Inverse Association of Fruit and Vegetable Consumption with Nonalcoholic Fatty Liver Disease in Chinese Patients with Type 2 Diabetes Mellitus.

We aimed to investigate the association of fruit and vegetable consumption with nonalcoholic fatty liver disease (NAFLD) in Chinese patients with type 2 diabetes mellitus (T2DM). This cross-sectional study included 2667 Chinese patients with T2DM aged 18 to 76 years from March 2017 to October 2021. Dietary intake was assessed using a food frequency questionnaire, and prevalent NAFLD was diagnosed with abdominal ultrasonography. High fruit−vegetable consumption was determined using ≥500 g/day consumption of both fruit and vegetable, and both fruit and vegetable consumption were divided into three categories of <200 g/day (low), 200−400 g/day (median) and >400 g (high). The primary outcome measurement was multivariate-adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for the prevalence of NAFLD in relation to the highest fruit and (or) vegetable intake compared with the lowest. Secondary analyses were conducted to assess the effects of either fruit or vegetable intake on the fatty liver index (FLI) using multivariable linear regressions. There were 1694 men and 973 women in this study, and 1445 (54.06%) participants had prevalent NAFLD. Patients with high fruit−vegetable intake had a lower prevalence of NAFLD than those with low fruit−vegetable intake (52.04% vs. 56.48%), but this difference was not statistically significant (p = 0.065). Vegetable intake had a significantly inverse association with NAFLD (OR: 0.68, 95% CI: 0.52−0.90), but this association was not pronounced with fruit intake (OR: 1.23, 95% CI: 0.89−1.69) or fruit−vegetable intake (OR: 0.90, 95% CI: 0.73−1.10). Additional analyses showed that an increase in vegetable intake was linearly associated with a significant reduction in FLI (ß: −1.028, 95% CI: −1.836, −0.219). In conclusion, higher vegetable consumption was associated with lower odds of NAFLD in Chinese patients with T2DM, which suggested that increased vegetable intake might protect patients with diabetes against NAFLD.

Elevated levels of fructosamine are independently associated with SARS-CoV-2 reinfection: A 12-mo follow-up study.

BACKGROUND: The association between blood levels of fructosamine (FMN) and recurrent coronavirus disease 2019 (COVID-19) is currently unclear. AIM: To investigate a prospective relationship between blood levels of FMN and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection. METHODS: A total of 146 Chinese hospitalized patients infected with SARS-CoV-2 were consecutively collectively recruited and followed from January 2020 to May 2021. Diagnosis of COVID-19 and SARS-CoV-2 reinfection was based on the diagnostic criteria and treatment protocol in China. The levels of FMN were determined in blood and divided into tertiles based on their distribution in the cohort of COVID-19 patients. Multivariate-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated for SARS-CoV-2 reinfection across the tertiles of FMN levels. A Cox regression model was used to generate the HR for SARS-CoV-2 reinfection in the participants in the top tertile of FMN levels compared with those at the bottom. Disease-free survival was used as the time variable, and relapse was used as the state variable, adjusted for age, gender, influencing factors such as diabetes mellitus, hypertension, and corticosteroid therapy, and clinical indexes such as acute liver failure, acute kidney failure, white blood cell (WBC) count, C-reactive protein, prognostic nutritional index (PNI), and blood lipids. Kaplan-Meier analysis with log-rank tests was used to compare the survival rate between patients with elevated FMN levels (FMN > 1.93 mmol/L, the top tertile) and those with nonelevated levels. RESULTS: Clinical data for the 146 patients with confirmed COVID-19 [age 49 (39-55) years; 49% males] were analyzed. Eleven patients had SARS-CoV-2 reinfection. The SARS-CoV-2 reinfection rate in patients with elevated FMN levels was significantly higher than that in patients with nonelevated FMN (17% vs 3%; P = 0.008) at the end of the 12-mo follow-up. After adjustments for gender, age, diabetes mellitus, hypertension, corticosteroid therapy, WBC count, PNI, indexes of liver and renal function, and blood lipids, patients with nonelevated FMN levels had a lower risk of SARS-CoV-2 reinfection than those with elevated FMN levels (HR = 6.249, 95%CI: 1.377-28.351; P = 0.018). Kaplan-Meier analysis showed that the cumulative survival rate of patients infected with SARS-CoV-2 was higher in patients with nonelevated FMN levels than in those with elevated FMN levels (97% vs 83%; log rank P = 0.002). CONCLUSION: Elevated levels of FMN are independently associated with SARS-CoV-2 reinfection, which highlights that patients with elevated FMN should be cautiously monitored after hospital discharge.

Neck-to-height ratio is positively associated with diabetic kidney disease in Chinese patients with type 2 diabetes mellitus.

Introduction: The aim of this study was to investigate the associations of neck circumference (NC) and neck-to-height (NHR) with diabetic kidney disease (DKD) in Chinese patients with type 2 diabetes mellitus (T2DM). Materials and methods: A total of 2,615 patients with prevalent T2DM were enrolled. NHR was calculated through NC (cm) divided by height (cm), and prevalent DKD was defined as the urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g or the estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m2 in the absence of other primary kidney diseases. Results: The levels of NC and NHR were higher in DKD patients compared with non-DKD patients (38.22 vs. 37.71, P = 0.003; 0.232 vs. 0.227, P < 0.001, respectively). After full adjustments, individuals at the highest tertile of NHR had higher odds of DKD than those at the lowest tertile (multivariate-adjusted OR = 1.63, 95% CI: 1.22, 2.18), but this association was not pronounced with NC (multivariate-adjusted OR = 1.24, 95% CI: 0.87, 1.76). Individuals at the highest tertile of NHR had lower eGFR (ß = -4.64, 95% CI: -6.55, -2.74) and higher UACR levels (ß = 0.27, 95% CI: 0.10, 0.45) than those at the lowest tertile. The adverse association between NHR and prevalent DKD remained statistically significant among most of the subgroups analyzed and no interaction effects were observed. Conclusion: The increase in NHR was adversely and independently associated with DKD in this Chinese T2DM population.

Expansion and differentiation of human hepatocyte-derived liver progenitor-like cells and their use for the study of hepatotropic pathogens.

The study of pathophysiological mechanisms in human liver disease has been constrained by the inability to expand primary hepatocytes in vitro while maintaining proliferative capacity and metabolic function. We and others have previously shown that mouse mature hepatocytes can be converted to liver progenitor-like cells in vitro with defined chemical factors. Here we describe a protocol achieving efficient conversion of human primary hepatocytes into liver progenitor-like cells (HepLPCs) through delivery of developmentally relevant cues, including NAD + -dependent deacetylase SIRT1 signaling. These HepLPCs could be expanded significantly during in vitro passage. The expanded cells can readily be converted back into metabolically functional hepatocytes in vitro and upon transplantation in vivo. Under three-dimensional culture conditions, differentiated cells generated from HepLPCs regained the ability to support infection or reactivation of hepatitis B virus (HBV). Our work demonstrates the utility of the conversion between hepatocyte and liver progenitor-like cells for studying HBV biology and antiviral therapies. These findings will facilitate the study of liver diseases and regenerative medicine.

The extent of liver injury determines hepatocyte fate toward senescence or cancer.

It is well known that induction of hepatocyte senescence could inhibit the development of hepatocellular carcinoma (HCC). Until now, it is still unclear how the degree of liver injury dictates hepatocyte senescence and carcinogenesis. In this study, we investigated whether the severity of injury determines cell fate decisions between hepatocyte senescence and carcinogenesis. After testing of different degrees of liver injury, we found that hepatocyte senescence is strongly induced in the setting of severe acute liver injury. Longer-term, moderate liver injury, on the contrary did not result into hepatocyte senescence, but led to a significant incidence of HCC instead. In addition, carcinogenesis was significantly reduced by the induction of severe acute injury after chronic moderate liver injury. Meanwhile, immune surveillance, especially the activations of macrophages, was activated after re-induction of senescence by severe acute liver injury. We conclude that severe acute liver injury leads to hepatocyte senescence along with activating immune surveillance and a low incidence of HCC, whereas chronic moderate injury allows hepatocytes to proliferate rather than to enter into senescence, and correlates with a high incidence of HCC. This study improves our understanding in hepatocyte cell fate decisions and suggests a potential clinical strategy to induce senescence to treat HCC.

Insulin-like growth factor 2 is a key mitogen driving liver repopulation in mice.

Hepatocyte transplantation holds great promise as an alternative to orthotopic organ transplantation in the treatment of liver diseases. However, obtaining clinically meaningful levels of liver repopulation has not been achieved because the mechanisms regulating hepatocyte proliferation in recipient livers have not yet been well characterized. In the mouse model of Hereditary Tyrosinemia Type I, the fumarylacetoacetate hydrolase-deficient (Fah-/-) mouse, we found gradually increasing expression level of insulin-like growth factor 2 (IGF2) in the hepatocytes of host livers. Similarly, high levels of IGF2 were found in the livers of patients with deficient FAH activity. Recombinant IGF2 directly promotes proliferation of primary hepatocytes in vitro. Inhibition on IGF2 expression through the interruption of PI3K/Akt and MAPK pathways significantly reduced the level of liver repopulation in Fah-/- mice. Interestingly, treatment with IGF2 before hepatocyte transplantation generally improved the amount of liver repopulation seen in various mice models of liver injury. Altogether, these findings underscore the underlying mechanisms of therapeutic liver repopulation in Fah-/- mice, and indicate that IGF2 is a potential hepatocyte mitogen for liver cell transplantation therapies.

Iron overload in hereditary tyrosinemia type 1 induces liver injury through the Sp1/Tfr2/hepcidin axis.

BACKGROUND & AIMS: Iron is an essential metal for fundamental metabolic processes, but little is known regarding the involvement of iron in other nutritional disorders. In the present study, we investigated disordered iron metabolism in a murine model of hereditary tyrosinemia type I (HT1), a disease of the tyrosine degradation pathway. METHODS: We analysed the status of iron accumulation following NTBC withdrawal from Fah(-/-) mice, a murine model for HT1. Liver histology and serum parameters were used to assess the extent of liver injury and iron deposition. To determine the physiological significance of iron accumulation, mice were subjected to a low-iron food intake to reduce the iron accumulation. Mechanistic studies were performed on tissues and cells using immunoblotting, qRT-PCR, adenovirus transfection and other assays. RESULTS: Severe iron overload was observed in the murine model of HT1 with dramatically elevated hepatic and serum iron levels. Mechanistic studies revealed that downregulation and dysfunction of Tfr2 decreased hepcidin, leading to iron overload. The Fah(-/-) hepatocytes lost the ability of transferrin-sensitive induction of hepcidin. Forced expression of Tfr2 in the murine liver reduced the iron accumulation. Moreover, transcription factor Sp1 was downregulated and identified as a new regulator of Tfr2 here. Additionally, low-iron food intake effectively reduced the iron deposits, protected the liver and prolonged the survival in these mice. CONCLUSIONS: Iron was severely overloaded in the HT1 mice via the Sp1/Tfr2/Hepcidin axis. The iron overload induced liver injury in the HT1 mice, and reduction of the iron accumulation ameliorated liver injury. LAY SUMMARY: Primary and secondary iron overload is an abnormal status affecting millions of people worldwide. Here, we reported severe iron overload in a murine model of HT1, a disease of the tyrosine degradation pathway, and elucidated the mechanistic basis and the physiological significance of iron overload in HT1. These studies are of general interest not only with respect to secondary iron-induced liver injury in HT1 but also are important to elucidate the crosstalk between the two metabolic pathways.

Reversal of hepatocyte senescence after continuous in vivo cell proliferation.

UNLABELLED: A better understanding of hepatocyte senescence could be used to treat age-dependent disease processes of the liver. Whether continuously proliferating hepatocytes could avoid or reverse senescence has not yet been fully elucidated. We confirmed that the livers of aged mice accumulated senescent and polyploid hepatocytes, which is associated with accumulation of DNA damage and activation of p53-p21 and p16(ink4a)-pRB pathways. Induction of multiple rounds continuous cell division is hard to apply in any animal model. Taking advantage of serial hepatocyte transplantation assays in the fumarylacetoacetate hydrolase-deficient (Fah(-/-)) mouse, we studied the senescence of hepatocytes that had undergone continuous cell proliferation over a long time period, up to 12 rounds of serial transplantations. We demonstrated that the continuously proliferating hepatocytes avoided senescence and always maintained a youthful state. The reactivation of telomerase in hepatocytes after serial transplantation correlated with reversal of senescence. Moreover, senescent hepatocytes harvested from aged mice became rejuvenated upon serial transplantation, with full restoration of proliferative capacity. The same findings were also true for human hepatocytes. After serial transplantation, the high initial proportion of octoploid hepatocytes decreased to match the low level of youthful liver. CONCLUSION: These findings suggest that the hepatocyte "ploidy conveyer" is regulated differently during aging and regeneration. The findings of reversal of hepatocyte senescence could enable future studies on liver aging and cell therapy.

Transcriptome profiling of the cancer and normal tissues from gastric cancer patients by deep sequencing.

Gastric cancer is the second highest cause of global cancer mortality. Genome-wide screening of transcriptome dysregulation between cancer and normal tissues would provide insights into the molecular basis of gastric cancer initiation and progression. Recently, next-generation sequencing technique has started to revolutionize biomedical studies. RNA-seq method has become a superior approach in cancer studies, which enables accurate measurement of gene expression levels. In this work, we used RNA-seq data from tumor and matched normal samples to investigate their transcriptional changes. We totally identified 114 significantly differentially expressed genes, and these genes are highly enriched in some gene ontology (GO) categories, such as "digestive system process," "regulation of body fluid levels," "secretion," "digestion," etc. This study provided the preliminary survey of the transcriptome of Chinese gastric cancer patients, which provides better insights into the complexity of regulatory changes during tumorgenesis.

Reprogramming fibroblasts into bipotential hepatic stem cells by defined factors.

Recent studies have demonstrated direct reprogramming of fibroblasts into a range of somatic cell types, but to date stem or progenitor cells have only been reprogrammed for the blood and neuronal lineages. We previously reported generation of induced hepatocyte-like (iHep) cells by transduction of Gata4, Hnf1α, and Foxa3 in p19 Arf null mouse embryonic fibroblasts (MEFs). Here, we show that Hnf1ß and Foxa3, liver organogenesis transcription factors, are sufficient to reprogram MEFs into induced hepatic stem cells (iHepSCs). iHepSCs can be stably expanded in vitro and possess the potential of bidirectional differentiation into both hepatocytic and cholangiocytic lineages. In the injured liver of fumarylacetoacetate hydrolase (Fah)-deficient mice, repopulating iHepSCs become hepatocyte-like cells. They also engraft as cholangiocytes into bile ducts of mice with DDC-induced bile ductular injury. Lineage conversion into bipotential expandable iHepSCs provides a strategy to enable efficient derivation of both hepatocytes and cholangiocytes for use in disease modeling and tissue engineering.

Murine embryonic stem cell-derived hepatocytes correct metabolic liver disease after serial liver repopulation.

Although embryonic stem (ES) cell-derived hepatocytes have the capacity for liver engraftment and repopulation, their in vivo hepatic function has not been analyzed yet. We aimed to determine the metabolic function and therapeutic action of ES cell-derived hepatocytes after serial liver repopulations in fumaryl acetoacetate hydrolase knockout (Fah(-/-)) mice. Albumin expressing (Alb(+)) cells were obtained by hepatic differentiation of ES cells using two frequently reported methods. After transplantation, variable levels of liver repopulation were found in Fah(-/-) mice recipients. FAH expressing (FAH(+)) hepatocytes were found either as single cells or as nodules with multiple hepatocytes. After serial transplantation, the proportion of the liver that was repopulated by the re-transplanted FAH(+) hepatocytes increased significantly. ES cell-derived FAH(+) hepatocytes were found in homogenous nodules and corrected the liver metabolic disorder of Fah(-/-) recipients and rescued them from death. ES cell-derived hepatocytes had normal karyotype, hepatocytic morphology and metabolic function both in vitro and in vivo. In conclusion, ES cell-derived hepatocytes were capable of liver repopulation and correction of metabolic defects after serial transplantation. Our results are an important piece of evidence to support future clinical applications of ES cell-derived hepatocytes in treating liver diseases.

H3K27 trimethylation is an early epigenetic event of p16INK4a silencing for regaining tumorigenesis in fusion reprogrammed hepatoma cells.

Stable epigenetic silencing of p16(INK4a) is a common event in hepatocellular carcinoma (HCC) cells, which is associated with abnormal cell proliferation and liberation from cell cycle arrest. Understanding the early epigenetic events in silencing p16(INK4a) expression may illuminate a prognostic strategy to block HCC development. Toward this end, we created a reprogram cell model by the fusion mouse HCC cells with mouse embryonic stem cells, in which the ES-Hepa hybrids forfeited HCC cell characteristics along with reactivation of the silenced p16(INK4a). HCC characteristics, in terms of gene expression pattern and tumorigenic potential, was restored upon induced differentiation of these reprogrammed ES-Hepa hybrids. The histone methylation pattern relative to p16(INK4a) silencing during differentiation of the ES-Hepa hybrids was analyzed. H3K27 trimethylation at the p16(INK4a) promoter region, occurring in the early onset of p16(INK4a) silencing, was followed by H3K9 dimethylation at later stages. During the induced differentiation of the ES-Hepa hybrids, H3K4 di- and trimethylations were maintained at high levels during the silencing of p16(INK4a), strongly suggesting that H3K4 methylation events did not cause the silencing of p16(INK4a). Our results suggested that the enrichment of H3K27 trimethylation, independent of H3K9 dimethylation, trimethylation, and DNA methylation, was an early event in the silencing of p16(INK4a) during the tumor development. This unique chromatin pattern may be a heritable marker of epigenetic regulation for p16(INK4a) silencing during the developmental process of hepatocellular carcinogenesis.

Oncoprotein BMI-1 induces the malignant transformation of HaCaT cells.

BMI-1 (B-cell-specific Moloney murine leukemia virus integration site 1), a novel oncogene, has attracted much attention in recent years for its involvement in the initiation of a variety of tumors. Recent evidence showed that BMI-1 was highly expressed in neoplastic skin lesions. However, whether dysregulated BMI-1 expression is causal for the transformation of skin cells remains unknown. In this study, we stably expressed BMI-1 in a human keratinocyte cell line, HaCaT. The expression of wild-type BMI-1 induced the malignant transformation of HaCaT cells in vitro. More importantly, we found that expression of BMI-1 promoted formation of squamous cell carcinomas in vivo. Furthermore, we showed that BMI-1 expression led to the downregulation of tumor suppressors, such as p16INK4a and p14ARF, cell adhesion molecules, such as E-Cadherin, and differentiation related factor, such as KRT6. Therefore, our findings demonstrated that dysregulated BMI-1 could indeed lead to keratinocytes transformation and tumorigenesis, potentially through promoting cell cycle progression and increasing cell mobility.

Conversion of immortal liver progenitor cells into pancreatic endocrine progenitor cells by persistent expression of Pdx-1.

The conversion of expandable liver progenitor cells into pancreatic beta cells would provide a renewable cell source for diabetes cell therapy. Previously, we reported the establishment of liver epithelial progenitor cells (LEPCs). In this work, LEPCs were modified into EGFP/Pdx-1 LEPCs, cells with stable expression of both Pdx-1 and EGFP. Unlike previous work, with persistent expression of Pdx-1, EGFP/Pdx-1 LEPCs acquired the phenotype of pancreatic endocrine progenitor cells rather than giving rise to insulin-producing cells directly. EGFP/Pdx-1 LEPCs proliferated vigorously and expressed the crucial transcription factors involved in beta cell development, including Ngn3, NeuroD, Nkx2.2, Nkx6.1, Pax4, Pax6, Isl1, MafA and endogenous Pdx-1, but did not secrete insulin. When cultured in high glucose/low serum medium supplemented with cytokines, EGFP/Pdx-1 LEPCs stopped proliferating and gave rise to functional beta cells without any evidence of exocrine or other islet cell lineage differentiation. When transplanted into diabetic SCID mice, EGFP/Pdx-1 LEPCs ameliorated hyperglycemia by secreting insulin in a glucose regulated manner. Considering the limited availability of beta cells, we propose that our experiments will provide a framework for utilizing the immortal liver progenitor cells as a renewable cell source for the generation of functional pancreatic beta cells.

Expression and cytotoxicity of EGFP-labeled D-amino acid oxidase in HeLa cells.

To observe the expression of R. gracilis D-amino acid oxidase (DAAO) gene labeled by EGFP in HeLa cells and how it mediates cytotoxicity, DAAO cDNA and EGFP gene were cloned into Eukaryotic expression vector pIRES to construct DAAO gene expression vector pIRES-DAAO. HeLa cells were transfected with pIRES-DAAO in vitro. Expression of EGFP gene in HeLa-D cells was observed under a fluorescent microscope. The efficiency of transfection was analyzed by flow cytometry (FCM). The fluorescent cells were screened by FCM and were named HeLa-D. The activity of HeLa-D cells was detected by MTT colorimetric assay after they were treated with D-Ala at various concentrations. The results indicted that expression of EGFP gene in HeLa-D cells was seen under fluorescent microscope and HeLa-D cells were screened by FCM. Apparently,the prodrug D-Ala killed HeLa-D cells. These results demonstrate that EGFP gene can be regarded as a reporter gene to screen the cells transduced with DAAO quickly, and DAAO/D-Ala suicide gene system may prove helpful in gene therapy of cancer.