The role of macrophage polarization and interaction with renal tubular epithelial cells in ischemia-reperfusion induced acute kidney injury / 生理学报

Acute kidney injury (AKI) is a common critical clinical disease characterized by a sharp decline of renal function. Ischemia-reperfusion (IR) is one of the main causes of AKI. The mortality of AKI remains high due to the lack of early diagnosis and cause specific treatment. IR rapidly initiates innate immune responses, activates complement and innate immune cells, releasing a large number of injury-related molecules such as high mobility group box-1 (HMGB1), inflammatory mediators such as caspase-3, and then recruits immune inflammatory cells including M1 macrophages (Mϕ) to the microenvironment of injury, causing apoptosis and necrosis of renal tubular epithelial cells (TECs). Dead cells and associated inflammation further activate the adaptive immune system, which not only aggravates tissue damage, but also initiates M2 Mϕ participated inflammatory clearance, tissue repair and regeneration. Mϕ, professional phagocytes, and TECs, semi-professional phagocytes, can phagocytose around damaged cells including apoptotic Mϕ and TECs, which are key innate immune cells to regulate the outcome of injury, repair or fibrosis. In recent years, it has been found that erythropoietin (EPO) not only binds to the homodimeric receptor (EPOR)2 to induce erythropoiesis, but also binds to the heterodimeric receptor EPOR/βcR, also known as innate repair receptor, which plays renoprotective roles. Properdin is the only positive regulator in the complement activation of alternative pathway. It also can effectively identify and bind to early apoptotic T cells and facilitate phagocytic clearing by Mϕ through a non-complement activation-dependent mechanism. Our previous studies have shown that Mϕ and TECs associated with EPO and its receptors and properdin are involved in IR injury and repair, but the underlying mechanism needs to be further explored. As an important carrier of cell-to-cell signal transmission, exosomes participate in the occurrence and development of a variety of renal diseases. The role of exosomes involved in the interaction between Mϕ and TECs in IR-induced AKI is not fully defined. Based on the available results in the role of Mϕ and TECs in renal IR-induced AKI, this review discussed the role of Mϕ polarization and interaction with TECs in renal IR injury, as well as the participation of EPO and its receptors, properdin and exosomes.

Down-regulated clusterin expression enhances sensitivity of hepatoma cells to anti-cancer drugs / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between and underlying mechanistic pathway of clusterin (CLU) and chemo-resistance ofhepatocellular carcinoma (HCC) cells.</p><p><b>METHODS</b>CLU protein expression in HCC cell lines (Hep3B, SMMC7721, PLC, and HepG2) and HepG2/ADM cells was quantified by western blotting. Four short-hairpin (sh)RNAs designed to block CLU-mRNA were generated, screened by RT-PCR, and transfected into the cells to determine effects of CLU on cell viability and apoptosis. Effects of CLU blockade on drug efflux pump activity were measured by flow cytometry.</p><p><b>RESULTS</b>CLU was found to be over-expressed in HCC cell lines and HepG2/ADM cells. The four shRNAs inhibited CLU-mRNA as follows (vs. levels in untransfected cells): shRNA-1: 73.68% (q =23.011, P < 0.01), shRNA-2: 39.26% (q =11.991, P < 0.01), shRNA-3: 62.36% (q =19.392, P < 0.01), and shRNA-4: 55.35% (q =17.149, P < 0.01). shRNA-mediated depletion of CLU led to increased sensitivity to anti-cancer drugs and increased doxorubicin-induced apoptosis in HepG2/ADM cells, as evidenced by the apoptosis ratio of the shRNA-1 group of 39.28% vs. the apoptosis ratio of the untransfected control group of 4.92%. Silencing of CLU also decreased drug etflux pump activity, and the level of MDR1/P-gp expression was significantly reduced (shRNA-1 group vs.untransfected control group: q =14.604, P < 0.01).</p><p><b>CONCLUSION</b>CLU repression may enhance sensitivity of HCC cells to anti-cancers drugs and represents a potential molecular-target for reversal of multidrug-resistant HCC.</p>

Expression characteristics of hypoxia inducible factor-1a and its clinical values in hepatocellular carcinoma / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the dynamic expression of hypoxia inducible factor-1alpha (HIF-1alpha) and its clinical values in hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>The dynamic changes of liver pathology, HIF-1alpha transcription and expression were observed through the hepatoma model. The self-control specimens from 35 human HCC patients were collected and the expression, cellular distribution, and clinicopathological features of HIF-1alpha and its gene was analyzed by immunohistochemistry, western blotting and nested- PCR, respectively.</p><p><b>RESULTS</b>Both levels of hepatic HIF-1alpha and HIF-1alpha mRNA expression increased during the HCC development course. The incidence of HIF-1alpha and the ratio of HIF-1alpha to beta-actin was 0% and 0.16+/-0.02 in the control rats, 77.8% and 0.29+/-0.04 in the denatured rats, 88.9% and 0.52+/-0.03 in the precancerous rats, and 100% and 0.84+/-0.02 in the cancerous rats respectively, with significant difference between the control group and any of the experimental groups (P = 0.000). The positive HIF-1alpha was brown and granule-like and mainly presented in cytoplasm and few in nucleus. The incidence of HIF-1alpha was 80% (28/35) in HCC and 100% (35/35) in its surrounding tissues. The clinical pathological features indicated HIF-1alpha expression associated with tumor size and differentiation degree the of HCC. No correlation was found between HIF-1alpha and tumor numbers or positive-HBsAg.</p><p><b>CONCLUSIONS</b>HIF-1alpha expression is associated with occurrence and development of HCC, and is perhaps a target molecule for HCC therapy.</p>

Effect of siRNA-mediated inhibition of nuclear transcription factor-kappa B on apoptosis of hepatocarcinoma cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effect of siRNA-mediated inhibition of NF-κB on apoptosis of hepatocarcinoma cells.</p><p><b>METHODS</b>Specific small interfering RNA Targeting NF-κB gene was synthesized and transfected into HepG2 cells by liposomes. Nested RT-PCR and quantitative RT-PCR were used to detect the mRNA expression of NF-κB. Immunohistochemistry, enzyme-linked immunosorbent assay and Western blot were performed to examine the protein expression of NF-κB. Annexin V-FITC was used to test cell apoptosis.</p><p><b>RESULTS</b>The expression of NF-κB in HepG2 cells (1.13+/-0.03) was significantly higher (t=27.02, P<0.05) than that in normal hepatocytes (0.29+/-0.07). The down-regulation of NF-κB expression was depended on the dosage of siRNA and the time after transfection. 72 h after siRNA transfection, NF-κB expression reduced by 93% and 62% at the mRNA and protein levels, respectively. The apoptosis of HepG2 cells increased by 85% with NF-κB inhibition.</p><p><b>CONCLUSIONS</b>NF-κB is abnormally active in HepG2 cells and NF-κB inhibition mediated by siRNA promotes HepG2 cells apoptosis. It suggested that NF-κB could be a potential target for HCC prevention gene therapy.</p>

Sequence analysis on drug-resistant gene of rpoB in Mycobacterium tuberculosis L-forms among pneumocoulosis patients complicated with tuberculosis / 中华流行病学杂志

Objective To study the drug-resistant characteristics genetic mutation of rpoB in Mycobacterium tuberculosis L-forms among patients of pneumoconiosis complicated with pulmonary tuberculosis. Methods A total of 42 clinical isolated strains of Mycobacterium tuberculosis L-forms were collected, including 31 drug-resistant strains. Their genomes DNA were extracted and target genes amplified by PCR. Hot regions in the rpoB gene were analyzed by automated DNA sequenator. Results No mutation of rpoB was identified in 11 rifampicin-sensitive strains while conformation changes were fotmd in 31 rifampicin-resistant strains. The mutation rate was 93.55% (29/31) in resistant strains, mainly concentrated in codon 531 (51.6%, 16/31) and 526 (32.26%, 10/31), happened base substitutions, including 27 unit point mutation and 2 two point mutation. The newly found mutation of codon 516 had not been reported by internal or overseas scholars. Conclusion The substitution of highly conserved amino acids encoded by rpoB gene resulted in the molecular mechanism was responsible for RFP resistance in Mycobacterium tuberculosis L-forms. It also proved that rpoB gene was in diversiform.