Chemical Evolution of Enzyme-Catalyzed Glycosylation.

ConspectusThe limited availability of structurally well-defined diverse glycans remains a major obstacle for deciphering biological functions as well as biomedical applications of carbohydrates. Despite tremendous progress that has been made in past decades, the synthesis of structurally well-defined complex glycans still represents one of the most challenging topics in synthetic chemistry. Chemical synthesis of glycans is a time-consuming and labor-intensive process that requires elaborate planning and skilled personnel. In contrast, glycosyltransferase-catalyzed enzymatic synthesis provides a more efficient, convenient, low-cost, and sustainable alternative to affording diverse and complex glycans. However, the existing methods are still insufficient to fulfill the increasing demand for specific synthetic glycan libraries necessary for functional glycomics research. This is mainly attributed to the inherent character of the glycan biosynthetic pathway. In nature, there are too many glycosyltransferases involved in the in vivo glycan synthesis, but only a small number of them are available for in vitro enzymatic synthesis. For instance, humans have over 200 glycosyltransferases, but only a few of them could be produced from the conventional bacterial expression system, and most of these membrane-associated enzymes could be overexpressed only in eukaryotic cells. Moreover, the glycan biosynthetic pathway is a nontemplate-driven process, which eventually ends up with heterogeneous glycan product mixtures. Therefore, it is not a practical solution for the in vitro enzymatic synthesis of complex glycans by simply copying the glycan biosynthetic pathway.In the past decade, we have tried to develop a simplified and transformable approach to the enzymatic modular assembly of a human glycan library. Despite the structural complexity of human glycans, the glycoinformatic analysis based on the known glycan structure database and the human glycosyltransferase database indicates that there are approximately 56 disaccharide patterns present in the human glycome and only 16 disaccharide linkages are required to account for over 80% of the total disaccharide fragments, while 35 disaccharide linkages are sufficient to cover over 95% of all disaccharide fragments of human glycome. Regardless of the substrate specificity, if one glycosyltransferase could be used for the synthesis of all of the same glycosidic linkages in human glycome, it will require only a few dozen glycosyltransferases for the assembly of entire human glycans. According to the glycobioinformatics analysis results, we rationally designed about two dozen enzyme modules for the synthesis of over 20 common glycosidic linkages in human glycome, in which each enzyme module contains a glycosyltransferase and a group of enzymes for the in situ generation of a nucleotide-activated sugar donor. By sequential glycosylation using orchestrated enzyme modules, we have completed the synthesis of over 200 structurally well-defined complex human glycans including blood group antigens, O-mannosyl glycans, human milk oligosaccharides, and others. To overcome the product microheterogeneity problem of enzymatic synthesis in the nontemplate-driven glycan biosynthetic pathway, we developed several substrate engineering strategies to control or manipulate the outcome of glycosyltransferase-catalyzed reactions for the precise synthesis of structurally well-defined isomeric complex glycans.

Aspirin inhibits rotavirus replication and alters rat gut microbial composition.

BACKGROUND: Aspirin is widely used to treat various clinical symptoms. Evidence suggests that aspirin has antiviral properties, but little is known about its specific effect against rotavirus. METHODS: MA104, Caco-2, and CV-1 cells were infected with rotavirus, and aspirin was added after 12 h. Viral mRNA and titer levels were measured by qRT-PCR and immunofluorescence assays. For in vivo validation, forty specific-pathogen-free SD rats were randomly divided into oral aspirin (ASP) groups and control (NC) groups. 16 S rRNA gene sequencing was performed to identify gut microbiota. After 6 months of continuous ASP/NC administration, the rats were infected with rotavirus. Fecal samples were collected over a 30-day time course, and viral levels were quantified. Proinflammatory cytokines/chemokine levels were measured by ELISA. RESULTS: Aspirin inhibited rotavirus infection in cell lines and in rats. The effects of aspirin on viral replication were associated with the alteration of gut microbiota composition by aspirin, including increased abundance of Firmicutes and decreased abundance of Bacteroidetes after aspirin treatment. Mechanistically, aspirin reduced IL-2 and IL-10 levels, and increased IRF-1 and COX-2 levels. Aspirin blocked rotavirus replication in vitro and in vivo, which might be related to effects on IRF-1, COX-2, chemokines, and gut microbial composition. CONCLUSION: These results indicate that long-term oral aspirin administration reduces rotavirus infection. Intestinal virus infection may be suppressed in elderly patients who take aspirin for a long time. The change of their Gut microbiota may lead to functional disorder of the intestinal tract, which may provide some reference for clinical adjuvant probiotics treatment.

Synthesis and Immunological Evaluation of Pentamannose-Based HIV-1 Vaccine Candidates.

Dense glycosylation and the trimeric conformation of the human immunodeficiency virus-1 (HIV-1) envelope protein limit the accessibility of some cellular glycan processing enzymes and end up with high-mannose-type N-linked glycans on the envelope spike, among which the Man5GlcNAc2 structure occupies a certain proportion. The Man5GlcNAc2 glycan composes the binding sites of some potent broadly neutralizing antibodies, and some lectins that can bind Man5GlcNAc2 show HIV-neutralizing activity. Therefore, Man5GlcNAc2 is a potential target for HIV-1 vaccine development. Herein, a highly convergent and effective strategy was developed for the synthesis of Man5 and its monofluoro-modified, trifluoro-modified, and S-linked analogues. We coupled these haptens to carrier protein CRM197 and evaluated the immunogenicity of the glycoconjugates in mice. The serological assays showed that the native Man5 conjugates failed to induce Man5-specific antibodies in vivo, while the modified analogue conjugates induced stronger antibody responses. However, these antibodies could not bind the native gp120 antigen. These results demonstrated that the immune tolerance mechanism suppressed the immune responses to Man5-related structures and the conformation of glycan epitopes on the synthesized glycoconjugates was distinct from that of native glycan epitopes on gp120.

A Redox-Controlled Substrate Engineering Strategy for Site-Specific Enzymatic Fucosylation.

Fucosylation is one of the most common modifications of oligo-N-acetyllactosamine (oligo-LacNAc) glycans. However, none of known fucosyltransferases (FucTs) could install the α1,3-linked fucose to the oligo-LacNAc substrates in a site-specific manner. Here, we report a facile and general redox-controlled substrate engineering strategy for the site-specific α1,3-fucosylation of complex glycans containing multiple LacNAc units. This strategy takes advantage of an operationally simple oxidation enzyme module by using galactose oxidase (GOase) to convert the LacNAc unit into oxidized C6'-aldehyde LacNAc sequence, which is not a good substrate for recombinant α1,3-FucT from Helicobacter pylori strain 26695 (Hpα1,3FucT), enabling the site-specific α1,3-fucosylation at intact LacNAc sites. The general applicability and robustness of this strategy were demonstrated by the synthesis of a variety of structurally well-defined fucosides of linear and branched O- and N-linked glycans.

Analysis of the intestinal microbial community altered during rotavirus infection in suckling mice.

BACKGROUND: Rotavirus (RV) is a principal cause of diarrhea. However, there is a limited understanding regarding alteration of the gut microbial community structure and abundance during RV infection. This study was to characterize any potential associations between RV infection and the intestinal microbiota. METHODS: Suckling mice were divided into normal group (NC) and infected group (RV) randomly. All of the suckling mice were euthanized four days post-RV infection. The virus titer was counted as fluorescent focus assay, and viral load was quantified by QPCR. Five sucking mice were randomly selected from each RV group and NC group for sample collection and pathological analysis. Mixed intestinal contents of the colon and rectum were collected from all of the suckling mice. To investigate the detailed relationship between RV infection and intestinal microbiota, the composition and distribution of intestinal microbiota from suckling mice were first analyzed using 16S rRNA sequencing technology. RESULTS: The results of the pathological characteristics showed that vacuolar degeneration, vasodilation, hyperemia, and destruction of the intestinal epithelium were apparent in the RV group. Representative genera from Lactobacillus and Fusobacterium were enriched in the NC group, while the Enterococcus and Escherichia/Shigella genera were enriched in the RV group. Helicobacter, Alloprevotrlla, Brevundimonas, Paenibacillus, and Parabacteroides were completely undetectable in the RV group. The predicted intestinal flora metabolic function results showed that "carbohydrate metabolism" and "lipid metabolism" pathways were significantly enriched within the NC group. A significant difference has been observed in the gut microbiota composition between the two groups. CONCLUSIONS: Our results demonstrated a significant difference in the gut microbiota composition in RV-infected suckling mice as compared to the RV un-infected suckling mice group. This work may provide meaningful information regarding the bacterial genera changed during RV infection. Moreover, the changes in these bacteria may be related with the replication and pathogenesis of RV infection.

Cancer Cell Preferential Penetration and pH-Responsive Drug Delivery of Oligorutin.

We report herein a novel delivery system, derived from the facile enzymatic synthesis of oligorutin (OR), for cancer cell targeting and pH-responsive drug delivery. In this study, we demonstrate that OR could preferentially penetrate cancer cells via the lipid raft-mediated endocytosis pathway, and cell membrane cholesterol was critical to the internalization of OR. The accumulation of OR in the tumor region was further confirmed by an in vivo biodistribution study. Considering the tumor-targeting property of OR, a pH-responsive drug delivery system (OR-BTZ) was developed by covalent conjugation of the catechol groups on OR with antitumor drug bortezomib (BTZ) through a pH-sensitive borate ester bond. OR-BTZ exerted cytotoxicity as well as inhibition of the migration and invasion to hepatoma carcinoma cells and showed no apparent cytotoxicity with liver normal cells. The OR-BTZs also presented significant therapeutic efficacy and low systematic toxicity in the murine hepatocellular carcinoma model. To our knowledge, this study presents the first attempt to exploit the potential of oligoflavonoids for cancer cell-targeted drug delivery and will motivate the development of flavonoids and their derivatives as a new type of biomaterials for tumor-targeted therapy.

Enzymatic modular assembly of hybrid Lewis antigens.

The enzymatic synthesis of hybrid Lewis antigens including KH-1 (Lewis y-Lewis x-Lactose, Ley-Lex-Lac), Lewis a-Lewis x-Lactose (Lea-Lex-Lac), and Lewis b-Lewis x-Lactose (Leb-Lex-Lac) has been achieved using a facile enzymatic modular assembly strategy. Starting from a readily available tetrasaccharide, 3 complex hybrid Lewis antigens were achieved in over 40% total yields in less than 5 linear steps of sequential enzymatic glycosylation using 6 enzyme modules. The regio-selective fucosylation was achieved by simply controlling the donor-acceptor ratio. This strategy provides an easy access to these biologically important complex hybrid Lewis antigens at preparative scales.

Chemoenzymatic Synthesis of O-Mannose Glycans Containing Sulfated or Nonsulfated HNK-1 Epitope.

The human natural killer-1 (HNK-1) epitope is a unique sulfated trisaccharide sequence presented on O- and N-glycans of various glycoproteins and on glycolipids. It is overexpressed in the nervous system and plays crucial roles in nerve regeneration, synaptic plasticity, and neuronal diseases. However, the investigation of functional roles of HNK-1 in a more complex glycan context at the molecular level remains a big challenge due to lack of access to related structurally well-defined complex glycans. Herein, we describe a highly efficient chemoenzymatic approach for the first collective synthesis of HNK-1-bearing O-mannose glycans with different branching patterns, and for their nonsulfated counterparts. The successful strategy relies on both chemical glycosylation of a trisaccharide lactone donor for the introduction of sulfated HNK-1 branch and substrate promiscuities of bacterial glycosyltransferases that can tolerate sulfated substrates for enzymatic diversification. Glycan microarray analysis with the resulting complex synthetic glycans demonstrated their recognition by two HNK-1-specific antibodies including anti-HNK-1/N-CAM (CD57) and Cat-315, which provided further evidence for the recognition epitopes of these antibodies and the essential roles of the sulfate group for HNK-1 glycan-antibody recognition.

Redox-Controlled Site-Specific α2-6-Sialylation.

The first bacterial α2-6-sialyltransferase cloned from Photobacterium damselae (Pd2,6ST) has been widely applied for the synthesis of various α2-6-linked sialosides. However, the extreme substrate flexibility of Pd2,6ST makes it unsuitable for site-specific α2-6-sialylation of complex substrates containing multiple galactose and/or N-acetylgalactosamine units. To tackle this problem, a general redox-controlled site-specific sialylation strategy using Pd2,6ST is described. This approach features site-specific enzymatic oxidation of galactose units to mask the unwanted sialylation sites and precisely controlling the site-specific α2-6-sialylation at intact galactose or N-acetylgalactosamine units.

Chemoenzymatic Assembly of Mammalian O-Mannose Glycans.

O-Mannose glycans account up to 30 % of total O-glycans in the brain. Previous synthesis and functional studies have only focused on the core M3 O-mannose glycans of α-dystroglycan, which are a causative factor for various muscular diseases. In this study, a highly efficient chemoenzymatic strategy was developed that enabled the first collective synthesis of 63 core M1 and core M2 O-mannose glycans. This chemoenzymatic strategy features the gram-scale chemical synthesis of five judiciously designed core structures, and the diversity-oriented modification of the core structures with three enzyme modules to provide 58 complex O-mannose glycans in a linear sequence that does not exceed four steps. The binding profiles of synthetic O-mannose glycans with a panel of lectins, antibodies, and brain proteins were also explored by using a printed O-mannose glycan array.

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.

Synthetic and immunological studies of N-acyl modified S-linked STn derivatives as anticancer vaccine candidates.

It is well known that tumor cells express some aberrant glycans, termed tumor-associated carbohydrate antigens (TACAs). TACAs are good targets for the development of carbohydrate-based anticancer vaccines. However, one of the major problems is that carbohydrate antigens possess a weak immunogenicity. To tackle this problem, a number of unnatural N-modified S-linked STn analogues were designed and prepared. Reaction of the modified STn disaccharides with bifunctional adipic acid p-nitrophenyl diester provided the corresponding activated esters, which was followed by the conjugation with keyhole limpet hemocyanin (KLH), affording the corresponding protein conjugates. The immunological properties of these glycoconjugates were evaluated in a mouse model. The results showed that the modified glycoconjugates stimulated the production of IgG antibodies that are capable of recognizing the naturally occurring STn antigen, helping the discovery of carbohydrate-based anticancer vaccine candidates.

Protective effect of calcitonin on lumbar fusion-induced adjacent-segment disc degeneration in ovariectomized rat.

BACKGROUND: Intervertebral disc (IVD) degeneration and pathological changes in the spinal cord are major causes of back pain. In addition to its well-established anti-resorptive effect on bone, calcitonin (CT) potentially exerts protective effects on IVD degeneration in ovariectomized rats. However, possible therapeutic effects of CT on lumbar fusion-induced adjacent-segment disc degeneration (ASDD) have not been investigated yet. In this study, we examined the effects of CT on IVD degeneration adjacent to a lumbar fusion in ovariectomized rats. METHODS: Posterolateral lumbar fusion (PLF) at L4-5 was performed 4 weeks after ovariectomy (OVX) or sham surgery in female Sprague-Dawley rats. Following PLF + OVX, rats received either salmon CT (OVX + PLF + sCT, 16 IU/Kg/2d) or vehicle (OVX + PLF + V) treatment for 12 weeks; the remaining rats were divided into Sham + V, OVX + V, and PLF + V groups. Fusion status was analyzed by manual palpation and radiography. Adjacent segment disc was assessed by histological, histomorphometric, immunohistochemical analysis. L6 vertebrae microstructures were evaluated by micro-computed tomography. RESULTS: Histological analysis showed more severe ASDD occurred in OVX + PLF + V rats compared with the OVX + V or PLF + V groups. CT treatment suppressed the score for ASDD, increased disc height, and decreased the area of endplate calcification. Immunohistochemical staining demonstrated that CT decreased the expression of collagen type-I, matrix metalloproteinase-13, and a disintegrin and metalloproteinase with thrombospondin motifs-4, whereas it increased the expression of collagen type-II and aggrecan in the disc. Micro-computed tomography indicated that CT increased bone mass and improved the microstructure of the L6 vertebrae. CONCLUSIONS: These results suggest that CT can prevent ASDD, induce beneficial changes in IVD metabolism, and inhibit deterioration of the trabecular microarchitecture of vertebrae in osteoporotic rats with lumbar fusion.

Comparison of stigmatizing views towards COVID-19 and mental disorders among adolescent and young adult students in China.

Objective: Infectious diseases including COVID-19 and mental disorders are two of the most common health conditions associated with stigma. However, the comparative stigma of these two conditions has received less attention in research. This study aimed to compare the prevalence of stigmatizing views toward people with COVID-19 and mental disorders and the factors associated with these views, among a large sample of adolescent and young adult students in China. Methods: A total of 9,749 adolescents and young adults aged 15-24 years completed a survey on stigmatizing attitudes toward COVID-19 and mental disorders, as well as mental health-related factors, including general mental health status and symptoms of depression, anxiety, insomnia, and post-traumatic stress disorder (PTSD). Multivariable linear regression analyses were conducted to identify factors associated with stigmatizing views. Findings: The prevalence of COVID-19 and mental disorders-related stigma was 17.2% and 40.7%, respectively. COVID-19-related stigma scores were significantly higher among male students (ß = 0.025, p < 0.05), those without quarantine experience (ß = 0.035, p < 0.001), those with lower educational level (p < 0.001), those with lower family income (p < 0.01), and those with higher PTSD symptoms (ß = 0.045, p < 0.05). Mental disorder-related stigma scores were significantly higher among individuals with average and lower-than-average levels of family income (p < 0.01), depression symptoms (ß = 0.056, p < 0.001), anxiety symptoms (ß = 0.051, p < 0.001), and mental health problems (ß = 0.027, p < 0.05). Conclusion: The stigma of mental disorders is higher in the youth population than the stigma of COVID-19. Factors associated with stigmatizing attitudes toward people with COVID-19 and mental disorders varied across the youth. Stigma-reduction interventions among the youth should be targeted specifically to COVID-19 or mental disorders conditions.

Carbohydrate-based cancer vaccines: target cancer with sugar bullets.

With the booming development of glycobiology and glycochemistry, more and more structures of tumor-associated carbohydrate antigens (TACAs) are identified. Their broad expression and high specificity in cancer make them important targets to develop cancer vaccines or immunotherapies. However, most of the TACAs are T cell-independent antigens, they cannot elicit a powerful enough immune response to prevent or treat cancer. Immunotolerance and immunosuppression are more easily induced due to their endogenous properties and the declining immunity of the patients. This review summarizes the recent efforts to overcome these obstacles: coupling the carbohydrate antigens to proper carriers such as proteins or some small molecule carriers, and chemically modifying the structures of the TACAs to enhance the immunogenicity of TACAs and break the immunotolerance.

Vegetation Classification and Distribution Patterns in the South Slope of Yarlung Zangbo Grand Canyon National Nature Reserve, Eastern Himalayas.

Yarlung Zangbo Grand Canyon National Nature Reserve has the most complete vertical vegetation belts in China. However, identification and distribution of vertical vegetation belts is still uncertain and in debate. To explore the above issues, 190 plots were surveyed within the reserve from 2019 to 2021. Based on the vegetation plot data, cluster analysis, ordination analysis, and biodiversity statistics were performed to reveal the structure of vertical vegetation belts-the driving factors of vegetation distribution-to describe the main biodiversity patterns. Five vertical vegetation belts were identified by clustering. NMDS ordination showed that the main factor of vegetation distribution is elevation. Based on the results of the analysis and previous literature, a new scheme of vertical vegetation belts in the south slope of the reserve was proposed. There was a lower montane seasonal rainforest belt (600-1100 m), a lower montane evergreen broadleaf forest belt (1100-1800 m), a middle montane semi-evergreen broadleaf forest belt (1800-2400 m), a subalpine evergreen needleleaf forest belt (2400-3800 m), a alpine shrubland and meadow belt (3800-4400 m), an alpine sparse vegetation belt (4400-4800 m), and a nival belt (4800-7782 m). Among them, the seasonal rainforest belts are the northernmost distribution of this type, and the semi-evergreen broadleaf forest belts exist only in the Eastern Himalayas. The study showed a unimodal pattern in plant species diversity, the peak of which is about 1900 m. The middle montane semi-evergreen broadleaf forest belt had the highest species diversity in the reserve. This study settled the issues regarding the vertical vegetation belts, the main drivers of vegetation and assessment of plant species diversity in the south slope of the Yarlung Zangbo Grand Canyon National Nature Reserve. It provides essential support for the management and conservation of these ecosystems in the reserve.

Influence of drought intensity on the response of six woody karst species subjected to successive cycles of drought and rewatering.

Tolerance to the effects of drought and subsequent recovery after a rainfall appear to be critical for plants in the karst regions of southwestern China, which are characterized by frequent but temporary drought events. This study investigated the effects of drought intensity and repetition on photosynthesis and photoprotection mechanisms of karst plants during successive cycles of drought and subsequent recovery. Leaf water potential, gas exchange, chlorophyll fluorescence and several associated metabolic processes were studied in six plant species, including Pyracantha fortuneana (PF), Rosa cymosa (RC), Broussonetia papyrifera (BP), Cinnamomum bodinieri (CB), Platycarya longipes (PL) and Pteroceltis tatarinowii (PT) during three cycles of drought treatments at four different intensities. The four treatments were: well-watered, mild drought, moderate drought and severe drought, each followed by rewatering events. We found that limitations to CO(2) diffusion accounted for photosynthetic declines under mild and moderate drought treatments, while metabolic limitations dominated the response to severe drought. Repetition of drought did not intensify the impairment of photosynthetic metabolism regardless of drought intensity in the six species studied. Repetition of severe drought delayed the photosynthetic recoveries in PF, RC and CB after rewatering. Repetition of drought increased thermal dissipation in PF, CB and BP, as well as superoxide dismutase (EC 1.15.1.1) activity in RC and CB. Enhanced photosynthetic performance, measured as increased intrinsic water use efficiency, photosynthetic performance per unit of photosynthetic pigment, maintenance of high thermal dissipation and high ratios of carotenoids to chlorophylls, was observed during the rewatering periods. This enhanced photosynthetic performance allowed for the complete recovery of the six karst species from successive intermittent drought events.

Enzymatic modular synthesis and microarray assay of poly-N-acetyllactosamine derivatives.

A facile enzymatic modular assembly strategy for the preparative-scale synthesis of poly-N-acetyllactosamine (poly-LacNAc) glycans with varied lengths and designed sialylation and/or fucosylation patterns is described. These glycans were printed as a microarray to investigate their interactions with a panel of glycan binding proteins (GBPs). Binding affinities revealed that the avidity of GBPs could be largely affected by the length and the patterns of sialylation and fucosylation.

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.

Internalized stigma in people with severe mental illness in rural China.

BACKGROUND: It is unknown whether there are differences in self-stigma among persons with different types of severe mental illness (SMI) in rural communities. AIM: This study was to examine the differences of self-stigma and its correlates in persons with schizophrenia, major depressive disorder or bipolar disorder in a rural community in China. METHODS: A total of 453 persons with schizophrenia, major depressive disorder or bipolar disorder in a rural community participated in the study. The Internalized Stigma of Mental Illness (ISMI) was used to measure self-stigma. The t-test and analyses of variance (ANOVA) were used to examine the differences in mean scores of ISMI and subscales among the three diagnoses. Logistic regression was used to explore the contributing factors to the level of self-stigma among the three groups. RESULTS: Self-stigma was moderate and severe with 94.7% of the total sample. Persons with schizophrenia had significantly higher mean scores of total ISMI, alienation and discrimination experience than those with bipolar disorders. Lower family income was significantly associated with higher levels of self-stigma in persons with schizophrenia and major depressive disorder. Factors predicting the level of self-stigma among the three groups were various. CONCLUSION: Self-stigma is common and severe in persons with schizophrenia, major depressive disorder and bipolar disorder, especially those with lower income status in rural community in China. Persons with schizophrenia may have higher levels of self-stigma than those with bipolar disorder. Individual-level interventions should be developed to reduce self-stigma among persons with SMI in Chinese rural communities.