Over expression of HIF-1α in human mesenchymal stem cells increases their supportive functions for hematopoietic stem cells in an experimental co-culture model

Introduction

Bone marrow transplantation is a critical approach for the treatment of many hematological disorders. Success of this approach is dependent on many factors the most important of which is the number of hematopoietic stem cells along with an efficient stroma. Co-transplantation of efficient mesenchymal stem cells can greatly improve the outcome of transplantations. Current researches assign a critical role for hypoxia inducible factor (HIF)-1α in protection of various cells and tissues probably through induction of cytokines. To make this feature applicable to human bone marrow-derived mesenchymal stem cells, we manipulated these cells to over express HIF-1α gene.

Materials and methods

Full-length cDNA of human HIF-1α was inserted into human bone marrow mesenchymal stem cells by pcDNA.3.1 non-viral plasmid vector, and the effect of this over expression on production of some hematopoietic growth factors was explored. Moreover, using a co-culture system, the interactive impact of HIF-1α-overexpressed mesenchymal stem cells on hematopoietic stem cells was evaluated.

Results

Over expression of HIF-1α in mesenchymal stem cells in normoxia increased production of one of the most important hematopoietic growth factors, Stem cell factor (also known as Steel factor or c-kit ligand). HIF-1α overexpression had no effect on production of other hematopoietic growth factors. In co-culture of mesenchymal stem cells-HIF-1α with hematopoietic stem cells, enhancement of colony formation and reduced differentiation of hematopoietic stem cells were observed.

Conclusion

Over expression of HIF-1α in human bone marrow-derived mesenchymal stem cells can augment the production of some hematopoietic growth factors, and we suggest this response of mesenchymal stem cells could help to improve the outcome of bone marrow transplantation.     

Cohen syndrome: report of nine cases and review of the literature, with emphasis on ophthalmic features.

PURPOSE: To review the clinical features of reported cases of Cohen syndrome with a focus on ophthalmic features and report nine new cases. METHODS: Retrospective case series and literature review. RESULTS: Cohen syndrome is a rare autosomal-recessive condition with about 136 reported cases. The typical phenotype of Cohen syndrome is variable and includes mild to severe psychomotor retardation, microcephaly, a cheerful disposition, characteristic facial features, childhood hypotonia and joint laxity, truncal obesity, intermittent neutropenia, along with a progressive retinal dystrophy and refractive myopia. We present nine cases that illustrate the typical clinical features of the disorder at different ages, including a woman with the less common finding of ectopia lentis. CONCLUSIONS: Cohen syndrome remains underdiagnosed or misdiagnosed by ophthalmologists. Awareness of this condition among ophthalmologists is important because the typical systemic and ophthalmologic findings may lead to an accurate diagnosis and counseling. Although diagnostic criteria exist based on clinical studies of patients with confirmed VPS13B (COH1) gene mutations, no minimal clinical diagnostic criteria are widely accepted at this time.     

A Dermal Equivalent Engineered with TGF‐β3 Expressing Bone Marrow Stromal Cells and Amniotic Membrane: Cosmetic Healing of Full‐Thickness Skin Wounds in Rats

Transforming growth factor beta‐3 (TGF‐β3) has been shown to decrease scar formation after scheduled topical applications to the cutaneous wounds. This study aimed to continuously deliver TGF‐β3, during the early phase of wound healing, by engineering a dermal equivalent (DE) using TGF‐β3 expressing bone marrow stromal cells (BM‐SCs) and human dehydrated amniotic membrane (hDAM). To engineer a DE, rat BM‐SCs were seeded on the hDAM and TGF‐β3 was transiently transfected into the BM‐SCs using a plasmid vector. Pieces of the dermal equivalent were transplanted onto the full‐thickness excisional skin wounds in rats. The process of wound healing was assessed by image analysis, Manchester Scar Scale (MSS), and histopathological studies 7, 14, 21, and 85 days after the excision. The results confirmed accurate construction of recombinant pcDNA3.1‐TGF‐β3 expression system and showed that the transfected BM‐SCs seeded on hDAM expressed TGF‐β3 mRNA and protein from day 3 through day 7 after transfection. After implantation of the DE, contraction of the wounds was measured from day 7 through 21 and analyzed by linear regression, which revealed that the rate of wound contraction in all experimental groups was similar. Histologic evaluation demonstrated that transfected BM‐SCs decreased retention and recruitment of the cells during the early stage of wound healing, decreased the formation of vascular structures and led to formation of uniformly parallel collagen bundles. MSS scores showed that TGF‐β3 secreting cells significantly improved the cosmetic appearance of the healed skin and decreased the scar formation. From these results, it could be concluded that transient secretion of TGF‐β3, during the early phase of healing, by BM‐SCs seeded on hDAM can improve the cosmetic appearance of the scar in cutaneous wounds without negatively affecting the process of wound repair.     

Upregulation of neutrophil gelatinase-associated lipocalin, NGAL/Lcn2, in beta-thalassemia patients

BACKGROUND: One of the major consequences in beta- thalassemia is iron overload. Oxidative statuses have been reported in beta-thalassemia patients by several studies. It has been proven that iron plays a critical role in the formation of reactive oxygen species (ROS). More recently, we have found the induction of Lcn2/NGAL expression under oxidative stress condition. In this study, it was assumed that NGAL should be upregulated in beta-thalassemia patients because of oxidative stress condition. METHODS: Assessment of NGAL expressions in 25 adult beta-thalassemia and 9 pediatric patients was performed by semiquantitative RT-PCR, real-time RT-PCR and ELISA. RESULTS: Adult beta-thalassemia patients upregulated NGAL expression compared with the normal samples but no upregulation was observed in pediatric patients. CONCLUSIONS: Upregulation may play an important role in decreasing ROS or iron in beta-thalassemia patients.     

The relationship between uric acid and metabolic syndrome in normal glucose tolerance and normal fasting glucose subjects

Elevated serum uric acid (SUA) concentrations have been suggested to associate with metabolic syndrome (MetS) and its components. However, limited information is available regarding the relationship between SUA and MetS in subjects with normal glucose levels. A total of 501 subjects with normal fasting glucose and normal glucose tolerance were included in the study. Anthropometrical and biochemical parameters were examined using standard methods. The updated NECP criteria were used to define the MetS. Values of SUA above the sex-specific percentile 75 were used to define hyperuricemia. The prevalence of general and abdominal obesity, hypertension, hypertriglyceridemia, low-HDL, smokers, MetS and insulin resistance was significantly greater in the fourth SUA quartile. Multiple regression indicated that SUA was independently predicted by BMI, triglyceride and 2 h glucose in women, and BMI, triglyceride, 2 h glucose and cholesterol in men. Logistic regression analysis showed that the obesity, hypertriglyceridemia, MetS and insulin resistance were independent determinants of hyperuricemia in women. In men, hyperuricemia was associated with the obesity, hypertriglyceridemia and hypercholesterolemia. Factor analysis yielded three factors interpreted as weight/waist, blood pressure and lipid/glucose. Including SUA in the model did not affect total variance of factor analysis. Our results indicate that SUA is associated with MetS and its components even in subjects with normal glucose levels. General obesity was the major determinant of hyperuricemia in this population. The data from this study do not show the contribution of SUA as an additional component of the MetS.     

Oral and dental health status in patients with primary antibody deficiencies

Primary antibody deficiencies (PAD) are a group of immune system disorders, associated with decreased levels of secretory and protective immunoglobulins. Because of the important role of immunoglobulins in the protection of oral cavity, patients with PADs are more susceptible to dental caries or oral manifestations. This study was performed to investigate the oral and dental manifestations of PADs patients. In this study, 33 patients with PADs (21 common variable immunodeficiency, 8 X-linked agammaglobulinemia and 4 hyper IgM syndrome) and 66 controls were examined; the number of decayed, missed and filled teeth (DMFT) were investigated. Aphthous was the most frequent manifestation in PADs patients (38.7%), which was significantly 16.7% higher than the controls (p=0.03). The patients with PADs showed significantly higher presentation of other oral and dental manifestations, including herpes sores, candidiasis tonsillitis, gingivitis, calculus, enamel hypoplasia and other ulcerations. The mean DMFT scores were 6.15±3.6 and 1.93±0.4 in PADs patients and controls, respectively (p<0.001). Although the patients with common variable immunodeficiency had higher means of DMFT in comparison with other groups of PADs, this difference was not statistically significant. This study showed significantly higher frequency of oral and dental manifestations in the patients with PADs compared to controls. Therefore, regular examination of oral cavity could be suggested in this group of immunodeficient patients.     

Incidence of fever and bacteriemia following flexible fiberoptic bronchoscopy: a prospective study

The latest American Heart Association (AHA) statement for preventing infectious endocarditis, has not recommended prophylactic antibiotic therapy prior to fiberoptic bronchoscopy (FB) except for patients with preexisting predisposing cardiac conditions. Our aim was to determine the incidence of bacteriemia and fever following FB in our experience and compare with those which have been mentioned in AHA guideline as well as other studies. Venous blood of 85 consecutive patients was evaluated for both aerobic and anaerobic cultures before (for detecting possible previous bacteriemia) and after FB. None of the patients were treated with antibiotics prior to the procedure. All the patients were examined during the first 24 hours after FB for detecting fever defined as temperature more than 38 °C. Positive hemocultures were noted in 7 (8.2 %) patients after FB examination. Coagulase negative Staphylococcus, coagulase positive Staphylococcus, beta haemolytic Streptococcus, Citrobacter freundii and Streptococcus viridans were found in 4, 1, 1 and 1 cultures of patients, respectively. By excluding 6 contaminated samples, the rate of bacteriemia reduced to 1 (1.1%) patient in whom the identical pathogen (Streptococcus viridans) was found both in bronchial lavage and venous blood culture. We also found fever in 9 (10.5 %) cases in the first 24 hours following the bronchoscopy. Our results were in consistent with AHA recommendations regarding prevention of infectious endocarditis as a practical gridline in patients who schedule for FB. Besides, transient fever following bronchoscopy is a common self-limited event which does not need medical intervention.     

Mesenchymal Stem Cells on Horizon: A New Arsenal of Therapeutic Agents

Over 10 years, mesenchymal stem cells (MSCs) have been considered as valuable and suitable cells for cell-based therapy applications, particularly in clinical trials. In any case, they are as yet not utilized routinely in clinics. At first, it was believed that MSCs play their roles, especially in regenerative medicine due to their differentiation and cell replacement properties. Interestingly, it is well-known that MSCs mainly exert their therapeutic effects through their vast bioactive factors. These findings turned scientists’ consideration toward cell-free therapy concepts. From this point of view, MSCs can be considered as an arsenal of natural bioreactors in variety of therapeutic agents. MSCs inherently express various important therapeutic agents such as growth factors and cytokines that can be manufactured, handled and stored as a prepared-to-go biologic product. In this review, we provide a vision, highlight as well as discuss in order to introduce competitive natural robust bioreactor MSCs on the horizon.