The sex-dependent weight of autoimmunity.

Obesity exacerbates inflammation to a greater extent in female patients and mice with multiple sclerosis.

Unhealthy visceral fat is associated with improved efficacy of immunotherapy in endometrial cancer.

Obesity is a known driver of endometrial cancer. In this issue of the JCI, Gómez-Banoy and colleagues investigated a cohort of patients with advanced endometrial cancer treated with immune checkpoint inhibitors targeting the interaction between programmed cell death receptor-1 (PD-1) and its ligand (PD-L1). Notably, a BMI in the overweight or obese range was paradoxically associated with improved progression-free and overall survival. A second paradox emerged from CT analyses of visceral adipose tissue, viewed as an unhealthy fat depot in most other contexts, the quantity of which was also associated with improved treatment outcomes. Though visceral adiposity may have value as a biomarker to inform personalized treatment strategies, of even greater impact would be if a therapeutic strategy emerges from the future identification of adipose-derived mediators of this putative anticancer immune-priming effect.

Obesity, dysbiosis and inflammation: interactions that modulate the efficacy of immunotherapy.

Recent years have seen an outstanding growth in the understanding of connections between diet-induced obesity, dysbiosis and alterations in the tumor microenvironment. Now we appreciate that gut dysbiosis can exert important effects in distant target tissues via specific microbes and metabolites. Multiple studies have examined how diet-induced obese state is associated with gut dysbiosis and how gut microbes direct various physiological processes that help maintain obese state in a bidirectional crosstalk. Another tightly linked factor is sustained low grade inflammation in tumor microenvironment that is modulated by both obese state and dysbiosis, and influences tumor growth as well as response to immunotherapy. Our review brings together these important aspects and explores their connections. In this review, we discuss how obese state modulates various components of the breast tumor microenvironment and gut microbiota to achieve sustained low-grade inflammation. We explore the crosstalk between different components of tumor microenvironment and microbes, and how they might modulate the response to immunotherapy. Discussing studies from multiple tumor types, we delve to find common microbial characteristics that may positively or negatively influence immunotherapy efficacy in breast cancer and may guide future studies.

Unraveling the obesity paradox in small cell lung cancer immunotherapy: unveiling prognostic insights through body composition analysis.

Background: The advent of immunotherapy has changed the landscape of SCLC treatment, although the identification of reliable prognostic biomarkers remains a formidable challenge. Our objective was to investigate the prognostic implications of obesity and body composition in SCLC immunotherapy while seeking a straightforward anthropometric measure. Methods: This retrospective study analyzed data from patients with SCLC who underwent immunotherapy between 2019 and 2023. Body composition and waist circumference (WC) were analyzed using 3D slicer software on baseline CT images. Quantitative measures, including skeletal muscle index (SMI), total adipose tissue index (TATI), and other indicators at the L3 level, along with body shape index (BSI) and additional indicators based on WC, were obtained. The relationships between these indicators, response, PFS, OS, and their interconnections were examined. Results: A total of 145 SCLC patients who received immunotherapy were identified, of whom 133 met the inclusion criteria. In univariate analysis, a BMI≥28 kg/m2 was associated with a PFS advantage (HR 0.42, p=0.04), but this trend vanished in multivariate analysis. Body measurements exhibited stronger correlations with adipose tissue content, with BSI showing the highest correlation with muscle. In multivariate analysis, lower BSI was associated with poorer OS (HR 1.79, p=0.02). The association between muscle composition and prognosis was robust in univariate analysis but dissipated in multivariate analysis. However, accounting for a high TATI background significantly heightened the adverse effect of SMI on prognosis in the multivariate model. Conclusion: No clear association between BMI and SCLC immunotherapy prognosis was observed. However, high adiposity exacerbated the adverse effects of sarcopenia in SCLC immunotherapy, and BSI demonstrated potential as a straightforward prognostic measure.

Characterizing Human Peripheral Blood Lymphocyte Phenotypes and Their Correlations with Body Composition in Normal-Weight, Overweight, and Obese Healthy Young Adults.

Background and Objectives: Obesity-associated chronic low-grade inflammation supports various systemic alterations. In this descriptive study, 122 apparently healthy adults aged 20 to 35 years were voluntarily included and classified based on body mass index (BMI) as normal-weight (NW), overweight (OW), and obese (OB). This study aims to characterize peripheral blood (PB) lymphocyte (Ly) phenotypes and investigate their correlations with body composition indices (BCIs) in healthy young adults. Materials and Methods: The following BCIs were measured: waist circumference, hip circumference, height, waist-to-hip ratio, waist-to-height ratio, total body fat mass, visceral fat level, weight, and BMI. White blood cell count (WBC), Ly absolute count, serum TNF-α, and IFN-γ were quantified. Ly subpopulations were analyzed as follows: total TLy (TTLy-CD45+CD3+), early activated TLy (EATLy-CD45+3+69+), total NKLy (TNKLy-CD45+CD3-CD56+CD16+), NKdim (low expression of CD56+), NKbright (high expression of CD56+), BLy (CD45+CD3-CD19+), T helper Ly (ThLy-CD45+CD3+CD4+), and T cytotoxic Ly (TcLy-CD45+CD3+CD8+). Results: Higher BMI has significantly higher WBC and BLy (p < 0.0001; p = 0.0085). EATLy significantly decreased from NW to OB (3.10-NW, 1.10-OW, 0.85-OB, p < 0.0001). Only EATLy exhibited significant negative correlations with all the BCIs. A significantly higher TNF-α was observed in the OW and OB groups compared to the NW group. IFN-γ increased linearly but nonsignificantly with BMI. TTLy showed a nonsignificant positive correlation with both IFN-γ and TNF-α, while EATLy showed a negative correlation, significant only for IFN-γ. NKLy subpopulations exhibited a consistent negative correlation with TNF-α, significant only for NKdim (p = 0.0423), and a nonsignificant consistent positive correlation with IFN-γ. A nonsignificant negative correlation between age and both TNKLy (r = -0.0927) and NKdim (r = -0.0893) cells was found, while a positive correlation was found with NKbright (r = 0.0583). Conclusions: In conclusion, the baseline immunological profile of PB is influenced by excessive adipose tissue in healthy young adults.

The Impact of the Endocrine and Immunological Function of Adipose Tissue on Reproduction in Women with Obesity.

Obesity, which leads to metabolic dysregulation and body function impairment, emerges as one of the pressing health challenges worldwide. Excessive body fat deposits comprise a dynamic and biologically active organ possessing its own endocrine function. One of the mechanisms underlying the pathophysiology of obesity is low-grade systemic inflammation mediated by pro-inflammatory factors such as free fatty acids, lipopolysaccharides, adipokines (including leptin, resistin and visfatin) and cytokines (TNF-α, IL-1ß, Il-6), which are secreted by adipose tissue. Together with obesity-induced insulin resistance and hyperandrogenism, the exacerbated immune response has a negative impact on the hypothalamic-pituitary-gonadal axis at all levels and directly affects reproduction. In women, it results in disrupted ovarian function, irregular menstrual cycles and anovulation, contributing to infertility. This review focuses on the abnormal intracellular communication, altered gene expression and signaling pathways activated in obesity, underscoring its multifactorial character and consequences at a molecular level. Extensive presentation of the complex interplay between adipokines, cytokines, immune cells and neurons may serve as a foundation for future studies in search of potential sites for more targeted treatment of reproductive disorders related to obesity.

Astragalus polysaccharide (APS) improves the immune function in diet-induced obese (DIO) mice.

Obesity is a major health hazard, suppressing the immune system and complicating inflammatory symptoms treatment. Traditional Chinese medicine emphasizes holistic principles and syndrome-based diagnosis/therapy. Its primary focus is on enhancing overall well-being, rather than solely aiming for weight loss. Astragalus polysaccharide (APS), extracted from Astragalus membranaceus, has demonstrated promising effects in enhancing the health status of obese individuals. Therefore, this study employed DIO mouse model to explore the immunomodulatory effects of APS in obese mice. The findings revealed a dose-dependent effect of APS on obesity prevention in DIO mice. Specifically, a 4% concentration of APS significantly reduced body weight, whereas a 2% concentration tended to increase it. Furthermore, APS effectively modulated blood glucose and lipid profiles, demonstrating varying degrees of improvement in blood glucose and blood lipid-related factors. Notably, APS also facilitated the reactivation of suppressed immune function in obese mice, regulating a range of immunological variables associated with obesity and thereby maintaining homeostasis. In conclusion, the functional benefits of APS were dose-related, with a 4% concentration demonstrating promising results in obesity prevention and immune system modulation. These findings provide a potential reference for treating inflammatory conditions associated with obesity, contributing academic understanding of obesity management and immunomodulation.

Interleukin-27 signaling resists obesity by promoting the accumulation of Treg cells in visceral adipose tissue.

The prevalence of obesity and its associated metabolic disorders has emerged as one of the most significant health threats worldwide. The visceral adipose tissue regulatory T cells (VAT Treg) play an essential role in maintaining homeostasis and preventing obesity mainly by secreting Interleikin-10 (IL-10) and Transforming Growth Factor ß (TGF-ß). However, the mechanism that regulates VAT Treg quantity and function remains unclear. Here we elucidate the pivotal role of IL-27 signaling in sustaining the accumulation of VAT Treg cells, thereby conferring protection against obesity. We found that mice with the deficiency of IL-27 receptor Wsx1 gained more body weight and VAT weight than their wild-type littermates when fed both a normal-fat diet (NFD) and a high-fat diet (HFD). Notably, the population of VAT Treg cells was reduced in Wsx1 knockout (KO) mice, regardless of whether they were fed a normal-fat diet (NFD) or a high-fat diet (HFD). Correspondingly, the expression levels of the transcription factors FOXP3 and PPAR-γ, essential for VAT Treg function, were also diminished in Wsx1 KO mice. Taken together, our findings indicate that IL-27 signaling plays a protective role in obesity by supporting the maintenance and accumulation of VAT Treg cells.

Blunted inflammatory response is associated with a lower response to a weight loss dietary intervention in liver recipients.

BACKGROUND & AIMS: Obesity is associated with chronic low-grade inflammation, and adipose tissue inflammation is required for fatty tissue remodeling. Interestingly, immunosuppressed patients, as liver transplant recipients, often experience excessive weight gain. We investigated how liver recipients' inflammatory response affects body weight loss induced by dietary treatment. METHODS: Overweight liver recipients were paired with non-transplanted subjects to compare their peripheral immune profiles. RESULTS: Transplanted patients had similar profiles of peripheral blood mononuclear cells compared to controls but lower CD8lowCD56+CD16+NK cells and higher B lymphocytes. Patients showed lower serum concentrations of IFN-γ, TNF, IL-4, IL-2, and IL-10 and lower inflammatory responsiveness of peripheral blood mononuclear cells under inflammatory stimuli. Liver recipients paired with non-transplanted subjects followed a weight loss dietary plan for 6 months to verify body composition changes. After 3 and 6 months of nutritional follow-up, the control group lost more body weight than the liver recipient group. The control group decreased fat mass and waist circumference, which was not observed in transplanted patients. CONCLUSION: Therefore, liver recipients under immunosuppressant treatment responded less to different inflammatory stimuli. This impaired inflammatory milieu might be implicated in the lack of response to weight loss dietary intervention. Inflammation may be essential to trigger the weight loss induced by dietary prescription. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov identification number: NCT03103984.

Anti-obesity and immunomodulatory effects of Allium hookeri leaves cultivated with artificial light of different intensities on immune-depressed obese mice.

This study was conducted to evaluate the effects of Allium hookeri (AH) leaves cultivated with different light-emitting diode (LED) intensities (L: low, 100 µmol/m2/s; M: medium, 150 µmol/m2/s; H: high, 200 µmol/m2/s). Alliin concentration increased as light intensity increased in AH and showed the highest level at LED-H condition. The anti-obesity and immunomodulatory properties of AH were evaluated in a cyclophosphamide (CPA)-induced immunosuppressed obese animal model. C57BL/6 J mice were randomly divided into control (CON), high-fat diet (HFD) control (CON-H), negative control (NC), positive control (PC, ß-glucan, 50 mg/kg body weight (BW)), AH L, M, and H groups. The three kinds of AH extracts were orally administered to the mice at 300 mg/kg BW for 2 weeks. Except for CON and CON-H, all the other groups were intraperitoneally treated with CPA. Epididymal and abdominal fat weight decreased as LED intensity increased while spleen weight increased in the AH groups. Serum glucose decreased as LED intensity increased in the AH groups and H group showed the lowest level. Triglycerides, total, and LDL-cholesterol levels decreased while HDL-cholesterol level increased in the AH groups compared to the NC group. Moreover, AH effectively reduced serum ALT and AST levels and increased the total white blood cell count, particularly elevating lymphocyte and monocyte levels. Furthermore, NK cell activity was higher in the AH groups. These findings suggest that AH cultivated at optimal LED intensity could be used as a novel biomedicine and in pharmacotherapy to treat related diseases to improve public health without any toxicity.

Calenduloside E Ameliorates Inflammatory Responses in Adipose Tissue via Sirtuin 2-NLRP3 Inflammasome Axis.

Obesity-related metabolic diseases are associated with a chronic inflammatory state. Calenduloside E (CE) is a triterpene saponin from sugar beet. In mouse models, CE reduced pro-inflammatory cytokines in white adipose tissue (WAT) and decreased macrophage infiltration of WAT. And CE inhibited pyroptosis in J774A.1 cells and WAT by inhibiting the activation of the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome. Moreover, CE could trigger the activation of Sirtuin 2 (SIRT2), leading to a decrease in the acetylation of NLRP3, particularly at the K24 site. In addition, it has been shown that CE can reduce inflammation in adipocytes that have been induced by macrophage-conditioned medium. However, the selective SIRT2 inhibitor AGK2 hindered the beneficial effects of CE. In summary, CE has the capacity to impede NLRP3-mediated pyroptosis by triggering SIRT2 activity, thus positioning CE as a promising therapeutic avenue for combating obesity-related metabolic disorders.

High-fat diet led to testicular inflammation and ferroptosis via dysbiosis of gut microbes.

The disorder of gut microbiota has negative impact on male reproductive, and testicular damage is associated with obesity. However, the detailed mechanism of gut microbiota on the obesity-induced testis injury are still unknown. Therefore, we constructed a mouse model to investigate the effects of obesity on testis injury. In this study, we found that HFD-induced obesity could disorder gut microbiota homeostasis, which increased the abundance of Brevundimonas, Desulfovibrionaceae_unclassified and Ralstonia, ultimately leading to the overproduction of lipopolysaccharides (LPS). Meanwhile, HFD-feeding promoted intestinal permeability via inhibiting expression of tight junction proteins (ZO-1, Occludin and Claudin) and reducing excretion of mucus, leading to translocation of LPS. The over-accumulation of LPS in the bloodstream triggered an inflammatory response by activating TLR4/NF-κB pathway in testis. On the other hand, the gut microbiota produced-LPS also could induce ferroptosis in testis, as reflected by enhancing iron content and lipid peroxidation (MDA), as well as decreasing ferroptosis-related proteins, including GPX4, FTH1 and SLC1A11. Moreover, inhibition of LPS ligand (TLR4) with Resatorvid (TAK-242) alleviated obesity-induced testis injury through suppression of inflammation and ferroptosis. In conclusion, this study provides novel insights into the underlying mechanisms of obesity-related testis injury induced by gut microbiota disorder via the gut-testis axis, thus offering potential targets to counteract obesity-induced male reproductive disorder.

Immunological roles for resistin and related adipokines in obesity-associated tumors.

Rationale Obesity is an independent risk factor for the occurrence and development of tumors. Obesity is influenced by signaling of adipokines, which are secreted factors from adipocytes and resident immune cells within adipose tissues that mediate lipid metabolism. More recently, adipokines have been implicated in chronic inflammation as well as in tumor formation and growth. Among them, resistin has received increasing attention in research related to the growth and expansion of solid tumors and hematological cancers through various signaling pathways. Objective and findings We reviewed the physiological, biochemical, and immune functions of adipose tissue, with a focus on the structure and expression of resistin and adipokines within multiple adipose cell types, their signaling pathways and putative effects on tumor cells, as well as their in vivo regulation. Current evidence indicates that adipokines such as resistin act as pro-inflammatory factors to stimulate immune cells which, in turn, promotes tumor angiogenesis, connective tissue proliferation, and matrix fibrosis. Concurrently, in states of metabolic dysfunction and lipotoxicity in obese individuals, the numbers and functions of immune cells are compromised, leading to an immunosuppressive environment that fosters tumor cell survival and weak cancer immune monitoring. Conclusion Adipokines such as resistin are important to the development of obesity-related tumors. Clarifying the roles for obesity-related factors in immune regulation and tumor progression may lead to the discovery of novel anti-tumor strategies for targeting obesity factors such as resistin to limit tumor growth and manage obesity, or both.

Reappraisal of Adipose Tissue Inflammation in Obesity.

Chronic low-grade inflammation is a central component in the pathogenesis of obesity-related expansion of adipose tissue and complications in other metabolic tissues. Five different signaling pathways are defined as dominant determinants of adipose tissue inflammation: These are increased circulating endotoxin due to dysregulation in the microbiota-gut-brain axis, systemic oxidative stress, macrophage accumulation, and adipocyte death. Finally, the nucleotide-binding and oligomerization domain (NOD) leucine-rich repeat family pyrin domain-containing 3 (NLRP3) inflammasome pathway is noted to be a key regulator of metabolic inflammation. The NLRP3 inflammasome and associated metabolic inflammation play an important role in the relationships among fatty acids and obesity. Several highly active molecules, including primarily leptin, resistin, adiponectin, visfatin, and classical cytokines, are abundantly released from adipocytes. The most important cytokines that are released by inflammatory cells infiltrating obese adipose tissue are tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), monocyte chemoattractant protein 1 (MCP-1) (CCL-2), and IL-1. All these molecules mentioned above act on immune cells, causing local and then general inflammation. Three metabolic pathways are noteworthy in the development of adipose tissue inflammation: toll-like receptor 4 (TLR4)/phosphatidylinositol-3'-kinase (PI3K)/Protein kinase B (Akt) signaling pathway, endoplasmic reticulum (ER) stress-derived unfolded protein response (UPR), and inhibitor of nuclear factor kappa-B kinase beta (IKKß)-nuclear factor kappa B (NF-κB) pathway. In fact, adipose tissue inflammation is an adaptive response that contributes to a visceral depot barrier that effectively filters gut-derived endotoxin. Excessive fatty acid release worsens adipose tissue inflammation and contributes to insulin resistance. However, suppression of adipose inflammation in obesity with anti-inflammatory drugs is not a rational solution and paradoxically promotes insulin resistance, despite beneficial effects on weight gain. Inflammatory pathways in adipocytes are indeed indispensable for maintaining systemic insulin sensitivity. Cannabinoid type 1 receptor (CB1R) is important in obesity-induced pro-inflammatory response; however, blockade of CB1R, contrary to anti-inflammatory drugs, breaks the links between insulin resistance and adipose tissue inflammation. Obesity, however, could be decreased by improving leptin signaling, white adipose tissue browning, gut microbiota interactions, and alleviating inflammation. Furthermore, capsaicin synthesized by chilies is thought to be a new and promising therapeutic option in obesity, as it prevents metabolic endotoxemia and systemic chronic low-grade inflammation caused by high-fat diet.

Systemic immunity-inflammation index is associated with body fat distribution among U.S. adults: evidence from national health and nutrition examination survey 2011-2018.

OBJECTIVE: The systemic immunity-inflammation index (SII) is a newly developed biomarker that provides an integrated measure of inflammation in the body. We aim to evaluate the relationship between SII and body fat distribution. METHODS: Adults from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 were included. The SII was computed using lymphocyte (LC), neutrophil (NC), and platelet (PC) counts as its components. Body fat distribution was assessed by (total, android, gynoid) percentage fat, total abdominal fat area, subcutaneous adipose tissue area, visceral adipose tissue area, and the ratio of visceral to subcutaneous adipose tissue area (V/S ratio). Multivariable weighted linear regression and subgroup analysis were use to examine the relationships between fat distribution and SII. Restricted cubic splines (RCS) and threshold effect analysis were used to examine analyze nonlinear associations. RESULTS: After exclusions, a total of 11,192 adults with a weighted mean age of 38.46 ± 0.26 years were studied. In multivariable weighted linear regression, each level increase in log2SII was associated with increased of 0.23 SDs total percentage fat (95% CI = 0.03, 0.43) and 0.26 SDs android percentage fat (95% CI = 0.06, 0.47). Besides, the subgroup analysis showed that the positive association between SII and android percentage fat was mainly among obese individuals (BMI > 30 kg/m2) and non-obese individuals without DM or hypertension. Meanwhile, the relationship between SII and the V/S ratio was found to be significant in the female subgroup, the obese subgroup, individuals with non-alcoholic fatty liver disease (NAFLD), and those without diabetes mellitus. Finally, SII exhibited an inverted U-shaped relationship with total percentage fat, android percent fat and total abdominal fat. Accordingly, threshold effect analysis indicated a positive association between lower SII levels and total percentage fat, android percentage fat and total abdominal fat area. CONCLUSIONS: In the nationwide study, it was observed that the SII exhibited a significant correlation with higher levels of body fat, specifically android fat. This association was particularly noticeable within specific subgroups of the population.

Obesity-compromised immunity in post-COVID-19 condition: a critical control point of chronicity.

Post-COVID-19 condition is recognized as a multifactorial disorder, with persistent presence of viral antigens, discordant immunity, delayed viral clearance, and chronic inflammation. Obesity has emerged as an independent risk factor for both SARS-CoV-2 infection and its subsequent sequelae. In this study, we aimed to predict the molecular mechanisms linking obesity and post-COVID-19 distress. Viral antigen-exposed adipose tissues display remarkable levels of viral receptors, facilitating viral entry, deposition, and chronic release of inflammatory mediators and cells in patients. Subsequently, obesity-associated inflammatory insults are predicted to disturb cellular and humoral immunity by triggering abnormal cell differentiation and lymphocyte exhaustion. In particular, the decline in SARS-CoV-2 antibody titers and T-cell exhaustion due to chronic inflammation may account for delayed virus clearance and persistent activation of inflammatory responses. Taken together, obesity-associated defective immunity is a critical control point of intervention against post-COVID-19 progression, particularly in subjects with chronic metabolic distress.

Obesity-derived macrophages upregulate TNF-α to induce apoptosis in glial cell via the NF-κB/PHLPP1 axis.

Macrophages in obese adipose tissue have been shown to damage nerve fibers, however, the mechanism underlying how macrophages cause glial cell damage remains unknown. This study aimed to characterize the mechanism by which macrophages induce apoptosis in glial cell during obesity formation in mice by single-nucleus RNA sequencing (snRNA-seq). Cells obtained from paraepididymal adipose tissue in obese mice underwent snRNA-seq. Eighteen different clusters were identified, and 12 cell types were annotated, including glial cells, macrophages, and fibroblasts. There was a negative correlation between the number of glial cells and macrophages in mouse adipose tissue during the formation of obesity. The pro-apoptotic factor PHLPP1 was identified in GO Terms. The interaction between adipose tissue glial cells and macrophages was revealed via in-depth analysis, and the cell-cell communication mechanism between the TNF-α and NF-KB/PHLPP1 axes was perfected. Apoptosis of glial cell by upregulation of TNF-α via obesity-derived macrophages and activation of the NF-κB/PHLPP1 axis. We further revealed how macrophages induce apoptosis in glial cells during obesity formation, as well as different changes in the two cell populations. This study provides valuable resources and foundations for understanding the mechanistic effects of macrophages and glial cells during obesity formation, as well as diseases and potential interventions.