Coinfection with HIV-1 alleviates iron accumulation in patients with chronic hepatitis C virus infection

Serum hepcidin levels in chronic liver disease: a systematic review and meta-analysis

OBJECTIVES

Dysregulation of hepcidin-iron axis is presumed to account for abnormal iron status in patients with chronic liver disease (CLD). Our aim is to determine the effect of specific etiologies of CLD and of cirrhosis on serum hepcidin levels.

METHODS

PubMed, Embase, Web of Science were searched for studies comparing serum hepcidin levels in patients with CLD to that in controls using enzyme-linked immunosorbent assay. The study was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Guidelines. Statistical analysis was carried out with STATA using random effects model to calculate the mean difference (MD) between two groups.

RESULTS

Hepcidin levels were significantly lower in subjects with hepatitis C virus (16 studies) [MD -1.6 (95 % CI: -2.66 to -0.54), p<0.01] and alcoholic liver disease (3 studies) [MD -0.84 (95 % CI: -1.6 to -0.07), p=0.03] than controls. Serum hepcidin was significantly higher in subjects with non-alcoholic fatty liver disease (12 studies) [MD 0.62 (95 % CI: 0.21 to 1.03), p<0.01], but did not differ in subjects with hepatitis B and controls (eight studies) [MD -0.65 (95 % CI: -1.47 to 0.16), p=0.12]. Hepcidin levels were significantly lower in patients with cirrhosis of any etiology (four studies) [MD -1.02 (CI: -1.59 to -0.45), p<0.01] vs. controls (CI: confidence interval).

CONCLUSIONS

Serum hepcidin levels are altered in common forms of CLD albeit not in a consistent direction. Additional study is needed to determine how changes in hepcidin levels are related to dysregulation of iron metabolism in CLD.

Effects of Feeding 5-Aminolevulinic Acid on Iron Status in Weaned Rats from the Female Rats during Gestation and Lactation

Using female Sprague−Dawley (SD) rats as a model, the current study aimed to investigate whether feeding 5-aminolevulinic acid (5-ALA) to female SD rats during gestation and lactation can affect the iron status of weaned rats and provide new ideas for the iron supplementation of piglets. A total of 27 pregnant SD rats were randomly assigned to three treatments in nine replicates, with one rat per litter. Dietary treatments were basal diet (CON), CON + 50 mg/kg 5-ALA (5-ALA50), and CON + 100 mg/kg 5-ALA (5-ALA100). After parturition, ten pups in each litter (a total of 270) were selected for continued feeding by their corresponding mother, and the pregnant rats were fed diets containing 5-ALA (0, 50 and 100 mg/kg diet) until the newborn pups were weaned at 21 days. The results showed that the number of red blood cells (RBCs) in weaned rats in the 5-ALA100 group was significantly higher (p < 0.05) than that in the CON or 5-ALA50 group. The diet with 5-ALA significantly increased (p < 0.05) the hemoglobin (HGB) concentration, hematocrit (HCT) level, serum iron (SI) content, and transferrin saturation (TSAT) level in the blood of weaned rats, as well as the concentration of Hepcidin in the liver and serum of weaned rats and the expression of Hepcidin mRNA in the liver of weaned rats, with the 5-ALA100 group having the highest (p < 0.05) HGB concentration in the weaned rats, and the 5-ALA50 group having the highest (p < 0.05) Hepcidin concentration in serum and in the expression of Hepcidin mRNA in the liver of weaned rats. The other indicators between the 5-ALA groups had no effects. However, the level of total iron binding capacity (TIBC) was significantly decreased (p < 0.05) in the 5-ALA50 group. Moreover, the iron content in the liver of weaned rats fed with 5-ALA showed an upward trend (p = 0.085). In addition, feeding a 5-ALA-supplemented diet could also significantly reduce (p < 0.05) the expression of TfR1 mRNA in the liver of weaning rats (p < 0.05), and the expression of Tfr1 was not affected between 5-ALA groups. In conclusion, dietary supplementation with 5-ALA could improve the blood parameters, increase the concentration of Hepcidin in the liver and serum, and affect the expression of iron-related genes in the liver of weaned rats. Moreover, it is appropriate to add 50 mg/kg 5-ALA to the diet under this condition.

HIV-1 infection in sickle cell disease and sickle cell trait: role of iron and innate response

INTRODUCTION

Sickle cell disease (SCD), an inherited hemoglobinopathy, affects primarily African Americans in the U.S.A. In addition, about 15% African Americans carry sickle cell trait (SCT). Despite the risk associated with blood transfusions, SCD patients have lower risk of acquiring HIV-1 infection. SCT individuals might also have some protection from HIV-1 infection.

AREAS COVERED

Here, we will review recent and previous studies with the focus on molecular mechanisms that might underlie and contribute to the protection of individuals with SCD and SCT from HIV-1 infection. As both of these conditions predispose to hemolysis, we will focus our discussion on the effects of systemic and intracellular iron on HIV-1 infection and progression. We will also review changes in iron metabolism and activation of innate antiviral responses in SCD and SCT and their effects on HIV-1 infection.

EXPERT OPINION

Previous studies, including ours, showed that SCD might protect from HIV-1 infection. This protection is likely due to the upregulation of complex protein network in response to hemolysis, hypoxia and interferon signaling. These findings are important not only for HIV-1 field but also for SCD cure efforts as antiviral state of SCD patients may adversely affect lentivirus-based gene therapy efforts.

Hepatic transferrin plays a role in systemic iron homeostasis and liver ferroptosis

Although the serum-abundant metal-binding protein transferrin (encoded by the Trf gene) is synthesized primarily in the liver, its function in the liver is largely unknown. Here, we generated hepatocyte-specific Trf knockout mice (Trf-LKO), which are viable and fertile but have impaired erythropoiesis and altered iron metabolism. Moreover, feeding Trf-LKO mice a high-iron diet increased their susceptibility to developing ferroptosis-induced liver fibrosis. Importantly, we found that treating Trf-LKO mice with the ferroptosis inhibitor ferrostatin-1 potently rescued liver fibrosis induced by either high dietary iron or carbon tetrachloride (CCl4) injections. In addition, deleting hepatic Slc39a14 expression in Trf-LKO mice significantly reduced hepatic iron accumulation, thereby reducing ferroptosis-mediated liver fibrosis induced by either a high-iron diet or CCl4 injections. Finally, we found that patients with liver cirrhosis have significantly lower levels of serum transferrin and hepatic transferrin, as well as higher levels of hepatic iron and lipid peroxidation, compared with healthy control subjects. Taken together, these data indicate that hepatic transferrin plays a protective role in maintaining liver function, providing a possible therapeutic target for preventing ferroptosis-induced liver fibrosis.

HIV and Aging in Mainland China: Implications for Control and Prevention Research

PURPOSE OF REVIEW

The last 15 years have witnessed a dramatic change in HIV-related epidemiology amidst improvements in treatment and care in China. With proper treatment, HIV is now considered a chronic disease. As a consequence, many people living with HIV (PLWH) now present age-related comorbidities. We reviewed 13 topical issues concerning the epidemiology of aging with HIV in mainland China.

RESULTS

Many of aging-related issues associated with the biological and physical aspects of living with HIV addressed in mainland China are consistent with the global literature. Greater prevalence of age-related comorbidities among PLWH was observed. Beyond biological mechanisms associated with HIV infection and traditional risk factors, other factors play a vital role in the aging process among PLWH. A stronger focus on screening, prevention, and management of non-HIV co-morbidities among PLWH is now warranted. Macro-social factors need to be integrated into next generation of clinical and/or behavioral HIV research to inform disease progression and management as well as prevention.

Non-neutralizing epitopes induce robust hepatitis C virus (HCV)-specific antibody-dependent CD56+ natural killer cell responses in chronic HCV-infected patients

Natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (NK-ADCC) is of considerable interest in viral infection. However, little is known about NK-ADCC responses in chronic hepatitis C virus (HCV) infection. In this study, impaired non-specific antibody-dependent CD56⁺ NK cell responses were observed in chronic HCV infection, as shown by decreased degranulation (extracellular CD107a expression) and interferon (IFN)-γ production in response to antibody-bound P815 cells. A peptide pool composed of epitopes recognized by anti-HCV-E1/E2 antibodies could induce pronounced HCV-specific antibody-dependent NK cell responses in sera from approximately half the chronic HCV carriers. Additionally, HCV-specific epitopes with the capacity to induce robust NK-ADCC activity were identified. Five linear NK-ADCC epitopes (aa211-aa217, aa384-aa391, aa464-aa475, aa544-aa551 and aa648-aa659 of the HCV envelope) were identified and do not overlap with putative linear neutralizing epitopes. This study revealed the dysfunctional characteristics of antibody-dependent CD56⁺ NK cell responses in chronic HCV carriers. The key non-neutralizing NK-ADCC epitopes identified in this study may act as new targets for immunological intervention.

Liver Damage in Patients with HCV/HIV Coinfection Is Linked to HIV-Related Oxidative Stress

HIV infection aggravates the progression of liver damage in HCV-coinfected patients, with the underlying pathogenesis being multifactorial. Although high level of oxidative stress has been observed frequently in patients infected with HIV or HCV, the status of oxidative stress in HIV/HCV coinfection and its contribution to HCV liver damage have not been determined. This study involved 363 HBsAg-negative, anti-HCV-positive former blood donors recruited from a village in central China in July 2005; of these, 140 were positive for HIV. Of these 363 subjects, 282 were successfully followed up through July 2009. HIV/HCV-coinfected subjects had higher rates of end-stage liver disease-related death than those monoinfected with HCV. Liver ultrasound manifestations were poor in HIV-positive than in HIV-negative individuals, in both chronic HCV carriers and those with resolved HCV. Serum concentrations of total glutathione (tGSH), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), GSSG, and reduced GSH were higher in HIV-positive than HIV-negative subjects. GSSG concentrations were higher in HIV-infected subjects with abnormal ALT/AST levels than in those with normal ALT/AST levels and were associated with poorer liver ultrasound manifestations. These finding indicated that HIV infection accelerated HCV-associated liver damage in HIV/HCV-coinfected individuals. Increased oxidative stress, induced primarily by HIV coinfection, may contribute to aggravated liver damage.

Hepatitis C in human immunodeficiency virus co-infected individuals: Is this still a "special population"?

A substantial proportion of individuals with chronic hepatitis C virus (HCV) are co-infected with human immunodeficiency virus (HIV). Co-infected individuals are traditionally considered as one of the "special populations" amongst those with chronic HCV, mainly because of faster progression to end-stage liver disease and suboptimal responses to treatment with pegylated interferon alpha and ribavirin, the benefits of which are often outweighed by toxicity. The advent of the newer direct acting antivirals (DAAs) has given hope that the majority of co-infected individuals can clear HCV. However the "special population" designation may prove an obstacle for those with co-infection to gain access to the new agents, in terms of requirement for separate pre-licensing clinical trials and extensive drug-drug interaction studies. We review the global epidemiology, natural history and pathogenesis of chronic hepatitis C in HIV co-infection. The accelerated course of chronic hepatitis C in HIV co-infection is not adequately offset by successful combination antiretroviral therapy. We also review the treatment trials of chronic hepatitis C in HIV co-infected individuals with DAAs and compare them to trials in the HCV mono-infected. There is convincing evidence that HIV co-infection no longer diminishes the response to treatment against HCV in the new era of DAA-based therapy. The management of HCV co-infection should therefore become a priority in the care of HIV infected individuals, along with public health efforts to prevent new HCV infections, focusing particularly on specific patient groups at risk, such as men who have sex with men and injecting drug users.