Despite therapy with potent antiviral agents, chronic hepatitis B (CHB) patients remain at high risk of hepatocellular carcinoma (HCC). While metabolites have been rediscovered as active drivers of biological processes including carcinogenesis, the specific metabolites modulating HCC risk in CHB patients are largely unknown. Here, we demonstrate that baseline plasma from CHB patients who later developed HCC during follow-up exhibits growth-promoting properties in a case-control design nested within a large-scale, prospective cohort. Metabolomics analysis reveals a reduction in long-chain acylcarnitines (LCACs) in the baseline plasma of patients with HCC development. LCACs preferentially inhibit the proliferation of HCC cells in vitro at a physiological concentration and prevent the occurrence of HCC in vivo without hepatorenal toxicity. Uptake and metabolism of circulating LCACs increase the intracellular level of acetyl coenzyme A, which upregulates histone H3 Lys14 acetylation at the promoter region of KLF6 gene and thereby activates KLF6/p21 pathway. Indeed, blocking LCAC metabolism attenuates the difference in KLF6/p21 expression induced by baseline plasma of HCC/non-HCC patients. The deficiency of circulating LCACs represents a driver of HCC in CHB patients with viral control. These insights provide a promising direction for developing therapeutic strategies to reduce HCC risk further in the antiviral era.

A ketogenic diet(KD)refers to an eating pattern designed to achieve a low-calorie content,minimum carbohydrate intake,high-fat consumption,and standard protein levels.A ketogenic diet is used in clinical practice to treat conditions including heart disease,diabetes,obesity,autism,glioblastoma,and other cancers.Although a ketogenic diet has not been recommended for any neurological disorders except epilepsy,extensive recent research suggests that such a diet may have a neuroprotective effect and may thus represent a new dietary therapy for the treatment of Parkinson's disease(PD).In this review,we discuss in detail the mechanisms responsible for the neuroprotective effects of a ketogenic diet in Parkinson's disease,with the aim of providing references for future clinical and experimental studies.

Cyclic GMP-AMP synthase(cGAS)is a congenital immune sensor that can recognize cytoplasm abnormal dsDNA.By catalyzing the second messenger cyclic GMP-AMP(cGAMP)formation,it activates stimulator of interferon genes(STING),releases type Ⅰ interferon and inflammatory cytokines,activates the host immune response,and participates in cerebral ischemia reperfusion injury(CIRI)cascade reaction.This article reviews the research progress of the mechanism of cGAS-STING signaling pathway participation in CIRI,hoping to provide ideas for its treatment.

A ketogenic diet(KD)refers to an eating pattern designed to achieve a low-calorie content,minimum carbohydrate intake,high-fat consumption,and standard protein levels.A ketogenic diet is used in clinical practice to treat conditions including heart disease,diabetes,obesity,autism,glioblastoma,and other cancers.Although a ketogenic diet has not been recommended for any neurological disorders except epilepsy,extensive recent research suggests that such a diet may have a neuroprotective effect and may thus represent a new dietary therapy for the treatment of Parkinson's disease(PD).In this review,we discuss in detail the mechanisms responsible for the neuroprotective effects of a ketogenic diet in Parkinson's disease,with the aim of providing references for future clinical and experimental studies.

Cyclic GMP-AMP synthase(cGAS)is a congenital immune sensor that can recognize cytoplasm abnormal dsDNA.By catalyzing the second messenger cyclic GMP-AMP(cGAMP)formation,it activates stimulator of interferon genes(STING),releases type Ⅰ interferon and inflammatory cytokines,activates the host immune response,and participates in cerebral ischemia reperfusion injury(CIRI)cascade reaction.This article reviews the research progress of the mechanism of cGAS-STING signaling pathway participation in CIRI,hoping to provide ideas for its treatment.

Parkinson's disease is a neurodegenerative disease associated with abnormal copper metabolism in the brain,which leads to misfolding and aggregation of α-synuclein-copper complexes,which is an important pathological sign of Parkinson's disease.Copper metabolism,i.e.,cellular metabolic processes involving copper ions,is closely related to the pathogenesis of α-synuclein aggregation,dopamine metabolism,mitochondrial dysfunction,oxidative stress,and ferroptosis in Parkinson's disease.In this review,we summarize the molecular metabolic mechanism of copper toxicity by studying the pathological role of copper metabolism in Parkinson's disease,to support our further understanding of the mechanism of action and drug development.

Aim To investigate the dynamic changes of neuronal cells at different time points following acute cerebral ischemia-reperfusion injury by establishing a model of brain ischemia-reperfusion injury.Methods Thirty male Sprague-Dawley(SD)rats were ran-domly divided into six groups:sham group and cere-bral ischemia-reperfusion injury(IR)groups at differ-ent time points.Focal cerebral ischemia-reperfusion injury model was established using the middle cerebral artery occlusion(MCAO)technique.The Longa sco-ring method was used to assess neurobehavioral scores in rats.After successful model preparation,routine paraffin sections were made,and TUNEL staining and immunohistochemistry staining with NeuN antibody were performed to observe cell apoptosis and neuronal cell survival,respectively.Immunohistochemistry stai-ning was also performed to investigate the changes in glial fibrillary acidic protein(GFAP)as a marker for astrocytes,ionized calcium-binding adapter molecule 1(IBA-1)as a marker for microglia,and CD31 as a marker for endothelial cells at different time points.Results No significant changes were observed in neu-ronal cells of the sham group at different time points.In the cerebral ischemia-reperfusion injury groups,cell apoptosis was activated at IR3h and increased in quan-tity with morphological damage as time progressed.Ne-uN+neurons showed signs of ischemic injury after IR3h,with abnormal cell morphology.From 12 h,Ne-uN+neurons decreased in a time-dependent manner and reached their peak severity at 24 h.GFAP+astro-cytes decreased significantly after IR3h,while poorly labeled GFAP+astrocytes increased at IR 6 h and al-most disappeared in the infarcted area at 24 h and 48 h.The number of IBA-1+microglia-positive cells de-creased at IR3h,and their volume increased at IR6h.Microglial cell death was observed in the infarcted area at IR12h.CD31+endothelial cells around the infarc-ted cortex and striatum increased significantly after IR3h and persisted until 48 h.Conclusions After cerebral ischemia-reperfusion injury,the number of ap-optotic cells increases with the prolongation of time,and NeuN+neurons exhibit the most severe damage at 24 h.GFAP+astrocytes and microglial cells gradually die over time.The number of CD31+endothelial cells increases significantly around the infarcted cortex and striatum after 3 h of reperfusion and persists until 48 h.

Parkinson's disease(PD)is a neurodegenerative disease that primarily affects middle-aged and older adults.Its main clinical manifestations include resting tremor,bradykinesia,myotonia,and balance disorders.Berberine is a naturally occurring isoquinoline alkaloid.Several studies over the previous decade have reported that berberine plays a crucial role in the pathophysiologic processes of a range of diseases,including playing an active role in the development of PD via different pathways.This paper systematically reviews the mechanism of action of berberine in the prevention and treatment of PD and the current status of research,to provide references for the future clinical application of berberine for the treatment of PD.

Parkinson's disease(PD)is a neurodegenerative disease that primarily affects middle-aged and older adults.Its main clinical manifestations include resting tremor,bradykinesia,myotonia,and balance disorders.Berberine is a naturally occurring isoquinoline alkaloid.Several studies over the previous decade have reported that berberine plays a crucial role in the pathophysiologic processes of a range of diseases,including playing an active role in the development of PD via different pathways.This paper systematically reviews the mechanism of action of berberine in the prevention and treatment of PD and the current status of research,to provide references for the future clinical application of berberine for the treatment of PD.

Cinnamomum camphora is an important economic tree species in China. According to the type and content of main components in the volatile oil of leaf, C. camphora were divided into five chemotypes, including borneol-type, camphor-type, linalool-type, cineole-type, and nerolidol-type. Terpene synthase(TPS) is the key enzyme for the formation of these compounds. Although several key enzyme genes have been identified, the biosynthetic pathway of(+)-borneol, which has the most economic value, has not been reported. In this study, nine terpenoid synthase genes CcTPS1-CcTPS9 were cloned through transcriptome analysis of four chemical-type leaves. After the recombinant protein was induced by Escherichia coli, geranyl pyrophosphate(GPP) and farnesyl pyrophosphate(FPP) were used as substrates for enzymatic reaction, respectively. Both CcTPS1 and CcTPS9 could catalyze GPP to produce bornyl pyrophosphate, which could be hydrolyzed by phosphohydrolase to obtain(+)-borneol, and the product of(+)-borneol accounted for 0.4% and 89.3%, respectively. Both CcTPS3 and CcTPS6 could catalyze GPP to generate a single product linalool, and CcTPS6 could also react with FPP to generate nerolidol. CcTPS8 reacted with GPP to produce 1,8-cineol(30.71%). Nine terpene synthases produced 9 monoterpene and 6 sesquiterpenes. The study has identified the key enzyme genes responsible for borneol biosynthesis in C. camphora for the first time, laying a foundation for further elucidating the molecular mechanism of chemical type formation and cultivating new varieties of borneol with high yield by using bioengineering technology.
Cinnamomum camphora/enzymology* ; Alkyl and Aryl Transferases/chemistry*