Single-Cell Transcriptomic Analysis Revealed the Cell Population Changes and Cell-Cell Communication in the Liver of a Carnivorous Fish in Response to High-Carbohydrate Diet.

BACKGROUND: Carnivorous fish have a low carbohydrate utilization ability, and the physiologic and molecular basis of glucose intolerance has not been fully illustrated. OBJECTIVES: This study aimed to use largemouth bass as a model to investigate the possible mechanism of glucose intolerance in carnivorous fish with the help of single-nuclei RNA sequencing (snRNA-seq). METHODS: Two diets were formulated, a low-carbohydrate (LC) diet and a high-carbohydrate (HC) diet. The feeding trial lasted for 6 wk, and then, growth performance, biochemical parameters, liver histology, and snRNA-seq were performed. RESULTS: Growth performance of fish was not affected by the HC diet, while liver glucolipid metabolism disorder and liver injury were observed. A total of 13,247 and 12,848 cells from the liver derived from 2 groups were isolated and sequenced, and 7 major liver cell types were annotated by the marker genes. Hepatocytes and cholangiocytes were lower and hepatic stellate cells (HSCs) and immune cells were higher in the HC group than those in the LC group. Reclustering analysis identified 7 subtypes of hepatocytes and immune cells, respectively. The HSCs showed more cell communication with other cell types, and periportal hepatocytes showed more cell communication with other hepatocyte subtypes. Cell-cell communication mainly focused on cell junction-related signaling pathways. Uncovered by the pseudotime analysis, midzonal hepatocytes were differentiated into 2 major branches-biliary epithelial hepatocytes and hepatobiliary hybrid progenitor. Cell junction and liver fibrosis-related genes were highly expressed in the HC group. HC diet induced the activation of HSCs and, therefore, led to the liver fibrosis of largemouth bass. CONCLUSIONS: HC diet induces liver glucolipid metabolism disorder and liver injury of largemouth bass. The increase and activation of HSCs might be the main reason for the liver injury. In adaption to HC diet, midzonal hepatocytes differentiates into 2 major branches-biliary epithelial hepatocytes and hepatobiliary hybrid progenitors.

Muscular lipidomics and transcriptomics reveal the effects of bile acids on lipid metabolism in high-fat diet-fed grouper.

Little information is available on how exogenous bile acids alter lipid metabolism in muscle of fish. In the present study, an 8-week feeding trial were used to investigate the impacts of bile acids on lipid deposition, lipid metabolism, lipidomics, and transcriptomics in muscle of pearl gentian grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) fed a high-fat diet (HD). The HD treatment significantly increased the crude lipid content, while bile acids diet (BD) treatment decreased it (p = 0.057). BD treatment significantly decreased triglycerides level and significantly increased phosphatidylcholines, phosphatidylethanolamines, and phosphatidylglycerol levels. The contents of TG (17:0/18:2/18:2), TG (17:1/18:2/22:6), PC (6:0/22:1), PC (9:0/26:1), PC (26:1/6:0), PC (17:2/18:2), PE (16:0/18:1), PE (18:0/17:1), PG (18:0/20:5), PG (18:3/20:5), PG (19:0/16:1), and PG (18:0/18:1) in muscle were well response to dietary lipid level and bile acids supplementation. HD and BD groups induced a variety of adaptive metabolic responses in transcriptomics. HD treatment increased the lipogenesis and decreased lipolysis, whereas BD treatment decreased the lipogenesis and increased lipolysis. Present study revealed the improvement of muscular lipid metabolism and lipid composition in response to bile acids administration in pearl gentian grouper.

Effects of replacing fishmeal with different proportions of mixed protein source in the diet of largemouth bass (Micropterus salmoides).

Fishmeal is an important protein source for largemouth bass (Micropterus salmoides). However, the production of fishmeal is decreasing each year and the price of fishmeal is rising. Therefore, it is necessary to find new high-quality and suitable protein sources. This study used a mixed animal protein source (chicken meal:blood meal:shrimp meal:brewer's yeast = 50:12.5:25:12.5) to replace fishmeal. Using a 48 % fishmeal group as the control, five diets with different fishmeal levels (FM48, FM44, FM40, FM36, FM32) were established to determine the effects on largemouth bass growth performance, liver health and intestinal health. There were no significant differences in the percentage weight gain, specific growth rate, feed conversion rate, and condition factor of largemouth bass, but the hepatosomatic and viscerosomatic indexes were significantly decreased when the dietary fishmeal level was reduced to 40 %. The content of taurine, glycine, and histidine was significantly reduced in the muscle of largemouth bass fed the FM32 diet compared with those fed the FM48 and FM44 diets. Mixed protein feed reduced the total bile acid content and increased the low-density lipoprotein cholesterol content in the plasma of largemouth bass. The replacement of fishmeal with the mixed protein source inhibited the expression of tnf-α and caspase 3 and enhanced the expression of apoa1 in the liver, as well as enhancing the protein expression of FXR and SREBP and inhibiting the protein expression of P-PPARA in the liver. The intestinal pparα expression was suppressed when dietary fishmeal was replaced. When dietary fishmeal decreased, the mucosal folds height and muscle layer thickness also decreased. In conclusion, partial replacement of fishmeal with the mixed protein source did not affect the growth performance, while lipid metabolism and intestinal health were negatively affected when dietary fishmeal levels were below 36 %.

Spatial Accessibility Evaluation and Location Optimization of Primary Healthcare in China: A Case Study of Shenzhen.

The unbalanced allocation of healthcare resources is a major challenge that hinders access to healthcare. Taking Shenzhen as an example, this study aimed to enhance equity in obtaining healthcare services, through measuring and visualizing the spatial accessibility of community healthcare centers (CHC), and optimizing CHC geospatial allocation. We used the number of health technicians per 10,000 to represent the CHC's service capacity, combined with resident points and census data to calculate the population the CHC needs to carry, and then analyzed the accessibility based on the Gaussian two-step floating catchment area method. In 2020, five regions in Shenzhen had better spatial accessibility scores: Nanshan (0.250), Luohu (0.246), Futian (0.244), Dapeng (0.226), and Yantian (0.196). The spatial accessibility of CHCs shows a gradual decrease from the city center to the edge, which is affected by economic and topographic factors. With the support of the maximal covering location problem model, we selected up to 567 candidate locations for the new CHC, which could improve Shenzhen's accessibility score from 0.189 to 0.361 and increase the coverage population by 63.46% within a 15-min impedance. By introducing spatial techniques and maps, this study provides (a) new evidence for promoting equitable access to primary healthcare services in Shenzhen and (b) a foundation for improving the accessibility of public service facilities in other areas.

Drought risk and water resources assessment in the Beijing-Tianjin-Hebei region, China.

Drought is a natural disaster that can influence all aspects of human life owing to its extensive and long-term implications. Global warming and rapid economic development have led to an increase in the drought risk. Meanwhile, rural communities are more drought-susceptible due to their greater closeness to nature and agriculture-based economies. Therefore, the scientific drought risk assessment and water resource utilization are of great significance. Drought risk refers to the potential losses from hazards imposed by drought events, which are a result of combined hazard, vulnerability, and exposure. This study focuses on drought risks in rural areas to provide references for risk assessment, disaster prevention, and water resource allocation. We chose the Beijing-Tianjin-Hebei region (where is water-scarce and suffers severe drought disasters) as the study area. We used the standardized precipitation evapotranspiration index (SPEI) to define the drought events and to extract the drought duration (D) and drought severity (S) according to the run theory. We also established three vulnerability curves based on the loss data, and assessed the risk of the primary industry, rural population, and cultivated areas, then superimposed it on the spatial distribution of water resources. The results indicated that Beijing has a high level of urbanization with a relatively low drought risk, and there are some high-risk areas in Tianjin and southeastern Hebei. Domestic water consumption is stable, and agricultural consumption has decreased. With the rapid increase in green areas in recent years, ecological water consumption has also increased. It has less water and a high-risk level of drought in southern areas. It is crucial to construct emergency water source projects for drought relief and make efficient use of limited water resources available.

Association between Th17-related cytokines and risk of non-small cell lung cancer among patients with or without chronic obstructive pulmonary disease.

BACKGROUND: CD4 (+) T helper 17 (Th17) cells play critical roles in inflammation and tumor development. The involvement of Th17 cells in chronic obstructive pulmonary disease (COPD)-type inflammation-associated lung cancer has also been confirmed in animal models. However, to the authors' knowledge, it is unknown whether the role of Th17 cells is different in patients with lung cancer complicated with COPD compared with those without COPD. In the current study, the authors attempted to determine the association between the circulating levels of Th17-related cytokines and the clinical characteristics of non-small cell lung cancer (NSCLC) in patients with or without COPD. METHODS: The authors designed a matched case-control study that included 70 patients with NSCLC with COPD, 148 patients with NSCLC without COPD, and 148 healthy controls. The data regarding the clinicopathological features of these participants were collected. Circulating levels of Th17-related cytokines, including interleukin (IL) 23 (IL-23), IL-17A, IL-17F, IL-22, and tumor necrosis factor-α, were measured. RESULTS: The circulating levels of IL-23, IL-17A, IL-17F, IL-22, and tumor necrosis factor-α were found to be significantly higher in the patients with NSCLC compared with the healthy controls (P<.05). The elevated levels were found to be significantly associated with lung cancer risk (P<.05). However, no significant differences were found between patients with NSCLC with COPD and patients without COPD. It is interesting to note that, among patients with NSCLC without COPD, the levels of these cytokines were consistently higher among patients with stage I to stage IIIA disease compared with those with stage IIIB to stage IV disease (P<.05). In addition, the 5 Th17-related cytokines demonstrated pairwise correlations, with Spearman rank correlation coefficients of 0.646 to 0.888 (P<.05). CONCLUSIONS: The results of the current study indicate a clear association between the Th17-related cytokine profile and the risk of NSCLC complicated by the presence or absence of COPD.

Lipopolysaccharide Induces Autophagic Cell Death through the PERK-Dependent Branch of the Unfolded Protein Response in Human Alveolar Epithelial A549 Cells.

BACKGROUND: Alveolar epithelial cell death plays a critical role in the pathogenesis of lipopolysaccharide (LPS)-induced acute lung injury. Increased autophagy has a dual effect on cell survival. However, it is not known whether autophagy promotes death or survival in human alveolar epithelial cells exposed to LPS. METHODS: Genetic and pharmacological approaches were used to evaluate the effect of autophagy on A549 cell viability upon LPS exposure. The endoplasmic reticulum (ER) stress and unfolded protein response (UPR) pathways were examined with immunoblotting studies to further explore underlying mechanisms. RESULTS: Treatment with LPS (50 µg/ml) led to autophagy activation and decreased cell viability in A549 cells. Blocking autophagy via short interfering RNA or inhibitor significantly decreased, whereas rapamycin increased, the LPS-induced effect on viability. ER stress was activated in LPS-stimulated A549 cells, and ER stress inhibitor reduced LPS-induced autophagy. LPS activated only the PERK pathway and had rarely effect on the ATF6 and IRE1 branches of the UPR in A549 cells. Moreover, the knockdown of PERK and ATF4 attenuated LPS-induced autophagy and promoted cell survival. CONCLUSION: In human alveolar epithelial A549 cells, LPS induces autophagic cell death that depends on the activation of the PERK branch of the UPR upon ER stress.