Protective effect of ghrelin on intestinal I/R injury in rats.

This study aimed to investigate whether ghrelin affected the autophagy and inflammatory response of intestinal intraepithelial lymphocytes (IELs) by regulating the NOD2/Beclin-1 pathway in an intestinal ischemia-reperfusion (I/R) injury model. Twenty hours after implementing the intestinal I/R injury rat model, the small intestine and both lungs were collected for histological analysis. The morphological changes in the intestinal mucosa epithelium and lung tissues were evaluated using hematoxylin-eosin staining. The activity of autophagic vacuoles and organ injury were evaluated using electron microscopy. The cytokine levels (IL-10 and TNF-α) in IEL cells and lung tissue were determined using enzyme-linked immunosorbent assay. RT-qPCR and western blot assays were conducted to check the NOD2, Beclin-1, and ATG16 levels. Ghrelin relieved the I/R-induced destruction of the intestinal mucosa epithelium and lung tissues. Moreover, ghrelin enhanced autophagy in the intestinal epithelium and lungs of I/R rats. In addition, the levels of autophagy-associated proteins (Beclin-1, ATG16, and NOD2) were higher in the ghrelin treatment group than in rats with I/R. Ghrelin reduced significantly the IL-10 and TNF-α levels. However, these changes were reversed by the NOD2 antagonist. In conclusion, ghrelin may relieve I/R-induced acute intestinal mucosal damage, autophagy disorder, and inflammatory response in IELs by regulating the NOD2/Beclin-1 pathway.

Assessment of hypokalemia and clinical prognosis in Patients with COVID-19 in Yangzhou, China.

BACKGROUND: Hypokalemia is a frequent electrolyte imbalance in patients with COVID-19. The aim of this study was to estimate the association between hypokalemia and clinical prognosis in patients with moderate COVID-19. METHODS: A single-center, retrospective, observational study was conducted on 81 non-ICU admitted patients with moderate COVID-19 according to the criteria issued by the Chinese Health Bureau in the Third People's Hospital of Yangzhou (Northern Jiangsu People's Hospital New District Branch) from 4th to 25th August 2021. The demographic, clinical, and laboratory data were reviewed and collected, then the correlation between hypokalemia and prognosis was determined. RESULTS: The level of serum potassium of patients ranged from 2.80 mmol/L to 4.70 mmol/L. Hypokalemia was detected in 39 out of the 81 included patients (48.15%) during hospitalization. Patients with hypokalemia had prolonged days of negative nucleic acid conversion and hospital stay. Correlation analysis showed that the level of serum potassium was negatively correlated with days of negative nucleic acid conversion and length of hospital stay. Bivariate logistic regression analysis proved that hypokalemia was a risk factor for prolonged hospital stay in patients with moderate COVID-19. CONCLUSION: Hypokalemia was prevalent in patients with moderate COVID-19 in Yangzhou, China. Hypokalemia was associated with the prolonged hospital stay in patients with moderate COVID-19.

Downregulation of ATP13A2 in midbrain dopaminergic neurons is related to defective autophagy in a mouse model of Parkinson's disease.

Parkinson's disease (PD) is one of the most common diseases of the nervous system characterized by movement disorders arising from loss of midbrain dopaminergic neurons. The relationship between PD and autophagy has received considerable attention. This study aimed to investigate the involvement of the ATP13A2 gene in damage of dopaminergic neurons induced by abnormal autophagy in a MPTP-induced PD mouse model. MPTP was intraperitoneally injected into C57BL mice at 40 mg/kg for 7 days in experimental group. Saline was injected into mice in the control group. After the injection, the mice were tested at different time points for abnormal limb movement by a swimming test. The brain tissue was collected on day 1, 5, and 7 to measure concentration of intracellular calcium. The expression of ATP13A2 was evaluated by real-time PCR. The expression of α-synclein, LC3, LAMP-2, and CaMKK protein was detected by western blot. We found significant motor dysfunction on day 7 in the experimental group, and the expression of α-synclein in the substantia nigra of the midbrain was significantly increased while the expression of ATP13A2 gene was reduced significantly compared with the control group. The concentration of intracellular calcium in the experimental group was significantly higher than in the control group. Autophagy associated proteins LC3-II and LAMP-2 were downregulated and CaMKK protein was upregulated in midbrain tissues of the experimental group compared to control group. In conclusion, our findings suggest that decreased expression of ATP13A2 may lead to defective autophagy and damage to midbrain dopaminergic neurons.

Ghrelin upregulates PepT1 activity in the small intestine epithelium of rats with sepsis.

BACKGROUND: Sepsis causes nutritional substrate malabsorption; hence, preventing gut barrier problems and improving the nutritional status in sepsis is a compelling issue. AIMS: We tested whether ghrelin administration affects peptide transporter 1 (PepT1) activity in the intestinal epithelium of rats with sepsis. METHODS: Sixty male Sprague-Dawley rats were randomly divided into sham-operated, sepsis, and ghrelin-treated groups. The cecum of sham-operated rats was separated after laparotomy without ligation and perforation. Sepsis group rats underwent cecal ligation and puncture (CLP). Mucosal specimens were used for immunohistochemstry, real-time PCR, and western blotting to detect PepT1 distribution, and mRNA and protein expression levels, respectively. TNF-α, IL-1ß, and ghrelin levels were estimated in serum and intestinal mucosal tissue by ELISA. High-performance liquid chromatography was used to measure PepT1 uptake by the epithelial cells. Moreover, survival, body weight, and food intake of the rats were recorded during the 7-day treatment period. RESULTS: All rats in the sham-operated group survived, and 80% of rats in the sepsis group died within 7d of CLP. Treatment with ghrelin attenuated the CLP-induced body weight loss, intestine mucosa damage, and the survival rate was better. In addition, ghrelin attenuated increases in TNF-α and IL-1ß production. The expressions of PepT1 mRNA and protein were higher in ghrelin-treated group rats than in sepsis rats. Moreover, the uptake function of PepT1 was better in ghrelin-treated group rats. CONCLUSION: Ghrelin treatment can reduce the inflammatory response and greatly upregulate the physiological function of PepT1 in intestinal epithelial cells of rats with sepsis.

Ghrelin protects small intestinal epithelium against sepsis-induced injury by enhancing the autophagy of intestinal epithelial cells.

BACKGROUND: Ghrelin is a hormone that protects against hypoxic injury of cardiac cells by inducing autophagy, but the role of autophagy in sepsis remains unclear. This study aimed to evaluate whether ghrelin could enhance autophagy in rats with intestinal sepsis. METHODS: The cecal ligation and perforation (CLP) method was used to induce sepsis in Sprague-Dawley rats. The rats were assigned to four groups: normal group, sham-operated group, sepsis group, and Ghrelin-treated group. Sera and small intestinal tissues were collected from all groups. The sepsis was evaluated by histological analysis, and autophagy of small intestinal epithelial cells was assessed by electron microscopy, immunofluorescence, and biochemical methods. RESULTS: The expression of autophagy-associated proteins such as LC3, Atg 7 and Beclin 1 increased by 8h post-CLP and declined to basal levels by 12h post-CLP. The expression of LC3, Atg 7 and Beclin 1 in Ghrelin-treated rats was higher than that in rats with sepsis. Furthermore, compared to rats with sepsis, Ghrelin-treated rats showed significantly reduced intestinal mucosa injury at 20h post-CLP. CONCLUSION: Autophagy is induced in the early stages of sepsis. Ghrelin could enhance the autophagy of intestinal epithelial cells in rats with sepsis and protect the small intestinal epithelium against sepsis-induced injury.

Emodin alleviates lung injury in rats with sepsis.

BACKGROUND: Sepsis has high morbidity and mortality. The aim of this study was to investigate whether emodin, an anthraquinone derived from Chinese herb, exerts protective effects on lung injury in rat model of sepsis. MATERIALS AND METHODS: Forty-eight male Wistar rats were randomly divided into four groups (n = 12): normal group, sham-operated group, cecal ligation and puncture (CLP) model group, and emodin-treated group. Saline or emodin (25 mg/kg) was injected intraperitoneally 0.5 h before CLP. The rats were sacrificed 48 h after CLP. Lung wet-to-dry weight ratio and pathologic changes in the lung were examined, the contents of malondialdehyde and myeloperoxidase in lung tissue were detected, serum tumor necrosis factor alpha and interleukin 6 levels were measured by enzyme-linked immunosorbent assay, and the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) was detected by Western blot analysis. RESULTS: Compared with control group, CLP group exhibited higher wet-to-dry weight ratio and water content in the lung (P < 0.01), but these indexes were reduced and pathologic changes in the lung were relieved in the emodin-treated group. In addition, lung malondialdehyde and myeloperoxidase contents, serum levels of tumor necrosis factor alpha and interleukin 6, and phosphorylation of p38 MAPK increased in the CLP group but decreased in the emodin-treated group (P < 0.05). CONCLUSIONS: Emodin exerts protective effects on lung injury in septic rats, which is related to the inhibition of p38 MAPK pathway and the reduction of oxidative stress and inflammation response during sepsis.

Nod2-Rip2 Signaling Contributes to Intestinal Injury Induced by Muramyl Dipeptide Via Oligopeptide Transporter in Rats.

BACKGROUND AND AIMS: PepT1 can transport bacterial oligopeptide products and induce intestinal inflammation. Our aim was to investigate the mechanism of the small intestine injury induced by bacterial oligopeptide product muramyl dipeptide (MDP) which is transported by PepT1. METHODS: We perfused the jejunum with a solution with or without MDP, or with a solution of MDP + Gly-Gly and explored the degree of inflammation to determine the role of PepT1-Nod2 signaling pathway in small intestine mucosa. RESULTS: MDP perfusion induced inflammatory cell accumulation and intestinal damage, accompanied by an increase in mucosal Nod2 and Rip2 transcript expression. NFκB activity and inflammatory cytokine expression, including serum levels of TNF-α, IL-1ß, and IL-6, increased in the MDP group compared to the controls; these effects were reversed by perfusion of the nutritional dipeptide Gly-Gly. CONCLUSION: MDP can be transported through PepT1, causing inflammatory damage in the rat small intestine. Nod2-Rip2-NFκB signaling involved in the small intestinal inflammatory injury caused by MDP which is transported through PepT1.

[Significance of erythrocytes phosphatidylserine exposure on occurrence of anemia in sepsis].

OBJECTIVE: To investigate the role of phosphatidylserine (PS) exposure of erythrocytes in the development of anemia in sepsis patients. METHODS: A self-control study was conducted. Thirty sepsis patients admitted to intensive care unit (ICU) were enrolled. Peripheral venous blood was collected on 1 day and 7 days after ICU admission, and hemoglobin (Hb) concentration was examined routinely. A flow-cytometric assay based on Annexin V/ propidium iodide (Annexin V/PI) was used to measure the PS exposure of erythrocytes. The relationship between PS exposure and Hb concentration was analyzed. RESULTS: Hb concentrations in 30 sepsis patients at 7 days after ICU admission were significantly decreased compared with those of patients at 1 day (81.59±3.31 g/L vs. 121.90±3.34 g/L, t=8.570, P=0.000), but the percentage of PS exposure of erythrocytes was significantly higher [(17.19±1.35)% vs. (7.87±0.83)%, t=-6.557, P=0.000]. An inverse correlation was found between percentage of PS-positive RBCs and Hb concentration by Pearson analysis (r=-0.838, P=0.000). CONCLUSIONS: The percentage of PS exposure in erythrocytes is significantly increased in sepsis, and it might contribute to the development of anemia in sepsis patients during hospital stay. The more severe the anemia, the higher the PS in erythrocytes.