Therapeutic advances in non-alcoholic fatty liver disease:A microbiota-centered view

Non-alcoholic fatty liver disease(NAFLD)is a highly prevalent metabolic disorder with steadily increasing incidence rates worldwide,especially in the West.There are no drugs available at present to treat NAFLD,and the primary therapeutic options include weight loss and the combination of healthy diet and exercise.Therefore,novel interventions are required that can target the underlying risk factors.Gut microbiota is an“invisible organ”of the human body and vital for normal metabolism and immuno-modulation.The number and diversity of microbes differ across the gastrointestinal tract from the mouth to the anus,and is most abundant in the intestine.Since dysregulated gut microbiota is an underlying pathological factor of NAFLD,it is a viable therapeutic target that can be modulated by antibiotics,probiotics,prebiotics,synbiotics,fecal microbiota transplantation,and microbial metabolites.In this review,we summarize the most recent advances in gut microbiota-targeted therapies against NAFLD in clinical and experimental studies,and critically evaluate novel targets and strategies for treating NAFLD.

Characterizing the composition of intestinal microflora by 16S rRNA gene sequencing

BACKGROUND This study determined the composition and diversity of intestinal microflora in patients with colorectal adenoma(CRA),which may provide precedence for investigating the role of intestinal microflora in the pathogenesis of colorectal tumors,the composition of intestinal microflora closely related to CRA,and further validating the possibility of intestinal flora as a biomarker of CRA.AIM To study the relationship between intestinal microflora and CRA.METHODS This is a prospective control case study from October 2014 to June 2015 involving healthy volunteers and patients with advanced CRA.High-throughput sequencing and bioinformatics analysis were used to investigate the composition and diversity of intestinal microflora in 36 healthy subjects and 49 patients with advanced CRA.Endpoints measured were operational taxonomic units of intestinal flora,as well as their abundance and diversity(αandβtypes).RESULTS In this study,the age,gender,body mass index,as well as location between controls and patients had no significant differences.The mucosa-associated gut microbiota diversity and bacterial distribution in healthy controls and colorectal adenomas were similar.The operational taxonomic unit,abundance,andαandβdiversity were all reduced in patients with CRA compared to controls.At the phylum level,the composition of intestinal microflora was comparable between patients and controls,but the abundance of Proteobacteria was increased,and Firmicutes and Bacteroides were significantly decreased(P<0.05).The increase in Halomonadaceae and Shewanella algae,and reduction in Coprococcus and Bacteroides ovatus,could serve as biomarkers of CRA.High-throughput sequencing confirms the special characteristics and diversity of intestinal microflora in healthy controls and patients with CRA.CONCLUSION The diversity of intestinal microflora was decreased in patients with CRA.An increase in Halomonadaceae and Shewanella algae are markers of CRA.

The prognostic value of serum C-reactive protein-bound serum amyloid A in early-stage lung cancer

Background:Elevated levels of serum C-reactive protein(CRP) have been reported to have prognostic significance in lung cancer patients.This study aimed to further identify CRP-bound components as prognostic markers for lung cancer and validate their prognostic value.Methods:CRP-bound components obtained from the serum samples from lung cancer patients or healthy controls were analyzed by differential proteomics analysis.CRP-bound serum amyloid A(CRP-SAA) was evaluated by coimmunoprecipitation(IP).Serum samples from two independent cohorts with lung cancer(retrospective cohort,242patients;prospective cohort,222 patients) and healthy controls(159 subjects) were used to evaluate the prognostic value of CRP-SAA by enzyme-linked immunosorbent assay.Results:CRP-SAA was identified specifically in serum samples from lung cancer patients by proteomic analysis.CRP binding to SAA was confirmed by co-IP in serum samples from lung cancer patients and cell culture media.The level of CRP-SAA was significantly higher in patients than in healthy controls(0.37 ± 0.58 vs.0.03 ± 0.04,P < 0.001).Elevated CRP-SAA levels were significantly associated with severe clinical features of lung cancer.The elevation of CRPSAA was associated with lower survival rates for both the retrospective(hazard ration[HR]= 2.181,95%confidence interval[CI]= 1.641-2.897,P < 0.001) and the prospective cohorts(HR = 2.744,95%CI = 1.810-4.161,P < 0.001).Multivariate Cox analysis showed that CRP-SAA was an independent prognostic marker for lung cancer.Remarkably,in stages l-ll patients,only CRP-SAA,not total SAA or CRP,showed significant association with overall survival in two cohorts.Moreover,univariate and multivariate Cox analyses also showed that only CRP-SAA could be used as an independent prognostic marker for early-stage lung cancer patients.Conclusion:CRP-SAA could be a better prognostic marker for lung cancer than total SAA or CRP,especially in earlystage patients.

Exosomes derived from 3D-cultured MSCs improve therapeutic effects in periodontitis and experimental colitis and restore the Th17 cell/Treg balance in inflamed periodontium

Although mesenchymal stem cell-derived exosomes(MSC-exos)have been shown to have therapeutic effects in experimental periodontitis,their drawbacks,such as low yield and limited efficacy,have hampered their clinical application.These drawbacks can be largely reduced by replacing the traditional 2D culture system with a 3D system.However,the potential function of MSC-exos produced by 3D culture(3D-exos)in periodontitis remains elusive.This study showed that compared with MSC-exos generated via 2D culture(2D-exos),3D-exos showed enhanced anti-inflammatory effects in a ligature-induced model of periodontitis by restoring the reactive T helper 17(Th17)cell/Treg balance in inflamed periodontal tissues.Mechanistically,3D-exos exhibited greater enrichment of miR-1246,which can suppress the expression of Nfat5,a key factor that mediates Th17 cell polarization in a sequence-dependent manner.Furthermore,we found that recovery of the Th17 cell/Treg balance in the inflamed periodontium by the local injection of 3D-exos attenuated experimental colitis.Our study not only showed that by restoring the Th17 cell/Treg balance through the miR-1246/Nfat5 axis,the 3D culture system improved the function of MSC-exos in the treatment of periodontitis,but also it provided a basis for treating inflammatory bowel disease(IBD)by restoring immune responses in the inflamed periodontium.

Iron metabolism in non-alcoholic fatty liver disease: A promising therapeutic target

Non-alcoholic fatty liver disease(NAFLD)has become the most common cause of chronic liver disease worldwide,and is closely associated with the increased risk of the prevalence of obesity and diabetes.NAFLD begins with the presence of>5%excessive lipid accumulation in the liver,and potentially de-velops into non-alcoholic steatohepatitis,fibrosis,cirrhosis and hepatocellular carcinoma.Therefore,insight into the pathogenesis of NAFLD is of key importance to its effective treatment.Iron is an essential element in the life of all mammalian organisms.However,the free iron deposition is positively associated with histological severity in NAFLD patients due to the production of reactive oxygen species via the Fenton reaction.Recently,several iron metabolism-targeted therapies,such as phlebotomy,iron chela-tors,nanotherapeutics.and ferroptosis,have shown their potential as a therapeutic option in the treatment of NAFLD and as a clinical strategy to intervene in the progression of NAFLD.Herein,we review the recent overall evidence on iron metabolism and provide the mechanism of hepatic iron overload-induced liver pathologies and the recent advances in iron metabolism-targeted therapeutics in the treatment of NAFLD.

Nutrient mTORC1 signaling contributes to hepatic lipid metabolism in the pathogenesis of non-alcoholic fatty liver disease

Energy metabolism is maintained by the complex homeostatic system in multiple cells and organs involving“nutrient signaling”or“nutrient sensor”.Overnutrient-induced chronic metabolic diseases,as the hallmarks of the 21st century’s public health,are growing threat worldwide.In the past two decades,non-alcoholic fatty liver disease(NAFLD)has emerged as the most prevalent form of chronic liver dis-ease,affecting globally,and increases the risk of incident obesity,type 2 diabetes,and insulin resistance.NAFLD begins with the excessive triglyceride accumulation in hepatocytes,and develops to hepatocel-lular steatosis with inflammation(non-alcoholic steatohepatitis,NASH),fibrosis,cirrhosis,and ultimately hepatocellular carcinoma(HCC).The liver is the central mediator of lipid metabolism by regulation of fatty acid(FA)uptake,manufacture,store,export,and oxidation in response to physiological fluctuations of nutrient.Sterol regulatory element-binding protein c(SREBP-1c)-mediated de novo lipogenesis(DNL)is an important nutritional regulator in biosynthesis of FAs and triglyceride in the liver.Mechanistic target of rapamycin complex 1(mTORC1),as a central hub of nutrient signaling,controls cellular metabolism and growth mainly via increasing anabolic processes and inhibiting catabolic processes in response to physiological fluctuations of nutrient.mTORC1 activation contributes to regulation of DNL by increasing SREBP1 transcription,which contributes to NAFLD pathogenesis and accelerates NAFLD-related HCC development.In this review,we provide the comprehensive understanding of the molec-ular mechanism of SREBPs and autophagy to control hepatic lipid homeostasis under nutrient availability in physiological and pathophysiological states,and highlight how nutrient mTORC1 signaling coordi-nately to integrate the lipid metabolic regulation and therapeutic targets in NAFLD and HCC.

Risk factors and clinical outcomes of incomplete endoscopic resection of small rectal neuroendocrine tumors in southern China:a 9-year data analysis

Background:The histologically complete resection(CR)rate of small rectal neuroendocrine tumors(RNETs)is unsatisfactory at the first endoscopy.Risk factors and clinical outcomes associated with incomplete resection(IR)have not been explicitly elucidated.This study aims to explore the relevant factors of IR.Methods:This retrospective study reviewed patients with small RNETs(10mm)in eight centers from January 2013 to December 2021.Clinicopathological characteristics and clinical outcomes were compared between the CR and IR groups,and the polypectomy and advanced treatment groups.Results:Of the 326 patients included,83(25.5%)were diagnosed with IR.Polypectomy(odds ratio[OR]=16.86),a central depression(OR=7.50),and treatment in the early period(OR=2.60)were closely associated with IR.Further analysis revealed that an atypical hyperemic appearance(OR=7.49)and treatment in the early period(OR=2.54)were significantly associated with the inappropriate use of polypectomy(both P<0.05).In addition,a total of 265(81.3%)were followed up with a median follow-up period of 30.9 months.No death,metastasis,or recurrence was found during the follow-up period.Conclusions:Polypectomy,a central depression,and treatment in the early period were risk factors for IR.Further,an atypical hyperemic appearance and treatment in the early period were significant predisposing factors for inappropriate choice of polypectomy.For histologically incompletely resected small RNETs,follow-up may be a safe and feasible alternative to rigorous salvage therapy.

Tumor-targeted delivery of siRNA to silence Sox2 gene expression enhances therapeutic response in hepatocellular carcinoma

RNA interference(RNAi)is one of the most promising methods for the treatment of malignant tumors.However,developing an efficient biocompatible delivery vector for small interfering RNA(siRNA)remains a challenging issue.This study aimed to prepare a non-viral tumor-targeted carrier,named RGDfC-modified functionalized selenium nanoparticles(RGDfC-SeNPs).RGDfC-SeNPs were used to selectively deliver siSox2 to HepG2 liver cancer cells and tissues for the treatment of hepatocellular carcinoma(HCC).In the current study,RGDfC-SeNPs were successfully synthesized and characterized.It was shown that RGDfC-SeNPs could effectively load siSox2 to prepare an antitumor prodrug RGDfC-Se@siSox2.RGDfC-Se@siSox2 exhibited selective uptake in HepG2 liver cancer cells and LO2 normal liver cells,indicating RGDfC-SeNPs could effectively deliver siSox2 to HepG2 liver cancer cells.RGDfC-Se@siSox2 entered HepG2 cells via clathrin-mediated endocytosis by firstly encircling the cytoplasm and then releasing siSox2 in the lysosomes.RGDfC-Se@siSox2 could effectively silence Sox2 and inhibit the proliferation,migration and invasion of HepG2 cells.RGDfC-Se@siSox2 induced HepG2 cells apoptosis most likely via overproduction of reactive oxygen species and disruption of the mitochondrial membrane potentials.Most importantly,RGDfC-Se@siSox2 significantly inhibited the tumor growth in HepG2 tumor-bearing mice without obvious toxic side effects.These studies indicated that RGDfC-SeNPs may be an ideal gene carrier for delivering siSox2 to HepG2 cells and that RGDfC-Se@siSox2 may be a novel and highly specific gene-targeted prodrug therapy for HCC.

Liver-resident NK cells suppress autoimmune cholangitis and limit the proliferation of CD4^(+) T cells

Liver-resident NK cells are distinct from conventional NK cells and play an important role in the maintenance of liver homeostasis.How liver-resident NK cells participate in autoimmune cholangitis remains unclear.Here,we extensively investigated the impact of NK cells in the pathogenesis of autoimmune cholangitis utilizing the well-established dnTGFβRII cholangitis model,NK cell-deficient(Nfil3−/−)mice,adoptive transfer and in vivo antibody-mediated NK cell depletion.Our data demonstrated that disease progression was associated with a significantly reduced frequency of hepatic NK cells.Depletion of NK cells resulted in exacerbated autoimmune cholangitis in dnTGFβRII mice.We further confirmed that the DX5−CD11c^(hi) liver-resident NK cell subset colocalized with CD4^(+) T cells and inhibited CD4^(+) T cell proliferation.Gene expression microarray analysis demonstrated that liver-resident NK cells had a distinct gene expression pattern consisting of the increased expression of genes involved in negative regulatory functions in the context of the inflammatory microenvironment.