Gut microbiota-melatonin signaling axis in acute pancreatitis: Revealing the impact of gut health on pancreatic inflammation and disease severity in a case-control study.

Acute pancreatitis (AP), a severe inflammatory condition affecting the pancreas requires investigation into its predictors. Melatonin, a compound with anti-inflammatory and antioxidant properties, has shown promise in managing AP. Additionally, the gut microbiota, a community of microorganisms residing in the intestines has been linked to AP development. This study aims to explore the correlation between melatonin and gut microbiota in predicting AP severity. This study involved 199 participants, with 99 diagnosed with AP and 100 serving as healthy controls. The AP patients were categorized into 2 groups based on the severity of their condition: mild AP (MAP) and severe AP (SAP). Serum melatonin levels were measured on Days 1, 3, and 5 of hospitalization, and gut microbiota composition was examined via 16S rRNA gene sequencing. Other parameters were evaluated, such as the Acute Physiology and Chronic Health Evaluation (APACHE) score, Ranson, and Acute Gastrointestinal Injury (AGI) scores. Melatonin levels were significantly lower in subjects with severe AP compared those with mild AP (18.2 ng/mL vs 32.2 ng/mL, P = .001), and melatonin levels decreased significantly in patients with AP on Days 3 and 5. The study also revealed that individuals with AP exhibited a significantly altered gut microbiota composition compared to control individuals, with a lower Shannon index and higher Simpson index. The AUCs for Simpson index and F/B ratio were significantly higher than those for other biomarkers, indicating that these gut microbiota markers may also be useful for AP prediction. The study proposes that there is a relationship between melatonin levels and the dynamics of gut microbiota profiles in relation to the severity of AP. As a result, the severity of the disease can be assessed by assessing the levels of serum melatonin and gut microbiota profiles.

Perinatal Nicotine Exposure Increases Obesity Susceptibility in Adult Male Rat Offspring by Altering Early Adipogenesis.

The present study aims to evaluate whether perinatal nicotine (NIC) exposure increases obesity susceptibility in adult male rat offspring by altering early adipogenesis. NIC was sc administered (2.0 mg/kg per day) to pregnant rats from gestational day 9 to the time of weaning (postnatal day 28). At weaning, NIC-exposed male pups had an increased body weight and inguinal sc fat mass and a decreased average cell area of adipocyte, which was accompanied by an overexpression of adipogenic and lipogenic genes in the epididymal white adipose tissue. Additionally, the hepatic lipogenic gene levels from NIC-exposed male pups were also affected. At 12 and 26 weeks of age, body weight and fat mass were increased, whereas there was no change in food intake in NIC-exposed male offspring. Adipogenic and lipogenic genes, glucose transporter 4, and leptin mRNA levels were increased, whereas adiponectin mRNA levels were decreased in the epididymal white adipose tissue of NIC-exposed males. The hepatic lipogenic gene expression of NIC-exposed males was increased. NIC-exposed male offspring showed normal glycemia and a higher serum insulin level, homeostasis model assessment of insulin resistance, and homeostasis model assessment of ß-cell function. Furthermore, the NIC-exposed male offspring showed higher serum lipids and Castelli index I and lower nonesterified fatty acid. At 26 weeks, in the ip glucose and insulin tolerance tests, the glucose clearance was delayed, and the area under the curve was higher in the NIC-exposed male offspring. In conclusion, perinatal NIC exposure increased obesity susceptibility in adult male rat offspring by altering early adipogenesis.

Prenatal and lactation nicotine exposure affects morphology and function of brown adipose tissue in male rat offspring.

The aim of this study was to investigate the effects of prenatal and lactation nicotine exposure on the morphology and function of brown adipose tissue (BAT) in male rat offspring. We conducted a morphological assay and gene expression study of interscapular BAT (iBAT) in male rat offspring. The male offspring from nicotine-exposed dams exhibited higher body weight and iBAT weight. Hematoxylin and eosin staining and transmission electron microscopy showed that iBAT from nicotine-exposed male offspring presented a "whitening" phenotype characterized by lipid droplet accumulation and impaired mitochondria with a randomly oriented and fractured cristae. The expression of the iBAT structure and function-related genes all decreased in nicotine-exposed male offspring. These data indicate that prenatal and lactation nicotine exposure affects morphology and function of iBAT in male rat offspring.

Nicotine Suppressed Fetal Adrenal StAR Expression via YY1 Mediated-Histone Deacetylation Modification Mechanism.

Steroidogenic acute regulatory (StAR) protein plays a pivotal role in steroidogenesis. Previously, we have demonstrated that prenatal nicotine exposure suppressed fetal adrenal steroidogenesis via steroidogenic factor 1 deacetylation. This study further explored the potential role of the transcriptional repressor Yin Yang 1 (YY1) in nicotine-mediated StAR inhibition. Nicotine was subcutaneously administered (1.0 mg/kg) to pregnant rats twice per day and NCI-H295A cells were treated with nicotine. StAR and YY1 expression were analyzed by real-time PCR, immunohistochemistry, and Western blotting. Histone modifications and the interactions between the YY1 and StAR promoter were assessed using chromatin immunoprecipitation (ChIP). Prenatal nicotine exposure increased YY1 expression and suppressed StAR expression. ChIP assay showed that there was a decreasing trend for histone acetylation at the StAR promoter in fetal adrenal glands, whereas H3 acetyl-K14 at the YY1 promoter presented an increasing trend following nicotine exposure. Furthermore, in nicotine-treated NCI-H295A cells, nicotine enhanced YY1 expression and inhibited StAR expression. ChIP assay showed that histone acetylation decreased at the StAR promoter in NCI-H295A cells and that the interaction between the YY1 and StAR promoter increased. These data indicated that YY1-medicated histone deacetylation modification in StAR promoters might play an important role in the inhibitory effect of nicotine on StAR expression.

Selection of Suitable Reference Genes for Quantitative Real-Time PCR Normalization in Three Types of Rat Adipose Tissue.

Quantitative real-time PCR (qRT-PCR) is the most classical technique in the field of gene expression study. This method requires an appropriate reference gene to normalize mRNA levels. In this study, the expression stability of four frequently-used reference genes in epididymal white adipose tissue (eWAT), inguinal beige adipose tissue (iBeAT) and brown adipose tissue (BAT) from obese and lean rats were evaluated by geNorm, NormFinder and BestKeeper. Based on the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines, the two most stable reference genes were recommended in each type of adipose tissue. Two target genes were applied to test the stability of the reference genes. The geNorm and NormFinder results revealed that GAPDH and 36B4 exhibited the highest expression stabilities in eWAT, while 36B4 and ß-actin had the highest expression stabilities in iBeAT and BAT. According to the results of the BestKeeper analysis, 36B4 was the most stable gene in eWAT, iBeAT and BAT, in terms of the coefficient of variance. In terms of the coefficient of correlation, GAPDH, 36B4 and ß-actin were the most stable genes in eWAT, iBeAT and BAT, respectively. Additionally, expected results and statistical significance were obtained using a combination of two suitable reference genes for data normalization. In conclusion, 36B4 and GAPDH, in combination, are the best reference genes for eWAT, while 36B4 and ß-actin are two most suitable reference genes for both iBeAT and BAT. We recommend using these reference genes accordingly.

Effects of prenatal and lactation nicotine exposure on glucose homeostasis, lipogenesis and lipid metabolic profiles in mothers and offspring.

There is increasing evidence suggesting that maternal nicotine (NIC) exposure alone can lead to many deleterious consequences in the fetus. In this study, we aimed to evaluate the effects of prenatal and lactation NIC exposure on glucose homeostasis, lipogenesis and lipid metabolism in mothers and pups. After maternal NIC exposure (from gestational day 9 to weaning), NIC mothers showed lower body weight, decreased parametrial white adipose tissue (pWAT) and inguinal WAT weights, lower homeostasis model assessment of beta cell function, higher serum total cholesterol (TC) and low-density lipoprotein cholesterol levels, higher Castelli index values, lower hepatic mRNA levels of sterol regulatory element binding protein-1c (SREBP1c), lipoprotein lipase, acetyl-CoA carboxylase, fatty acid synthase (FAS) and glucose transporters 4 (GLUT4), as well as lower SREBP1c, FAS, leptin and GLUT4 mRNA levels in pWAT. However, female NIC pups presented higher body weights and serum TC levels, and increased trends for high density lipoprotein-cholesterol and Castelli index I. Male NIC pups had higher body weight, serum TC levels and Castelli index I values, and lower glycemia levels. Additionally, hepatic and adipose FAS gene expression from the female NIC pups presented a decreasing trend, while the male NIC pups had lower hepatic FAS expression and higher adipose FAS expression. In conclusion, prenatal and lactation NIC exposure induced deleterious effects on the glucose homeostasis, lipogenesis and lipid metabolism in both mothers and pups, which may promote several important metabolic disorders in the progeny. Additionally, there are gender-specific effects on pups.