Cardio-, hepato- and pneumoprotective effects of autophagy checkpoint inhibition by targeting DBI/ACBP

DBI/ACBP (diazepam binding inhibitor, also known as acyl coenzyme A binding protein), acts as a paracrine inhibitor of macroautophagy/autophagy. We characterized a monoclonal antibody neutralizing mouse DBI/ACBP (a-DBI) for its cytoprotective effects on several organs (heart, liver and lung) that were damaged by surgical procedures (ligation of coronary and hepatic arteries or bile duct ligation), a variety of different toxins (acetaminophen, bleomycin, carbon tetrachloride or concanavalin A) or a methionine/choline-deficient diet (MCD). In all these models of organ damage, a-DBI prevents cell loss, inflammation and fibrosis through pathways that are blocked by pharmacological or genetic inhibition of autophagy. The hepatoprotective effects of a-DBI against MCD are mimicked by three alternative strategies to block DBI/ACBP signaling, in particular (i) induction of DBI/ACBP-specific autoantibodies, (ii) tamoxifen-inducible knockout of the Dbi gene, and (iii) a point mutation in Gabrg2 (gamma-aminobutyric acid A receptor, subunit gamma 2; Gabrg2F77I) that abolishes binding of DBI/ACBP. We conclude that a-DBI-mediated neutralization of extracellular DBI/ACBP mediates potent autophagy-dependent organ protection by on-target effects, hence unraveling a novel and potentially useful strategy for autophagy enhancement. "Autophagy checkpoint inhibition" can be achieved by targeting DBI/ACBP.

Preparation and Characterisation of Liposomes of Bergenia Ciliata Extract and Evaluation of their Hepatoprotective Activity

Acute liver damage (ALD) can cause biochemical and pathological changes, which can lead to major complications and even death. The goal of the study was to examine the therapeutic efficacy of liposomes of Bergenia ciliata extract against thioacetamide-induced liver damage in rats. Liposomal batches of B. ciliata extract were prepared by altering the kind and amount of phospholipids and characterized through various physiochemical properties such as laser diffraction, TEM, encapsulation efficiency, stability and in-vitro release studies. In-vivo hepatoprotective studies were performed on TAA-induced acute hepatic damage model. Further, in-silico studies of bergenin against the three hepatic damage markers viz. TGF-β1, TNF-α and interleukin-6 were also performed. Laser diffraction and TEM showed that most stable liposome batch of B. ciliata extract were in the range of 678-1170 nm with encapsulation efficiency of 84.3±3.5. Extract was found to be rapidly dissociated from B. ciliata liposomes in HCl than PBS, according to in-vitro release data. In-vivo data revealed a significant decline in LFT indicators, amelioration of pathological changes and high bergenin bioavailability in the liposomal group. Protective activity of bergenin against ALD targets like TGF-β1, TNF-α and interleukin-6 was anticipated via molecular docking research. As a result, the current findings of the study indicate that B. ciliata liposomes and bergenin have promising ameliorative potential in the management of ALD.

A pectic polysaccharide from fresh okra (Abelmoschus esculentus L.) beneficially ameliorates CCl4-induced acute liver injury in mice by antioxidation, inhibition of inflammation and modulation of gut microbiota

Okra [Abelmoschus esculentus (Linn.) Moench], as a well-known medicinal and food plant, has important physiological activities and health benefits, and polysaccharide is its main bioactive component. In this study, a pectic polysaccharide (OPS-50) prepared from fresh okra pods by three-phase partitioning and gradient (NH4)2SO4 precipitation at a saturation of 50% was employed in carbon tetrachloride (CCl4)-caused acute liver damage in mice to evaluate the hepatoprotective potential. Results indicated that OPS-50 was mainly composed of a limited linear homogalacturonan backbone and abundant rhamnogalacturonan-I domains as side chains. OPS-50 exerted positively protective effects on acute liver damage induced by CCl4 in mice through relieving weight reduction and organ damage, ameliorating liver function and dyslipidemia, alleviating oxidative stress, suppressing pro-inflammatory cytokines, modulating gut microbiota, and promoting short-chain fatty acid secretion. Moreover, liver histopathology demonstrated the protective benefit of OPS-50 on CCl4-caused acute liver damage in mice. Therefore, our data suggested that the pectic OPS-50, as a dietary supplement, have great potential in preventing and treating chemical liver damages.

Andrographolide derivative as STAT3 inhibitor that protects acute liver damage in mice

Sustained activation of the Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway contributed to the progression of cancer and liver diseases. STAT3 signaling inhibitor has been extensively investigated for pharmacological use. We synthesized a series of andrographolide derivatives, and characterized their activity against STAT3 signaling pathway both in vitro and in the CCl₄-induced acute liver damage mice model. Among these derivatives, compound 24 effectively inhibited phosphorylation and dimerization of STAT3 but not its DNA binding activity. Compound 24 significantly ameliorated carbon tetrachloride-induced acute liver damage in vivo without changing mice body weight. Treatment with 24 attenuated hepatic pathologic damage and promoted hepatic proliferation and activation of STAT3. Compound 24 inhibited elevated expression of α-smooth muscle actin and serum pro-inflammatory cytokines downstream of STAT3 but not those factors that are regulated by NF-κB or SMADs. In summary, our results suggest that compound 24 may serve as a potential therapeutic agent for the treatment of hepatic damage or a liver protection agent via regulating STAT3 activation.

Reabsorption of iron into acutely damaged rat liver: A role for ferritins

AIM

To studied iron metabolism in liver, spleen, and serum after acute liver-damage, in relation to surrogate markers for liver-damage and repair.

METHODS

Rats received intraperitoneal injection of the hepatotoxin thioacetamide (TAA), and were sacrificed regularly between 1 and 96 h thereafter. Serum levels of transaminases and iron were measured using conventional laboratory assays. Liver tissue was used for conventional histology, immunohistology, and iron staining. The expression of acute-phase cytokines, ferritin light chain (FTL), and ferritin heavy chain (FTH) was investigated in the liver by qRT-PCR. Western blotting was used to investigate FTL and FTH in liver tissue and serum. Liver and spleen tissue was also used to determine iron concentrations.

RESULTS

After a short initial decrease, iron serum concentrations increased in parallel with serum transaminase (aspartate aminotransferase and alanine aminotransferase) levels, which reached a maximum at 48 h, and decreased thereafter. Similarly, after 48 h a significant increase in FTL, and after 72h in FTH was detected in serum. While earliest morphological signs of inflammation in liver were visible after 6 h, increased expression of the two acute-phase cytokines IFN-γ (1h) and IL-1β (3h) was detectable earlier, with maximum values after 12-24 h. Iron concentrations in liver tissue increased steadily between 1 h and 48 h, and remained high at 96 h. In contrast, spleen iron concentrations remained unchanged until 48 h, and increased mildly thereafter (96 h). Although tissue iron staining was negative, hepatic FTL and FTH protein levels were strongly elevated. Our results reveal effects on hepatic iron concentrations after direct liver injury by TAA. The increase of liver iron concentrations may be due to the uptake of a significant proportion of the metal by healthy hepatocytes, and only to a minor extent by macrophages, as spleen iron concentrations do not increase in parallel. The temporary increase of iron, FTH and transaminases in serum is obviously due to their release by damaged hepatocytes.

CONCLUSION

Increased liver iron levels may be the consequence of hepatocyte damage. Iron released into serum by damaged hepatocytes is obviously transported back and stored via ferritins.

Experimental approach to IGF-1 therapy in CCl4-induced acute liver damage in healthy controls and mice with partial IGF-1 deficiency

Background

Cell necrosis, oxidative damage, and fibrogenesis are involved in cirrhosis development, a condition in which insulin-like growth factor 1 (IGF-1) levels are diminished. This study evaluates whether the exogenous administration of low doses of IGF-1 can induce hepatoprotection in acute carbon tetrachloride (CCl₄)-induced liver damage compared to healthy controls (Wt Igf^+/+). Additionally, the impact of IGF-1 deficiency on a damaged liver was investigated in mice with a partial deficit of this hormone (Hz Igf1^+/−).

Methods

Three groups of 25 ± 5-week-old healthy male mice (Wt Igf^+/+) were included in the protocol: untreated controls (Wt). Controls that received CCl₄ (Wt + CCl₄) and Wt + CCl₄ were treated subcutaneously with IGF-1 (2 µg/100 g body weight/day) for 10 days (Wt + CCl₄ + IGF1). In parallel, three IGF-1-deficient mice (Hz Igf1^+/−) groups were studied: untreated Hz, Hz + CCl₄, and Hz + CCl₄ + IGF-1. Microarray and real-time quantitative polymerase chain reaction (RT-qPCR) analyses, serum aminotransferases levels, liver histology, and malondialdehyde (MDA) levels were assessed at the end of the treatment in all groups. All data represent mean ± SEM.

Results

An altered gene coding expression pattern for proteins of the extracellular matrix, fibrosis, and cellular protection were found, as compared to healthy controls, in which IGF-1 therapy normalized in the series including healthy mice. Liver histology showed that Wt + CCl₄ + IGF1 mice had less oxidative damage, fibrosis, lymphocytic infiltrate, and cellular changes when compared to the Wt + CCl₄. Moreover, there was a correlation between MDA levels and the histological damage score (Pearson’s r = 0.858). In the IGF-1-deficient mice series, similar findings were identified, denoting a much more vulnerable hepatic parenchyma.

Conclusions

IGF1 treatment improved the biochemistry, histology, and genetic expression of pro-regenerative and cytoprotective factors in both series (healthy and IGF-1-deficient mice) with acute liver damage, suggesting that low doses of IGF-1, in acute liver damage, could be a feasible therapeutic option.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1198-4) contains supplementary material, which is available to authorized users.

Insulin-Like Growth Factor-1 Deficiency and Cirrhosis Establishment

Cirrhosis represents the final stage of chronic liver damage, which can be due to different factors such as alcohol, metabolic syndrome with liver steatosis, autoimmune diseases, drugs, toxins, and viral infection, among others. Nowadays, cirrhosis is an important health problem and it is an increasing cause of morbidity and mortality, being the 14th most common cause of death worldwide. The physiopathological pathways that lead to fibrosis and finally cirrhosis partly depend on the etiology. Nevertheless, some common features are shared in this complex mechanism. Recently, it has been demonstrated that cirrhosis is a dynamic process that can be altered in order to delay or revert fibrosis. In addition, when cirrhosis has been established, insulin-like growth factor-1 (IGF-1) deficiency or reduced availability is a common condition, independently of the etiology of chronic liver damage that leads to cirrhosis. IGF-1 deprivation seriously contributes to the progressive malnutrition of cirrhotic patient, increasing the vulnerability of the liver to establish an inflammatory and oxidative microenvironment with mitochondrial dysfunction. In this context, IGF-1 deficiency in cirrhotic patients can justify some of the common characteristics of these individuals. Several studies in animals and humans have been done in order to test the replacement of IGF-1 as a possible therapeutic option, with promising results.

Acute liver damage following intravenous glucocorticoid treatment for Graves' ophthalmopathy

PURPOSE

Over the last years, there have been several reports on the occurrence of acute liver damage (ALD) in patients affected with Graves' ophthalmopathy (GO) receiving intravenous glucocorticoids (ivGCs). This article is aimed at reviewing the literature on this specific topic and reporting two new cases of ALD occurring in GO patients while on ivGCs.

METHODS

The terms "glucocorticoid therapy" and "Graves' Ophthalmopathy"/"Graves' Orbitopathy"/"Thyroid eye disease" were used both separately and in conjunction with the terms "liver disease," "liver damage," "hepatotoxicity," "liver failure," to search MEDLINE for articles published since the first report of ALD in 2000 and up to 2015.

RESULTS

ALD [defined as an increase in alanine aminotransferase (ALT) >300 U/L] during or after completion of ivGCs has been so far reported in 17 fully documented cases. Overall, one-half of those patients were diagnosed as having autoimmune hepatitis (AIH) and in the vast majority of the remaining cases a diagnosis of methylprednisolone(MP)-induced hepatotoxicity was suspected. The clinical course of liver injury varied from asymptomatic hypertransaminasemia in the vast majority of patients to fatal hepatic failure in four patients receiving higher (>8 g) cumulative doses of MP.

CONCLUSIONS

The overall risk of ALD is relatively low (~1 %), and seems higher using a single dose >0.5 g and a cumulative dose >8.5 g MP. Whenever ivGC treatment is required, serum liver enzymes, viral hepatitis markers, and autoantibodies related to AIH should be obtained prior to ivGC administration. Liver function should be monitored during ivGC and up to 6 months after the end of treatment. Prolonging observation after 6 months is likely unnecessary, since all cases of ALD so far reported always occurred well within this term.

Fine-tuning the expression of microRNA-155 controls acetaminophen-induced liver inflammation

Treatment of acetaminophen (APAP) in overdose can cause a potentially serious and fatal liver injury. MicroRNA-155 (miR-155), a multifunctional microRNA, is known to mediate inflammatory responses via regulating various target genes. In this study, we aimed to study the role of miR-155 in APAP-induced liver injury, using miR-155-/- mice and miR-155 in vivo intervention. We noted that miR-155 expression was significantly increased in liver and blood after APAP treatment. Knockout of miR-155 deteriorated APAP-induced liver damage, with the elevated serum levels of AST and ALT. The levels of various inflammatory mediators, such as TNF-α and IL-6, were markedly augmented in livers in the absence of miR-155. Moreover, miR-155 deficiency aberrantly activated NF-kappa-B signaling via enhancing p65 and IKKε expression. Finally, in vivo administration of miR-155 agomir attenuated APAP-induced liver damage, reduced the serum levels of AST and ALT, and dampened the NF-kB signaling. In conclusion, our data demonstrated that miR-155 protects the mice against APAP-induced liver damage via mediating NF-KB signaling pathway, suggesting that miR-155 might be a potential pharmaceutic target for treatment of APAP-induced liver inflammation.