Loss of EMP2 Inhibits Melanogenesis of MNT1 Melanoma Cells via Regulation of TRP-2

Melanogenesis is the production of melanin from tyrosine by a series of enzyme-catalyzed reactions, in which tyrosinase and DOPA oxidase play key roles. The melanin content in the skin determines skin pigmentation. Abnormalities in skin pigmentation lead to various skin pigmentation disorders. Recent research has shown that the expression of EMP2 is much lower in melanoma than in normal melanocytes, but its role in melanogenesis has not yet been elucidated. Therefore, we investigated the role of EMP2 in the melanogenesis of MNT1 human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during melanogenesis in MNT1 melanoma cells by gene silencing of EMP2. Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2 siRNA in MNT1 cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2 gene was knocked out of the cell line (EMP2 CRISPR/Cas9) by using a CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2 CRISPR/Cas9 cell lines. Loss of EMP2 also reduced migration and invasion of MNT1 melanoma cells. In addition, the melanosome transfer from the melanocytes to keratinocytes in the EMP2 KO cells cocultured with keratinocytes was reduced compared to the cells in the control coculture group. In conclusion, these results suggest that EMP2 is involved in melanogenesis via the regulation of TRP-2 expression.

Crosstalk between the Producers and Immune Targets of IL-9

IL-9 has been reported to play dual roles in the pathogenesis of autoimmune disorders and cancers. The collaboration of IL-9 with microenvironmental factors including the broader cytokine milieu and other cellular components may provide important keys to explain its conflicting effects in chronic conditions. In this review, we summarize recent findings on the cellular sources of, and immunological responders to IL-9, in order to interpret the role of IL-9 in the regulation of immune responses. This knowledge will provide new perspectives to improve clinical benefits and limit adverse effects of IL-9 when treating pathologic conditions.

Crosstalk between the Producers and Immune Targets of IL-9

IL-9 has been reported to play dual roles in the pathogenesis of autoimmune disorders and cancers. The collaboration of IL-9 with microenvironmental factors including the broader cytokine milieu and other cellular components may provide important keys to explain its conflicting effects in chronic conditions. In this review, we summarize recent findings on the cellular sources of, and immunological responders to IL-9, in order to interpret the role of IL-9 in the regulation of immune responses. This knowledge will provide new perspectives to improve clinical benefits and limit adverse effects of IL-9 when treating pathologic conditions.

Antidiabetic and antioxidant activities of red seaweed Laurencia dendroidea

Objective: To investigate antidiabetic and antioxidant activities of the extract and fractions from Vietnamese red seaweed Laurencia dendroidea. Methods: The seaweed Laurencia dendroidea was extracted by using microwave-assisted extraction method in 80% methanol. The seaweed extract was then fractionated using different solvents (n-hexane, chloroform, ethyl acetate, butanol and water). These obtained fractions were evaluated for α -glucosidase inhibitory and antioxidant activities. Antioxidant activities were tested using DPPH, nitric oxide radical scavenging and metal chelating assays. The enzyme inhibition mode was determined using Lineweaver-Burk plot. For acidic and thermal stabilities, the ethyl acetate fraction was treated at pH 2.0 and 100 °C, respectively. The residual inhibitory activity of the fraction was calculated based on the initial inhibitory activity. For in vivo antidiabetic activity, mice were divided into four groups, including normal control, diabetic control, diabetic mice treated with ethyl acetate fraction and diabetic mice treated with gliclazide. Blood glucose level of treated mice during acute and prolonged treatments was measured. To evaluate the toxicity of the ethyl acetate fraction, the body weight changes and activities of liver function enzymes (aspartate transaminase, alanine transaminase and gamma-glutamyl transferase) were carried out. Results: The extract of Laurencia dendroidea showed strong α-glucosidase inhibitory and DPPH radical scavenging activities. Methanolic concentrations affected both α-glucosidase inhibitory and antioxidant activities. A 80% aqueous methanol was the suitable solvent for extraction of enzyme inhibitors and antioxidants. Among solvent fractions, ethyl acetate fraction had the highest inhibitory activities against α -glucosidase with a mixed type of inhibition and the strongest antioxidant activities, and was stable under acidic and thermal conditions. The ethyl acetate fraction treated diabetic mice significantly reduced blood glucose level compared with the diabetic control group (13.16 mmol/L vs. 22.75 mmol/L after 3 hours of treatment). Oral administration of ethyl acetate fraction did not exhibit toxicity at a dose of 100 mg/kg body weight as determined by body weight changes and liver biochemical parameters. Conclusions: Laurencia dendroidea could be a potential source for production of antidiabetic and antioxidative agents.

Ectopically Expressed Membrane-bound Form of IL-9 Exerts Immune-stimulatory Effect on CT26 Colon Carcinoma Cells

IL-9 is a known T cell growth factor with pleiotropic immunological functions, especially in parasite infection and colitis. However, its role in tumor growth is controversial. In this study, we generated tumor clones expressing the membrane-bound form of IL-9 (MB-IL-9) and investigated their influences on immune system. MB-IL-9 tumor clones showed reduced tumorigenicity but shortened survival accompanied with severe body weight loss in mice. MB-IL-9 expression on tumor cells had no effect on cell proliferation or major histocompatibility complex class I expression in vitro. MB-IL-9 tumor clones were effective in amplifying CD4⁺ and CD8⁺ T cells and increasing cytotoxic activity against CT26 cells in vivo. We also observed a prominent reduction in body weights and survival period of mice injected intraperitoneally with MB-IL-9 clones compared with control groups. Ratios of IL-17 to interferon (IFN)-γ in serum level and tumor mass were higher in mice implanted with MB-IL-9 tumor clones than those observed in mice implanted with control cells. These results indicate that the ectopic expression of the MB-IL-9 on tumor cells exerts an immune-stimulatory effect with toxicity. To exploit its benefits as a tumor vaccine, a strategy to control the toxicity of MB-IL-9 tumor clones should be developed.

Phytoremediation potential of indigenous plants from Thai Nguyen province, Vietnam.

This study was focused on determining Arsenic (As), Lead (Pb), Cadmium (Cd) and Zinc (Zn) in 33 indigenous plants and 12 soil in-situ plant samples in Thai Nguyen Province, Vietnam. The results showed that the soils of surveyed mining areas contained 181.2- 6754.3 mg kg-1 As, 235.5-4337.2 mg kg-1 Pb, 0.8- 419 mg kg-1 Cd and 361.8-17565.1 mg kg-1 Zn depending on the characteristics of each mining site. These values are much higher than those typical for normal soil. The heavy metal uptake into shoots and roots of 33 indigenous plant species was also determined. Two species of the plants investigated, Pteris vittata L. and Pityrogramma calomelanos L. were As hyperaccumulators, containing more than 0.1% heavy metals in their shoots. Eleusine indica L., Cynodon dactylon L., Cyperus rotundus L. and Equisetum ramosissimum (Vauch) accumulate very high Pb (0.15-0.65%) and Zn (0.22-1.56%) concentration in their roots. Additional experiments to clarify the potential of six these plants as good candidates for phytoremediation of heavy metal pollution soil are being carried out in our laboratory.

The relationship between genetic factors and plasma lipids in Vietnamese living in rural areas

Background: Plasma lipids are affected not only by dietary intake and life style but also by genetic factor. Objective: To discover the relationship between plasma lipids and the presence of LPL S447X and PAF-AH V279F in the bodies of rural Vietnamese population. Subject and Method: One hundred and ninety three subjects were randomly selected from rural areas in Ho Chi Minh city. The presence of LPL S447X and PAF-AHV279F polymorphism was determined using an Invader assay, and the plasma lipid levels were measured by an enzymatic method. A profile regarding the dietary intake was also made for each subject. Result and Conclusion: The frequency of LPL 447SX/XX (12.2%) polymorphism, PAF-AH Val279Phe mutation allele frequency (5.4%) in the Vietnamese was closely similar to that of other Asian populations. LPL447X polymorphism was found to be significantly associated with a higher HDL-C level in comparison to LPL 447S. LPL S447X affects plasma HDL-C and TG concentration in Vietnamese rural population.

Results of mitral valve reconstruction in Viet Duc hospital

Background: Mitral valve diseases are the most frequent in the cardiac valvular acquired diseases. Valvuloplasty is a very good surgical treatment, also its techniques are difficult. Objective: (1) To describe features of valvular lesion and technique of valvuloplasty. (2) To evaluate the effects of these operations. Subject and Method: 95 cases of mitral valve reconstruction were studied and described retrospectively about pre- operative features, mitral valvuloplasty, and post-operative results. Results: Pre-operative cardiac failure >=2 nd level (NYHA) is 96.8%, with 100% of mitral valve insufficiency, 28.4% associated with valvular stenosis. Mean age of patient is 34.5 +/- 13.2. Each case must do an average 4/15 valvuloplasty techniques, the most frequent are: mitral valvular ring (67.4%), commissurotomy (57.9%), cordage section (45.3%)\u2026 Early post \u2013 operative result is very good: no mortality, mitral valvular function is improved significantly than pre-operative (p<0.001), no severe mitral stenosis or insufficiency. Long-term post operative control (3 months, 3 years, 5 years post \u2013 operation) present the stability of this valvuloplasty with high survival frequency (96.8% in 3 months, 96.2% in 3 years, 93.4% in 5 years), in the 78.5% ranges a good level, re-operation is only required in 3 cases with valvular replacement. Conclusions: Although the difficult technique of valvuloplasty \u2013 especially in rheumatic lesion, mitral valve reconstruction is a good and safe technique to treat the mitral valve diseases.

Results of treating flail chest by technique of open fixation

Background: Flail chest is a severe condition of thoracic trauma, and it requires diagnosis and treatment as soon as possible. From year 2000, we developed an improved technique of open fixation in order to adapt the situations of Vietnam health settings. Objectives: To report preliminary results of application of improved open fixation technique in Viet Duc Hospital from 2001 to 2006. Subjects and method: This descriptive, prospective and retrospective study involved 19 patients with flail chest due to closed thoracic trauma or multiple traumas, treated by open fixation technique. The parameters included features of patients, characteristics of this technique and postoperative progression.Results: Of 19 patients, there were 16 males and 3 females, mean age: 47.8 years. All patients presented obvious signs of flail chest preoperatively, but only 9 cases were treated by open fixation technique and pleural drainage immediately. This technique canbe applied in all sugical settings with single local anaesthesia, and any kind of common surgical threads. The most suitable initial pulled weight is 2000 g. All cases of flail chest required pleural drainage. All patients had good outcomes with open fixation technique, no death. There were 3 patients with postoperative complications, all were severe multiple trauma patients. Conclusion: Improved open fixation technique applied in Viet Duc Hospital is simple, effective and safe, and can be widely used in all surgical settings.

Assessing the emergency situation for peripheral vascular wounds/trauma in Viet Duc Hospital from 2004 to 2006

Background: peripheral vascular wounds/trauma is a severe type of surgical emergency, the increasing rate due to the rapid increase of traffic, labor and living accidents. Subjectives and Method: retrospective study, all patients with peripheral vascular wounds/traumas (alone or combination in multiple trauma) were emergency operated at Viet Duc Hospital from January 2004 to June 2006. Results: A total of 310 patients with peripheral vascular injuries in the study, of which accounted for 62.3% of injury, trauma group accounted for 37.7%. The mean age of 30. In first aid, pressed tape accounted for high rate (71.5%). Rate of popliteal vascular trauma due to fractures around the knee accounted for 65.5%, the rate of brachial vascular trauma with fractures around the elbow was 50%. Rate of late diagnosis of arterial trauma was 14.6%, higher than the arterial wounds (2.6%). The rate of ultrasound for forelimbs - where vessels were many wounds, was lower than that for hindlimbs - where vessels were many traumas (44% vs 67.9%). For vascular wounds, more directly vascular connection and more intervention on veins, whereas, for arterial trauma, more vascular graft. Rate of complications was low (7.4%), with no deaths. Conclusions: Overall, the results of emergency surgery for peripheral vascular wounds/trauma were well. No cases was death from vascular lesions, rate of complications was low.