Iranian Journal of Basic Medical Sciences
Volume:19 Issue: 1, Jan 2016

The physiologic function of the immune system is defense against infectious microbes and internal tumour cells, Therefore, need to have precise modulatory mechanisms to maintain the body homeostasis. The mammalian cellular CD200 (OX2)/CD200R interaction is one of such modulatory mechanisms in which myeloid and lymphoid cells are regulated. CD200 and CD200R molecules are membrane proteins that their immunomodulatory effects are able to suppress inflammatory responses, particularly in the privilege sites such as CNS and eyes. Kaposi’s sarcoma-associated herpesvirus (KSHV), encodes a wide variety of immunoregulatory proteins which play central roles in modulating inflammatory and anti-inflammatory responses in favour of virus dissemination. One such protein is a homologue of the, encoded by open reading frame (ORF) K14 and therefore called vOX2. Based on its gene expression profile during the KSHV life cycle, it is hypothesised that vOX2 modulates host inflammatory responses. Moreover, it seems that vOX2 involves in cell adhesion and modulates innate immunity and promotes Th2 immune responses. In this review the activities of mammalian CD200 and KSHV CD200 in cell adhesion and immune system modulation are reviewed in the context of potential therapeutic agents.

The limited homing potential of bone-marrow-derived mesenchymal stem cells (BM-MSC) is the key obstacle in MSC-based therapy. It is believed that chemokines and chemokine receptor interactions play key roles in cellular processes associated with migration. Meanwhile, MSCs express a low level of distinct chemokine receptors and they even lose these receptors on their surface after a few passages which influence their therapeutic applications negatively. This study investigated whether treatment of BM-MSCs with hypoxia-mimicking agents would increase expression of some chemokine receptors and cell migration. BM-MSCs were treated at passage 2 for our gene expression profiling. All qPCR experiments were performed by SYBR Green method in CFX-96 Bio-Rad Real-Time PCR. The Boyden chamber assay was utilized to investigate BM-MSC homing. Possible approaches to increasing the expression level of chemokine receptors by different hypoxia-mimicking agents such as valproic acid (VPA), CoCl2, and desferrioxamine (DFX) are described. Results show DFX efficiently up-regulate the CXCR7 and CXCR4 gene expression while VPA increase only the CXCR7 gene expression and no significant change in expression level of CXCR4 and the CXCR7 gene was detectable by CoCl2 treatment. Chemotaxis assay results show that pre-treatment with DFX, VPA, and Cocl2 enhances significantly the migration ability of BM-MSCs compared with the untreated control group and DFX treatment accelerates MSCs homing significantly with a higher rate than VPA and Cocl2 treatments. Our data supports the notion that pretreatment of MSC with VPA and DFX improves the efficiency of MSC therapy by triggering homing regulatory signaling pathways.

This study examined whether conjugated linoleic acid (CLA) supplementation affects insulin sensitivity and peroxisome proliferator-activated receptor gamma (PPAR-γ) and glucose transporter type 4 (GLUT-4) protein expressions in the skeletal muscles of rats during endurance exercise. Sprague-Dawley male rats were randomly divided into HS (high-fat diet (HFD) sedentary group, n = 8), CS (1.0% CLA supplemented HFD sedentary group, n = 8), and CE (1.0% CLA supplemented HFD exercise group, n = 8). The rats in the CE swam for 60 min a day, 5 days a week for 8 weeks. The serum glucose and insulin contents and homeostasis model assessment of insulin resistance (HOMA-IR) value of the CS and CE were significantly decreased compared to those of the HS. The PPAR-γ protein expressions in the soleus muscle (SOM) and extensor digitorum longus muscle (EDL) were significantly higher in the CE than in the HS. In addition, the PPAR-γ protein expression in the SOM of the CS was significantly higher than that in the HS. On the other hand, the GLUT-4 protein expression of the SOM in the CE was significantly higher compared to that in the HS. However, there was no significant difference in GLUT-4 protein expression in the EDL among the groups. CLA supplementation with/without endurance exercise has role in improvement of insulin sensitivity. Moreover, when CLA supplementation was accompanied by endurance exercise, the PPAR-γ protein expression in SOM and EDL and the GLUT-4 protein expression in SOM were enhanced compared with the control group.

Several investigations have revealed that caspase-14 is responsible for the epidermal differentiation and cornification, as well as the regulation of moisturizing effect. However, the precise regulation mechanism is still not clear. This study was aimed to investigate the expression of caspase-14 in filaggrin-deficient normal human epidermal keratinocytes (NHEKs) and to explore the possible mechanism that contributes to the regulation of caspase-14. The filaggrin-deficient NHEKs were induced by transfection with lentivirus (LV) vector encoding small hairpin RNAs (shRNA). The inhibitors SB203580, PD98059 and SP600125 were used for suppressing the expression of p38 mitogen-activated protein kinase (MAPK), p44/42 MAPK and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). The expression of filaggrin, p38 MAPK, p44/42 MAPK and SAPK/JNK, caspase-14, keratin1and keratin2 were detected by western blot. In filaggrin-deficient NHEKs, the expression of p38, p44/42 MAPK and SAPK/JNK and caspase-14 were significantly decreased. The inhibition of p38 and SAPK/JNK reduced the expression of caspase-14, while the p44/42 MAPK showed no consistent effects. Moreover, the filaggrin knockdown decreased the expression of keratin2, but had no effects on the level of keratin1. The decreased expression of caspase-14 in filaggrin-deficient NHEKs may be induced by the inactivation of MAPK signaling pathway. These provide a novel perspective to understand the mechanism for the protective effects of filaggrin and caspase-14 on skin barrier function.

The application of stem cells holds great promises in cell transplants. Considering the lack of optimal in vitro model for hepatogenic differentiation, this study was designed to examine the effects of laminin matrix on the improvement of in vitro differentiation of human bone marrow mesenchymal stem cells (hBM-MSC) into the more functional hepatocyte-like cells. Characterization of the hBM-MSCs was performed by immunophenotyping and their differentiation into the mesenchymal-derived lineage. Then, cells were seeded on the laminin-coated or tissue culture polystyrene (TCPS). The differentiation was carried out during two steps. Afterward, the expression of hepatocyte markers such as AFP, ALB, CK-18, and CK-19 as well as the expression of C-MET, the secretion of urea, and the activity of CYP3A4 enzyme were determined. Moreover, the cytoplasmic glycogen storage was examined by periodic acid–Schiff (PAS) staining. The results demonstrated that the culture of hBM-MSC on laminin considerably improved hepatogenic differentiation compared to TCP group. A significant elevated level of urea biosynthesis and CYP3A4 enzyme activity was observed in the media of the laminin-coated differentiated cells (P<0.05). Furthermore higher expressions of both AFP and ALB were determined in cells differentiated on laminin matrix. Glycogen accumulation was not detected in the undifferentiated hBM-MSCs, however, both differentiated cells in laminin and TCPS groups demonstrated the intracellular glycogen accumulation on day 21 of hepatogenic differentiation. Taken together, these findings may indicate that laminin matrix can improve terminal differentiation of hepatocyte-like cells from hBM-MSCs. Thus, laminin might be considered as a suitable coating in hepatic tissue engineering designs.

Higher cellular reactive oxygen species (ROS) levels is important in reducing cellular energy charge (EC) by increasing the levels of key metabolic protein, and nitrosative modifications, and have been shown to damage the cardiac tissue of diabetic mice. However, the relation between energy production and heart function is unclear. Streptozotocin (STZ, 150 mg/kg body weight) was injected intraperitoneally once to mice that had been fasted overnight for induction of diabetes. After diabetic induction, mice received citrate (5 µg/kg) through intraperitoneal injection every other day for 5 weeks. The caspase-3, plasminogen activator inhibitor 1 (PAI1), protein kinase B (PKB), commonly known as AKT and phosphorylated-AKT (p-AKT) proteins were examined to elucidate inflammation and apoptosis in the heart. For histological analysis, heart samples were fixed with 10% formalin and stained with hematoxylin-eosin (HE) and Sirius red to assess pathological changes and fibrosis. The expression levels[AGA1] of marker proteins, tyrosine nitration, activity of ATP synthase and succinyl-CoA:3-ketoacid coenzyme A transferase-1 (SCOT), and EC were measured. Intraperitoneal injection of citrate significantly reduced caspase-3 and PAI-1 protein levels and increased p-AKT level on the 5th week; EC in the heart was found to be increased as well. Further, the expression level, activity, and tyrosine nitration of ATP synthase and SCOT were not affected after induction of diabetes. Results indicate that application of citrate, a tricarboxylic acid (TCA) cycle intermediate, might alleviate cardiac dysfunction by reducing cardiac inflammation, apoptosis, and increasing cardiac EC.

The study aimed to investigate the effects of adrenomedullin (ADM) and proadrenomedullin N- terminal 20 peptide (PAMP) on angiotensin II (AngII)-stimulated proliferation in vascular smooth muscle cells (VSMCs). Thoracic aorta was obtained from Wistar rats and VSMCs were isolated from aorta tissues and then cultured. In vitro cultured VSMCs were stimulated with Ang II (10-8 mol/l) followed by various doses of PAMP or ADM (10-9, 10-8, or 10-7 mol/l). Cell proliferation as assessed by 3H-TdR incorporation. Protein kinase C (PKC) activity was measured by counting γ-32P radioactivity with liquid scintillation. In a separate cohort, in vitro cultured rat aortic vessels were treated with different doses of Ang II or PAMP (10-9, 10-8, or 10-7 mol/l). Cellular and secreted levels of PAMP, ADM and Ang II were measured using radioimmunoassay in the tissues and intubation mediums, respectively. Ang II (10-8 mol/l) treatment significantly increased both 3H-TdR incorporation and PKC activity in VSMCs (by 2.68 and 1.02-fold, respectively; both P<0.01 vs. the control). However, Ang II-induced elevation of 3H-TdR incorporation, and PKC activity was significantly inhibited by various doses of ADM and PAMP (all P<0.01 vs. the Ang II group). In rat aortic vascular tissues or intubation media, Ang II treatments stimulated the expression and secretion of PAMP and ADM in a dose-dependent manner, while PAMP treatments had no significant effects on Ang II levels. ADM and PAMP inhibit Ang II-induced VSMCs proliferation. The interaction of Ang II, ADM and PAMP may regulate VSMCs and cardiovascular function.

Bone marrow-derived mesenchymal stem cells (BMSCs) have attracted significant interest to treat asthma and its complication. In this study, the effects of BMSCs on lung pathology and inflammation in an ovalbumin-induced asthma model in mouse were examined. BALB/c mice were divided into three groups: control group (animals were not sensitized), asthma group (animals were sensitized by ovalbumin), asthma+BMSC group (animals were sensitized by ovalbumin and treated with BMSCs). BMSCs were isolated and characterized and then labeled with Bromodeoxyuridine (BrdU). After that the cells transferred into asthmatic mice. Histopathological changes of the airways, BMSCs migration and total and differential white blood cell (WBC) count in bronchoalveolar lavage (BAL) fluid were evaluated. A large number of BrdU-BMSCs were found in the lungs of mice treated with BMSCs. The histopathological changes, BAL total WBC counts and the percentage of neutrophils and eosinophils were increased in asthma group compared to the control group. Treatment with BMSCs significantly decreased airway pathological indices, inflammatory cell infiltration, and also goblet cell hyperplasia. The results of this study revealed that BMSCs therapy significantly suppressed the lung pathology and inflammation in the ovalbumin induced asthma model in mouse.

Sublingual allergen-specific immunotherapy is a safe and effective method for treatment of IgE-mediated respiratory allergies; however, the underlying mechanisms are not fully understood. This study was planned to test whether sublingual immunotherapy (SLIT) can exert epigenetic mechanisms through which the airway allergic responses can be extinguished. BALB/c mice were sensitized intraperitoneally and challenged intranasally. Then, they received sublingual treatment with recombinant Che a 2 (rChe a 2), a major allergen of Chenopodium album. After SLIT, allergen-specific antibodies in sera, cytokine profiles of spleen cell cultures, mRNA and protein expression of lung-derived IL-33, IL-25, and TSLP (thymic stromal lymphopoietin), and histone modifications of these three genes were assessed. Following Immunotherapy, systemic immune responses shifted from Th2 to Th1 profile as demonstrated by significant decrease in IgE and IL-4 and substantial increase in IgG2a and IFN-γ. At local site, mRNA and protein levels of lung-derived pro-inflammatory cytokines IL-33 and TSLP were markedly down-regulated following SLIT that was associated with marked enrichment of trimethylated lysine 27 of histone H3 at promoter regions of these two cytokines. In our study, sublingual immunotherapy with recombinant allergen effectively attenuated allergic immune responses, at least partly, by induction of distinct histone modifications at specific loci. Additionally, the lung-derived pro-allergic cytokines IL-33 and TSLP could be promising mucosal candidates for either monitoring allergic conditions or therapeutic approaches.

Vagal pathways in gastrointestinal tract are the most important pathways that regulate ischemia/reperfusion (I/R). Gastrointestinal tract is one of the important sources of melatonin production. The aim of this study was to investigate probable protective effect of the interaction between vagus nerve and melatonin after I/R. This study was performed in male rats that were divided into six groups. Cervical vagus nerve was cut bilaterally after induction of I/R and the right one was stimulated by stimulator. Melatonin or vehicle was injected intraperitoneally. The stomach was removed for histopathological and biochemical investigations. A significant decrease in infiltration of gastric neutrophils and malondialdehyde (MDA) level after I/R was induced by melatonin and was disappeared after vagotomy. The stimulation of vagus nerve significantly enhanced these effects of melatonin. However, a stimulation of vagus nerve alone increased neutrophils infiltration and MDA level. Melatonin significantly increased the activities of catalase, glutathione peroxidase (GPx), superoxide dismutases (SOD). Unlike stimulation of vagus nerve, vagotomy decreased these effects of melatonin. According to these results, it is probable that protective effects of melatonin after I/R may be mediated by vagus nerve. Therefore, there is an interaction between melatonin and vagus nerve in their protective effects.

Multiple sclerosis (MS) is a demyelinating disease. The prevalence of MS is highest where environmental supplies of vitamin D are low. Cognitive deficits have been observed in patients with MS. Oxidative damage may contribute to the formation of MS lesions. Considering the involvement of hippocampus in MS, an attempt is made in this study to investigate the effects of vitamin D3 on behavioral process and the oxidative status in the dorsal hippocampus (CA1 area) following the induction of experimental demyelination in rats. Animals were divided into six groups. Control group: animals received no surgery and treatment; saline group: animals received normal saline; sham group: animals received 150 μl sesame oil IP; vitamin D3 group: animals received 5 μg/kg vitamin D3 IP; lysophosphatidyl choline (LPC) group (toxic demyelination’s model): animals received LPC by stereotaxic intra-hippocampal injection of 2 μl LPC in CA1 area; Vitamin D3- treated group: animals were treated with vitamin D3 at doses of 5 μg/kg IP for 7 and 21 days post lesion. The spatial memory, biochemical parameters including catalase (CAT) activities and lipid peroxidation levels were investigated. Animals in LPC group had more deficits in spatial memory than the control group in radial arm maze. Vitamin D3 significantly improved spatial memory compared to LPC group. Also, results indicated that vitamin D3 caused a decrease in lipid peroxidation levels and an increase in CAT activities. Current findings suggest that vitamin D3 may have a protective effect on cognitive deficits and oxidative stress in toxic demyelination’s model.

Umbilical cord blood is a good source of the mesenchymal stem cells that can be banked, expanded and used in regenerative medicine. The objective of this study was to test whether amniotic membrane extract, as a rich source of growth factors such as basic-fibroblast growth factor, can promote the proliferation potential of the umbilical cord mesenchymal stem cells. The study design was interventional. Umbilical cord mesenchymal stem cells were isolated from voluntary healthy infants from hospitals in Shiraz, Iran, cultured in the presence of basic-fibroblast growth factor and amniotic membrane extracts (from pooled - samples), and compared with control cultures. Proliferation assay was performed and duplication number and time were calculated. The expression of stem cell’s specific markers and the differentiation capacity toward osteogenic and adipogenic lineages were evaluated. Amniotic membrane extract led to a significant increase in the proliferation rate and duplication number and a decrease in the duplication time without any change in the cell morphology. Both amniotic membrane extract and basic-fibroblast growth factor altered the expressing of CD44 and CD105 in cell population. Treating basic-fibroblast growth factor but not the amniotic membrane extract favored the differentiation potential of the stem cells toward osteogenic lineage. The amniotic membrane extract administration accelerated cell proliferation and modified the CD marker characteristics which may be due to the induction of differentiation toward a specific lineage. Amniotic membrane extract may enhance the proliferation rate and duplication number of the stem cell through changing the duplication time.

Pharmacological studies showed that the extracts of Jin Yin Hua and its active constituents have lipid lowering, antipyretic, hepatoprotective, cytoprotective, antimicrobial, antibiotic, antioxidative, antiviral, and anti-inflammatory effects. The purpose of the present study was to investigate the protective effects of caffeoylquinic acids (CQAs) from Jin Yin Hua against hydrogen peroxide (H2O2)-induced and hypoxia-induced cytotoxicity using neonatal rat cardiomyocytes. Seven CQAs (C1 to C7) isolated and identified from Jin Yin Hua were used to examine the effects of H2O2-induced and hypoxia-induced cytotoxicity. We studied C4 and C6 as preventative bioactive compounds of the reactive oxygen species (ROS) production, apoptotic pathway, and apoptosis-related gene expression. C4 and C6 were screened as bioactive compounds to exert a cytoprotective effect against oxidative injury. Pretreatment with C4 and C6, dose-dependently attenuated hypoxia-induced ROS production and reduced the ratio of GSSG/GStotal. Western blot data revealed that the inhibitory effect of C4 on H2O2-induced up and down-regulation of Bcl-2, Bax, caspase-3, and cleaved caspase-3. Apoptosis was evaluated by detection of DNA fragmentation using TUNEL assay, and quantified with Annexin V/PI staining. In vitro experiments revealed that both C4 and C6 protect cardiomyocytes from necrosis and apoptosis during H2O2-induced injury, via inhibiting the generation of ROS and activation of caspase-3 apoptotic pathway. These results demonstrated that CQAs might be a class of compounds which possess potent myocardial protective activity against the ischemic heart diseases related to oxidative stress.

Herbal medicines are promising cancer preventive candidates. It has been shown that Punica granatum L. could inhibit angiogenesis and tumor invasion. In this study, we investigated whether the anti-angiogenic effect of pomegranate peel extract (PPE) is partly attributable to Peroxisome proliferator-activated receptors (PPARs) activation in the Human Umbilical Vein Endothelial Cells (HUVECs). Ethanol extract from PPE was prepared. HUVECs were treated in four groups (with PPE (10 μg/ml) alone, PPE with or without PPARγ (T0070907) and α (GW6471) antagonists, and control group). The possible effect of PPARs on angiogenic regulation was checked by Matrigel assay. The mRNA expression levels of vascular endothelial growth factor (VEGF) was detected by Quantitative reverse transcription-polymerase chain reaction (QRT-PCR). PPE significantly inhibited both tube formation (size, length, and junction of tubes) and VEGF mRNA expression (P<0.05). Our results showed that the anti-angiogenic effects of PPE were significantly reversed by both PPAR antagonists (P<0.05). There was no difference between PPE plus antagonists groups and the control group. In summary our results showed that the anti-angiogenic effects of PPE could be mediated in part through PPAR dependent pathway.

Hyperglycemia mediated oxidative stress plays a key role in the pathogenesis of diabetic complications like nephropathy. In the present study, we evaluated the effect of ethanolic extract of Ensete superbum seeds (ESSE) on renal dysfunction and oxidative stress in streptozotocin-induced diabetic rats. Glucose, HbA1c, total protein, albumin, renal function markers (urea, uric acid and creatinine), and lipid peroxidation levels were evaluated. Renal enzymatic and non-enzymatic antioxidants were examined along with renal histopathological study. ESSE (400 mg/kg BW t) administration reduced glucose and HbA1c, and improved serum total protein and albumin in diabetic rats. ESSE in diabetic rats recorded decrement in renal function markers and renal lipid peroxidation products along with significant increment in enzymatic and non-enzymatic antioxidants. Renal morphological abnormalities of diabetic rats were markedly ameliorated by E.superbum. These results suggest that the antioxidant effect of E. superbum could ameliorate oxidative stress and delay/prevent the progress of diabetic nephropathy in diabetes mellitus.