Leptin Aggravates Reflux Esophagitis by Increasing Tissue Levels of Macrophage Migration Inhibitory Factor in Rats

Untangling immune cell contributions in the progression from GERD to Barrett's esophagus and esophageal cancer: Insights from genetic causal analysis

BACKGROUND

Esophageal adenocarcinoma (EAC) is a rapidly increasing malignancy with significant morbidity and mortality. The progression from gastroesophageal reflux disease (GERD) to Barrett's esophagus (BE) and ultimately to EAC is thought to be influenced by chronic inflammation and immune cell dynamics. Despite the observed correlations in observational studies, the causal relationships between immune cell phenotypes and this disease continuum remain unclear.

METHODS

This study utilized a two-sample Mendelian Randomization (MR) approach to investigate the causal roles of 731 distinct immune cell phenotypes in the GERD-BE-EAC continuum. The analysis leveraged genome-wide association study (GWAS) data for immune phenotypes from a Sardinian cohort and data for GERD, BE, and EAC from the FinnGen and Open GWAS databases. A comprehensive set of MR methods, including inverse variance weighted (IVW), MR-Egger, and weighted median estimators, was employed to assess causality. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy, ensuring the robustness of the findings.

RESULTS

The study revealed complex and multifaceted roles of immune cells across the GERD-BE-EAC continuum. In GERD, 34 immune phenotypes were found to be causally associated with either increased or decreased risk. Protective effects were observed in phenotypes such as Unswitched Memory B cells, while others like CD45RA- CD4+ T cells were linked to an elevated risk. In the context of BE, 28 immune phenotypes demonstrated significant causal associations, with the majority being protective, including Unswitched Memory B cells and CD62L on Granulocytes. Conversely, certain phenotypes, such as CD24 on Transitional B cells, were identified as risk factors for BE. For EAC, 34 immune phenotypes were implicated, with various B cell subsets, particularly those expressing BAFF-R and CD24, associated with an increased risk, while Switched Memory B cells and specific myeloid cell phenotypes showed protective effects.

CONCLUSIONS

This study provides novel insights into the complex role of immune cells in the pathogenesis of EAC, revealing a dynamic interplay where certain immune phenotypes may be protective in early stages but become risk-enhancing in later stages of disease progression. These findings highlight the potential of immune cell phenotypes to serve as biomarkers for early detection and targeted therapeutic interventions across the GERD-BE-EAC continuum. Further research is warranted to validate these findings in diverse populations and to explore the underlying mechanisms driving these immune-mediated effects.

Effect of Leptin Receptor Q223R Polymorphism on Clostridioides difficile Infection-Induced Macrophage Migration Inhibitory Factor Production

Proinflammatory cytokine levels and host genetic makeup are key determinants of Clostridioides difficile infection (CDI) outcomes. We previously reported that blocking the inflammatory cytokine macrophage migration inhibitory factor (MIF) ameliorates CDI. Here, we determined kinetics of MIF production and its association with a common genetic variant in leptin receptor (LEPR) using blood from patients with CDI. We found highest plasma MIF early after C difficile exposure and in individuals who express mutant/derived LEPR. Our data suggest that early-phase CDI provides a possible window of opportunity in which MIF targeting, potentially in combination with LEPR genotype, could have therapeutic utility.

Molecular mechanism, regulation, and therapeutic targeting of the STAT3 signaling pathway in esophageal cancer (Review)

Esophageal cancer (EC) is the seventh most common cancer globally, and the overall 5‑year survival rate is only 20%. Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in EC, and its activation is associated with a poor prognosis. STAT3 can be activated by canonical pathways such as the JAK/STAT3 pathway as well as non‑canonical pathways including the Wnt/STAT3 and COX2/PGE2/STAT3 pathways. Activated STAT3, present as phosphorylated STAT3 (p‑STAT3), can be transported into the nucleus to regulate downstream genes, including VEGF, cyclin D1, Bcl‑xL, and matrix metalloproteinases (MMPs), to promote cancer cell proliferation and induce resistance to therapy. Non‑coding RNAs, including microRNAs (miRNAs/miRs), circular RNAs (circRNAs), and long non‑coding RNAs (lncRNAs), play a vital role in regulating the STAT3 signaling pathway in EC. Several miRNAs promote or suppress the function of STAT3 in EC, while lncRNAs and circRNAs primarily promote the effects of STAT3 and the progression of cancer. Additionally, various drugs and natural compounds can target STAT3 to suppress the malignant behavior of EC cells, providing novel insights into potential EC therapies.

Lean/normal-weight metabolic dysfunction-associated fatty liver disease is a risk factor for reflux esophagitis

AIM

Reflux esophagitis is associated with metabolic dysfunction. Recently, fatty liver has been redefined as metabolic dysfunction-associated fatty liver disease (MAFLD). We investigated the impact of MAFLD and its subtypes on the incidence of reflux esophagitis.

METHODS

This multicenter, observational cohort study enrolled 9100 consecutive health-check examinees who underwent esophagogastroduodenoscopy and ultrasonography. All patients were classified into the MAFLD or non-MAFLD group. Based on the Asian cut-off value for body mass index (BMI), the MAFLD group was further classified into the lean/normal-weight (BMI <23 kg/m2 ) and overweight/obese (BMI ≥23 kg/m2 ) subgroups. The impact of MAFLD and its subtypes on the cumulative incidence of reflux esophagitis was evaluated using multivariable Cox proportional hazards regression analysis.

RESULTS

MAFLD was diagnosed in 26.5% (2416/9100) of patients. Multivariable Cox proportional hazards regression analysis indicated that MAFLD (hazard ratio [HR] 1.2183; 95% confidence interval [CI] 1.0954-1.3550; p = 0.0003), hiatal hernia, and aging were independent risk factors for reflux esophagitis. Stratification analysis indicated that cumulative incidence of reflux esophagitis among patients with MAFLD was significantly higher in the lean/normal-weight than in the overweight/obese group (HR 1.3274; 95% CI 1.0043-1.7547; p = 0.0466). Among various metabolic factors, visceral adiposity was the only independent metabolic risk factor for reflux esophagitis (HR 2.8331; 95% CI 1.0201-7.8691; p = 0.0457) in the lean/normal-weight MAFLD group.

CONCLUSIONS

MAFLD, in particular lean/normal-weight MAFLD, is independent risk factor for reflux esophagitis. Furthermore, visceral adiposity was identified as the most strong metabolic risk factor for reflux esophagitis in lean/normal-weight patients with MAFLD.

Role of Obesity, Physical Exercise, Adipose Tissue-Skeletal Muscle Crosstalk and Molecular Advances in Barrett's Esophagus and Esophageal Adenocarcinoma

Both obesity and esophageal adenocarcinoma (EAC) rates have increased sharply in the United States and Western Europe in recent years. EAC is a classic example of obesity-related cancer where the risk of EAC increases with increasing body mass index. Pathologically altered visceral fat in obesity appears to play a key role in this process. Visceral obesity may promote EAC by directly affecting gastroesophageal reflux disease and Barrett’s esophagus (BE), as well as a less reflux-dependent effect, including the release of pro-inflammatory adipokines and insulin resistance. Deregulation of adipokine production, such as the shift to an increased amount of leptin relative to “protective” adiponectin, has been implicated in the pathogenesis of BE and EAC. This review discusses not only the epidemiology and pathophysiology of obesity in BE and EAC, but also molecular alterations at the level of mRNA and proteins associated with these esophageal pathologies and the potential role of adipokines and myokines in these disorders. Particular attention is given to discussing the possible crosstalk of adipokines and myokines during exercise. It is concluded that lifestyle interventions to increase regular physical activity could be helpful as a promising strategy for preventing the development of BE and EAC.

Hyperleptinemia results in systemic inflammation and the exacerbation of ischemia-reperfusion myocardial injury

Aim

Hyperleptinemia potentiates the effects of many atherogenic factors, such as inflammation, platelet aggregation, migration, hypertrophy, proliferation of vascular smooth muscle cells, and endothelial cell dysfunction. The present study analysed the effects of long-term hyperleptinemia in an in vivo myocardial ischemia-reperfusion model to demonstrate whether the in vivo deleterious effect also affects cardiac structure and function.

Main methods

Rats were subcutaneously administered leptin for 8 days to estimate the involvement of the JAK/STAT pathway. Data from 58 male Wistar rats were included in the final analysis. Myocardial infarction (MI) was modelled by the 30-minute ligation of the main left coronary artery followed by 120-minute reperfusion. Hemodynamic measurements, electrocardiography monitoring, echocardiography, myocardial infarct size and area at risk, blood biochemical parameters, leptin, IL-6, TNF-alpha, FGF-21, and cardiomyocyte morphology were measured. The expression of JAK2, p-JAK2, STAT3, p-STAT3 was assessed by Western Blot analysis. Statistical analyses were performed using IBM SPSS Statistics v.26.

Key findings

Eight-day hyperleptinemia in rats leads to an increase in blood pressure and heart rate, myocardial hypertrophy, impaired LV function, the frequency of ischemic arrhythmias, dyslipidemia, systemic inflammation, and the size of induced myocardial infarction. Significance: The blockade of the JAK/STAT signalling pathway effectively reverses the negative effects of leptin, including increased blood pressure and total cholesterol.

IFN-I Mediates Dysfunction of Endothelial Progenitor Cells in Atherosclerosis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease including the cardiovascular system. Atherosclerosis is the most common cardiovascular complication of SLE and a significant risk factor for morbidity and mortality. Vascular damage/protection mechanism in SLE patients is out of balance, caused by the cascade reaction among oxidative stress, proinflammatory cytokines, Neutrophil Extracellular Traps, activation of B cells and autoantibodies and abnormal T cells. As a precursor cell repairing vascular endothelium, endothelial progenitor cells (EPCs) belong to the protective mechanism and show the reduced number and impaired function in SLE. However, the pathological mechanism of EPCs dysfunction in SLE remains ill-defined. This paper reviews the latest SLE epidemiology and pathogenesis, discusses the changes in the number and function of EPCs in SLE, expounds the role of EPCs in SLE atherosclerosis, and provides new guidance and theoretical basis for exploring novel targets for SLE treatment.

Roles of Adipokines in Digestive Diseases: Markers of Inflammation, Metabolic Alteration and Disease Progression

Adipose tissue is a highly dynamic endocrine tissue and constitutes a central node in the interorgan crosstalk network through adipokines, which cause pleiotropic effects, including the modulation of angiogenesis, metabolism, and inflammation. Specifically, digestive cancers grow anatomically near adipose tissue. During their interaction with cancer cells, adipocytes are reprogrammed into cancer-associated adipocytes and secrete adipokines to affect tumor cells. Moreover, the liver is the central metabolic hub. Adipose tissue and the liver cooperatively regulate whole-body energy homeostasis via adipokines. Obesity, the excessive accumulation of adipose tissue due to hyperplasia and hypertrophy, is currently considered a global epidemic and is related to low-grade systemic inflammation characterized by altered adipokine regulation. Obesity-related digestive diseases, including gastroesophageal reflux disease, Barrett's esophagus, esophageal cancer, colon polyps and cancer, non-alcoholic fatty liver disease, viral hepatitis-related diseases, cholelithiasis, gallbladder cancer, cholangiocarcinoma, pancreatic cancer, and diabetes, might cause specific alterations in adipokine profiles. These patterns and associated bases potentially contribute to the identification of prognostic biomarkers and therapeutic approaches for the associated digestive diseases. This review highlights important findings about altered adipokine profiles relevant to digestive diseases, including hepatic, pancreatic, gastrointestinal, and biliary tract diseases, with a perspective on clinical implications and mechanistic explorations.

Inhibition of macrophage migration inhibitory factor prevents thyroid dysfunction in pregnant rats with acute pancreatitis

Acute pancreatitis during pregnancy (APIP) rarely occurs but may lead to preterm delivery and be associated with high fetal mortality. Macrophage migration inhibitory factor (MIF) participates in various inflammatory diseases as a pro-inflammatory cytokine. In this study, we aimed to explore the effects of (S, R)-3-(4-hydroxyphenyl)-4, 5dihydro-5-isoxazole acetic methyl ester (ISO-1), an inhibitor of MIF, on maternal thyroid injury associated with APIP and its potential mechanisms in a pregnant rat model. APIP model was induced by retrograde injection of sodium taurocholate. ISO-1 was injected intraperitoneally 30 min before model establishment. The severity of pancreatitis was assessed by levels of tumor necrosis factor (TNF)‑α, interleukin (IL)‑1β, IL-6 of maternal serum as well as histopathological score. Thyroid injury was determined by free triiodothyronine (FT3), free tetraiodothyronine (FT4) and thyroid histopathological score. Levels of MIF in maternal serum and the expression of MIF, CD68, CD3 and intercellular cell adhesion molecule-1 (ICAM-1) as well as oxidative stress status in maternal thyroid tissues were detected. Ultrastructure of maternal thyroid tissues was observed by transmission electron microscope. Thyroid injuries occurred in APIP and the lesions were attenuated with the pretreatment of ISO-1. Moreover, ISO-1 reduced the expression of MIF, attenuated the activations of CD68, CD3, ICAM-1 while improved oxidative stress status in maternal thyroid. Our research suggested a protective role of ISO-1 on thyroid injury and endocrine disorder during APIP, which may be associated with the inhibition of biological functions of MIF.

Leptin: an unappreciated key player in SLE

Leptin is the forerunner of the adipokine superfamily and plays a key role in regulating energy expenditure and neuroendocrine function. Researches into leptin put emphasize not only on the metabolic role but also its immunoregulatory effect on immune response through immunocyte activation and cytokine secretion. Leptin acts on receptors that are widespread throughout the body and that are expressed across many tissue types. As a consequence, the abnormal expression of leptin has been found to correlate with a number of diseases, including cancers, autoimmune diseases, and cardiovascular diseases. The significance of leptin in the development of autoimmune diseases is becoming increasingly prominent. Systemic lupus erythematosus (SLE) is a severe atypical autoimmune disease that causes damage to multiple organ systems. It is characterised by the following: impaired clearance of apoptotic cells, loss of tolerance to self-antigens, aberrant activation of T cells and B cells, and chronic inflammation. The heightened immunocyte response in SLE means that these physiological systems are particularly vulnerable to regulation by leptin in addition to being of great significance to the research field. Our current review provides insight into the regulatory roles that leptin plays on immune effector cells in SLE.