BACKGROUND: Many factors are associated with the development and progression of liver fat and fibrosis; however, genetics and the gut microbiota are representative factors. Moreover, recent studies have indicated a link between host genes and the gut microbiota. This study investigated the effect of patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 (C > G), which has been reported to be most involved in the onset and progression of fatty liver, on liver fat and fibrosis in a cohort study related to gut microbiota in a non-fatty liver population. METHODS: This cohort study included 214 participants from the health check-up project in 2018 and 2022 who had non-fatty liver with controlled attenuation parameter (CAP) values <248 dB/m by FibroScan and were non-drinkers. Changes in CAP values and liver stiffness measurement (LSM), liver-related items, and gut microbiota from 2018 to 2022 were investigated separately for PNPLA3 rs738409 CC, CG, and GG genotypes. RESULTS: Baseline values showed no difference among the PNPLA3 rs738409 genotypes for any of the measurement items. From 2018 to 2022, the PNPLA3 rs738409 CG and GG genotype groups showed a significant increase in CAP and body mass index; no significant change was observed in the CC genotype group. LSM increased in all genotypes, but the rate of increase was highest in the GG genotype, followed by the CG and CC genotypes. Fasting blood glucose levels increased in all genotypes; however, HOMA-IR (Homeostasis Model Assessment of Insulin Resistance) increased significantly only in the GG genotype. HDL (high-density lipoprotein) and LDL (low-density lipoprotein) cholesterol levels significantly increased in all genotypes, whereas triglycerides did not show any significant changes in any genotype. As for the gut microbiota, the relative abundance of Feacalibacterium in the PNPLA3 rs738409 GG genotype decreased by 2% over 4 years, more than 2-fold compared to CC and GG genotypes. Blautia increased significantly in the CC group. CONCLUSION The results suggest that PNPLA3 G-allele carriers of non-fatty liver develop liver fat and fibrosis due to not only obesity and insulin resistance but also the deterioration of gut microbiota, which may require a relatively long course of time, even years.
Humans ; Gastrointestinal Microbiome ; Male ; Female ; Membrane Proteins/metabolism* ; Lipase/genetics* ; Middle Aged ; Liver Cirrhosis/epidemiology* ; Cohort Studies ; Genotype ; Adult ; Non-alcoholic Fatty Liver Disease/microbiology* ; Polymorphism, Single Nucleotide ; Acyltransferases ; Phospholipases A2, Calcium-Independent

The pathogenesis and pathophysiology of Acanthamoeba infections remain incompletely understood. Phos-pholipases are known to cleave phospholipids, suggesting their possible involvement in the host cell plasma membrane disruption leading to host cell penetration and lysis. The aims of the present study were to determine phospholipase activities in Acanthamoeba and to determine their roles in the pathogenesis of Acanthamoeba. Using an encephalitis isolate (T1 genotype), a keratitis isolate (T4 genotype), and an environmental isolate (T7 genotype), we demonstrated that Acanthamoeba exhibited phospholipase A2 (PLA2) and phospholipase D (PLD) activities in a spectrophotometry-based assay. Interestingly, the encephalitis isolates of Acanthamoeba exhibited higher phospholipase activities as compared with the keratitis isolates, but the environmental isolates exhibited the highest phospholipase activities. Moreover, Acanthamoeba isolates exhibited higher PLD activities compared with the PLA2. Acanthamoeba exhibited optimal phospholipase activities at 37degrees C and at neutral pH indicating their physiological relevance. The functional role of phospholipases was determined by in vitro assays using human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. We observed that a PLD-specific inhibitor, i.e., compound 48/80, partially inhibited Acanthamoeba encephalitis isolate cytotoxicity of the host cells, while PLA2-specific inhibitor, i.e., cytidine 5'-diphosphocholine, had no effect on parasite-mediated HBMEC cytotoxicity. Overall, the T7 exhibited higher phospholipase activities as compared to the T4. In contract, the T7 exhibited minimal binding to, or cytotoxicity of, HBMEC.
Acanthamoeba/*enzymology/genetics/*isolation & purification/physiology ; Cell Adhesion ; Cells, Cultured ; Endothelial Cells/parasitology ; Humans ; Keratitis/*parasitology ; Phospholipase D/genetics/*metabolism ; Phospholipases A2/genetics/*metabolism ; Protozoan Proteins/genetics/*metabolism ; Soil/*parasitology

AIMTo explore the changes of rat platelet phospholipase A2 (PLA2) mRNA content in bacteria infected rat and study the cDNA and amino acid sequences of the PLA2 structure to lay a good foundation for the development of new antibiotics.

METHODSThe PLA2 mRNA level in blood was determined by RT-PCR. The DNA sequence was cloned and analyzed.

RESULTSAfter injection of bacteria in rats, the mRNA level of PLA2 in blood increased markedly. The cDNA and amino acid sequence were highly homologous to other PLA2 cDNA from different tissues of the rat.

CONCLUSIONPlatelet PLA2 in blood responded quickly to bacteria infection in gene level. Therefore, the PLA2 protein was produced increasingly which was shown to control the infection with bacteria. Although there are little difference between PLA2 cDNA cloned from blood and other sources in DNA and amino acid sequences, the catalytic site for enzymatic activity and basic structure are identical.

Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; metabolism ; Male ; Molecular Sequence Data ; Phospholipases A ; blood ; genetics ; metabolism ; Phospholipases A2 ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Staphylococcal Infections ; blood ; Staphylococcus aureus