discussion

Our results validate modifying liposomes with albumin-binding domain as a way to target them to sites of inflammation for efficient drug delivery against rheumatoid arthritis.

Elevated SPARC Disrupts the Intestinal Barrier Integrity in Crohn's Disease by Interacting with OTUD4 and Activating the MYD88/NF-κB Pathway

Disruption of the intestinal epithelial barrier results in increased permeability and is a key factor in the onset and progression of Crohn's disease (CD). The protein SPARC is primarily involved in cell interaction and migration, but its specific role in the intestinal epithelial barrier remains unclear. This study demonstrates that SPARC is significantly overexpressed in both CD patients and murine models of colitis. Furthermore, mice deficient in SPARC exhibits resistance to chemically induced colitis, a phenomenon associated with the modulation of barrier-associated proteins. Mechanistically, it is elucidated that SPARC competitively binds to OTUD4 in conjunction with MYD88, facilitating the translocation of p65 from the cytoplasm to the nucleus and subsequent activation of the p65-MLCK/MLC2 pathway, thereby compromising barrier integrity. Additionally, it is identified that the elevated expression of SPARC in CD is regulated via the METTL3-YTHDF1 axis. These findings indicate that SPARC levels are elevated in patients with CD and in colitis-induced mice, leading to intestinal barrier damage through direct interaction with OTUD4 and subsequent activation of the MYD88/p65/MLCK/MLC2 signaling pathway. Consequently, targeting SPARC or the OTUD4/MYD88/p65/MLCK/MLC2 axis may offer novel insights into the molecular mechanisms underlying CD and represent a potential therapeutic strategy.

Circulating osteonectin predicts postural imbalance and cardiac dysfunction in heart failure

Osteonectin, a secreted glycoprotein, plays a role in muscle-wasting disease. However, its role in chronic heart failure (CHF) -induced systemic inflammation and postural control is unknown. Here we aim to assess the potential association of soluble osteonectin with cardiac dysfunction and postural imbalance in CHF. The cardiac function, physical performance, including short physical performance battery (SPPB) for balance, handgrip strength (HGS), and the levels of plasma osteonectin and c-reactive protein (CRP) were assessed in controls (n = 56) and CHF patients (n = 286) presented with ischemic and non-ischemic CHF. CHF patients exhibited significantly lower HGS and postural balance accompanied by higher cardiac contractile dysfunction. Regardless of HF etiologies, the osteonectin and CRP levels were significantly higher in CHF patients vs. controls. The osteonectin exhibited a significant inverse correlation with left ventricular ejection fraction (LVEF) in both ischemic (r2 = 0.13, P < 0.0001) and non-ischemic (r2 = 0.18, P < 0.0001) CHF patients. Similarly, osteonectin has shown a strong negative correlation with cumulative SPPB score in both ischemic (r2 = 0.19, P < 0.0001) and non-ischemic (r2 = 0.22, P < 0.0001) patients. Further SPPB balance-based analysis demonstrated lower LVEF and markedly elevated osteonectin and CRP (P < 0.0001), particularly in patients with poor postural balance compared to those with relatively good balance. Importantly, osteonectin demonstrated significantly higher sensitivity and specificity for CHF diagnosis on ROC curve analysis. Taken together, higher osteonectin level is associated with LV dysfunction and postural imbalance irrespective of CHF etiologies. It may serve as a biomarker for physical disability and contractile dysfunction in CHF patients.

Relaxation of mucosal fibronectin fibers in late gut inflammation following neutrophil infiltration in mice

The continuously remodeled extracellular matrix (ECM) plays a pivotal role in gastrointestinal health and disease, yet its precise functions remain elusive. In this study, we employed laser capture microdissection combined with low-input proteomics to investigate ECM remodeling during Salmonella-driven inflammation. To complement this, we probed how fibronectin fiber tension is altered using a mechanosensitive peptide probe. While fibronectin fibers in healthy intestinal tissue are typically stretched, many lose their tension in intestinal smooth muscles only hours after infection, despite the absence of bacteria in that area. In contrast, within the mucosa, where Salmonella is present starting 12 h post infection, fibronectin fiber relaxation occurred exclusively during late-stage infection at 72 h and was localized to already existing clusters of infiltrated neutrophils. Using N-terminomics, we identified three new cleavage sites in fibronectin in the inflamed cecum. The unique, tissue layer-specific changes in the molecular compositions and ECM fiber tension revealed herein might trigger new therapeutic strategies to fight acute intestinal inflammation.

The immunosenescence clock: A new method for evaluating biological age and predicting mortality risk

Precisely assessing an individual's immune age is critical for developing targeted aging interventions. Although traditional methods for evaluating biological age, such as the use of cellular senescence markers and physiological indicators, have been widely applied, these methods inherently struggle to capture the full complexity of biological aging. We propose the concept of an 'immunosenescence clock' that evaluates immune system changes on the basis of changes in immune cell abundance and omics data (including transcriptome and proteome data), providing a complementary indicator for understanding age-related physiological transformations. Rather than claiming to definitively measure biological age, this approach can be divided into a biological age prediction clock and a mortality prediction clock. The main function of the biological age prediction clock is to reflect the physiological state through the transcriptome data of peripheral blood mononuclear cells (PBMCs), whereas the mortality prediction clock emphasizes the ability to identify people at high risk of mortality and disease. We hereby present nearly all of the immunosenescence clocks developed to date, as well as their functional differences. Critically, we explicitly acknowledge that no single diagnostic test can exhaustively capture the intricate changes associated with biological aging. Furthermore, as these biological functions are based on the acceleration or delay of immunosenescence, we also summarize the factors that accelerate immunosenescence and the methods for delaying it. A deep understanding of the regulatory mechanisms of immunosenescence can help establish more accurate immune-age models, providing support for personalized longevity interventions and improving quality of life in old age.

Systematic Mendelian Randomization Exploring Druggable Genes for Hemorrhagic Strokes

Patients with hemorrhagic stroke have high rates of morbidity and mortality, and drugs for prevention are very limited. Mendelian randomization (MR) analysis can increase the success rate of drug development by providing genetic evidence. Previous MR analyses only analyzed the role of individual drug target genes in hemorrhagic stroke; therefore, we used MR analysis to systematically explore the druggable genes for hemorrhagic stroke. We sequentially performed summary-data-based MR analysis and two-sample MR analysis to assess the associations of all genes within the database with intracranial aneurysm, intracerebral hemorrhage, and their subtypes. Validated genes were further analyzed by colocalization. Only genes that were positive in all three analyses and were druggable were considered desirable genes. We also explored the mediators of genes affecting hemorrhagic stroke incidence. Finally, the associations of druggable genes with other cardiovascular diseases were analyzed to assess potential side effects. We identified 56 genes that significantly affected hemorrhagic stroke incidence. Moreover, TNFSF12, SLC22A4, SPARC, KL, RELT, and ADORA3 were found to be druggable. The inhibition of TNFSF12, SLC22A4, and SPARC can reduce the risk of intracranial aneurysm, subarachnoid hemorrhage, and intracerebral hemorrhage. Gene-induced hypertension may be a potential mechanism by which these genes cause hemorrhagic stroke. We also found that blocking these genes may cause side effects, such as ischemic stroke and its subtypes. Our study revealed that six druggable genes were associated with hemorrhagic stroke, and the inhibition of TNFSF12, SLC22A4, and SPARC had preventive effects against hemorrhagic strokes.

Caloric restriction and its mimetics in heart failure with preserved ejection fraction: mechanisms and therapeutic potential

The global increase in human life expectancy, coupled with an unprecedented rise in the prevalence of obesity, has led to a growing clinical and socioeconomic burden of heart failure with preserved ejection fraction (HFpEF). Mechanistically, the molecular and cellular hallmarks of aging are omnipresent in HFpEF and are further exacerbated by obesity and associated metabolic diseases. Conversely, weight loss strategies, particularly caloric restriction, have shown promise in improving health status in patients with HFpEF and are considered the gold standard for promoting longevity and healthspan (disease-free lifetime) in model organisms. In this review, we implicate fundamental mechanisms of aging in driving HFpEF and elucidate how caloric restriction mitigates the disease progression. Furthermore, we discuss the potential for pharmacologically mimicking the beneficial effects of caloric restriction in HFpEF using clinically approved and emerging caloric restriction mimetics. We surmise that these compounds could offer novel therapeutic avenues for HFpEF and alleviate the challenges associated with the implementation of caloric restriction and other lifestyle modifications to reduce the burden of HFpEF at a population level.

Inhibition of miR-92a normalizes vascular gene expression and prevents diastolic dysfunction in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) remains a major public health burden with increasing prevalence but only few effective therapies. Endothelial dysfunction and inflammation are identified as pathophysiological drivers of HFpEF disease progression. MicroRNAs are increasingly recognized as key regulators of these pathological processes, while antimiR-based therapies have been emerged as promising therapeutics in mice and humans. Therefore, we tested whether miR-92a-3p inhibition is a promising therapeutic intervention to target HFpEF in vivo. By injection of locked nucleic acid (LNA)-based antimiR (LNA-92a) weekly, we demonstrate that inhibition of miR-92a-3p attenuates the development of diastolic dysfunction and left atrial dilation following experimental induction of HFpEF in mice. Indeed, LNA-92a depleted miR-92a-3p expression in the myocardium and peripheral blood, and derepressed predicted target genes in a cell type-specific manner. Furthermore, cell-type specific efficacy of LNA-92a treatment was assessed by single-nuclear RNA sequencing of HFpEF hearts either treated with LNA-92a or LNA-Control. Endothelial cells of LNA-92a treated mice showed normalized vascular gene expression and reduced gene signatures associated with endothelial-mesenchymal transition. CONCLUSION: This study demonstrates that LNA-based antimiR-92a is an effective therapeutic strategy to target diastolic dysfunction and left atrial dilation in HFpEF.

Choroidal macrophages in homeostasis, aging and age-related macular degeneration

With increasing age, the optimal functioning of the choroid is essential for efficient removal of waste products formed from photoreceptor renewal. A decline in regulatory elements of the immune system, termed immunosenescence, and the failure of para-inflammation to restore tissue homeostasis can result in the progression of healthy aging to sight-threatening inflammation of the choroid. Macrophages are uniquely situated between the innate and adaptive immune systems, with a high capacity for phagocytosis, recognition of complement components, as well as antigen presentation. In this review, we provide an overview of macrophages and their properties in the healthy choroid and cover the impact of aging, immunosenescence and inflammaging on the function of choroidal macrophages. We will discuss the impact of age on macrophage phenotype and behaviour in the pathophysiology of age-related macular degeneration.

Elevated Serum Extracellular Vesicle-Packaged SPARC in Hypertension: A Cross-Sectional Study in a Middle-Aged and Elderly Population

Elevated blood pressure has previously been associated with increased levels of circulating extracellular vesicles (EVs). However, studies on the relevance of EV cargos to hypertension are limited. Secreted protein acidic and rich in cysteine (SPARC) is involved in many metabolic diseases and endothelial dysfunction pathological processes. This study aimed to explore the association of serum EV-derived SPARC with hypertension incidence. We conducted a cross-sectional study on 125 Chinese, including 76 hypertension patients and 49 normotensive patients. Serum EVs were prepared via ultracentrifugation. The concentrations of serum EV-derived SPARC and serum SPARC were measured by Luminex Assay. The correlations between serum EV-derived SPARC and clinical variables were analyzed. Multivariate logistic regression analysis determined the association of serum EV-derived SPARC levels with hypertension. Interaction subgroup analysis was used to evaluate the interaction of the relevant baselines on the association between serum EV-derived SPARC levels and hypertension. Our findings revealed that the levels of SPARC derived from serum EVs were markedly elevated in individuals with hypertension, averaging 20.60 ng/mL (p < 0.01), when contrasted with the levels observed in normotensive subjects, which were 14.25 ng/mL (p < 0.01) in average. Multivariate logistic regression analysis revealed that serum EV-derived SPARC levels were positively associated with hypertension (odds ratio [OR] 1.095; 95% confidence interval [CI] = 1.031-1.163; p value, 0.003), after adjusting for confounding factors. Interaction subgroup analysis demonstrated that no significant interaction with hypertension was observed for any particular covariate. The present study reveals that the elevated levels of serum EV-derived SPARC were independently associated with hypertension.

Ibuprofen modulates macrophage polarization by downregulating poly (ADP-ribose) polymerase 1

Ibuprofen, a non-steroidal drug, is well known for its anti-inflammatory activity. The effects of ibuprofen on the polarization of macrophages are still not clear. Herein, we used THP-1 monocyte-derived macrophages to find that ibuprofen has inhibitory effects on the polarization of both classically activated M1 macrophages and alternatively activated M2 macrophages by downregulating NF-κB and JAK/STAT signaling pathways. During M1 or M2 polarization, ibuprofen also downregulated the expression of poly (ADP-ribose) polymerase 1 (PARP1). Furthermore, knockdown of PARP1 by either small interfering RNA or PARP1 inhibitor PJ34 can exert inhibitory effects on the polarization of M1 and M2, and alter the immune response of macrophages to the infection of Mycobacterium tuberculosis H37Ra. The results demonstrate that PARP1 plays a regulatory role in the ibuprofen-modulated polarization of macrophage, revealing the interplay between the DNA repair response process and macrophage polarization.

Small interfering RNA microneedle patches versus silicone sheets in reducing postoperative scars: a randomized single-blinded intraindividually controlled clinical trial

BACKGROUND

A common complication of wounds is the excessive production of fibrotic scar tissue, which can lead to hypertrophic scars or keloids. Currently, no treatments with good evidence for preventing excessive scar tissue formation are available. We explored the use of microneedle patches containing small interfering RNA (siRNA) to inhibit SPARC mRNA in reducing the volume of postoperative scars.

OBJECTIVES

To compare differences in postoperative scar volume with the daily application of siRNA-embedded dissolving microneedle patches vs. silicone sheets.

METHODS

This was an 8-week, single-blinded intraindividually controlled randomized trial at a tertiary dermatological centre. Patients with 2-week-old postoperative wounds were included. Each half of the scar was randomly assigned to the microneedle patch or silicone sheet. Three-dimensional (3D) volumes were obtained from the scars via a high-resolution scanner at days 0, 30 and 60. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622000558729).

RESULTS

At day 30, scars treated with microneedle patches had a lower geometric mean volume of 0.79 mm3 vs. scars treated with silicone sheets, with a difference in mean percentage volume reduction of 10.7%. At day 60, scars treated with microneedle patches had a statistically significant lower volume (8.88 mm3) compared with the side treated with silicone sheets (12.77 mm3; P = 0.005), with a difference in mean percentage reduction of 9.7%. Additionally, there was also a statistically significant difference between the percentage reduction in scar volume vs. baseline on the side treated with microneedle patches (mean 83.8%) compared with the side treated with silicone sheets (mean 74.1%).

CONCLUSIONS

There was a significantly greater reduction in the volume of postoperative scars on the side of the scar treated with microneedle patches compared with the side treated with silicone sheets. This demonstrates the use of transdermal gene-silencing technology in scar inhibition and that siRNA microneedle patches can be effective and safe in reducing scar tissue formation.

Immune aging and infectious diseases

ABSTRACT

The rise in global life expectancy has led to an increase in the older population, presenting significant challenges in managing infectious diseases. Aging affects the innate and adaptive immune systems, resulting in chronic low-grade inflammation (inflammaging) and immune function decline (immunosenescence). These changes would impair defense mechanisms, increase susceptibility to infections and reduce vaccine efficacy in older adults. Cellular senescence exacerbates these issues by releasing pro-inflammatory factors, further perpetuating chronic inflammation. Moreover, comorbidities, such as cardiovascular disease and diabetes, which are common in older adults, amplify immune dysfunction, while immunosuppressive medications further complicate responses to infections. This review explores the molecular and cellular mechanisms driving inflammaging and immunosenescence, focusing on genomic instability, telomere attrition, and mitochondrial dysfunction. Additionally, we discussed how aging-associated immune alterations influence responses to bacterial, viral, and parasitic infections and evaluated emerging antiaging strategies, aimed at mitigating these effects to improve health outcomes in the aging population.

Dissolvable microneedle-based wound dressing transdermally and continuously delivers anti-inflammatory and pro-angiogenic exosomes for diabetic wound treatment

Due to overactive inflammation and hindered angiogenesis, self-healing of diabetic wounds (DW) remains challenging in the clinic. Platelet-derived exosomes (PLT-Exos), a novel exosome capable of anti-inflammation and pro-angiogenesis, show great potential in DW treatment. However, previous administration of exosomes into skin wounds is topical daub or intradermal injection, which cannot intradermally deliver PLT-Exos into the dermis layer, thus impeding its long-term efficacy in anti-inflammation and pro-angiogenesis. Herein, a dissolvable microneedle-based wound dressing (PLT-Exos@ADMMA-MN) was developed for transdermal and long-term delivery of PLT-Exos. Firstly, a photo-crosslinking methacrylated acellular dermal matrix-based hydrogel (ADMMA-GEL), showing physiochemical tailorability, fast-gelling performance, excellent biocompatibility, and pro-angiogenic capacities, was synthesized as a base material of our dressing. For endowing the dressing with anti-inflammation and pro-angiogenesis, PLT-Exos were encapsulated into ADMMA-GEL with a minimum effective concentration determined by our in-vitro experiments. Then, in-vitro results show that this dressing exhibits excellent properties in anti-inflammation and pro-angiogenesis. Lastly, in-vivo experiments showed that this dressing could continuously and transdermally deliver PLT-Exos into skin wounds to switch local macrophage into M2 phenotype while stimulating neovascularization, thus proving a low-inflammatory and pro-angiogenic microenvironment for DW healing. Collectively, this study provides a novel wound dressing capable of suppressing inflammation and stimulating vascularization for DW treatment.

Matricellular proteins: From cardiac homeostasis to immune regulation

Tissue repair after myocardial injury is a complex process involving changes in all aspects of the myocardial tissue, including the extracellular matrix (ECM). The ECM is composed of large structural proteins such as collagen and elastin and smaller proteins with major regulatory properties called matricellular proteins. Matricellular cell proteins exert their functions and elicit cellular responses by binding to structural proteins not limited to interactions with cell surface receptors, cytokines, or proteases. At the same time, matricellular proteins act as the "bridge" of information exchange between cells and ECM, maintaining the integrity of the cardiac structure and regulating the immune environment, which is a key factor in determining cardiac homeostasis. In this review, we present an overview of the identified matricellular proteins and summarize the current knowledge regarding their roles in maintaining cardiac homeostasis and regulating the immune system.

Ultra-small platinum nano-enzymatic spray with ROS scavenging and anti-inflammatory properties for photoaging treatment

Photoaging induced by ultraviolet (UV) results in oxidative stress and inflammation. Noble metal nanozymes have strong antioxidant and anti-inflammatory capacity, which are expected to eliminate the excessive reactive oxygen species (ROS) and inflammatory factors in the photoaged skin. Hence, we have synthesized ultrasmall platinum nanoparticles coated with polyvinylpyrrolidone (Pt NPs) with a diameter of nearly 5 nm for photoaging treatment. Thanks to multi-enzymatic capacities (catalase, peroxidase, and superoxide dismutase) of Pt NPs, they can effectively protect fibroblasts from UV-induced ROS attack, relieve fibroblasts from UV-induced cell cycle arrest, downregulate matrix metalloproteinases (MMPs) to regenerate type I collagen, and inhibit M1 macrophage polarization to decrease the expression of inflammatory factors. For photoaged mice treatment, we employ the concept of routine spray skincare and encapsulate Pt NPs solution in a spray bottle. In combination with roller needle, following Pt NPs nano-enzymatic spray given, UV-induced photoaged mice display reduced wrinkle formation in the collagen-depleted dermal tissue of mice and more youthful performance in both appearance and organizational structure. Consequently, multi-enzymatic functions of Pt NPs nano-spray offers a promising avenue for anti-photoaging therapy, providing potential benefits in both preventative and restorative skincare applications.

Exploring the roles of SPARC as a proinflammatory factor and its potential as a novel therapeutic target against cardiovascular disease

Cardiovascular disease (CVD) is a leading cause of death worldwide, and the number of patients with CVD continues to increase despite extensive research and developments in this field. Chronic inflammation is a pivotal pathological component of CVD, and unveiling new proinflammatory factors will help devise novel preventive and therapeutic strategies. The extracellular matrix (ECM) not only provides structural support between cells but also contributes to cellular functions. Secreted protein acidic and rich in cysteine (SPARC) is a collagen-binding matricellular protein that is particularly induced during development and tissue remodeling. A proinflammatory role for SPARC has been demonstrated in various animal models, such as in the lipopolysaccharide-induced footpad model and dextran sodium sulfate-induced colitis model. Recent clinical studies reported a positive correlation between elevated plasma SPARC levels and hypertension, obesity, and the inflammatory marker high-sensitive C-reactive protein. In addition, SPARC gene deletion attenuates the cardiac injury induced by aging, myocardial infarction, and pressure load, suggesting that SPARC has deleterious effects on CVD. This review summarizes the regulatory and proinflammatory mechanisms of SPARC on CVD, chronic kidney disease (CKD), and cerebrovascular disease and discusses the rationale behind measuring SPARC as a biomarker of CVD and the effects of inhibition of SPARC in the prevention and treatment of CVD.

Regulatory Mechanisms of Aging Through the Nutritional and Metabolic Control of Amino Acid Signaling in Model Organisms

Life activities are supported by the intricate metabolic network that is fueled by nutrients. Nutritional and genetic studies in model organisms have determined that dietary restriction and certain mutations in the insulin signaling pathway lead to lifespan extension. Subsequently, the detailed mechanisms of aging as well as various nutrient signaling pathways and their relationships have been investigated in a wide range of organisms, from yeast to mammals. This review summarizes the roles of nutritional and metabolic signaling in aging and lifespan with a focus on amino acids, the building blocks of organisms. We discuss how lifespan is affected by the sensing, transduction, and metabolism of specific amino acids and consider the influences of life stage, sex, and genetic background on the nutritional control of aging. Our goal is to enhance our understanding of how nutrients affect aging and thus contribute to the biology of aging and lifespan.

Quantification of healthspan in aging mice: introducing FAMY and GRAIL

The population around the world is graying, and as many of these individuals will spend years suffering from the burdens of age associated diseases, understanding how to increase healthspan, defined as the period of life free from disease and disability, is an urgent priority of geroscience research. The lack of agreed-upon quantitative metrics for measuring healthspan in aging mice has slowed progress in identifying interventions that do not simply increase lifespan, but also healthspan. Here, we define FAMY (Frailty-Adjusted Mouse Years) and GRAIL (Gauging Robust Aging when Increasing Lifespan) as new summary statistics for quantifying healthspan in mice. FAMY integrates lifespan data with longitudinal measurements of a widely utilized clinical frailty index, while GRAIL incorporates these measures and also adds information from widely utilized healthspan assays and the hallmarks of aging. Both metrics are conceptually similar to quality-adjusted life years (QALY), a widely utilized measure of disease burden in humans, and can be readily calculated from data acquired during longitudinal and cross-sectional studies of mouse aging. We find that interventions generally thought to promote health, including calorie restriction, robustly improve healthspan as measured by FAMY and GRAIL. Finally, we show that the use of GRAIL provides new insights, and identify dietary restriction of protein or isoleucine as interventions that robustly promote healthspan but not longevity in female HET3 mice. We suggest that the routine integration of these measures into studies of aging in mice will allow the identification and development of interventions that promote healthy aging even in the absence of increased lifespan.

GDF3 promotes adipose tissue macrophage-mediated inflammation via altered chromatin accessibility during aging

Age-related susceptibility to sepsis and endotoxemia is poorly defined, although hyperactivation of the immune system and the expansion of the visceral adipose as an immunological reservoir are underlying features. Macrophages from older organisms exhibit substantial changes, including chronic NLRP3 inflammasome activation, genomic remodeling and a dysfunctional, amplified inflammatory response upon new exposure to pathogen. However, the mechanisms by which old macrophages maintain their inflammatory phenotype during endotoxemia remains elusive. We previously identified Gdf3 , a TGFβ superfamily cytokine, as a top-regulated gene by age and the NLRP3 inflammasome in adipose tissue macrophages (ATMs). Here, we demonstrate that endotoxemia increases inflammatory (CD11c + ) ATMs in a Gdf3- dependent manner in old mice. Lifelong systemic or myeloid-specific deletion of Gdf3 leads to reduced endotoxemia- induced inflammation, with decreased CD11c + ATMs and inflammatory cytokines, and protection from hypothermia. Moreover, acute blockade of Gdf3 using JQ1, a BRD4 inhibitor, phenocopies old mice with lifelong Gdf3- deficiency. We show that GDF3 promotes the inflammatory phenotype in ATMs by phosphorylating SMAD2/3. Mechanistically, the differential chromatin landscape of ATMs from old mice with or without myeloid-driven Gdf3 indicates that GDF3- SMAD2/3 signaling axis shifts the chromatin accessibility of ATMs towards an inflammatory state during aging. Furthermore, pharmaceutical inhibition of SMAD3 with a specific inhibitor of SMAD3 (SIS3) mimics Gdf3 deletion. SIS3 reduces endotoxemia-mediated inflammation with fewer CD11c + ATMs and less severe hypothermia in old, but not young mice, as well as reduced mortality. In human adipose tissue, age positively correlates with GDF3 level, while inflammation correlates with pSMAD2/3 level. Overall, these results highlight the importance of GDF3-SMAD2/3 axis in driving inflammation in older organisms and identify this signaling axis as a promising therapeutic target for mitigating endotoxemia-related inflammation in the aged.

Matricellular proteins in immunometabolism and tissue homeostasis

Matricellular proteins are integral non-structural components of the extracellular matrix. They serve as essential modulators of immunometabolism and tissue homeostasis, playing critical roles in physiological and pathological conditions. These extracellular matrix proteins including thrombospondins, osteopontin, tenascins, the secreted protein acidic and rich in cysteine (SPARC) family, the Cyr61, CTGF, NOV (CCN) family, and fibulins have multi-faceted functions in regulating immune cell functions, metabolic pathways, and tissue homeostasis. They are involved in immune-metabolic regulation and influence processes such as insulin signaling, adipogenesis, lipid metabolism, and immune cell function, playing significant roles in metabolic disorders such as obesity and diabetes. Furthermore, their modulation of tissue homeostasis processes including cellular adhesion, differentiation, migration, repair, and regeneration is instrumental for maintaining tissue integrity and function. The importance of these proteins in maintaining physiological equilibrium is underscored by the fact that alterations in their expression or function often coincide with disease manifestation. This review contributes to our growing understanding of these proteins, their mechanisms, and their potential therapeutic applications. [BMB Reports 2024; 57(9): 400-416].

Cellular senescence and metabolic reprogramming: Unraveling the intricate crosstalk in the immunosuppressive tumor microenvironment

The intrinsic oncogenic mechanisms and properties of the tumor microenvironment (TME) have been extensively investigated. Primary features of the TME include metabolic reprogramming, hypoxia, chronic inflammation, and tumor immunosuppression. Previous studies suggest that senescence-associated secretory phenotypes that mediate intercellular information exchange play a role in the dynamic evolution of the TME. Specifically, hypoxic adaptation, metabolic dysregulation, and phenotypic shifts in immune cells regulated by cellular senescence synergistically contribute to the development of an immunosuppressive microenvironment and chronic inflammation, thereby promoting the progression of tumor events. This review provides a comprehensive summary of the processes by which cellular senescence regulates the dynamic evolution of the tumor-adapted TME, with focus on the complex mechanisms underlying the relationship between senescence and changes in the biological functions of tumor cells. The available findings suggest that components of the TME collectively contribute to the progression of tumor events. The potential applications and challenges of targeted cellular senescence-based and combination therapies in clinical settings are further discussed within the context of advancing cellular senescence-related research.

Molecular Mechanisms of Healthy Aging: The Role of Caloric Restriction, Intermittent Fasting, Mediterranean Diet, and Ketogenic Diet-A Scoping Review

As the population ages, promoting healthy aging through targeted interventions becomes increasingly crucial. Growing evidence suggests that dietary interventions can significantly impact this process by modulating fundamental molecular pathways. This review focuses on the potential of targeted dietary strategies in promoting healthy aging and the mechanisms by which specific nutrients and dietary patterns influence key pathways involved in cellular repair, inflammation, and metabolic regulation. Caloric restriction, intermittent fasting, the Mediterranean diet, as well as the ketogenic diet showed promising effects on promoting healthy aging, possibly by modulating mTORC1 AMPK, an insulin signaling pathway. By understanding the intricate interplay between diet and molecular pathways, we can develop personalized dietary strategies that not only prevent age-related diseases, but also promote overall health and well-being throughout the aging process.

Cysteine depletion triggers adipose tissue thermogenesis and weight-loss

Dietary interventions such as caloric restriction (CR)1 and methionine restriction2 that prolong lifespan induce the 'browning' of white adipose tissue (WAT), an adaptive metabolic response that increases heat production to maintain health3,4. However, how diet influences adipose browning and metabolic health is unclear. Here, we identified that weight-loss induced by CR in humans5 reduces cysteine concentration in WAT suggesting depletion of this amino-acid may be involved in metabolic benefits of CR. To investigate the role of cysteine on organismal metabolism, we created a cysteine-deficiency mouse model in which dietary cysteine was eliminated and cystathionine γ-lyase (CTH)6, the enzyme that synthesizes cysteine was conditionally deleted. Using this animal model, we found that systemic cysteine-depletion causes drastic weight-loss with increased fat utilization and browning of adipose tissue. The restoration of dietary cysteine in cysteine-deficient mice rescued weight loss together with reversal of adipose browning and increased food-intake in an on-demand fashion. Mechanistically, cysteine deficiency induced browning and weight loss is dependent on sympathetic nervous system derived noradrenaline signaling via β3-adrenergic-receptors and does not require UCP1. Therapeutically, in high-fat diet fed obese mice, one week of cysteine-deficiency caused 30% weight-loss and reversed inflammation. These findings thus establish that cysteine is essential for organismal metabolism as removal of cysteine in the host triggers adipose browning and rapid weight loss.

Six drivers of aging identified among genes differentially expressed with age

Many studies have compared gene expression in young and old samples to gain insights on aging, the primary risk factor for most major chronic diseases. However, these studies only describe associations, failing to distinguish drivers of aging from compensatory geroprotective responses and incidental downstream effects. Here, we introduce a workflow to characterize the causal effects of differentially expressed genes on lifespan. First, we performed a meta-analysis of 25 gene expression datasets comprising samples of various tissues from healthy, untreated adult mammals (humans, dogs, and rodents) at two distinct ages. We ranked each gene according to the number of distinct datasets in which the gene was differentially expressed with age in a consistent direction. The top age-upregulated genes were TMEM176A, EFEMP1, CP, and HLA-A; the top age-downregulated genes were CA4, SIAH, SPARC, and UQCR10. Second, the effects of the top ranked genes on lifespan were measured by applying post-developmental RNA interference of the corresponding ortholog in the nematode C. elegans (two trials, with roughly 100 animals per genotype per trial). Out of 10 age-upregulated and 9 age-downregulated genes that were tested, two age-upregulated genes (csp-3/CASP1 and spch-2/RSRC1) and four age-downregulated genes (C42C1.8/DIRC2, ost-1/SPARC, fzy-1/CDC20, and cah-3/CA4) produced significant and reproducible lifespan extension. Notably, the data do not suggest that the direction of differential expression with age is predictive of the effect on lifespan. Our study provides novel insight into the relationship between differential gene expression and aging phenotypes, pilots an unbiased workflow that can be easily repeated and expanded, and pinpoints six genes with evolutionarily conserved, causal roles in the aging process for further study.

Role of macrophage polarization in heart failure and traditional Chinese medicine treatment

Heart failure (HF) has a severe impact on public health development due to high morbidity and mortality and is associated with imbalances in cardiac immunoregulation. Macrophages, a major cell population involved in cardiac immune response and inflammation, are highly heterogeneous and polarized into M1 and M2 types depending on the microenvironment. M1 macrophage releases inflammatory factors and chemokines to activate the immune response and remove harmful substances, while M2 macrophage releases anti-inflammatory factors to inhibit the overactive immune response and promote tissue repair. M1 and M2 restrict each other to maintain cardiac homeostasis. The dynamic balance of M1 and M2 is closely related to the Traditional Chinese Medicine (TCM) yin-yang theory, and the imbalance of yin and yang will result in a pathological state of the organism. Studies have confirmed that TCM produces positive effects on HF by regulating macrophage polarization. This review describes the critical role of macrophage polarization in inflammation, fibrosis, angiogenesis and electrophysiology in the course of HF, as well as the potential mechanism of TCM regulation of macrophage polarization in preventing and treating HF, thereby providing new ideas for clinical treatment and scientific research design of HF.

Dysregulated cytokine and oxidative response in hyper-glycolytic monocytes in obesity

Introduction

Obesity is associated with a plethora of health complications, including increased susceptibility to infections or decreased vaccine efficacy, partly due to dysregulated immune responses. Monocytes play a crucial role in innate immunity, yet their functional alterations in obesity remain poorly understood.

Methods

Here, we employed proteomic and metabolomic analyses to investigate monocyte characteristics in individuals with overweight, obesity, impaired glucose tolerance (IGT), and type 2 diabetes (T2D), compared to lean donors.

Results and discussion

Our results revealed distinct molecular signatures in monocytes from individuals with obesity, with significant alterations in pathways related to metabolism, cellular migration, and phagocytosis. Moreover, LPS-induced activation of monocytes unveiled heightened metabolic reprogramming towards glycolysis in subjects with obesity accompanied by dysregulated cytokine responses and elevated oxidative stress. Additionally, monocytes from donors with obesity exhibited increased lipid droplet accumulation. These findings shed light on the immunometabolic dysregulation underlying obesity-associated immune dysfunction, highlighting potential targets for therapeutic intervention.

Adiposity, immunity, and inflammation: interrelationships in health and disease: a report from 24th Annual Harvard Nutrition Obesity Symposium, June 2023

The rapidly evolving field of immunometabolism explores how changes in local immune environments may affect key metabolic and cellular processes, including that of adipose tissue. Importantly, these changes may contribute to low-grade systemic inflammation. In turn, chronic low-grade inflammation affecting adipose tissue may exacerbate the outcome of metabolic diseases. Novel advances in our understanding of immunometabolic processes may critically lead to interventions to reduce disease severity and progression. An important example in this regard relates to obesity, which has a multifaceted effect on immunity, activating the proinflammatory pathways such as the inflammasome and disrupting cellular homeostasis. This multifaceted effect of obesity can be investigated through study of downstream conditions using cellular and systemic investigative techniques. To further explore this field, the National Institutes of Health P30 Nutrition Obesity Research Center at Harvard, in partnership with Harvard Medical School, assembled experts to present at its 24th Annual Symposium entitled "Adiposity, Immunity, and Inflammation: Interrelationships in Health and Disease" on 7 June, 2023. This manuscript seeks to synthesize and present key findings from the symposium, highlighting new research and novel disease-specific advances in the field. Better understanding the interaction between metabolism and immunity offers promising preventative and treatment therapies for obesity-related immunometabolic diseases.

Molecular mechanisms of aging and anti-aging strategies

Aging is a complex and multifaceted process involving a variety of interrelated molecular mechanisms and cellular systems. Phenotypically, the biological aging process is accompanied by a gradual loss of cellular function and the systemic deterioration of multiple tissues, resulting in susceptibility to aging-related diseases. Emerging evidence suggests that aging is closely associated with telomere attrition, DNA damage, mitochondrial dysfunction, loss of nicotinamide adenine dinucleotide levels, impaired macro-autophagy, stem cell exhaustion, inflammation, loss of protein balance, deregulated nutrient sensing, altered intercellular communication, and dysbiosis. These age-related changes may be alleviated by intervention strategies, such as calorie restriction, improved sleep quality, enhanced physical activity, and targeted longevity genes. In this review, we summarise the key historical progress in the exploration of important causes of aging and anti-aging strategies in recent decades, which provides a basis for further understanding of the reversibility of aging phenotypes, the application prospect of synthetic biotechnology in anti-aging therapy is also prospected.

Vascular endothelial-derived SPARCL1 exacerbates viral pneumonia through pro-inflammatory macrophage activation

Inflammation induced by lung infection is a double-edged sword, moderating both anti-viral and immune pathogenesis effects; the mechanism of the latter is not fully understood. Previous studies suggest the vasculature is involved in tissue injury. Here, we report that expression of Sparcl1, a secreted matricellular protein, is upregulated in pulmonary capillary endothelial cells (EC) during influenza-induced lung injury. Endothelial overexpression of SPARCL1 promotes detrimental lung inflammation, with SPARCL1 inducing 'M1-like' macrophages and related pro-inflammatory cytokines, while SPARCL1 deletion alleviates these effects. Mechanistically, SPARCL1 functions through TLR4 on macrophages in vitro, while TLR4 inhibition in vivo ameliorates excessive inflammation caused by endothelial Sparcl1 overexpression. Finally, SPARCL1 expression is increased in lung ECs from COVID-19 patients when compared with healthy donors, while fatal COVID-19 correlates with higher circulating SPARCL1 protein levels in the plasma. Our results thus implicate SPARCL1 as a potential prognosis biomarker for deadly COVID-19 pneumonia and as a therapeutic target for taming hyperinflammation in pneumonia.

Inhibition of SPARC signal by aerobic exercise to ameliorate atherosclerosis

BACKGROUND AND AIMS

Inflammation and atherosclerosis (AS) are closely associated to Secreted Protein Acidic and Rich in Cysteine (SPARC) and its related factors. This study attempted to define the role and the potential mechanism of SPARC and its related factors in ameliorating hyperlipidemia and AS by aerobic exercise intervention.

METHODS

The AS rat model was established with a high-fat diet plus vitamin D3 intraperitoneal injection. Treadmill exercises training (5 days/week at 14 m/min for 60 min/day) for 6 weeks was carried out for AS rat intervention method. Western blotting and qRT-PCR were used to analyze the mRNA and protein expression of SPARC and its related factors, respectively. H&E staining was applied to evaluate the morphological changes and inflammation damage. Von Kossa staining was used to measure the degree of vascular calcification. Fluorescence immunohistochemistry staining was used to detect the expression and distribution of SPARC signal molecules.

RESULTS

SPARC was highly expressed and co-localization with the smooth muscle marker α-SMC in the AS rat. And its downstream factors, NF-κB, Caspase-1, IL-1β and IL-18 were upregulated (P < 0.05 or P < 0.01), FNDC5 expression was downregulated in AS rat model. However, slight declined body weight, delayed AS progression, decreased hyperlipidemia and favorable morphology of skeletal muscle and blood vessels have been detected in AS rat with aerobic exercise intervention. Moreover, the expression of SPARC and its downstream factors were decreased (P < 0.05 or P < 0.01), while elevated the expression of FNDC5 (P < 0.01) was observed after aerobic exercise intervention.

CONCLUSIONS

This study suggested that aerobic exercise ameliorated hyperlipidemia and AS by effectively inhibiting SPARC signal, and vascular smooth muscle cells may contribute greatly to the protection of AS.

Cuproptosis-associated hub gene identification and immune cell infiltration patterns in silicosis

Recent research has hinted at a potential connection between silicosis, a fibrotic lung disease caused by exposure to crystalline silica particles, and cuproptosis. The aim of the study was to explore how cuproptosis-related genes (CRGs) may influence the development of silicosis and elucidate the underlying mechanisms. An analysis of genes associated with both silicosis and cuproptosis was conducted. Key gene identification was achieved through the application of two machine learning techniques. Additionally, the correlation between these key genes and immune cell populations was explored and the critical pathways were discerned. To corroborate our findings, the expression of key genes was verified in both a publicly available silica-induced mouse model and our own silicosis mouse model. A total of 12 differentially expressed CRGs associated with silicosis were identified. Further analysis resulted in the identification of 6 CRGs, namely LOX, SPARC, MOXD1, ALB, MT-CO2, and AOC2. Elevated immune cell infiltration of CD8 T cells, regulatory T cells, M0 macrophages, and neutrophils in silicosis patients compared to healthy controls was indicated. Validation in a silica-induced pulmonary fibrosis mouse model supported SPARC and MT-CO2 as potential signature genes for the prediction of silicosis. These findings highlight a strong association between silicosis and cuproptosis. Among CRGs, LOX, SPARC, MOXD1, ALB, MT-CO2, and AOC2 emerged as pivotal players in the context of silicosis by modulating CD8 T cells, regulatory T cells, M0 macrophages, and neutrophils.

Multi-omics reveals the switch role of abnormal methylation in the regulation of decidual macrophages function in recurrent spontaneous abortion

RSA, recurrent spontaneous abortion, often causes serious physical damage and psychological pressure in reproductive women with unclarified pathogenesis. Abnormal function of decidual cells and aberrant DNA methylation have been reported to cause RSA, but their association remains unclear. Here, we integrated transcriptome, DNA methylome, and scRNA-seq to clarify the regulatory relationship between DNA methylation and decidual cells in RSA. We found that DNA methylation mainly influenced the function of decidual macrophages (DMs), of which four hub genes, HLA-A, HLA-F, SQSTM1/P62, and Interferon regulatory factor 7 (IRF7), related to 22 hypomethylated CpG sites, regulated 16 hub pathways to participate in RSA pathogenesis. In particular, using transcription factor analysis, it is suggested that the upregulation of IRF7 transcription was associated with enhanced recruitment of the transcription factor STAT1 by the hypomethylated promoter region of IRF7. As the current research on DNA methylation of macrophages in the uterine microenvironment of RSA is still blank, our systematic picture of abnormal DNA methylation in regulating DM function provides new insights into the role of DNA methylation in RSA occurrence, which may aid in further prevention and treatment of RSA.

Citric acid promotes SPARC release in pancreatic cancer cells and inhibits the progression of pancreatic tumors in mice on a high-fat diet

Over the years, pancreatic cancer has experienced a global surge in incidence and mortality rates, largely attributed to the influence of obesity and diabetes mellitus on disease initiation and progression. In this study, we investigated the pathogenesis of pancreatic cancer in mice subjected to a high-fat diet (HFD) and observed an increase in citric acid expenditure. Notably, citrate treatment demonstrates significant efficacy in promoting tumor cell apoptosis, suppressing cell proliferation, and inhibiting tumor growth in vivo. Our investigations revealed that citrate achieved these effects by releasing secreted protein acidic and rich in cysteine (SPARC) proteins, repolarizing M2 macrophages into M1 macrophages, and facilitating tumor cell apoptosis. Overall, our research highlights the critical role of citric acid as a pivotal metabolite in the intricate relationship between obesity and pancreatic cancer. Furthermore, we uncovered the significant metabolic and immune checkpoint function of SPARC in pancreatic cancer, suggesting its potential as both a biomarker and therapeutic target in treating this patient population.

An integrative pan-cancer analysis of the molecular characteristics of dietary restriction in tumour microenvironment

BACKGROUND

Dietary restriction (DR), a general term for dieting, has been demonstrated as an effective intervention in reducing the occurrence of cancers. Molecular activities associated with DR are crucial in mediating its anti-cancer effects, yet a comprehensive exploration of the landscape of these activities at the pan-cancer level is still lacking.

METHODS

We proposed a computational approach for quantifying DR-related molecular activities and delineating the landscape of these activities across 33 cancer types and 30 normal tissues within 27,320 samples. We thoroughly examined the associations between DR-related molecular activities and various factors, including the tumour microenvironment, immunological phenotypes, genomic features, and clinical prognosis. Meanwhile, we identified two DR genes that show potential as prognostic predictors in hepatocellular carcinoma and verified them by immunohistochemical assays in 90 patients.

FINDINGS

We found that DR-related molecular activities showed a close association with tumour immunity and hold potential for predicting immunotherapy responses in various cancers. Importantly, a higher level of DR-related molecular activities is associated with improved overall survival and cancer-specific survival. FZD1 and G6PD are two DR genes that serve as biomarkers for predicting the prognosis of patients with hepatocellular carcinoma.

INTERPRETATION

This study presents a robust link between DR-related molecular activities and tumour immunity across multiple cancer types. Our research could open the path for further investigation of DR-related molecular processes in cancer treatment.

FUNDING

National Natural Science Foundation of China (Grant No. 82000628) and the Guangdong-Hong Kong-Macao University Joint Laboratory of Interventional Medicine Foundation of Guangdong Province (Grant No. 2023LSYS001).

Lipopolysaccharide delivery systems in innate immunity

Lipopolysaccharide (LPS), a key component of the outer membrane in Gram-negative bacteria (GNB), is widely recognized for its crucial role in mammalian innate immunity and its link to mortality in intensive care units. While its recognition via the Toll-like receptor (TLR)-4 receptor on cell membranes is well established, the activation of the cytosolic receptor caspase-11 by LPS is now known to lead to inflammasome activation and subsequent induction of pyroptosis. Nevertheless, a fundamental question persists regarding the mechanism by which LPS enters host cells. Recent investigations have identified at least four primary pathways that can facilitate this process: bacterial outer membrane vesicles (OMVs); the spike (S) protein of SARS-CoV-2; host-secreted proteins; and host extracellular vesicles (EVs). These delivery systems provide new avenues for therapeutic interventions against sepsis and infectious diseases.

CAF-associated genes putatively representing distinct prognosis by in silico landscape of stromal components of colon cancer

Comprehensive understanding prognostic relevance of distinct tumor microenvironment (TME) remained elusive in colon cancer. In this study, we performed in silico analysis of the stromal components of primary colon cancer, with a focus on the markers of cancer-associated fibroblasts (CAF) and tumor-associated endothelia (TAE), as well as immunological infiltrates like tumor-associated myeloid cells (TAMC) and cytotoxic T lymphocytes (CTL). The relevant CAF-associated genes (CAFG)(representing R index = 0.9 or beyond with SPARC) were selected based on stroma specificity (cancer stroma/epithelia, cS/E = 10 or beyond) and expression amounts, which were largely exhibited negative prognostic impacts. CAFG were partially shared with TAE-associated genes (TAEG)(PLAT, ANXA1, and PTRF) and TAMC-associated genes (TAMCG)(NNMT), but not with CTL-associated genes (CTLG). Intriguingly, CAFG were prognostically subclassified in order of fibrosis (representing COL5A2, COL5A1, and COL12A1) followed by exclusive TAEG and TAMCG. Prognosis was independently stratified by CD8A, a CTL marker, in the context of low expression of the strongest negative prognostic CAFG, COL8A1. CTLG were comprehensively identified as IFNG, B2M, and TLR4, in the group of low S/E, representing good prognosis. Our current in silico analysis of the micro-dissected stromal gene signatures with prognostic relevance clarified comprehensive understanding of clinical features of the TME and provides deep insights of the landscape.

Quantification of healthspan in aging mice: Introducing FAMY and GRAIL

The population around the world is graying, and as many of these individuals will spend years suffering from the burdens of age associated diseases, understanding how to increase healthspan, defined as the period of life free from disease and disability, is an urgent priority of geroscience research. The lack of agreed-upon quantitative metrics for measuring healthspan in aging mice has slowed progress in identifying interventions that do not simply increase lifespan, but also healthspan. Here, we define FAMY (Frailty-Adjusted Mouse Years) and GRAIL (Gauging Robust Aging when Increasing Lifespan) as new summary statistics for quantifying healthspan in mice. FAMY integrates lifespan data with longitudinal measurements of a widely utilized clinical frailty index, while GRAIL incorporates these measures and also adds information from widely utilized healthspan assays and the hallmarks of aging. Both metrics are conceptually similar to quality-adjusted life years (QALY), a widely-utilized measure of disease burden in humans, and can be readily calculated from data acquired during longitudinal and cross-sectional studies of mouse aging. We find that interventions generally thought to promote health, including calorie restriction, robustly improve healthspan as measured by FAMY and GRAIL. Finally, we show that the use of GRAIL provides new insights, and identify dietary restriction of protein or isoleucine as interventions that robustly promote healthspan but not longevity in female HET3 mice. We suggest that the routine integration of these measures into studies of aging in mice will allow the identification and development of interventions that promote healthy aging even in the absence of increased lifespan.

Deficiency of thioredoxin-interacting protein results in age-related thrombocytopenia due to megakaryocyte oxidative stress

BACKGROUND

Platelets are generated from megakaryocytes (MKs), mainly located in the bone marrow (BM). Megakaryopoiesis can be affected by genetic disorders, metabolic diseases, and aging. The molecular mechanisms underlying platelet count regulation have not been fully elucidated.

OBJECTIVES

In the present study, we investigated the role of thioredoxin-interacting protein (TXNIP), a protein that regulates cellular metabolism in megakaryopoiesis, using a Txnip-/- mouse model.

METHODS

Wild-type (WT) and Txnip-/- mice (2-27-month-old) were studied. BM-derived MKs were analyzed to investigate the role of TXNIP in megakaryopoiesis with age. The global transcriptome of BM-derived CD41+ megakaryocyte precursors (MkPs) of WT and Txnip-/- mice were compared. The CD34+ hematopoietic stem cells isolated from human cord blood were differentiated into MKs.

RESULTS

Txnip-/- mice developed thrombocytopenia at 4 to 5 months that worsened with age. During ex vivo megakaryopoiesis, Txnip-/- MkPs remained small, with decreased levels of MK-specific markers. Critically, Txnip-/- MkPs exhibited reduced mitochondrial reactive oxygen species, which was related to AKT activity. Txnip-/- MkPs also showed elevated glycolysis alongside increased glucose uptake for ATP production. Total RNA sequencing revealed enrichment for oxidative stress- and apoptosis-related genes in differentially expressed genes between Txnip-/- and WT MkPs. The effects of TXNIP on MKs were recapitulated during the differentiation of human cord blood-derived CD34+ hematopoietic stem cells.

CONCLUSION

We provide evidence that the megakaryopoiesis pathway becomes exhausted with age in Txnip-/- mice with a decrease in terminal, mature MKs that response to thrombocytopenic challenge. Overall, this study demonstrates the role of TXNIP in megakaryopoiesis, regulating mitochondrial metabolism.