Improving treatment and liver fibrosis outcomes with metformin in HCV-HIV co-infected and HCV mono-infected patients with insulin resistance: study protocol for a randomized controlled trial

Regulation of AMPK activation by extracellular matrix stiffness in pancreatic cancer

The adenosine monophosphate (AMP)-activated protein kinase (AMPK) sits at a central node in the regulation of energy metabolism and tumor progression. AMPK is best known to sense high cellular ADP or AMP levels, which indicate the depletion of energy stores. Previous studies have shown that the low expression of phosphorylated AMPK is associated with a poor prognosis of pancreatic cancer. In this study, we report that AMPK is also highly sensitive to extracellular matrix (ECM) stiffness. We found that AMPK is activated in cells when cultured under low ECM stiffness conditions and is functionally required for the metabolic switch induced by ECM stiffness. This regulation of AMPK requires the Hippo kinases but not LKB1/CaMKKβ. Hippo kinases directly phosphorylate AMPKα at Thr172 to activate AMPK at low ECM stiffness. Furthermore, we found AMPK activity is inhibited in patients with pancreatic ductal adenocarcinoma (PDAC) with high ECM stiffness and is associated with a poor survival outcome. The activation of Hippo kinases by ROCK inhibitor Y-27632 in combination with the mitochondrial inhibitor metformin synergistically activates AMPK and dramatically inhibits PDAC growth. Together, these findings establish a novel model for AMPK regulation by the mechanical properties of ECMs and provide a rationale for simultaneously targeting the ECM stiffness-Hippo kinases-AMPK signaling and low glucose-LKB1-AMPK signaling pathways as an effective therapeutic strategy against PDAC.

Metformin as adjuvant treatment in hepatitis C virus infections and associated complications

Hepatitis C virus is an important global cause of hepatitis and subsequently cirrhosis and hepatocellular carcinoma. These infections may also cause extrahepatic manifestations, including insulin resistance and type 2 diabetes mellitus. These two complications can potentially reduce sustained virologic responses (SVR) in some drug regimens for this infection. Metformin has important biochemical effects that can limit viral replication in cellular cultures and can improve the response to antiviral drug therapy based on ribavirin and interferon. Clinical studies comparing treatment regimens with interferon, ribavirin, metformin with these regimens without metformin have demonstrated that metformin increases viral clearance, establishes higher rates of SVRs, and increases insulin sensitivity. Metformin also reduces the frequency of hepatocellular carcinoma in patients who have had SVRs. Larger treatment trials are needed to determine metformin's short-term and long-term treatment effects in patients with diabetes using newer antiviral drugs. In particular, if metformin reduces the frequency of cirrhosis and hepatocellular carcinoma, this would significantly reduce the morbidity and mortality associated with this infection.

Cellular protein markers, therapeutics, and drug delivery strategies in the treatment of diabetes-associated liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix due to chronic injuries, such as viral infection, alcohol abuse, high-fat diet, and toxins. Liver fibrosis is reversible before it progresses to cirrhosis and hepatocellular carcinoma. Type 2 diabetes significantly increases the risk of developing various complications including liver diseases. Abundant evidence suggests that type 2 diabetes and liver diseases are bidirectionally associated. Patients with type 2 diabetes experience more severe symptoms and accelerated progression of live diseases. Obesity and insulin resistance resulting from hyperlipidemia and hyperglycemia are regarded as the two major risk factors that link type 2 diabetes and liver fibrosis. This review summarizes possible mechanisms of the association between type 2 diabetes and liver fibrosis. The cellular protein markers that can be used for diagnosis and therapy of type 2 diabetes-associated liver fibrosis are discussed. We also highlight the potential therapeutic agents and their delivery systems that have been investigated for type 2 diabetes-associated liver fibrosis.

The potential hepatoprotective effect of metformin in hepatitis C virus-infected adolescent patients with beta thalassemia major: Randomised clinical trial

BACKGROUND

Iron overload-induced oxidative stress and transfusion-acquired hepatitis C virus (HCV) infection are the main reasons of liver damage in beta thalassemia major (β-TM).

OBJECTIVES

Based on metformin's hepatic benefits in nondiabetic populations, the study aims to investigate the safety and the potential hepatoprotective effect of metformin in HCV-infected β-TM adolescent patients.

METHODS

This was a prospective, randomised, parallel, controlled, open-label study in which 60 HCV-infected β-TM adolescent patients aged 11 to 18 years and receiving no antiviral therapy were selected and randomly assigned to treatment or control group in 1:1 allocation. Both groups were receiving β-TM standard-of-care regimen, whereas metformin (500 mg, twice daily) was added to the treatment group's regimen only. Patients were prospectively followed up for 6 months with assessment of liver biochemical profile, oxidative stress markers, liver fibrosis, clinical symptom improvement and metformin's adverse effects.

RESULTS

Aspartate aminotransferase serum level decreased significantly over time in the treatment group only (P = .013). However, improvement was not clinically significant and did not attain normality. Change in total antioxidant capacity and malondialdehyde serum levels indicated significantly improved oxidative stress status in the treatment group versus significant deterioration in the control group (P < .001). Fibrosis grade improvement was observed in 14 patients in the treatment group versus one improved case in the control group.

CONCLUSION

The use of metformin in HCV-infected β-TM adolescent patients as an adjuvant antioxidant hepatoprotective agent is promising and can improve liver damage.

A geroscience perspective on immune resilience and infectious diseases: a potential case for metformin

We are in the midst of the global pandemic. Though acute respiratory coronavirus (SARS-COV2) that leads to COVID-19 infects people of all ages, severe symptoms and mortality occur disproportionately in older adults. Geroscience interventions that target biological aging could decrease risk across multiple age-related diseases and improve outcomes in response to infectious disease. This offers hope for a new host-directed therapeutic approach that could (i) improve outcomes following exposure or shorten treatment regimens; (ii) reduce the chronic pathology associated with the infectious disease and subsequent comorbidity, frailty, and disability; and (iii) promote development of immunological memory that protects against relapse or improves response to vaccination. We review the possibility of this approach by examining available evidence in metformin: a generic drug with a proven safety record that will be used in a large-scale multicenter clinical trial. Though rigorous translational research and clinical trials are needed to test this empirically, metformin may improve host immune defenses and confer protection against long-term health consequences of infectious disease, age-related chronic diseases, and geriatric syndromes.

Metformin as adjunctive therapy for dengue in overweight and obese patients: a protocol for an open-label clinical trial (MeDO)

Background:  Dengue is a disease of major global importance. While most symptomatic infections are mild, a small proportion of patients progress to severe disease with risk of hypovolaemic shock, organ dysfunction and death.  In the absence of effective antiviral or disease modifying drugs, clinical management is solely reliant on supportive measures. Obesity is a growing problem among young people in Vietnam and is increasingly recognised as an important risk factor for severe dengue, likely due to alterations in host immune and inflammatory pathways. Metformin, a widely used anti-hyperglycaemic agent with excellent safety profile, has demonstrated potential as a dengue therapeutic in vitro and in a retrospective observational study of adult dengue patients with type 2 diabetes.  This study aims to assess the safety and tolerability of metformin treatment in overweight and obese dengue patients, and investigate its effects on several clinical, immunological and virological markers of disease severity. Methods: This open label trial of 120 obese/overweight dengue patients will be performed in two phases, with a metformin dose escalation if no safety concerns arise in phase one. The primary endpoint is identification of clinical and laboratory adverse events.  Sixty overweight and obese dengue patients aged 10-30 years will be enrolled at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Participants will complete a 5-day course of metformin therapy and be compared to a non-treated group of 60 age-matched overweight and obese dengue patients. Discussion:  Previously observed antiviral and immunomodulatory effects of metformin make it a promising dengue therapeutic candidate in appropriately selected patients. This study will assess the safety and tolerability of adjunctive metformin in the management of overweight and obese young dengue patients, as well as its effects on markers of viral replication, endothelial dysfunction and host immune responses.  Trial registration: ClinicalTrials.gov: NCT04377451 (May 6 th 2020).

Metformin as adjunctive therapy for dengue in overweight and obese patients: a protocol for an open-label clinical trial (MeDO)

Background:  Dengue is a disease of major global importance. While most symptomatic infections are mild, a small proportion of patients progress to severe disease with risk of hypovolaemic shock, organ dysfunction and death.  In the absence of effective antiviral or disease modifying drugs, clinical management is solely reliant on supportive measures. Obesity is a growing problem among young people in Vietnam and is increasingly recognised as an important risk factor for severe dengue, likely due to alterations in host immune and inflammatory pathways. Metformin, a widely used anti-hyperglycaemic agent with excellent safety profile, has demonstrated potential as a dengue therapeutic in vitro and in a retrospective observational study of adult dengue patients with type 2 diabetes.  This study aims to assess the safety and tolerability of metformin treatment in overweight and obese dengue patients, and investigate its effects on several clinical, immunological and virological markers of disease severity.

Methods: This open label trial of 120 obese/overweight dengue patients will be performed in two phases, with a metformin dose escalation if no safety concerns arise in phase one. The primary endpoint is identification of clinical and laboratory adverse events.  Sixty overweight and obese dengue patients aged 10-30 years will be enrolled at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Participants will complete a 5-day course of metformin therapy and be compared to a non-treated group of 60 age-matched overweight and obese dengue patients.

Discussion:  Previously observed antiviral and immunomodulatory effects of metformin make it a promising dengue therapeutic candidate in appropriately selected patients. This study will assess the safety and tolerability of adjunctive metformin in the management of overweight and obese young dengue patients, as well as its effects on markers of viral replication, endothelial dysfunction and host immune responses. 

Trial registration: ClinicalTrials.gov: NCT04377451 (May 6 ^th 2020).

Design, fabrication, and optimization of a dual function three-layer scaffold for controlled release of metformin hydrochloride to alleviate fibrosis and accelerate wound healing

Abnormal wound healing caused by the over-expression of collagen and fibronectin leads to fibrosis, the major complication of all treatment modalities. A three-layer nanofiber scaffold was designed, optimized, and fabricated. This scaffold comprised two supportive polycaprolactone (PCL)-chitosan layers on the sides and a polyvinyl alcohol (PVA)-metformin hydrochloride (metformin-HCl) in the middle. The physico-chemical properties of scaffold, such as mechanical characteristics, degradation, swelling, and in-vitro drug release, were evaluated. The biological tests, including cell viability in response to metformin-HCl and Tween 80, scaffold biocompatibility, cell attachment, and antibacterial activity, were further conducted. The wound healing effect of scaffold loaded with metformin-HCl (MSc+Met) was assessed in donut-shaped silicone splints in rats. Histopathological and immunohistochemical evaluation as well as mRNA expression levels of fibrosis markers were also studied. SEM images indicated a uniform, bead-less morphology and high porosity. Surface modification of scaffold by Tween 80 improved the surface hydrophilicity and enhanced the adhesion and proliferation of fibroblasts. The scar area on day 15 in MSc+Met was significantly lower than that of other groups. Histopathological and immunohistochemical evaluation revealed that group MSc+Met was the best, having significantly lower inflammation, higher angiogenesis, the smallest scar width and depth, maximum epitheliogenesis score, and the most optimal modulation of collagen density. Local administration of metformin-HCl substantially down-regulated the expression of fibrosis-involved genes: transforming growth factor (TGF-β1), collagen type 1 (Col-I), fibronectin, collagen type 3 (Col-III), and alpha-smooth muscle actin (α-SMA). Inhibiting these genes alleviates scar formation but delays wound healing; thus, an engineered scaffold was used to prevent delay in wound healing. These results provided evidence for the first time to introduce an anti-fibrogenic slow-releasing scaffold, which acts in a dual role, both alleviating fibrosis and accelerating wound healing.

COVID-19 and Diabetes Mellitus: May Old Anti-diabetic Agents Become the New Philosopher's Stone?

Corona virus infectious disease (COVID-19) is a new pandemic. In subjects with diabetes mellitus, infection may be more frequent and severe. We discuss the potential contribution of two traditional oral antidiabetic agents, metformin and pioglitazone, to the improvement of liver injury in COVID-19. Clearly, further experience is needed to shed light on these hypotheses.

Diabetes Mellitus and Risk of Hepatic Fibrosis/Cirrhosis

Development of cirrhosis is two- to threefold greater in patients with diabetes mellitus (DM), and in this setting, the prevalence of cirrhosis is surging worldwide. The present review served to examine clinical ties between DM and liver fibrosis and hepatic cirrhosis and explore related biologic mechanisms. Pathways contributing to various etiologies of cirrhosis in conjunction with DM were key investigative targets.

Hepatitis C virus infection is associated with hepatic and adipose tissue insulin resistance that improves after viral cure

BACKGROUND

Chronic hepatitis C (CHC) is associated with systemic insulin resistance, yet there are limited data on the tissue-specific contribution in vivo to this adverse metabolic phenotype, and the effect of HCV cure.

METHODS

We examined tissue-specific insulin sensitivity in a cohort study involving 13 patients with CHC compared to 12 BMI-matched healthy control subjects. All subjects underwent a two-step clamp incorporating the use of stable isotopes to measure carbohydrate and lipid flux (hepatic and global insulin sensitivity) with concomitant subcutaneous adipose tissue microdialysis and biopsy (subcutaneous adipose tissue insulin sensitivity). Investigations were repeated in seven patients with CHC following antiviral therapy with a documented sustained virological response.

RESULTS

Adipose tissue was more insulin resistant in patients with CHC compared to healthy controls, as evidence by elevated glycerol production rate and impaired insulin-mediated suppression of both circulating nonesterified fatty acids (NEFA) and adipose interstitial fluid glycerol release during the hyperinsulinaemic euglycaemic clamp. Hepatic and muscle insulin sensitivity were similar between patients with CHC and controls. Following viral eradication, hepatic insulin sensitivity improved as demonstrated by a reduction in endogenous glucose production rate. In addition, circulating NEFA decreased with sustained virological response (SVR) and insulin was more effective at suppressing adipose tissue interstitial glycerol release with a parallel increase in the expression of insulin signalling cascade genes in adipose tissue consistent with enhanced adipose tissue insulin sensitivity.

CONCLUSION

Chronic hepatitis C patients have profound subcutaneous adipose tissue insulin resistance in comparison with BMI-matched controls. For the first time, we have demonstrated that viral eradication improves global, hepatic and adipose tissue insulin sensitivity.

Metformin Mitigates Fibrosis and Glucose Intolerance Induced by Doxorubicin in Subcutaneous Adipose Tissue

Doxorubicin (DX) is a chemotherapeutic drug that is used in clinical practice that promotes deleterious side effects in non-tumor tissues such as adipose tissue. We showed that DX leads to extensive damage in adipose tissue via a disruption in 5′-adenosine monophosphate-activated protein kinase (AMPK) and PPAR-gamma signaling. Thus, we investigated whether co-treatment with the biguanide drug metformin (MET) could prevent the side effects of DX through the activation of AMPK in adipose tissue. The goal of the present study was to verify the effects of DX and adjuvant MET treatment in subcutaneous adipose tissue (SAT) and to determine whether MET could protect against chemotherapy-induced side effects. C57/BL6 mice received DX hydrochloride (2.5 mg/kg) intraperitoneally 2 times per week for 2 weeks (DX), concomitantly or not, with MET administration (300 mg/kg oral daily) (DX + MET). The control group (CTRL) was pair-fed according to the food consumption of the DX group. After euthanasia, adipose tissue fat pads were collected, and SAT was extracted so that adipocytes could be isolated. Glucose uptake was then measured, and histological, gene, and protein analyses were performed. One-way analysis of variance was also performed, and significance was set to 5%. DX reduced retroperitoneal fat mass and epididymal pads and decreased glycemia. In cultured primary subcutaneous adipocytes, mice in the DX group had lower glucose uptake when stimulated with insulin compared with mice in the CTRL group. Adipocytes in the DX group exhibited a reduced area, perimeter, and diameter; decreased adiponectin secretion; and decreased fatty acid synthase gene expression. SAT from MET-treated mice also showed a reduction in collagen deposition. Treatment with MET prevented fibrosis and restored glucose uptake in SAT after insulin stimulation, yet the drug was unable to prevent other side effects of DX such as tissue loss and inflammatory response.

Racial Disparities in Hepatitis C Treatment Eligibility

BACKGROUND

Hepatitis C (HCV) is more prevalent in African Americans than in any other racial group in the United States. However, African Americans are more likely to be deemed ineligible for HCV treatment than non-African Americans. There has been limited research into the origins of racial disparities in HCV treatment eligibility.

AIM

The purpose of this study was to compare medical and non-medical characteristics commonly assessed in clinical practice that could potentially contribute to HCV treatment ineligibility disparities between African American and non-African American patients.

MATERIAL AND METHODS

Patients with confirmed HCV RNA considering treatment (n = 309) were recruited from university-affiliated and VA liver and infectious disease clinics.

RESULTS

African Americans and non-African Americans did not differ in prevalence of lifetime and current psychiatric disorders and risky behaviors, and HCV knowledge. HCV clinical characteristics were similar between both groups in terms of HCV exposure history, number of months aware of HCV diagnosis, stage of fibrosis, and HCV virologic levels. African Americans did have higher proportions of diabetes, renal disease, and bleeding ulcer.

CONCLUSIONS

No clinical evidence was found to indicate that African Americans should be more often deemed ineligible for HCV treatment than other racial groups. Diabetes and renal disease do not fully explain the HCV treatment ineligibility racial disparity, because HCV patients with these conditions are priority patients for HCV treatment because of their greater risk for cirrhosis, steatosis, and hepatocellular carcinoma. The findings suggest that an underlying contributor to the HCV treatment eligibility disparity disfavoring African Americans could be racial discrimination.

Screening for nonalcoholic steatohepatitis by using cytokeratin 18 and transient elastography in HIV mono-infection

BACKGROUND AND AIM

HIV-infected individuals are at high risk of developing nonalcoholic steatohepatitis (NASH), a leading cause of end-stage liver disease in Western countries. Nonetheless, due to the invasiveness of liver biopsy, NASH remains poorly understood in HIV mono-infection. We aimed to characterize the prevalence and predictors of NASH in unselected HIV mono-infected patients by means of non-invasive diagnostic tools.

METHODS

HIV-infected adults without significant alcohol intake or co-infection with hepatitis B or C underwent a routine screening program employing transient elastography (TE) with controlled attenuation parameter (CAP) and the serum biomarker cytokeratin-18 (CK-18). NASH was diagnosed non-invasively as the coexistence of fatty liver (CAP ≥248 dB/m) and CK-18 >246 U/L. Identified cases of NASH were offered a diagnostic liver biopsy. Predictors of NASH were determined by multivariate logistic regression analysis.

RESULTS

202 consecutive HIV mono-infected patients were included. NASH was non-invasively diagnosed in 23 cases (11.4%). Among them, 17 underwent a liver biopsy, and histology confirmed NASH in all cases. The prevalence of NASH was higher in patients with hypertriglyceridemia (17.1%), insulin resistance defined by homeostasis model for assessment of insulin resistance (HOMA-IR) (25%), those with detectable HIV viral load (42.9%) and those with elevated ALT (53.6%). After adjustment, higher HOMA-IR (adjusted odds ratio [aOR] = 1.20, 95% CI 1.01-1.43; p = 0.03) and ALT (aOR = 2.39, 95% CI 1.50-3.79; p<0.001) were independent predictors of NASH.

CONCLUSIONS

NASH, diagnosed by a non-invasive diagnostic approach employing CK-18 and TE with CAP, is common in unselected HIV mono-infected individuals, particularly in the presence of insulin resistance and elevated ALT.

Baicalin Ameliorates Experimental Liver Cholestasis in Mice by Modulation of Oxidative Stress, Inflammation, and NRF2 Transcription Factor

Experimental cholestatic liver fibrosis was performed by bile duct ligation (BDL) in mice, and significant liver injury was observed in 15 days. Administration of baicalin in mice significantly ameliorates liver fibrosis. Experimental cholestatic liver fibrosis was associated with induced gene expression of fibrotic markers such as collagen I, fibronectin, alpha smooth muscle actin (SMA), and connective tissue growth factor (CTGF); increased inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2); increased oxidative stress and reactive oxygen species- (ROS-) inducing enzymes (NOX2 and iNOS); dysfunctional mitochondrial electron chain complexes; and apoptotic/necrotic cell death markers (DNA fragmentation, caspase 3 activity, and PARP activity). Baicalin administration on alternate day reduced fibrosis along with profibrotic gene expression, proinflammatory cytokines, oxidative stress, and cell death whereas improving the function of mitochondrial electron transport chain. We observed baicalin enhanced NRF2 activation by nuclear translocation and induced its target genes HO-1 and GCLM, thus enhancing antioxidant defense. Interplay of oxidative stress/inflammation and NRF2 were key players for baicalin-mediated protection. Stellate cell activation is crucial for initiation of fibrosis. Baicalin alleviated stellate cell activation and modulated TIMP1, SMA, collagen 1, and fibronectin in vitro. This study indicates that baicalin might be beneficial for reducing inflammation and fibrosis in liver injury models.