Clinical science最新文献

Impaired glucose tolerance (IGT) and insulin resistance (IR), including prediabetes and diabetes, increase risk of developing age-related disorders, such as cardiovascular disorders, kidney disorders, and Alzheimer's disease. We analyzed mitochondrial bioenergetics of platelets collected from 208 adults, 55 years and older, with IGT and IR and without normoglycemic (NG). Platelets from IGT participants exhibited unique mitochondrial bioenergetic profiles exemplified by higher mitochondrial respiration compared with NG. IGT platelets exhibited higher glucose-dependent maximal respiration (Max) and spare respiratory capacities (SRCs) and higher fatty acid oxidation (FAO)-dependent maximal coupled (MaxOXPHOS) and uncoupled (maximal electron transport system) respiration compared with NG. Correlating mitochondrial bioenergetics from all 208 participants with measures of glucose tolerance (oral glucose tolerance test values measured 120 min after glucose administration, and oral glucose tolerance test area under the curve), and historical glucose measures [hemoglobin A1 (HbA1c)] revealed significant positive associations. Most associations were unaltered with age, sex, and body mass index adjustments. Examining NG and IGT participants separately, we found platelet respiration and HbA1c exhibited positive association in NG participants. Significant positive associations emerged between platelet SRC, FAO, FAO+CI (oxygen flux due to FAO + complex I activities), and HbA1c. No significant associations were observed in the IGT group. Given the utilization of blood-based mitochondrial bioenergetic profiling strategies in clinical research, this work provides new insights into the clinical features of IR that can affect platelet mitochondrial bioenergetics.

The onset of chronic lung allograft dysfunction (CLAD) represents the greatest long-term challenge in lung transplantation (LT). Here we aimed to identify early molecular signals of CLAD by analyzing the effects of bronchoalveolar lavage (BAL)-derived extracellular vesicles (EVs) on airway cells and validating these findings in patient lung tissues. In our BAL biobank, we identified 13 LT patients with a BAL sample at CLAD diagnosis and 13 patients with a stable graft function and a BAL sample obtained at least 12 months post LT (Ctrl). All patients were then followed for at least 18 months. EVs were isolated, immunophenotyped, and co-cultured with airway cells. The cells' transcriptome and proteome were profiled. Selected targets were validated by immunohistochemistry. Logistic regression and survival analyses were performed for prediction of CLAD progression. During follow-up, 7 CLAD patients experienced allograft dysfunction aggravation, and one control developed CLAD. CLAD patients showed more EVs originating from epithelial cells and leukocytes than stable LT recipients. Exposure of airway cells to CLAD-EVs led to the up-regulation of p70S6K and canonical NF-κB signaling, altering their intracellular and extracellular proteome. Activation of NF-κB was also detected at the onset of CLAD in transbronchial biopsies and BAL cytology, and it persisted throughout the progression to end-stage CLAD. RelA overexpression was associated with poorer graft performance and worse outcomes. RelA-driven NF-κB activation is a key factor in the development of CLAD by promoting persistent inflammation. This pathway may be a promising therapeutic target to improve long-term graft survival after LT.

Cardiorespiratory disorders, such as sympathoexcitation and disordered breathing, are main hallmarks of chronic heart failure (CHF) associated with high morbidity and mortality. We recently reported that rostral ventrolateral medulla (RVLM) catecholaminergic (C1) neurons are hyperactive in rats with CHF, contributing to cardiorespiratory distress. Notably, CHF without reductions in ejection fraction is more frequent in women than in men, but detailed sex differences in cardiorespiratory pathophysiology, as well as the existence of a sex-dependent neurophysiological remodeling within the RVLM, remain unclear. Therefore, we aimed to characterize sex differences in cardiac, autonomic/respiratory function, RVLM C1 neuron, and glial cell activation, followed by experimentally induced volume overload CHF (with preserved ejection fraction) in adult Sprague-Dawley rats. At week 8 post-CHF induction, male CHF rats showed ˜2.5-fold increased left ventricular dilation, while female CHF rats exhibited only ˜1-fold increase. Unlike the females, both cardiac systolic (end-systolic pressure-volume relationship) and diastolic function (end-diastolic pressure-volume relationship) were depressed in male CHF rats. Indeed, cardiomyocyte calcium handling was impaired only in CHF male rats. Cardiac arrhythmogenesis, sympathoexcitation, and disordered breathing were all significant in CHF male rats but were nearly absent in female rats. Consequently, we found that RVLM C1 neurons were not chronically active in female CHF rats compared with male CHF rats. In addition, we found that male CHF rats showed clear signs of astrocyte reactivity within the RVLM region that results in shifts towards higher astrocyte complexity. The latter was not present in female medullary astrocytes despite showing ventricular hypertrophy. Our results showed that gonadally intact female rats are somehow protected compared with intact male rats from RVLM astrocytic remodeling and chronic C1 neuronal activation following volume overload CHF, being the outcome a less severe cardiorespiratory pathology associated with the CHF phenotype.

During severe systemic infections, also known as sepsis, excessive cytokines and reactive oxygen species lead to endothelial dysfunction. Glycoprotein nonmetastatic melanoma protein B (GPNMB) has been implicated in regulating cellular functions, particularly within the vasculature during inflammation, but its effect on infection-mediated endothelial injury remains unclear. Data obtained from the Gene Expression Omnibus (GEO) show that GPNMB expression is systemically reduced following an infectious challenge. Therefore, to investigate the role of GPNMB during infection-mediated endothelial inflammation, we utilized human microvascular endothelial cells (HMVECs) with or without GPNMB knockdown (siGPNMB) and exposed them to heat-killed Escherichia coli (HKEC), one of the most common pathogens associated with sepsis. Silencing GPNMB altered the expression of 1453 genes via RNA sequencing, affecting cytoskeleton function and the response to stimuli. When assessing the endothelial monolayer under basal conditions, siGPNMB cells displayed higher transendothelial electrical resistance (TEER), consistent with RNA sequencing pathway analysis, but exposure to HKEC resulted in increased barrier dysfunction compared with controls. Furthermore, compared with controls, assessments of viability, proliferation, and migration were compromised in siGPNMB cells following HKEC exposure. Exposure to HKEC decreased the oxygen consumption rate in controls and increased the extracellular acidification rate, but neither was changed in siGPNMB cells, indicating impaired metabolic adaptation and further corroborating aspects of the RNA sequencing data. Our findings demonstrate that GPNMB reduction hinders the endothelial response to infectious stimuli, resulting in decreased metabolic fluxes and dysfunctional endothelium during infectious challenges.

Pregnancy necessitates dynamic maternal metabolic adaptations where fatty acids (FAs) serve dual roles as energy substrates and immunomodulators. However, the effects of specific FAs on gestational immunity and pregnancy outcomes remain elusive. In the present study, we administered saturated palmitic acid (PA), monounsaturated oleic acid (OA), polyunsaturated arachidonic acid (AA), or vehicle solutions daily to pregnant mice (gestational day 0.5 [GD0.5]-7.5) and performed comprehensive immune profiling at GD13.5. Mendelian randomization (MR) analysis was employed to evaluate translational relevance in human pregnancies. AA increased embryo resorption rates and decreased both embryonic and placental weights, aligning with MR evidence linking elevated maternal circulating AA to miscarriage risk. Decidual AA exposure amplified pro-inflammatory macrophages (CD11c+), cytotoxic natural killer (NK) cells (NKp46+, IFN-γ+), and cytotoxic T lymphocytes (CTLs, TNF-α+), contrasting OA-driven expansion of M2-like macrophages (CD206+) and pregnancy-protective NK cells (B220+CD11c+). Systemically, AA polarized Th1/CTL dominance (IFN-γ+CD8+) and Ly-6Chigh monocyte retention, whereas OA enhanced Th2 responses and Ly-6Clow monocyte maturation. Paradoxically, AA up-regulated ULN tolerogenic dendritic cells (DCs) and IL-10 expressing regulatory B cells, suggesting tissue-specific lipid sensing. PA activated splenic IFN-γ+ NKs but spared decidual/ULN tolerance. In summary, distinct FAs differentially program gestational immunity in a tissue-specific manner: OA enforces systemic tolerance, while AA drives localized inflammation despite compensatory ULN immunosuppression. These findings advocate personalized FA interventions to optimize pregnancy outcomes.

Obesity is a multifactorial health condition influenced by genetic predisposition and environmental factors, identified as a condition of persistent, mild systemic inflammation marked by an abnormal buildup of fat tissue, becoming clinical when accompanied by functional impairment of organs. This review explores the role of hyperinsulinemia and hypertriglyceridemia in driving the transition from a preclinical to a clinical state of obesity. Insulin resistance leads to compensatory hyperinsulinemia, impairing glucose homeostasis in skeletal muscle, liver, and adipose tissue. Concurrently, excessive dietary fat intake contributes to elevated triglyceride levels, which promote systemic inflammation and facilitate the onset of endocrine and cardio vascular disorders. Early risk factors, such as childhood obesity, as well as other contributors, including chronic psychological stress, alterations in gut microbiota, sleep disturbances, and vitamin D deficiency, are discussed in the context of their role in disease progression. Critically, the concept of a 'borderline' stage is introduced-a transitional phase characterized by elevated triglycerides, insulin resistance, and low-grade chronic inflammation-representing a critical point in the progression toward clinical obesity. Identifying this intermediary stage, even present in other pathologies, offers a valuable window for early interven tion, potentially preventing the establishment of chronic degenerative diseases associated with advanced obesity. Current strategies aimed at controlling hyperinsulinemia and hypertriglyceridemia, including dietary interventions, physical activity, and pharmacological approaches such as GLP-1 receptor agonists and SGLT2 inhibitors, should be considered.

Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract, characterized by ongoing intestinal inflammation, epithelial damage, and mucosal injury. Despite the identification of C-C motif chemokine ligand 5 (CCL5) as a key mediator in UC, the precise mechanisms underlying its role in immune activation and inflammation remain unclear. This study aimed to investigate CCL5 as a critical immune modulator in UC, focusing on its effects on immune cell activation, particularly regulatory T cell (Treg) formation, and the molecular pathways involved in these processes. Using the dextran sulfate sodium salt (DSS)-induced UC model and CCL5 knockout (Ccl5-KO) mice, we demonstrated that CCL5 deficiency exacerbates intestinal inflammation during the acute phase of colitis, partly due to impaired interleukin-33 (IL-33)-induced Treg formation. In addition, we observed a positive correlation between CCL5 expression and forkhead box protein 3 (FOXP3) levels in inflamed colon tissues of UC patients, suggesting a role for CCL5 in Treg regulation. Mechanistically, CCL5 deficiency disrupted the PI3K/Akt/NF-κB signaling pathway, resulting in reduced IL-33 expression, which in turn impaired CD4+ T cell activation and FOXP3+ Treg formation via the JAK1/STAT5 pathway. In vivo rescue experiments confirmed that restoring IL-33 signaling could alleviate inflammation and partially recover Treg function. Collectively, these findings highlight CCL5 as a novel immune modulator of Treg formation and immune responses in UC and suggest that targeting CCL5 may offer a promising therapeutic strategy for managing UC and related inflammatory diseases.

Fetal growth restriction (FGR) arises from chronic hypoxia and increases the risk of cardiovascular dysfunction following perinatal asphyxia, although underlying mechanisms remain unclear. We investigated whether cardiovascular responses to asphyxia are impaired in preterm FGR lambs and whether this arises from α1- and β1-adrenergic receptor dysfunction. Ewes underwent sterile fetal surgery at 89 days' gestation (d; term=148 d) to induce FGR (single umbilical artery ligation) or sham surgery (control). At 126 d, lambs were delivered, instrumented and randomised to immediate ventilation (ControlVENTn=6; FGRVENTn=6) or asphyxia (ControlASPHYXIAn=12; FGRASPHYXIAn=11) by umbilical cord occlusion until diastolic blood pressure (BP) decreased to 10 mmHg. Lambs were ventilated for 8 hours before baseline ex vivo cardiac function was assessed via Langendorff perfusion to measure left ventricular developed pressure (LVDP), heart rate (HR) and coronary perfusion pressure (CPP). Ex vivo α1- and β1-adrenergic responses were assessed via phenylephrine and dobutamine administration, respectively. FGRASPHYXIA lambs had lower BP during asphyxia and took longer to reach a diastolic BP of 10 mmHg (P<0.05 vs ControlASPHYXIA). FGRASPHYXIA lambs had lower BP in the first 5 minutes after return of spontaneous circulation due to impaired vascular contractility (P<0.05 vs ControlASPHYXIA). Baseline LVDP, HR and CPP were similar between groups. FGRASPHYXIA lambs had increased LVDP responses to phenylephrine and dobutamine (P<0.05 vs FGRVENT and ControlASPHYXIA), without significant changes to HR or CPP. Overall, FGR lambs exhibit impaired vascular contractility and heightened cardiac α1- and β1-adrenergic responsiveness after perinatal asphyxia, consistent with reduced autonomic regulation, potentially increasing susceptibility to cardiovascular dysfunction postnatally.

Klebsiella pneumoniae is a major pathogen responsible for severe pulmonary infections, yet the early mechanisms of infection remain incompletely understood. This study investigates the role of exosomes derived from K. pneumoniae in polarizing macrophages to the M1 phenotype, thereby facilitating early lung infections. Utilizing single-cell Raman spectroscopy, we rapidly detected K. pneumoniae within host cells and observed significant lipid expression changes. Metabolomic analysis of exosomes from infected epithelial cells uncovered an elevation of phosphatidylcholine, which disrupted endothelial tight junctions and promoted M1 macrophage recruitment and polarization. This process activated the NF-κB signaling pathway, increasing inflammatory responses and attracting neutrophils. Our findings, validated in infected tissue models, suggest that these exosomal mechanisms significantly contribute to the early stages of pulmonary infection by K. pneumoniae. This study offers crucial insights into potential therapeutic targets for controlling K. pneumoniae infections.