Untangling determinants of gut microbiota and tumor immunologic status through a multi-omics approach in colorectal cancer.

The changes in gut microbiota have been implicated in colorectal cancer (CRC). The interplays between the host and gut microbiota remain largely unclear, and few studies have investigated these interplays using integrative multi-omics data. In this study, large-scale multi-comic datasets, including microbiome, metabolome, bulk transcriptomics and single cell RNA sequencing of CRC patients, were analyzed individually and integrated through advanced bioinformatics methods. We further examined the clinical relevance of these findings in the mice recolonized with microbiota from human. We found that CRC patients had distinct microbiota compositions compared to healthy controls. A machine-learning model was developed with 28 biomarkers for detection of CRC, which had high accuracy and clinical applicability. We identified multiple significant correlations between genera and well-characterized genes, suggesting the potential role of gut microbiota in tumor immunity. Further analysis showed that specific metabolites worked as profound communicators between these genera and tumor immunity. Integrating microbiota and metabolome perspectives, we cataloged gut taxonomic and metabolomic features that represented the key multi-omics signature of CRC. Furthermore, gut microbiota transplanted from CRC patients compromised the response of CRC to immunotherapy. These phenotypes were strongly associated with the alterations in gut microbiota, immune cell infiltration as well as multiple metabolic pathways. The comprehensive interplays across multi-comic data of CRC might explain how gut microbiota influenced tumor immunity. Hence, we proposed that modifying the CRC microbiota using healthy donors might serve as a promising strategy to improve response to immunotherapy.

Short-term waterlogging-induced autophagy in root cells of wheat can inhibit programmed cell death.

Autophagy is a pathway for the degradation of cytoplasmic components in eukaryotes. In wheat, the mechanism by which autophagy regulates programmed cell death (PCD) is unknown. Here, we demonstrated that short-term waterlogging-induced autophagy inhibited PCD in root cells of wheat. The waterlogging-tolerant wheat cultivar Huamai 8 and the waterlogging-sensitive wheat cultivar Huamai 9 were used as experimental materials, and their roots were waterlogged for 0-48 h. Waterlogging stress increased the number of autophagic structures, the expression levels of autophagy-related genes (TaATG), and the occurrence of PCD in root cells. PCD manifested as morphological changes in the cell nucleus, significant enhancement of DNA laddering bands, and increases in caspase-like protease activity and the expression levels of metacaspase genes. The autophagy promoter rapamycin (RAPA) reduced PCD levels, whereas the autophagy inhibitor 3-methyladenine (3-MA) enhanced them. The expression levels of TaATG genes and the number of autophagic structures were lower in cortex cells than in stele cells, but the levels of PCD were higher in cortex cells. The number of autophagic structures was greater in Huamai 8 than in Huamai 9, but the levels of PCD were lower. In summary, our results showed that short-term waterlogging induced autophagy which could inhibit PCD. Mechanisms of response to waterlogging stress differed between cortex and stele cells and between two wheat cultivars of contrasting waterlogging tolerance.

Entecavir-induced interferon-λ1 suppresses type 2 innate lymphoid cells in patients with hepatitis B virus-related liver cirrhosis.

The immunomodulatory effects of entecavir (ETV) in anti-hepatitis B virus (HBV) therapy have long been recognized. This study aimed to determine the effects of ETV on non-natural killer innate lymphoid cells (non-NK ILCs) in HBV-related liver disease progression. We enrolled treatment-naïve chronic hepatitis B (CHB) and HBV-related liver cirrhosis (LC) patients treated with ETV for 24 months. Before and after therapy, the frequency and cytokine profiles of ILC2s and non-NK ILCs subset homeostasis and their clinical significance were determined, and serial serum interferon (IFN)-λ levels were analysed. Peripheral blood mononuclear cells (PBMCs) of untreated LC patients were cultured with serum from untreated and ETV-treated LC patients in addition to being subject to IFN-λ1 neutralization and stimulation, and the frequency and cytokine production of ILC2s as well as non-NK ILCs subset ratios were calculated. Furthermore, IFN-λ receptor expression on non-NK ILCs and dendritic cells (DCs) was measured. After 24 months of ETV treatment, the frequency and cytokine production of ILC2s (IL-4, IL-13, IFN-γ, TNF-α) decreased with increased ILC1/ILC2 and decreased ILC2/ILC3 ratios, revealing a close association with disease status in LC patients. Long-term ETV administration-induced serum IFN-λ1 levels were negatively correlated with ILC2s. ETV-treated LC serum culture and IFN-λ1 stimulation yielded similar effects on suppression of ILC2s, and IFN-λ1 neutralization in serum culture partly inhibited this effect. The IFN-λ receptor was detected on DCs but not on non-NK ILCs. In conclusion, ETV suppresses the frequency and cytokine profiles of ILC2s by increasing IFN-λ1 in LC patients.

Mutual regulation of ROS accumulation and cell autophagy in wheat roots under hypoxia stress.

Here, we explored the mutual regulation of radical oxygen species (ROS) and autophagy in wheat (Triticum aestivum L.) roots under hypoxia stress. We also analyzed differences between the responses of the stele and the cortex in the two wheat cultivars Huamai 8 (waterlogging-tolerant) and Huamai 9 (waterlogging-sensitive) to hypoxia stress. In situ detection and ultracytochemical localization analysis in wheat roots showed that hypoxia stress caused greater increases in ROS levels and the expression levels of alternative oxidase (AOX) and antioxidant enzymes in the stele than in the cortex. The analysis of exogenous ROS addition and the inhibition of its production revealed the pivotal roles played by ROS in autophagy. Moreover, transmission electron microscopy and qRT-PCR analysis indicated that the stele had a higher level of autophagy than the cortex and that the two wheat cultivars primarily differed in the type and number of autophagosomes. Additional research revealed that autophagy could remove excess ROS, as pre-treatment with the autophagy inhibitor 3-methyladenine increased ROS levels in roots and the addition of the autophagy inducer rapamycin reduced root ROS levels. In conclusion, hypoxia stress induced ROS accumulation in wheat roots where ROS acted as an autophagy signal. Furthermore, higher levels of autophagy and antioxidant enzyme expression in the stele facilitated the elimination of oxidative damage caused by excessive ROS and thereby increased cell survival; in the cortex, a large number of cells died and formed aerenchyma.

The small heterodimer partner inhibits activation of hepatic stellate cells via autophagy.

BACKGROUND: Hepatic fibrosis is a health concern worldwide, and it is of great importance to develop effective therapeutic targets. The small heterodimer partner (SHP) is a regulator of lipid and bile acid metabolism in the liver. OBJECTIVES: The objective of this study was to investigate the contribution of SHP to hepatic fibrosis and the underlying mechanism. MATERIAL AND METHODS: An in vivo rat model of hepatic fibrosis was created through treatment with carbon tetrachloride. We used arginine-glycine-aspartic acid-poly (ethylene glycol)-polyethyleneimine (RGD-PEG-PEI) for the specific transfer of SHP into hepatic stellate cells (HSC). The level of gene expression was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The LX2 cell line was selected for the in vitro assay. Artificial activation of LX2 in vitro was conducted through treatment with platelet-derived growth factor-BB (PDGF-BB), and autophagy was activated using rapamycin. Gain and loss of function assays were performed using a SHP-expressing plasmid or siRNA-SHP. Both qRT-PCR and western blotting were utilized to detect the level of gene expression. RESULTS: RGD-PEG-PEI-mediated the specific transduction of SHP into HSC in the liver and effectively increased the expression of SHP in the rat liver. After treatment with RGD-PEG-PEI-SHP, downregulation of liver fibrosis-associated genes was observed. The results of the in vitro assay indicated that SHP attenuated the stimulating effect of PDGF-BB on the activation of LX2 cells. Overexpression of SHP leads to significant downregulation of HSC activation-associated molecular factors, including α-smooth muscle actin, tissue inhibitor of metalloproteinase-1, and type I collagen. Conversely, increased expression of these molecules could be observed following knockdown of SHP. Furthermore, SHP affected fibrosis by inhibiting autophagy activated through treatment with rapamycin in LX2 cells. Overexpression of SHP may prevent liver fibrogenesis through inhibition of autophagy in HSC. CONCLUSIONS: The SHP may prevent liver fibrogenesis through inhibition of autophagy in HSC. A SHP-targeting therapy-based anti-fibrosis strategy possesses potential for application to the treatment of liver fibrosis.

Longitudinal monitoring of liver fibrosis status by transient elastography in chronic hepatitis B patients during long-term entecavir treatment.

The correlation between improvement in longitudinal liver stiffness and fibrosis regression has not been properly evaluated during long-term antiviral therapy in chronic hepatitis B (CHB) patients. In this study, liver stiffness was serially performed by FibroScan® every 26 weeks in a prospective cohort of CHB patients receiving entecavir. Results were compared with liver biopsies at baseline and week 78. A total of 120 treatment-naïve CHB patients were analyzed, in which 54 (45%) patients had fibrosis regression at 78 weeks of antiviral therapy. Liver stiffness measurement presented as a rapid-to-slow decline pattern and decreased more significantly in patients with fibrosis regression than those without improvement in fibrosis at week 78 (- 46.4 vs. - 28.6%, P < 0.001). Multivariate analysis revealed that percentage decline of 52-week and 78-week liver stiffness from baseline was independent predictive factors for fibrosis regression (OR = 46.6, P < 0.001; OR = 17.8, P = 0.002, respectively). Moreover, percentage decline of 78-week liver stiffness was moderately predictive of fibrosis regression (AUROC = 0.694, P < 0.001), while the optimal cutoff values were different between non-cirrhosis and cirrhosis patients (38 vs. 45%). Fibrosis regression could be predicted with a high positive predictive value (96%) in non-cirrhosis patients and could be excluded with a high negative predictive value (94%) in cirrhosis patients. In conclusion, serial liver stiffness measurement could be applied for longitudinal monitoring of fibrosis status in CHB patients. Continuous decline of liver stiffness after effective antiviral treatment could partially reflect fibrosis regression at an optimal cutoff value.

Longitudinal monitoring of liver stiffness by acoustic radiation force impulse imaging in patients with chronic hepatitis B receiving entecavir.

BACKGROUND: Acoustic radiation force impulse (ARFI) imaging measures liver stiffness (LS), which significantly correlates with the stage of liver fibrosis in treatment-naive patients with chronic hepatitis B (CHB). AIM: We aimed to prospectively assess the clinical usefulness of ARFI during long-term antiviral therapy in CHB. METHOD: Seventy-one CHB patients were consecutively recruited and paired liver biopsies were performed in 27 patients. LS was assessed by ARFI semiannually during entecavir therapy. RESULTS: LS gradually decreased with treatment and continued to decrease after normalization of alanine aminotransaminase. Overall, 97.2% patients achieved improvement of LS, whereas 19.7% patients had more than 30% reduction in LS values between baseline and week 104. Multivariate linear regression analysis showed that the degree of LS reduction significantly correlated with the baseline levels of LS value, platelet and cholinesterase. In the 27 patients who underwent paired liver biopsies, LS significantly correlated with stage of fibrosis and inflammatory grade at baseline. LS values decreased more significantly in patients with fibrosis regression than those with static histological fibrosis. CONCLUSION: In CHB patients, LS assessed by ARFI was gradually reduced during antiviral therapy. Longitudinal monitoring of LS may be a promising noninvasive assessment of fibrosis regression during long-term antiviral therapy in CHB. Further large sample studies are needed.

HMGB1-induced autophagy: a new pathway to maintain Treg function during chronic hepatitis B virus infection.

High-mobility group box-1 (HMGB1) protein, as one of the well-known damage-associated molecular pattern molecules (DAMPs), is enriched in chronic hepatitis B virus (HBV) infection and has a context-dependent role in autophagy, a highly conserved self-digestive process in response to environmental stress. Recent mouse studies indicate that autophagy is highly active in regulatory T (Treg)-cells. In the present study, we evaluated spontaneous and induced autophagy of peripheral Treg cells from 98 patients with chronic hepatitis B (CHB), by measuring levels of lipidated form of microtubule-associated light chain 3 (LC3-II, marker for closed autophagosomes) and observing autophagic vacuoles (AV) with transmission electron microscope. No significant difference was found in spontaneous autophagy of either Treg or CD4+ naive cells when comparing CHB patients with healthy subjects, apart from CHB-Treg showed significantly higher autophagic activity after activation by anti-CD3-CD28 beads. Besides, incubation of CHB-Treg cells with CHB-serum greatly maintained their autophagic behaviour, which could be significantly diminished by blocking HMGB1 with the neutralizing antibody. Further, we characterized time- and dose-dependent effects by recombinant HMGB1 protein on autophagy of CHB-Treg cells. We also documented a significant up-regulation of HMGB1 and its receptors [toll-like receptor (TLR4), receptor for advanced glycation end-product (RAGE)] in both peripheral and intra-hepatic microenvironments of CHB patients. Moreover, the RAGE-extracellular regulated protein kinases (ERK) axis and rapamycin-sensitive components of mammalian target of rapamycin (mTOR) pathways were demonstrated in vitro to be involved in HMGB1-induced autophagy of Treg cells. Additionally, HMGB1-induced autophagy could maintain cell survival and functional stability of CHB-Treg cells. Our findings could open new perspectives in developing therapeutic strategies to activate specific anti-HBV immunity by diminishing Treg autophagy.

IL-10-producing regulatory B-cells suppressed effector T-cells but enhanced regulatory T-cells in chronic HBV infection.

Non-specific immune responses to antigens have been demonstrated as being enhanced during chronic hepatitis B virus (HBV) infection. Here, we evaluated the role of interleukin-10 (IL-10)-producing regulatory B-cells (Bregs) in the pathogenesis of HBV-related liver fibrosis (HBV-LF) and assessed their immunoregulatory effects. Sixty-seven patients diagnosed with chronic hepatitis B (CHB) were enrolled in this study. Numbers and frequencies of peripheral B-cells (memory CD19(+)CD24(hi)CD27(+) cells, immature/transitional CD19(+)CD24(hi)CD38(hi) cells, mature CD19(+)CD24(int)CD38(int) cells) were tested and analysed. Flow cytometry-sorted CD4(+)T cells were cultured with autologous Bregs to elucidate the effects of Bregs on CD4(+)T cells, including effector T and regulatory T-cells (Tregs). The potential immunoregulatory mechanism of Bregs was also investigated. The numbers of total B-cells and Bregs were enriched in CHB patients. The frequency of Bregs was negatively correlated with elevated alanine aminotransferase (ALT) and histological inflammation grades (G), but positively correlated with advanced histological fibrosis stages (S) and enhanced HBV replication. The phenotype of Bregs was predominantly characterized as CD19(+)CD24(hi)CD38(hi) In co-culture with Bregs, CD4(+)CD25(-)T cells from CHB patients produced less interferon-γ (IFN-γ) and IL-17 but more IL-4 than CD4(+)CD25(-)T cells alone, whereas their conversions into Tregs and IL-10(+)T cells were enhanced. In addition, Breg depletion in CHB samples dramatically decreased Treg numbers and expression of cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), IL-10 and transforming growth factor-ß (TGF-ß). Moreover, the observed regulatory effect was partly dependent on IL-10 release and cell-to-cell contact. Elevated Bregs can suppress effector T but enhance Treg functions, which might influence immune tolerance in chronic HBV infection.

Indole-3-Carbinol (I3C) and its Major Derivatives: Their Pharmacokinetics and Important Roles in Hepatic Protection.

BACKGROUND: Indoles, including indole-3-carbinol (I3C) and its derivatives, are the products of glucosinolate hydrolysis catalyzed by the enzyme myrosinase. Under acidic conditions, I3C polymerizes into 3, 3- diindolylmethane (DIM), [2-(indol-3-ylmethyl)-indol-3-yl]indol-3-ylmethane (LTr1), 1-(3-hydroxymethyl)- indolyl-3-indolylmethane (HI-IM) and indolo[3,2b]carbazole (ICZ). Recently, I3C and its dimer DIM have shown pleiotropic protective effects on chronic liver injuries, including viral hepatitis, hepatic steatosis, hepatic cirrhosis, hepatocellular carcinoma, and so on. METHODS: We reviewed the published papers about the pharmacokinetics of I3C and its derivatives in vitro and in vivo, and summarized their multiple protective roles in the processes of chronic liver diseases. RESULTS: Indoles not only regulate transcriptional factors and their respective signaling pathways, but also relieve oxidative stress and inhibit the synthesis of DNA to influence the activation, proliferation and apoptosis of target cells. Moreover, indoles modulate the enzymes that are relevant to hepatitis viral replication, lipogenesis, and the metabolism of ethanol and some hepatotoxic substances to protect the liver. Currently, the immunomodulatory biofunction of indoles contributes to improving non-alcoholic steatohepatitis. In addition, indoles also function as the inhibitors of pro-inflammatory cytokines and chemokines to reduce microbial-induced liver injures. CONCLUSION: Indoles, especially I3C and DIM as phytochemicals, exert anti-fibrosis, anti-tumor, anti-oxidant, immunomodulatory, detoxification and anti-inflammation effects on hepatic protection through pleiotropic mechanism.

Restoring homeostasis of CD4⁺ T cells in hepatitis-B-virus-related liver fibrosis.

Immune-mediated liver injury is widely seen during hepatitis B virus (HBV) infection. Unsuccessful immune clearance of HBV results in chronic hepatitis and increases the risk of liver cirrhosis and hepatocellular carcinoma. HBV-related liver fibrosis (HBVLF), occurring as a result of HBV-induced chronic hepatitis, is a reversible, intermediate stage of chronic hepatitis B (CHB) and liver cirrhosis. Therefore, defining the pathogenesis of HBVLF is of practical significance for achieving better clinical outcomes. Recently, the homeostasis of CD4(+) T cells was considered to be pivotal in the process of HBVLF. To better uncover the underlying mechanisms, in this review, we systematically retrospect the impacts of different CD4(+) T-cell subsets on CHB and HBVLF. We emphasize CD4(+) T-cell homeostasis and the important balance between regulatory T (Treg) and T helper 17 (Th17) cells. We discuss some cytokines associated with Treg and Th17 cells such as interleukin (IL)-17, IL-22, IL-21, IL-23, IL-10, IL-35 and IL-33, as well as surface molecules such as programmed cell death protein 1, cytotoxic T lymphocyte-associated antigen 4, T cell immunoglobulin domain and mucin domain-containing molecule 3 and cannabinoid receptor 2 that have potential therapeutic implications for the homeostasis of CD4(+) T cells in CHB and HBVLF.