氧化应激与肝脏损伤

Adipose-derived stem cells alleviate liver injury induced by type 1 diabetes mellitus by inhibiting mitochondrial stress and attenuating inflammation

Background

Type 1 diabetes mellitus (T1D) is a worldwide health priority due to autoimmune destruction and is associated with an increased risk of multiorgan complications. Among these complications, effective interventions for liver injury, which can progress to liver fibrosis and hepatocellular carcinoma, are lacking. Although stem cell injection has a therapeutic effect on T1D, whether it can cure liver injury and the underlying mechanisms need further investigation.

Methods

Sprague–Dawley rats with streptozotocin (STZ)-induced T1D were treated with adipose-derived stem cell (ADSC) or PBS via the tail vein formed the ADSC group or STZ group. Body weights and blood glucose levels were examined weekly for 6 weeks. RNA-seq and PCR array were used to detect the difference in gene expression of the livers between groups.

Results

In this study, we found that ADSCs injection alleviated hepatic oxidative stress and injury and improved liver function in rats with T1D; potential mechanisms included cytokine activity, energy metabolism and immune regulation were potentially involved, as determined by RNA-seq. Moreover, ADSC treatment altered the fibroblast growth factor 21 (FGF21) and transforming growth factor β (TGF-β) levels in T1D rat livers, implying its repair capacity. Disordered intracellular energy metabolism, which is closely related to mitochondrial stress and dysfunction, was inhibited by ADSC treatment. PCR array and ingenuity pathway analyses suggested that the ADSC-induced suppression of mitochondrial stress is related to decreased necroptosis and apoptosis. Moreover, mitochondria-related alterations caused liver inflammation, resulting in liver injury involving the T lymphocyte-mediated immune response.

Conclusions

Overall, these results improve our understanding of the curative effect of ADSCs on T1D complications: ADSCs attenuate liver injury by inhibiting mitochondrial stress (apoptosis and dysfunctional energy metabolism) and alleviating inflammation (inflammasome expression and immune disorder). These results are important for early intervention in liver injury and for delaying the development of liver lesions in patients with T1D.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02760-z.

Chinese Tea Alleviates CCl4-Induced Liver Injury through the NF-κBorNrf2Signaling Pathway in C57BL-6J Mice

Liver injury is a life-threatening condition that is usually caused by excessive alcohol consumption, improperdiet, and stressful lifestyle and can even progress to liver cancer. Tea is a popular beverage with proven health benefits and is known to exert a protective effect on the liver, intestines, and stomach. In this study, we analyzed the therapeutic effects of six kinds of tea on carbon tetrachloride (CCl₄)-induced liver injury in a mouse model. The mice were injected with 10 mL/kg 5% CCl₄ to induce liver injury and then given oral gavage of green tea, yellow tea, oolong tea, white tea, black tea, and dark tea, respectively. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and the expression levels of inflammation and oxidative stress-related proteins in the liver tissues were quantified. All six kinds of tea partly reduced the liver index, restored the size of the enlarged liver in the CCl₄ model, and decreased the serum levels of ALT and AST. Furthermore, the highly fermented dark tea significantly reduced the expression levels of NF-κB and the downstream inflammatory factors, whereas the unfermented green tea inhibited oxidative stress by activating the antioxidant Nrf2 pathway. Taken together, tea can protect against liver inflammation, and unfermented tea can improve antioxidant levels. Further studies are needed on the bioactive components of tea to develop drugs against liver injury.

Effect of garden cress in reducing blood glucose, improving blood lipids, and reducing oxidative stress in a mouse model of diabetes induced by a high-fat diet and streptozotocin

BACKGROUND

A mouse model in which diabetes mellitus was induced by low-dose streptozotocin (STZ) injection combined with a high-fat diet was used to study the effect of two water cress (Lepidium savitum) preparations. Diabetic mice were treated with dried cress powder or with water-soluble extracts (tested at two doses), together with proper control groups. The mice were evaluated after 4 weeks of continuous intervention for type 2 diabetic and associated markers. We determined blood glucose, body weight, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), serum insulin levels, and DNA integrity of hepatic cells. The concentrations of malondialdehyde (MDA) and lipid peroxide (LPO) and the activities of four enzymes that are part of the antioxidant defense system were determined in liver samples, as well as gene expression (by semi-quantitative reverse transcription polymerase chain reaction) and enzyme activity of IRS-1, IRS-2, PI3K, AKT-2, and GLUT4.

RESULTS

After 4 weeks of intervention, the levels of TC, TG, and LDL cholesterol were significantly (P < 0.5) decreased and HDL cholesterol was significantly increased. Enzyme activities of liver superoxide dismutase, glutathione, glutathione peroxidase, and catalase were significantly increased, whereas MDA and LPO concentrations were significantly reduced. The transcription level of the five genes assessed was increased, with corresponding increases in protein expression.

CONCLUSION

Oral uptake of garden cress can significantly reduce the blood glucose and improve the blood lipid metabolism of diabetic mice. Considerable improvements in the activity of antioxidant defense enzymes were observed in type 2 diabetic mice that improved the body's antioxidant emergency response. © 2019 Society of Chemical Industry.

Polyphenols in Liubao Tea Can Prevent CCl₄-Induced Hepatic Damage in Mice through Its Antioxidant Capacities

The present study investigated the preventive effect of polyphenols in Liubao tea (PLT) on carbon tetrachloride (CCl₄)-induced liver injury in mice. The mice were initially treated with PLT, followed by induction of liver injury using 10 mL/kg CCl₄. Then liver and serum indices, as well as the expression levels of related messenger RNAs (mRNAs) and proteins in liver tissues were measured. The results showed that PLT reduces the liver quality and indices of mice with liver injury. PLT also downregulates aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides (TGs), and malondialdehyde (MDA), and upregulates superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the sera of mice with liver injury. PLT also reduces serum levels of interleukin-6 (IL-6), interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) cytokines in mice with liver injury. Pathological morphological observation also shows that PLT reduces CCl₄-induced central venous differentiation of liver tissues and liver cell damage. Furthermore, qPCR and Western blot also confirm that PLT upregulates the mRNA and protein expressions of Gu/Zn-SOD, Mn-SOD, catalase (CAT), GSH-Px, and nuclear factor of κ-light polypeptide gene enhancer in B-cells inhibitor-α (IκB-α) in liver tissues, and downregulates the expression of cyclooxygenase 2 (COX-2) and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB). Meanwhile, PLT also raised the phosphorylated (p)-NF-κB p65 and cytochrome P450 reductase protein expression in liver injury mice. The components of PLT include gallic acid, catechin, caffeine, epicatechin (EC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), and epicatechin gallate (ECG), which possibly have a wide range of biological activities. Thus, PLT imparts preventive effects against CCl₄-induced liver injury, which is similar to silymarin.

A mouse model of non-alcoholic steatohepatitis induced by feeding a methionine-choline-deficient diet: establishment and dynamic monitoring

AIM: To establish a mouse model of non-alcoholic steatohepatitis (NASH) by feeding a methionine-choline-deficient (MCD) diet and to dynamically monitor the pathological features of hepatic steatosis and inflammation in these mice.

METHODS: Forty mice were randomly divided into two groups and fed an MCD diet or a methionine-choline-sufficient (MCS) diet. At weeks 1 to 5, these mice were sacrificed to take serum samples for biochemical measurements and liver samples for HE staining and oil red O staining to grade the degree of fatty change and inflammation.

RESULTS: Steatosis and inflammation could be seen in mice fed an MCD diet for 2-3 wk. Serum ALT (U/L), AST (U/L) levels increased significantly (133.9 ± 6.3 vs 47.3 ± 1.3; 154.3 ± 24.6 vs 109.2 ± 50.4, both P < 0.05), whereas TG (mmol/L) levels decreased (0.97 ± 0.14 vs 1.45 ± 0.32, P < 0.01) at week 3 in rats fed an MCD diet than in those fed an MCS diet. At wk 5, TG (mmol/L) levels in the liver increased significantly in rats fed an MCD diet than in controls (1.50 ± 0.22 vs 0.98 ± 0.16, P < 0.01). Fibrosis could be seen at week 5 in mice fed an MCD diet.

CONCLUSION: A mouse model of NASH has been created successfully by feeding an MCD diet.

Effects of curcumin solid dispersion on oxidative stress of alcoholic hepatic injury in rats

AIM: To prepare curcumin solid dispersion and to investigate the effects of curcumin solid dispersion on oxidative stress of alcoholic hepatic injury in rats.

METHODS: Fifty Sprague-Dawley rats were randomly divided into 5 groups (n = 10): control group, model group, Bifendate group and two curcumin solid dispersion treatment (100, 200 mg/kg, respectively) groups. The SD rats were administrated with liquor and fat emulsion for 6 weeks to establish the alcoholic hepatic injury model, at the same time the rats were administrated Bifendate and curcumin solid dispersion. The content of alanine aminotransferase (ALT), asparate aminotransferase (AST) in serum and the activity or content of superoxide dismutase (SOD) and malondialdehtyde (MDA) in liver were measured to evaluate hepatic injury and oxidative stress.

RESULTS: Compared with control group, the value of liver weight/body weight was significantly increased (3.74 ± 0.38 vs 2.25 ± 0.13; P < 0.01); the serum ALT and AST were significantly increased (76.24 ± 9.14 vs 30.13 ± 4.99; 98.85 ± 10.50 vs 39.02 ± 6.79; P < 0.01) but the activity of SOD was significantly decreased (395.39 ± 28.26 vs 258.18 ± 22.18, P < 0.01) and the content of MDA was significantly increased (27.00 ± 1.08 vs 12.31 ± 1.26, P < 0.01) in the model group. However, in comparison with those in model group, the serum AST and ALT were significantly decreased (Bifendate 29.01 ± 9.24, 41.69 ± 3.67; Low dose 55.92 ± 5.49, 57.17 ± 10.88; High dose 40.94 ± 4.54, 52.59 ± 10.17) in the two treatment groups. For low dose and high dose curcumin solid dispersion groups, activity of SOD was significantly increased (Low dose 340.50 ± 36.26, High dose 365.20 ± 36.18, P < 0.01) and content of MDA was significantly decreased (Low dose 15.76 ± 0.68, High dose 13.19 ± 0.72, P < 0.01) in liver, but there was no significant change in Bifendate group.

CONCLUSION: The curcumin solid dispersion protects alcoholic hepatic injury and reduces oxidative stress in rats.