Long-chain acyl-CoA synthetase (ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-CoAs, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or loss-of-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolism-associated effects of ACSLs in diseases.

In December 2019, an ongoing outbreak of coronavirus disease 2019 (COVID-19) was first identified in Wuhan, China. The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully representative of patients outside Wuhan. Therefore, it is highly essential to analyze the epidemiological and clinical characteristics of COVID-19 in areas outside Wuhan or Hubei Province. To date, a limited number of studies have concentrated on the epidemiological and clinical characteristics of COVID-19 patients with different genders, clinical classification, and with or without basic diseases. To study the epidemiological and clinical characteristics of COVID-19 patients in Hengyang (China) and provide a reliable reference for the prevention and control of COVID-19. From January 16 to March 2, 2020, a total of 48 confirmed cases of COVID-19 were reported in Hengyang, and those cases were included in this study. The diagnostic criteria, clinical classification, and discharge standard related to COVID-19 were in line with the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (Trial Version 7) released by National Health Commission and National Administration of Traditional Chinese Medicine. The presence of SARS-CoV-2 in pharyngeal swab specimens was detected by quantitative reverse transcription polymerase chain reaction. All the data were imported into the excel worksheet and statistically analyzed by using SPSS 25.0 software. A total of 48 cases of COVID-19 were collected, of which 1 was mild, 38 were moderate, and 9 were severe. It was unveiled that there were 31 (64.6%) male patients and 17 (35.4%) female patients, with a female-to-male ratio of 1.82:1. The range of age of patients with COVID-19 was dominantly 30-49 years old [25 (52.1%) of 48], followed by those aged over 60 years old [11 (22.9%)]. Besides, 29.2% (14 of 48) of patients had basic diseases, and 57.2% (8 of 14) of patients with basic diseases were aged over 60 years old. The occupations of 48 COVID-19 patients were mainly farmers working in agricultural production [15 (31.5%) of 48], rural migrant workers from Hengyang to Wuhan [15 (31.5%)], and service workers operating in the service sector [8 (16.7%)]. The mean latent period was 6.86 ± 3.57 d, and the median was 7 [interquartile range (IQR): 4-9] d. The mean time from onset of symptoms to the first physician visit was 3.38 ± 2.98 (95%CI: 2.58-9.18) d, with a median of 2 (IQR: 1-5) d, and the mean time from hospital admission to confirmed diagnosis was 2.29 ± 2.11 (95%CI: 1.18-6.42) d, with a median of 2 (IQR: 1-3) d. The main symptoms were fever [43 (89.6%) of 48], cough and expectoration [41 (85.4%)], fatigue [22 (45.8%)], and chills [22 (45.8%)]. Other symptoms included poor appetite [13 (27.1%)], sore throat [9 (18.8%)], dyspnea [9 (18.8%)], diarrhea [7 (14.6%)], dizziness [5 (10.4%)], headache [5 (10.4%)], muscle pain [5 (10.4%)], nausea and vomiting [4 (8.3%)], hemoptysis [4 (8.3%)], and runny nose [1 (2.1%)]. The numbers of peripheral blood leukocytes, lymphocytes, and eosinophils were significantly reduced in the majority of the patients. The levels of C-reactive protein, fibrinogen, blood glucose, lactate dehydrogenase, D-dimer, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (γ-GT), myoglobin (MB), and creatine kinase (CK) were increased in 64.6%, 44.7%, 43.2%, 37.0%, 29.5%, 22.9%,20.8%, 21.6%, 13.6%, and 12.8% of patients, respectively. The incidence of ALT elevation in male patients was remarkably higher than that in females (P < 0.01), while the incidences of AST, CK, and blood glucose elevations in severe patients were remarkably higher than those in moderate patients (P < 0.05, respectively). Except for the mild patients, chest computed tomography showed characteristic pulmonary lesions. All the patients received antiviral drugs, 38 (79.2%) accepted traditional Chinese medicine, and 2 (4.2%) received treatment of human umbilical-cord mesenchymal stem cells. On March 2, 2020, 48 patients with COVID-19 were all cured and discharged. Based on our results, patients with COVID-19 often have multiple organ dysfunction or damage. The incidences of ALT elevation in males, and AST, CK, and blood glucose elevations in severe patients are remarkably higher.

β₂-microglobulin (B2M), the light chain of major histocompatibility complex class I (MHC I) molecules, has been found to impair hippocampal neurogenesis. Based on the crucial role of hippocampal neurogenesis disturbance in the process of depression and anxiety, the aim of the present study is to investigate whether B2M leads to depressive- and anxiety-like behaviors. We found that 6 days after intracerebroventricular injection with B2M (0.3 μg), the immobility times of rats in the tail suspension test and the forced swimming test were increased, the swimming and climbing time in the forced swimming test was decreased, and the latency to feed in the novelty-suppressed feeding test was increased, indicating that B2M induces depressive-like behaviors. In addition, in the elevated plus maze test, B2M-treated rats displayed obvious decline in the number of entries into and the proportion of time spent in the open arm, while the number of total arm entries was no change, which indicated that B2M induces anxiety-like behaviors. Our present findings suggest that target B2M might represent a novel approach for treatment of depression and anxiety.

Coronavirus disease 2019 (COVID-19) combined with liver injury has become a very prominent clinical problem. Due to the lack of a clear definition of liver injury in patients with COVID-19, the different selection of evaluation parameters and statistical time points, there are the conflicting conclusions about the incidence rate in different studies. The mechanism of COVID-19 combined with liver injury is complicated, including the direct injury of liver cells caused by severe acute respiratory syndrome coronavirus 2 replication and liver injury caused by cytokines, ischemia and hypoxia, and drugs. In addition, underlying diseases, especially chronic liver disease, can aggravate COVID-19 liver injury. In the treatment of COVID-19 combined with liver injury, the primary and basic treatment is to treat the etiology and pathogenesis, followed by support, liver protection, and symptomatic treatment according to the clinical classification and severity of liver injury. This article evaluates the incidence, pathogenesis and prevention and treatment of COVID-19 combined with liver injury, and aims to provide countermeasures for the prevention and treatment of COVID-19 combined with liver injury.

Introduction: Non-alcoholic fatty liver disease (NAFLD) has gradually become the primary cause of fatty liver disease. Betel nuts have been used to treat gastrointestinal diseases.Methods: In the present study, we analyzed the pathology, serology, gut flora, and metabolites in a rat model of NAFLD, with and without betel nut alkaloid treatment, using an integrated approach involving pathology, serological testing, 16S rRNA gene sequencing, and ultra-performance liquid chromatography-mass spectrometry metabolomics.Results: Two rats were used for model validation. Thirty SD rats were included and divided into the normal group (C group), NAFLD model group (M group), low-dose group, medium-dose group (T group), and high-dose group with intraperitoneal injection of arecoline. The expression of blood lipids was significantly downregulated at all three arecoline concentrations (p < 0.05). Alpha-diversity analysis of the intestinal flora showed significant differences among the three groups, with a significant reduction in population diversity in the M group and a recovery of population diversity after arecoline treatment. At the phylum level, the relative abundance of Firmicutes was significantly higher in the T group and Proteobacteria in the M group. The KEGG metabolic pathways included polyketide sugar unit biosynthesis and hypertrophic cardiomyopathy. Thirty-three significantly different metabolites were identified among the groups. Significantly different metabolites between groups T and M included indolepyruvate, 2-deoxystreptamine, sakuranetin, glycyl-leucine, and riboflavin. The KEGG metabolic pathway suggested a potential role for arachidonic acid metabolism, serotonergic synapses, neuroactive ligand-receptor interactions, tyrosine metabolism, and regiomelanin. Vitamin digestion and absorption, as well as regulation of lipolysis in adipocytes, were the main metabolic pathways that distinguished the T vs. M groups. PGE2 is involved in several metabolic pathways. Correlation analysis showed that 29 bacterial species were significantly associated with PGE2 levels in the M and T groups. Vagococcus, Lawsonia, Christensenella, unidentified Erysipelotrichaceae, unidentified Coriobacteriaceae, and five other bacterial groups are unique in the PGE2 metabolic pathway regulated by arecoline.Discussion: Arecoline has lipid-lowering effects and may exert therapeutic effects in NAFLD through intestinal metabolites and intestinal flora, as well as through the Butyricicoccus/Christensenella/Coriobacteriaceae-COX2/PGE2 pathway. Thus, arecoline may represent a potential drug or target for NAFLD treatment.