Recent advances in mesenchymal stem cell therapy for myocardial infarction

Myocardial infarction refers to the ischemic necrosis of myocardium, characterized by a sharp reduction or interruption of blood flow in the coronary arteries due to the coronary artery occlusion, resulting in severe and prolonged ischemia in the corresponding myocardium and ultimately leading to ischemic necrosis of the myocardium. Given its high risk, it is considered as one of the most serious health threats today. In current clinical practice, multiple approaches have been explored to diminish myocardial oxygen consumption and alleviate symptoms, but notable success remains elusive. Accumulated clinical evidence has showed that the implantation of mesenchymal stem cell for treating myocardial infarction is both effective and safe. Nevertheless, there persists controversy and variability regarding the standardizing MSC transplantation protocols, optimizing dosage, and determining the most effective routes of administration. Addressing these remaining issues will pave the way of integration of MSCs as a feasible mainstream cardiac treatment.

[Analysis of asymmetric hearing loss in both ears of patients with occupational noise-induced deafness]

Objective: To investigate the characteristics of asymmetric hearing loss in left and right ears of patients with occupational noise-induced deafness and to explore the possible causes of asymmetric hearing loss. Methods: A total of 423 cases of occupational noise-induced deafness diagnosed in Guangdong Province Hospital for Occupational Disease Prevention and Treatment from May 2015 to May 2018 were investigated retrospectively. On the basis of three consecutive pure tone audiometry (PTA) with intervals of more than 3 d in hospital, the minimum of hearing threshold of each frequency and the frequency response threshold of auditory steady-state response (ASSR) , and based on the GBZ 49-2014 "Diagnosis of Occupational Noise-induced Deafness". The statistical analysis of Wilcoxon signed rank test and Spearman correlation analysis were carried out by nonparametric test. The hearing threshold weight of PTA and the response threshold of ASSR were tested and compared from different dimensions according to sex, age, length of service of exposure noise, diagnosis grade and so on. Results: There were 369 male (87.23%) and 54 female (12.77%) ; the age was (41.8±7.6) years; the length of service was (10.1±6.2) years. The weighted values of left ear PTA and ASSR were higher than those of right ear (P<0.001) . The weighted values of left ear PTA and ASSR were higher than those of right ear (P<0.05) in men, patients with age ≤ 40 and 41-60 years, 3-9 years of service, and patients with mild grade (P<0.05) . After the equalization of characteristic variables, the weighted values of left ear PTA and ASSR were also higher than those of right ear (P<0.05) . There was a positive correlation between the weighted value of PTA and the weighted value of ASSR (P<0.001) . Conclusion: There is asymmetry in hearing loss of patients with occupational noise deafness, and hearing loss in the left ear is higher than that in the right ear.

Identification of cervical cancer markers using cDNA subtraction approach

PURPOSE OF INVESTIGATION

Cervical cancer markers are not well known for accurate detection of the disease.

MATERIALS AND METHODS

In the present study, cervical cancer samples were collected from the 42 patients in the Department of Surgery and Medicine of Weifang People's Hospital and Medical College, Shandong, China. The cDNA subtraction approach was performed to find out the specific transcripts, which are responsible for cervical cancer. The specific differentially expressed transcripts were identified by Basic Local Alignment Search Tool (BLAST) analysis and the results were validated by immunohistochemistry.

RESULTS

Following differentially expressed specific transcripts, such as ID-1, Hif 1a, and the Y-box were usefully employed as a marker to accurately detect cervical cancer. CONCLUSION. The identified markers are promising in the accurate detection of cervical cancer in terms of its molecular basis and management of the disease.

[IL-1β can promote proliferation and migration of Hepa1-6 cells and impair IFNα-induced cell growth inhibition in vitro]

AIM

To analyze the effect of recombinant IL-1β on proliferation, migration, and the effect on IFNα induced cell growth inhibtion.

METHODS

The vector pLIVE-mIL-1β was transfected into Hepa1-6 cells mediated by transIT-LT1. Gene expression level of IL-1β was analyzed by RT-PCR and Sandwich ELISA. Cell migration was assessed using wound healing assay.

RESULTS

IL-1β significantly stimulated proliferation and migration of Hepa1-6 cells. However, expression of IL-1β significantly down-regulated growth inhibition inducecd by IFNα.

CONCLUSION

The recombinant vector could stably express IL-1β and promote in vitro proliferation, migration, and impair IFNα-induced cell growth inhibition.

Effects of arsenic trioxide on cell proliferation, apoptosis and HIF-1α expression in human liver cancer HepG2 cells cultured under hypoxic conditions

AIM: To investigate the effects of arsenic trioxide (As₂O₃) on cell proliferation, apoptosis and hypoxia-inducible factor-1α (HIF-1α) expression in human liver cancer HepG2 cells cultured under hypoxic conditions.

METHODS: Hypoxia was induced with cobalt chloride (CoCl₂). After HepG2 cells were incubated with different concentrations of As₂O₃ (1.0, 2.0, 4.0 and 8.0 µmol/L) for 12, 24 and 48 h under hypoxic conditions, cell proliferation was determined by MTT assay, and cell apoptosis was evaluated by Hoechst staining. HepG2 cells were then divided into three groups: normal control group, hypoxia group, and As₂O₃ treatment group. After HepG2 cells were incubated with As₂O₃ at concentrations of 4.0 and 8.0 µmol/L for 48 h under hypoxia, the expression of HIF-1α protein was detected by immunocytochemistry.

RESULTS: As₂O₃ inhibited proliferation but induced apoptosis of HepG2 cells in a dose- and time-dependent manner under both normoxic and hypoxic conditions (both P < 0.01). No significant differences were noted in the reduced proliferation rates of cell proliferation (38.40% vs 37.83%, P > 0.05) and apoptosis rates (45.25% vs 49.28%, P > 0.05) between HepG2 cells treated with 8.0 µmol/L As₂O₃ for 48 h under normoxic and hypoxic conditions. Immunocytochemistry analysis revealed that HIF-1α was weakly expressed in HepG2 cells under normoxia. After hypoxic induction for 48 h, HIF-1α expression was significantly up-regulated (t = 114.37, P < 0.05). The expression of HIF-1α protein gradually decreased with the increase in the concentration of As₂O₃ under hypoxia (F = 347.042, P < 0.01).

CONCLUSION: As₂O₃ can inhibit proliferation but induce apoptosis of HepG2 cells under hypoxia possibly by down-regulating HIF-1α protein expression.

[Expression of recombinant mouse IL-1beta significantly down-regulates NK cell mediated cytolysis [corrected] against H22 hepatoma cells]

AIM

To investigate the effect of the expression of recombinant IL-1beta in H22 hepatoma cells on its response to NK cell mediated cytotoxicity.

METHODS

BALB/c mouse was stimulated by 6% of starch. Total RNA was prepared from peripheral blood monocytes (PBMCs). IL-1beta gene (843 bp) was obtained by RT-PCR. The purified PCR product digested by Xho I and EcoR I was cloned into pIRES2-EGFP to construct the recombinant pIRES2-EGFP-mIL-1beta expression vector which was verified by PCR, restriction enzyme assay (Xho I and EcoR I) and DNA sequencing. Then the purified pIRES2-EGFP-mIL-1beta plasmid was transfected into H22 hepatoma cells by jetPEI. The expression level of recombinant IL-1beta was detected by RT-PCR and confocal microscopy. The cytotoxicity of wild-type spleenic NK cells against H22 cells was assessed by MTT assay.

RESULTS

After the total RNA isolated from the starch stimulated BALB/c mouse PBMC, 843 bp IL-1beta gene in length was prepared by RT-PCR. The purified PCR product digested by EcoR I and Xho I was ligated by pIRES2-EGFP to create pIRES2-EGFP-mIL-1beta expression plasmid which was verified by PCR, restriction enzyme assay and DNA sequencing. Then pIRES2-EGFP-mIL-1beta was transfected into H22 hepatoma cells by jetPEI. RT-PCR and confocal microscopy assay showed these cells expressed high level of recombinant IL-1beta expression vector. In a 4-hour based MTT assay, IL-1beta in H22 cells was more resistant to NK92 cell mediated cytotoxicity compared with the cells transfected with pIRES2-EGFP. Meanwhile, the cytolytic capacity of the spleenic NK cells separated from wild-type mouse decreased about 10% when the ratio of effector to target was 40:1.

CONCLUSION

The expression of proinflammatory cytokine IL-1beta can significantly down-regulate the cytolytic activity of NK cells against H22 hepatoma cells. It plays a crucial role in the immune escape of hepatoma from NK cell mediated innate immunity.