Heme oxygenase-1 exerts pro-apoptotic effects on hepatic stellate cells in vitro through regulation of nuclear

Hui Yang1, Bangtao Chen2, Zhongfu Zhao3

  • 1Department of Infectious Diseases, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China.

Heme oxygenase-1 (HO-1) is an antioxidant and cytoprotective protein, which has been proven to alleviate the proliferation of hepatic stellate cells (HSCs) and the development of liver fibrosis. However, the role of HO-1 in HSC apoptosis remains unclear. The aim of the present study was to investigate the effect of HO-1 on HSC apoptosis and its possible underlying mechanisms. HSCs-T6 were incubated with different concentrations of hemin (HO-1 chemical inducer) and Znpp-IX (HO-1 chemical inhibitor) for 12, 24 and 48 h. Cell viability was determined using an MTT assay. HSCs were classified into 4 groups as follows: Control, hemin, Znpp-IX and hemin+Znpp-IX co-treatment groups. Apoptosis was quantitatively measured by Annexin V/propidium iodide double staining and a terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The mRNA and protein expression of HO-1, α-smooth muscle actin, B-cell lymphoma (Bcl)-2, caspase-3 and nuclear factor (NF)-κB p65 were measured using quantitative polymerase chain reaction and western blotting. The levels of tumor growth factor (TGF)-β and interleukin (IL)-6 in HSC supernatants were examined by ELISA. The results demonstrated that HO-1 exerted antiproliferative effects on HSCs in a time- and concentration-dependent manner. Increasing HO-1 expression induced HSC apoptosis in vitro as demonstrated by a significant decrease in Bcl-2 and an increase in caspase-3 expression. Additionally, the expression of NF-κB p65 and its downstream inflammatory factors TGF-β and IL-6 in the HO-1 overexpression group was significantly decreased compared with the control group. Therefore, the present study provided evidence that HO-1 serves an anti-fibrosis role in the liver by enhancing HSC apoptosis, which was partially associated with the regulation of NF-κB and its downstream effectors.

Related Concept Videos

Atomic Radii and Effective Nuclear Charge03:08

Atomic Radii and Effective Nuclear Charge

The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number and distribution of electrons in their valence shells.
62.2K
Hepatic Drug Excretion: Influencing Factors01:16

Hepatic Drug Excretion: Influencing Factors

The biliary system of the liver, crucial for bile secretion and drug excretion, comprises intrahepatic bile ducts that merge to form the common hepatic duct. This duct, carrying hepatic bile, combines with the cystic duct, draining the gallbladder and forming the common bile duct, which empties into the duodenum. Bile, produced by hepatic cells lining the bile canaliculi, is composed primarily of water, bile salts, pigments, electrolytes, and lesser amounts of cholesterol and fatty acids. Bile...
596
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
3.4K
Phagocytosis of Apoptotic Cells01:17

Phagocytosis of Apoptotic Cells

Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or  immature dendritic cells. Non-professional phagocytes such as  epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes. 
Normal cells contain receptors that prevent them from being recognized...
5.2K
Nuclear Transmutation03:20

Nuclear Transmutation

Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed...
20.7K
Nuclear Power02:36

Nuclear Power

Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons has six components: nuclear fuel consisting of fissionable material, a nuclear moderator, a neutron source, control rods, reactor coolant, and a shield and containment system.
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...
9.5K