Role of stem cells during diabetic liver injury

Alleviation of taurine on liver injury of type 2 diabetic rats by improving antioxidant and anti-inflammatory capacity

Type 2 diabetes mellitus (T2DM) is a serious metabolic disease characterized by insulin resistance and reduced insulin production, which causes abnormally elevated blood glucose. It has been reported that T2DM can enhance oxidative stress and inflammatory responses, and stimulate a variety of complications including liver injury. Studies have shown that taurine has antioxidant and anti-inflammatory effects that can not only ameliorate diabetes but also alleviate liver injury caused by various diseases. However, its effect on liver injury in T2DM is not clear. In our study, a high-fat diet and intraperitoneal injection of streptozotocin (STZ) was used to induce liver injury in T2DM rats, and taurine was given as a treatment. Through the use of HE staining on paraffin sections, ELISA, and qRT-PCR, the effects of taurine on liver pathological alterations, antioxidant capacity, and inflammatory response were investigated. We found that: hepatic transaminase levels of rats were reduced significantly following taurine administration; histopathological observations revealed that the morphology of rat hepatocytes was close to normal, and the number of inflammatory cells around liver vessels was significantly reduced; antioxidant-related indicators were significantly increased, including SOD, CAT, GSH-Px and T-AOC, while related factors of the Nrf2 signalling pathway and its downstream HO-1, NQO1 and γ-GCS were significantly increased; the expression of the JAK2-STAT1 signalling pathway, TLR4/NF-κB signalling pathway and NLRP3 inflammatory vesicle-related factors were significantly reduced. Our results suggest taurine can alleviate T2DM-induced liver injury by improving the antioxidant capacity of the liver and inhibiting macrophage M1-type polarization and the inflammatory response mediated thereby.

Effects of conditioned media derived from human Wharton's jelly mesenchymal stem cells on diabetic nephropathy and hepatopathy via modulating TGF-β and apelin signaling pathways in male rats

BACKGROUND

Diabetic nephropathy and hepatopathy are health problems described by specific renal and hepatic structure and function disturbances. The protective effects of the stem cell secretome have been shown in several kidney and liver diseases. The current study aims to evaluate the capability of conditioned media derived from human Wharton's jelly mesenchymal stem cells (hWJ-MSCs-CM) to alleviate diabetic complications.

METHODS

Twenty Sprague Dawley rats were made diabetic through injection of STZ (60 mg/kg, i.p.). At week 8, diabetic rats were divided into two groups: treated [DM + hWJ-MSCs-CM (500 µl/rat for three weeks, i.p.)] and not treated (DM). At the 11th week, three groups (control, DM, and DM + hWJ-MSCs-CM) were kept in metabolic cages, and urine was collected for 24 h. The serum samples were maintained for measuring fasting blood glucose (FBG) and kidney and liver functional analysis. The left kidney and liver parts were kept at -80 °C to assess apelin and transforming growth factor-beta (TGF-β) expression. The right kidney, pancreas, and liver parts were used for histopathologic evaluation.

RESULTS

DM was detected by higher FBG, microalbuminuria, increased albumin/creatinine ratio, and pancreas, renal, and hepatic structural disturbances. Diabetic hepatopathy was determined by increasing liver enzymes and decreasing total bilirubin. The TGF-β gene expression was significantly upregulated in the diabetic kidney and liver tissues. Apelin gene expression was significantly downregulated in the diabetic liver tissue but did not change in kidney tissue. Administration of hWJ-MSCs-CM improved renal and hepatic functional and structural disturbances. Moreover, CM therapy significantly decreased TGF-β expression and enhanced apelin expression in the kidney and liver tissues.

CONCLUSION

Human WJ-MSCs-CM may have protective effects on diabetic renal and hepatic complications. These effects may happen through the regulation of TGF-β and apelin signaling pathways.

The regenerative effect of stem cells on acetaminophen-induced hepatotoxicity in male albino rats

Background

Acetaminophen overdose is the leading cause of acute liver injury (ALI) and acute liver failure (ALF) in the developed world. We aimed at studying the therapeutic potential of bone marrow mesenchymal stem cells (MSCs) in accelerating healing of acetaminophen-induced hepatotoxicity.

Results

This prospective study included 50 male albino rats divided into 2 groups: hepatotoxic group and non-hepatotoxic group. Hepatotoxicity was induced in experimental rats by acetaminophen and then stem cells were transplanted into the rats and their effects on the liver cells were assessed. After injection of BM MSCs, the cells reached the targeted tissues. They were established in the central veins and blood sinusoids in the liver tissue. The hepatotoxic liver showed degeneration and loss of normal hepatic architecture as well as necrotic areas and congestion mainly in the portal tract vessels, dilation of blood sinusoids, and infiltration by inflammatory cells around the central veins. In addition, there were abnormal nuclei either irregular in shape or showing loss of open face compared to the normal control group. The liver tissue in BM MSC-treated group showed restoration of normal architecture of the liver tissue.

Conclusion

Administration of MSCs has hepato-therapeutic effect on acetaminophen-induced hepatotoxicity in rats. The mechanism of this hepatoprotective effect may be through anti-inflammatory, anti-apoptotic, and immunomodulatory actions of MSCs.

Paeoniflorin ameliorates diabetic liver injury by targeting the TXNIP-mediated NLRP3 inflammasome in db/db mice

BACKGROUND

Diabetic liver injury (DLI) is a complication that damages the quality of life in diabetes patients. While paeoniflorin (PF) exhibits anti-inflammatory and antioxidant effects, no data are available on whether PF protects against DLI. Therefore, we evaluated the effects of PF on hepatic steatosis and inflammation in db/db mice, a type 2 diabetes model.

METHODS

In this study, we investigated the effects of PF on DLI using diabetic mice model (db/db mice) and high glucose (HG)-induced mouse AML12 cells. The effects of PF on TXNIP-mediated NLRP3 inflammasome in vivo and in vitro were evaluated by Western bloting, RT-PCR, immunohistochemistry (IHC) and immunofluorescence (IF) analysis. Through molecular docking experiments and cellular thermal shift assay (CETSA), we studied the binding ability of PF to thioredoxin-interacting protein (TXNIP). We use TXNIP siRNA to knock down TXNIP in AML12 cells.

RESULTS

We found that PF reversed abnormal liver function and liver steatosis in db/db mice, while blocking the release of inflammatory cytokines. These effects are associated with PF inhibition of the TXNIP/NLRP3 signaling pathway. Molecular docking experiments and CETSA also demonstrated that TXNIP is a likely target of PF. In HG-treated AML12 cells, TXNIP knockdown eliminated the beneficial effects of PF.

CONCLUSION

Using a combination of animal and in vitro experiments, this study demonstrated for the first time that PF ameliorates DLI through targeting the TXNIP-activated NLRP3 inflammasome. Thus, PF may be a potential therapeutic agent against DLI.

The Effect of Stem Cell Transplantation Therapy for Post Viral Chronic Liver Cell Failure on Associated Type II Diabetes Mellitus: A Pilot Study

BACKGROUND

It was observed that type II diabetes mellitus associated with chronic liver failure improved after stem cell transplantation. However, there were no adequate studies regarding this issue. The aim of this study was to evaluate the effect of stem cell transplantation on associated type II diabetes mellitus and on the liver function tests.

METHODS

This pilot study included 30 patients of post-hepatitis chronic liver failure who were classified into two groups: Group I included patients with chronic liver cell failure associated with type 2 diabetes. Group II included patients without type II diabetes. Autologous CD34+ and CD133+ stem cells were percutaneously infused into the portal vein. Responders (regarding the improvement of diabetes as well as improvement of liver condition) and non-responders were determined. Patients were followed up for one, three and six months after the intervention evaluating their three-hour glucose tolerance test, C- peptide (Fasting and postprandial), Child-Pugh score and performance score one month, three months, and six months after stem cell therapy.

RESULTS

Both synthetic and excretory functions of the liver were improved in 10 patients (66.66 %) of group I and in 12 patients (80 %) of group II. Significant improvement in the Oral Glucose Tolerance Test in the responders of both the groups was well defined from the 3rd month and this was comparable to changes in liver function tests and Child-Pugh score.

CONCLUSION

Successful stem cell therapy in chronic liver cell failure patients can improve but not cure the associating type 2 diabetes by improving insulin resistance.

Pro-inflammatory signalling and gut-liver axis in non-alcoholic and alcoholic steatohepatitis: Differences and similarities along the path

Non-alcoholic fatty liver disease (NAFLD) and alcohol-associated liver disease (ALD) represent a spectrum of injury, ranging from simple steatosis to steatohepatitis and cirrhosis. In humans, in fact, fatty changes in the liver, possibly leading to end-stage disease, were observed after chronic alcohol intake or in conditions of metabolic impairment. In this article, we examined the features and the pro-inflammatory pathways leading to non-alcoholic and alcoholic steatohepatitis. The involvement of several events (hits) and multiple inter-related pathways in the pathogenesis of these diseases suggest that a single therapeutic agent is unlikely to be an effective treatment strategy. Hence, a combination treatment towards multiple pro-inflammatory targets would eventually be required. Gut-liver crosstalk is involved not only in the impairment of lipid and glucose homoeostasis leading to steatogenesis, but also in the initiation of inflammation and fibrogenesis in both NAFLD and ALD. Modulation of the gut-liver axis has been suggested as a possible therapeutic approach since gut-derived components are likely to be involved in both the onset and the progression of liver damage. This review summarizes the translational mechanisms underlying pro-inflammatory signalling and gut-liver axis in non-alcoholic and alcoholic steatohepatitis. With a multitude of people being affected by liver diseases, identification of possible treatments and the elucidation of pathogenic mechanisms are elements of paramount importance.

Molecular and Pathological Events Involved in the Pathogenesis of Diabetes-Associated Nonalcoholic Fatty Liver Disease

Diabetes mellitus is a rising epidemic in most part of the world and is often associated with multiple organ disorders such as kidney, liver, and cardiovascular diseases. Liver is a major metabolic hub, and the metabolic disorders associated with diabetes result in liver dysfunctions culminating in spectrum of liver diseases such as fatty liver disorders, cirrhosis, and hepatocellular carcinoma. The intervention strategies to prevent diabetes-associated liver injury require an overall understanding of the key factors and molecular pathways which can be strategically targeted. The present review focuses on some of the key aspects of fatty acid metabolism, fetuin-A regulation, inflammatory pathways, and genetic factors associated with insulin resistance, dyslipidemia, hyperglycemia, oxidative stress, and so on involved in the nexus between diabetes and liver injury. Further recent interventions, pharmacological target, and newer therapeutic agents are discussed briefly for the better clinical management of diabetes-associated hepatic disorders.

Vector-free in vivo trans-determination of adult hepatic stem cells to insulin-producing cells

A reduction in the number of functional β-cells is the central pathological event in diabetes. Liver and ventral pancreas differentiates simultaneously in the same general domain of cells within embryonic endoderm. In addition, the precursor cell population being bi-potential may be targeted for either pancreas or liver development. Hepatic stem cells were redirected in vivo to functional insulin producing cells in a acetylaminofluorene-partial hepatectomy (AAF/PH) adult male rat model with/without GLP-1 treatment. In routine H&E histology and immunohistochemistry, stem cells resembled β cells in GLP-1 injected rats. Immunoblots revealed involvement of adenylate cyclase, TLR4 and PDX1 in insulin synthesis. Expression of genes (GLP-1R, MAFA, PDX1, INS1 and INS2) augmented in the GLP-1 treated regenerated liver. Results strongly indicated the key role of GLP-1 in the induction of insulin secretion in trans-determined reprogrammed cell in vivo. The present method being vector free poses no risk of vector spillover in the host and holds promise.

Activating the Chromatin by Noncoding RNAs

SIGNIFICANCE

The extent and breadth of transcription have recently been uncovered and this has revealed an extensive array of noncoding RNAs (ncRNAs). The biological role and significance of these ncRNAs have been realized and to date it appears that ncRNAs may have many important regulatory functions. ncRNAs are multifaceted and they induce a complexity of different types of transcriptional and posttranscriptional regulation, including gene activation. Recent Advances: Association of ncRNAs with gene activation is an important finding. Not only enhancer RNA (eRNA) but other types of ncRNAs, including small RNA (sRNA), long-noncoding RNA (lncRNA), microRNA (miRNA), and PIWI-associated RNA (piRNA), have also been implicated in gene activation. Interestingly, they often coincide with histone modifications that favor an open chromatin. In addition, these ncRNAs can recruit key factors important for transcription, including RNA polymerase II. They may directly bind the genomic DNA or act as scaffolds; alternatively, they may loop the chromatin to enhance transcription.

CRITICAL ISSUES

Although the role of small activating (sa)RNAs has been considerably studied, the roles of miRNAs and piRNAs in gene activation still need to be substantiated and issues of specificity require further studies.

FUTURE DIRECTIONS

The ncRNA field is coming out of its infancy and we are gaining a global picture of the importance of ncRNAs. However, detailed mechanisms of action of the different ncRNAs are still to be determined. This may reveal novel ways of transcriptional regulation, which will facilitate our ability to utilize these regulatory pathways for research and therapeutic purposes. Antioxid. Redox Signal. 29, 813-831.

Co-occurrence of opisthorchiasis and diabetes exacerbates morbidity of the hepatobiliary tract disease

Complications arising from infection with the carcinogenic liver fluke Opisthorchis viverrini cause substantial morbidity and mortality in Thailand and adjacent lower Mekong countries. In parallel, the incidence rate of diabetes mellitus (DM) is increasing in this same region, and indeed worldwide. Many residents in opisthorchiasis-endemic regions also exhibit DM, but the hepatobiliary disease arising during the co-occurrence of these two conditions remains to be characterized. Here, the histopathological profile during co-occurrence of opisthorchiasis and DM was investigated in a rodent model of human opisthorchiasis in which diabetes was induced with streptozotocin. The effects of excretory/secretory products from the liver fluke, O. viverrini (OVES) on hepatocyte and cholangiocyte responses during hyperglycemic conditions also were monitored. Both the liver fluke-infected hamsters (OV group) and hamsters with DM lost weight compared to control hamsters. Weight loss was even more marked in the hamsters with both opisthorchiasis and DM (OD group). Hypertrophy of hepatocytes, altered biliary canaliculi, and biliary hyperplasia were more prominent in the OD group, compared with OV and DM groups. Profound oxidative DNA damage, evidenced by 8-oxo-2'-deoxyguanosine, proliferating cell nuclear antigen, and periductal fibrosis characterized the OD compared to OV and DM hamsters. Upregulation of expression of cytokines in response to infection and impairment of the pathway for insulin receptor substrate (IRS)/phosphatidylinositol-3-kinases (PI3K)/protein kinase B (AKT) signaling attended these changes. In vitro, OVES and glucose provoked time- and dose-dependent effects on the proliferation of both hepatocytes and cholangiocytes. In overview, the co-occurrence of opisthorchiasis and diabetes exacerbated pathophysiological damage to the hepatobiliary tract. We speculate that opisthorchiasis and diabetes together aggravate hepatobiliary pathogenesis through an IRS/PI3K/AKT-independent pathway.

Diabetes Mellitus Prevents an Improvement in the Serum Albumin Level During Interferon-free Sofosbuvir-based Therapy for Chronic Hepatitis C Patients: A Multi-institutional Joint Study

Objective Interferon-free regimens of direct-acting antiviral agents have improved the treatment response for chronic hepatitis C virus (HCV) infection, and improvement in the serum albumin level during interferon-free therapy has been reported. The aim of this study was to identify the factors that influence the improvement in the serum albumin level in patients receiving interferon-free antiviral therapy. Methods This retrospective, multicenter study consisted of 471 Japanese patients with chronic hepatitis and compensated liver cirrhosis infected with HCV who completed 12-week interferon-free sofosbuvir (SOF)-based therapy [SOF plus ledipasvir for genotype 1 (n=276) and SOF with ribavirin for genotype 2 (n=195)]. We evaluated the changes in the serum albumin level from baseline to the end of treatment (ΔAlb). Results When compared with the normal-albumin group (baseline serum albumin >35 g/L, n=406), the low-albumin group (baseline serum albumin ≤35 g/L, n=65) showed a significant increase in the mean ΔAlb (5.5 g/L vs. 1.0 g/L, p<0.001). In the low-albumin group, a multivariate logistic regression analysis extracted diabetes mellitus as a negative predictive factor of median ΔAlb >5.0 g/L (odds ratio: 0.19, 95% confidence interval: 0.048-0.79, p=0.020). In the low-albumin group, the mean ΔAlb was significantly lower in the diabetic patients (n=14) than in the non-diabetic patients (n=51) (3.9 g/L and 5.7 g/L, p=0.049). Conclusion Interferon-free SOF-based therapy significantly improved the serum albumin in the low-albumin group patients with chronic HCV infection. However, the improvement in the serum albumin level was significantly lower in the diabetic patients than in the non-diabetic patients.

Diabetes Mellitus and Liver Surgery: The Effect of Diabetes on Oxidative Stress and Inflammation

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycaemia and high morbidity worldwide. The detrimental effects of hyperglycaemia include an increase in the oxidative stress (OS) response and an enhanced inflammatory response. DM compromises the ability of the liver to regenerate and is particularly associated with poor prognosis after ischaemia-reperfusion (I/R) injury. Considering the growing need for knowledge of the impact of DM on the liver following a surgical procedure, this review aims to present recent publications addressing the effects of DM (hyperglycaemia) on OS and the inflammatory process, which play an essential role in I/R injury and impaired hepatic regeneration after liver surgery.

Effects of polysaccharide from Physalis alkekengi var. francheti on liver injury and intestinal microflora in type-2 diabetic mice

CONTEXT

Diabetic liver injury is a serious diabetic complication. The alterations of intestinal microbiota play an important role in induction and promotion of liver injury progression. Physalis alkekengi L. var. francheti (Mast.) Makino (Solanaceae) has been used as a water decoction for treating diabetes.

OBJECTIVE

To study the effects of a polysaccharide (PPSB) from Physalis alkekengi var. francheti on liver injury and intestinal microflora in type-2 diabetic mice.

MATERIALS AND METHODS

Streptozotocin (160 mg/kg) was injected i.p. for 3 days to build model. The diabetic mice were randomly divided into four groups together with control group (10 mice in each group). The doses of PPSB were 50 and 100 mg/kg, respectively. After 5 weeks administration, level of blood glucose, ALT and AST were measured. Alterations of intestinal microflora, and protein expression of TGF-β1, TNF-α and DCN were detected.

RESULTS

Level of blood glucose decreased from (25.38 ± 2.21) mmol/L to (18.01 ± 2.53) mmol/L, ALT and AST decreased to (24.67 ± 4.86) U/L and (30.84 ± 7.50) U/L in PPSB-H group. Lactobacillus, Clostridium butyricum, and Bacteroides increased remarkably with increasing concentration of PPSB, but Enterobacter was inhibited. The relative expression of TGF-β1 and TNF-α decreased to (0.70 ± 0.17) and (0.39 ± 0.06), and the expression of DCN increased to (0.65 ± 0.13).

DISCUSSION AND CONCLUSIONS

Probiotics have been promoted by PPSB, and protein expressions have been modulated in the progression of liver injury. PPSB could be used as a natural agent for treating diabetic liver injury and intestinal microflora imbalance.

Extracts of Magnolia Species-Induced Prevention of Diabetic Complications: A Brief Review

Diabetic complications are the major cause of mortality for the patients with diabetes. Oxidative stress and inflammation have been recognized as important contributors for the development of many diabetic complications, such as diabetic nephropathy, hepatopathy, cardiomyopathy, and other cardiovascular diseases. Several studies have established the anti-inflammatory and oxidative roles of bioactive constituents in Magnolia bark, which has been widely used in the traditional herbal medicines in Chinese society. These findings have attracted various scientists to investigate the effect of bioactive constituents in Magnolia bark on diabetic complications. The aim of this review is to present a systematic overview of bioactive constituents in Magnolia bark that induce the prevention of obesity, hyperglycemia, hyperlipidemia, and diabetic complications, including cardiovascular, liver, and kidney.