BACKGROUND: In our previous study, we found higher cytoglobin (Cygb) expression in keloid than normal tissue. Cytoglobin is a new globin family protein which function is still being studied to date. The purpose of this research is to elucidate the function of Cygb in human skin keloid fibroblasts (KFs), especially its role in intracellular reactive oxygen species (ROS) levels.METHODS: The study was conducted on human skin KFs obtained from primary culture. Inhibition of Cygb expression was achieved by using siRNA targeting Cygb. We compared the relative expression of Cygb between treatment and control group, and its effect on intracellular ROS levels. Gene expression was measured using quantitative real-time polymerase chain reaction (qRT-PCR) while the ROS level counted by dichlorodihydrofluorescein diacetate (DCFHDA) assay.RESULTS: There was an increase in intracellular ROS levels in the small interfering RNA (siRNA) (+) Cygb group compared to control group (1.673 vs. 1.260; 1.773 vs. 1.393; 1.710 vs. 1.360; respectively). There is a negative correlation between Cygb expression and ROS level (p<0.05; r=-0.651).CONCLUSION: There is a negative correlation between Cygb expression and intracellular ROS levels, we suggest Cygb acts as a ROS scavenger in human skin KFs.KEYWORDS: skin keloid fibroblasts, cytoglobin, siRNA, ROS

The house gecko (Hemidactylus platyurus) has evolved the ability to autotomize its tail when threatened. The lost part is then regrown via epimorphic regeneration in a process that requires high energy and oxygen levels. Oxygen demand is therefore likely to outstrip supply and this can result in relative hypoxia in the tissues of the regenerating tail. The hypoxic state is stabilized by the Hypoxia Inducible Factor-1α (HIF-1α) and HIF-2α proteins. We induced tail autotomy in 30 mal H. platyurus Correspondence to: Mohamad Sadikin, 69 adults using a standard procedure and then collected samples of the regenerated tail tissue on days 1, 3,5,8,10,13,17,21,25, and 30 post autotomy. For each sample, mRNA expression was analyzed by qPCR, proteins were analyzed using Western Blot tests and immunohistochemistry, and the histological structure was analyzed using Hematoxylin and Eosin staining. On day 1, HIF-1α mRNA expression increased and the tissue was dominated by leucocyte and erythrocyte cells. HIF-1α mRNA expression peaked on day 3, at which time some cells were actively proliferating, migrating, and differentiating. At the same time as HIF-1α expression decreased, HIF-2α mRNA expression increased, as did overall cellular activity. HIF-2α expression increased more gradually but was present over a longer period of time than HIF-1α. We hypothesize that HIF-1α helps to initially stimulate the tissue regeneration process while HIF-2α functionally takes over the role of HIF-1α after HIF-1α succumbs to the oxygen conditions, but we suspect that both HIF-1α and HIF-2α play a role in overcoming the tissue's hypoxic state.

Transplantation of bone marrow derived stem cells (BMSCs) has been reported inhibits liver fibrosis. Several in vitro studies by co-culturing BMSCs and hepatic stellate cells (HSCs) indirectly or directly in 2D models showed inhibition of HSC as the key player in liver fibrosis. In this study, we investigated direct effect of BMSCs on HSCs by co-culturing BMSCs and HSCs in 3D model as it represents the liver microenvironment with intricate cell-cell and cell-matrix interactions. Primary isolated rat HSCs and BMSCs were directly co-cultured at 1:1 ratio with hanging drop method. The monoculture of rat HSCs served as positive control. Mono-culture and co-culture samples were harvested on day 3, 5 and 7 for histological analysis. The samples were analyzed for extracellular matrix deposition by Masson’s Trichrome staining, tenascin-C immunocytochemistry, resting HSC’s state as shown by positive Oil Red O stained cells. Our results indicated CD90+CD34− BMSCs anti-liver fibrosis potency as evidenced by higher proportion of Oil Red O-positive cells in the co-culture group compared to the monoculture group and the significant decrease in extracellular matrix deposition as well as the decrease in tenascin-C expression in the co-culture group (p<0.05) compared to the monoculture group. These findings demonstrate that BMSCs have a potential therapeutic effect against liver fibrotic process through their capacity to inhibit HSCs activation and their effect in minimizing extracellular matrix deposition.

Abstrak AbstractBackground: Concomitant treatment with antimalaria and antiretroviral drug is a new challenge in the management of malaria and HIV co-infection. Primaquine is a substrate and also an inhibitor of CYP3A4, while ritonavir is a substrate, an inhibitor, and also an inducer for CYP3A4. the objective of this study is to measure the CYP3A4 mRNA expression in HepG2 cell culture induced by primaquine and ritonavir co-treatment.

Background: A keloid is a benign skin tumour characterised by excessive proliferation of fibroblasts, a process that requires a sufficient amount of energy. The energy needs are associated with adequate oxygen (O2) flow and well-functioning mitochondria. It is known that cytoglobin (CYGB) has a function in O2 distribution. The aim of the present study was to explore whether the inhibition of CYGB expression caused impaired mitochondrial function of keloid fibroblasts. Methods: An in vitro study was conducted on a keloid fibroblast derived from our previous study. The study was carried out in the laboratory of the Biochemistry & Molecular Biology Department, Faculty of Medicine, Universitas Indonesia (FMUI), from July to December 2018. CYGB expression was inhibited by small interfering ribonucleic acid (siRNA) and CYGB. Analysis of mitochondrial function was observed through peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), a mitochondrial biogenesis marker and the activity of the succinate dehydrogenase (SDH) enzyme in mitochondria. Results: The CYGB gene and protein were downregulated after treatment with CYGB siRNA. Inhibition of CYGB expression with siRNA also tended to decrease the levels of PGC-1α messenger ribonucleic acid (mRNA) and protein, as well as SDH enzyme activity. Conclusion: Inhibition of CYGB expression with siRNA tended to decrease mitochondrial biogenesis and function. This may be useful for understanding the excessive proliferation of fibroblasts in keloids and for development of treatment for keloids.