Rutin and quercetagetin enhance the regeneration potential of young and aging bone marrow-derived mesenchymal stem cells in the rat infarcted myocardium

Myocardial infarction (MI) damages cardiomyocytes permanently and compromises cardiac function. Mesenchymal stem cells (MSCs) with the potential to differentiate into multiple lineages are considered as one of the best options for the treatment of MI. However, aging affects their regeneration capability. With age, reactive oxygen species (ROS) accumulate in cells ultimately causing cell death. To successfully utilize these stem cells in clinic, novel strategies to improve their functional capability should be explored. In this study, we aimed to enhance the cardiac regeneration potential of bone marrow MSCs derived from aging rats by treating them with antioxidants, rutin or quercetagetin in separate in vivo experiments. Oxidative stress was induced by treating MSCs of young and aging rats with different concentrations of H₂O₂ which resulted in an increase in the ROS level. MSCs were treated with rutin or quercetagetin at varying concentrations and exposed to H₂O₂. It was observed that both antioxidants significantly (P < 0.001) suppressed H₂O₂-induced intracellular ROS accumulation in a dose-dependent manner. An optimized concentration of 10 µM rutin or quercetagetin was used for the in vivo experiments. MI models were developed in aging rats by ligation of left anterior descending artery and treated MSCs were transplanted in the MI models. Echocardiography was performed after 2 and 4 weeks of cell transplantation to evaluate the functional status of the infarcted heart and histological analysis was performed after 4 weeks to assess cardiac regeneration. Significant improvement was observed in cardiac parameters including LVEF% (P < 0.001), LVFS% (P < 0.01 and P < 0.001), LVIDd (P < 0.01 and P < 0.001), LVIDs (P < 0.001), LVEDV (P < 0.001) and LVESV (P < 0.001) in the treated young as well as aging MSCs. It is concluded from these findings that rutin and quercetagetin treatment enhance the regeneration efficiency of young and aging MSCs in vivo. These antioxidants can be effectively utilized to improve cellular therapy for myocardial infarction by suppressing ROS production.

The role of epigenetic modifiers in the hepatic differentiation of human umbilical cord derived mesenchymal stem cells

Human umbilical cord (hUC) derived mesenchymal stem cells (MSCs) can be progressively differentiated into multiple lineages including hepatic lineages, and thus provide an excellent in vitro model system for the study of hepatic differentiation. At present, hepatic differentiation protocols are based on the use of soluble chemicals in the culture medium and provide immature hepatic like cells. Histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) are two important epigenetic modifiers that regulate stem cell differentiation. Therefore, this study aimed to investigate the role of HDACi, valproic acid (VPA) and DNMTi,5-azacytidine (5-aza) along with a hepatic inducer in the hepatic differentiation of hUC-MSCs. hUC-MSCs were characterized via immunocytochemistry and flow cytometry. The final concentrations of VPA and 5-aza were optimized via MTT cytotoxicity assay. All treated groups were assessed for the presence of hepatic genes and proteins through qPCR and immunocytochemistry, respectively. The results showed that the pretreatment of epigenetic modifiers not only increased the hepatic genes but also increased the expression of the hepatic proteins. VPA induces hepatic differentiation in hUC-MSCs with significant gene expression of hepatic markers i.e., FOXA2 and CK8. Moreover, VPA pretreatment enhanced the expression of hepatic proteins AFP and TAT. The pretreatment of 5-aza shows significant gene expression of hepatic marker LDL-R. However, 5-aza treatment failed to induce hepatic protein expression. The results of the current study highlighted the effectiveness of epigenetic modifiers in the hepatic differentiation of hUC-MSCs. These differentiated cells can be employed in cell-based therapeutics for hepatic diseases in future.

Overexpression of GATA binding protein 4 and myocyte enhancer factor 2C induces differentiation of mesenchymal stem cells into cardiac-like cells

BACKGROUND

Heart diseases are the primary cause of death all over the world. Following myocardial infarction, billions of cells die, resulting in a huge loss of cardiac function. Stem cell-based therapies have appeared as a new area to support heart regeneration. The transcription factors GATA binding protein 4 (GATA-4) and myocyte enhancer factor 2C (MEF2C) are considered prominent factors in the development of the cardiovascular system.

AIM

To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells (hUC-MSCs).

METHODS

hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry, and by their potential to differentiate into osteocytes and adipocytes. hUC-MSCs were transfected with GATA-4, MEF2C, and their combination to direct the differentiation. Cardiac differentiation was confirmed by semiquantitative real-time polymerase chain reaction and immunocytochemistry.

RESULTS

hUC-MSCs expressed specific cell surface markers CD105, CD90, CD44, and vimentin but lack the expression of CD45. The transcription factors GATA-4 and MEF2C, and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e., GATA-4, MEF2C, NK2 homeobox 5 (NKX2.5), MHC, and connexin-43, and cardiac proteins GATA-4, NKX2.5, cardiac troponin T, and connexin-43.

CONCLUSION

Transfection with GATA-4, MEF2C, and their combination effectively induces cardiac differentiation in hUC-MSCs. These genetically modified MSCs could be a promising treatment option for heart diseases in the future.

Combination of mesenchymal stem cells and three-dimensional collagen scaffold preserves ventricular remodeling in rat myocardial infarction model

BACKGROUND

Cardiovascular diseases are the major cause of mortality worldwide. Regeneration of the damaged myocardium remains a challenge due to mechanical constraints and limited healing ability of the adult heart tissue. Cardiac tissue engineering using biomaterial scaffolds combined with stem cells and bioactive molecules could be a highly promising approach for cardiac repair. Use of biomaterials can provide suitable microenvironment to the cells and can solve cell engraftment problems associated with cell transplantation alone. Mesenchymal stem cells (MSCs) are potential candidates in cardiac tissue engineering because of their multilineage differentiation potential and ease of isolation. Use of DNA methyl transferase inhibitor, such as zebularine, in combination with three-dimensional (3D) scaffold can promote efficient MSC differentiation into cardiac lineage, as epigenetic modifications play a fundamental role in determining cell fate and lineage specific gene expression.

AIM

To investigate the role of collagen scaffold and zebularine in the differentiation of rat bone marrow (BM)-MSCs and their subsequent in vivo effects.

METHODS

MSCs were isolated from rat BM and characterized morphologically, immunophenotypically and by multilineage differentiation potential. MSCs were seeded in collagen scaffold and treated with 3 μmol/L zebularine in three different ways. Cytotoxicity analysis was done and cardiac differentiation was analyzed at the gene and protein levels. Treated and untreated MSC-seeded scaffolds were transplanted in the rat myocardial infarction (MI) model and cardiac function was assessed by echocardiography. Cell tracking was performed by DiI dye labeling, while regeneration and neovascularization were evaluated by histological and immunohistochemical analysis, respectively.

RESULTS

MSCs were successfully isolated and seeded in collagen scaffold. Cytotoxicity analysis revealed that zebularine was not cytotoxic in any of the treatment groups. Cardiac differentiation analysis showed more pronounced results in the type 3 treatment group which was subsequently chosen for the transplantation in the in vivo MI model. Significant improvement in cardiac function was observed in the zebularine treated MSC-seeded scaffold group as compared to the MI control. Histological analysis also showed reduction in fibrotic scar, improvement in left ventricular wall thickness and preservation of ventricular remodeling in the zebularine treated MSC-seeded scaffold group. Immunohistochemical analysis revealed significant expression of cardiac proteins in DiI labeled transplanted cells and a significant increase in the number of blood vessels in the zebularine treated MSC-seeded collagen scaffold transplanted group.

CONCLUSION

Combination of 3D collagen scaffold and zebularine treatment enhances cardiac differentiation potential of MSCs, improves cell engraftment at the infarcted region, reduces infarct size and improves cardiac function.

Abstract P1137: Combination Of Zebularine Treated Rat Bone Marrow Mesenchymal Stem Cells With 3d Collagen Scaffold Preserves Ventricular Remodeling In Rat Myocardial Infarction Model

Cardiovascular diseases (CVDs) are the leading cause of death globally due to immensely high morbidity and mortality ratio. The incidence of CVD, particularly myocardial infarction (MI), is expected to increase rapidly in the coming decades. MI causes the death of myocytes, which ultimately leads to heart failure. Advancements in medical and surgical treatments can only limit the disease progress but cannot improve the function of infarcted myocardium. Therefore, a promising treatment strategy for ischemic heart diseases is highly needed. Stem cell therapy holds great potential to regenerate the injured myocardium due to the self-renewal and differentiation potential of these cells. Among various types, mesenchymal stem cells (MSCs) are potential candidates for regenerating the damaged cardiac tissue due to their multi-lineage differentiation potential and ease of isolation. However, certain issues such as poor survival and engraftment can prevent them from fully restoring normal cardiac structure and function. The use of biomaterials provides suitable microenvironment to the cells to perform various biological functions, and can solve the poor cellular engraftment problem associated with cell transplantation alone. In this study, we used natural three dimensional (3D) collagen scaffold along with demethylating agent, zebularine, for in vivo transplantation in rat MI model. Treatment with zebularine is shown to enhance cardiac differentiation of MSCs. MSCs were isolated from rat bone marrow, characterized, seeded in collagen scaffold and treated with zebularine. Cytotoxicity analysis was performed to confirm the non-cytotoxic effect of the treatments, and gene and protein expression levels were analyzed using cardiac specific primers and antibodies, respectively. In vitro analysis revealed that treatment in the 3D environment significantly enhanced cardiac differentiation of MSCs both at gene and protein levels. For in vivo analysis, rat MI model was developed and zebularine treated MSC-seeded scaffold was transplanted and compared with the MI group, along with other groups in which only collagen scaffold and untreated MSC-seeded scaffold were transplanted. Echocardiographic analysis revealed enhanced functional improvement in zebularine treated MSC-seeded group as compared to the other groups. Histological analysis revealed tissue preservation, cardiac regeneration beneath the scaffold, reduction in the fibrotic scar and improvement in the ventricular wall thickness in the treated MSC group. This strategy is expected to overcome the problems associated with cell transplantation alone and to provide an effective therapeutic strategy for improved cardiac function.

Small molecule 2'-deoxycytidine differentiates human umbilical cord-derived MSCs into cardiac progenitors in vitro and their in vivo xeno-transplantation improves cardiac function

Small molecules are widely used to induce stem cell differentiation. 2'-deoxycytidine (2-DC) belongs to the cytidine family. It stimulates the expression of cardiac-specific genes and proteins, and directs mesenchymal stem cells towards cardiomyogenic differentiation. We aim to investigate the role of 2-DC-treated human umbilical cord mesenchymal stem cells (UC-MSCs) into myogenic lineage and explore their application in regeneration of infarcted myocardium. UC-MSCs were treated with 5, 10, 20, and 40 µM 2-DC following optimization by cytotoxicity analysis. Rat model of myocardial infarction (MI) was induced by ligating left anterior descending coronary artery. Normal, and 2-DC treated UC-MSCs were transplanted in the left ventricular wall immediately after ligation. Echocardiographic measurements were performed to assess cardiac function. Tissue architecture of the myocardium was examined by histological analysis to determine fate of the transplanted cells. MSCs were successfully isolated from human umbilical cord tissue. 2-DC treatment did not produce any significant cytotoxic effect in UC-MSCs at all concentrations. qPCR analysis of treated UC-MSCs showed induction of myogenic differentiation, which is more pronounced at 20 μM concentration. Fluorescently labeled 2-DC-treated UC-MSCs showed significant (**P < 0.01) homing in the infarcted myocardium as compared to normal UC-MSCs. Hearts transplanted with 2-DC-treated UC-MSCs significantly (***P < 0.001) improved the cardiac systolic and diastolic functions and pumping ability as compared to normal UC-MSCs and MI groups. Fibrotic area and left ventricular wall thickness were significantly improved (***P < 0.001) in 2-DC-treated group as compared to normal UC-MSCs. Immunohistochemical staining showed co-localization of fluorescently labeled cells and patches of differentiated myocytes which were stained for cardiac proteins in the infarct zone implying that the treated UC-MSCs regenerated cardiomyocytes. We report for the first time that 2-DC induces cardiac differentiation in UC-MSCs. Transplanted cells differentiated into functional cardiomyocytes and significantly improved cardiac performance. These pre-differentiated cardiac progenitors showed better survival, homing, and distribution in the infarcted zone. 2-DC treated cells not only improved cardiac function, but also restored tissue homeostasis, suggesting a better therapeutic option for the regeneration of cardiac tissue in the clinical setup.

Pregnancy outcome in women with active and inactive lupus nephritis: A prospective cohort study

Several studies have emphasized poor pregnancy outcomes associated with active lupus nephritis at the onset of conception. A few controversial studies have compared pregnancy outcome in patients with inactive lupus nephritis at conception and those without a history of lupus nephritis. This study aimed to find out if quiescent lupus nephritis at the onset of conception carries an increased risk of pregnancy complications compared to pregnancies without a history of lupus nephritis. This is a prospective cohort study carried out at the Rheumatology/Obstetrics Conjoint Clinic of Kasr Al-Ainy Hospital between January 2006 and December 2017. A total of 119 pregnancies were included: 72 pregnancies in group I (with a history of lupus nephritis) and 47 pregnancies in group II (non-renal systemic lupus erythematosus). They were subjected to full history taking, monthly clinical examination and laboratory investigations. In total, 16 (22.2%) renal pregnancies had renal flares at the onset of conception. Maternal complications, specifically renal flares, were reported in 36 (50%) pregnancies in group I and 13 (27.7) pregnancies in group II, with a significant difference ( p = 0.015). No significant differences were found concerning the frequency of pregnancy-related maternal and fetal complications between the two groups. When data were re-analyzed after excluding patients experiencing renal flares during the 6 months preceding pregnancy, there were no significant differences regarding the frequency of maternal and fetal complications between renal and non-renal pregnancies. In conclusion, lupus nephritis, per se, is not a risk factor for poor pregnancy outcome; rather, it is the lupus nephritis activity at the onset of pregnancy.

IL-7 overexpression enhances therapeutic potential of rat bone marrow mesenchymal stem cells for diabetic wounds

This study was aimed to enhance the healing potential of rat bone marrow mesenchymal stem cells against chronic diabetic wounds through interleukin-7 (IL-7) transfection. IL-7 plays an important role in wound healing and acts as a survival factor in some cell types. This study involves isolation, propagation, and characterization of mesenchymal stem cells (MSCs) and their modification with IL-7 gene via retroviral transfection. Transfected MSCs were assessed for their effect on angiogenic genes by qPCR. Wound healing potential of transfected MSCs was analyzed by scratch assay in vitro and by transplanting these cells in rat diabetic wound models in vivo. Wound area was measured for a period of 15 days and subsequent histological analysis was performed. qPCR results showed increased expression of IL-7 gene (p ≤ 0.05) and also principal angiogenic genes, vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), VEGF receptor 1 (FLT-1), and VEGF receptor 2 (FLK-1) (p ≤ 0.05). Neuropilin-1 (NRP-1) did not show any significant change. In vitro analysis of IL-7 MSCs showed intense cell-cell connections and tube formation as compared to the normal MSCs. Rate of wound closure was more (p ≤ 0.001) in case of diabetic group transplanted with IL-7 MSCs. Histological examination revealed enhanced vascular supply in skin tissues of diabetic animals transplanted with IL-7 transfected MSCs as compared to normal MSCs. Immunohistochemical results showed significantly higher expression of IL-7 (p ≤ 0.001) and α-smooth muscle actin(p ≤ 0.001) in the tissue sections of IL-7 transfected group as compared to normal MSCs and the diabetic control group; the latter indicates increase in the number of blood vessels. It is concluded from this study that IL-7 overexpression in MSCs can enhance the healing potential of MSCs and aid in wound closure in diabetic animals through the induction of angiogenic genes.

Role of interleukin-7 in fusion of rat bone marrow mesenchymal stem cells with cardiomyocytes in vitro and improvement of cardiac function in vivo

AIMS

Mesenchymal stem cells (MSCs) hold significant promise as potential therapeutic candidates following cardiac injury. However, to ensure survival of transplanted cells in ischemic environment, it is beneficial to precondition them with growth factors that play important role in cell survival and proliferation. Aim of this study is to use interleukin-7 (IL-7), a cell survival growth factor, to enhance the potential of rat bone marrow MSCs in terms of cell fusion in vitro and cardiac function in vivo.

METHODS

Mesenchymal stem cells were transfected with IL-7 gene through retroviral vector. Normal and transfected MSCs were co-cultured with neonatal cardiomyocytes (CMs) and cell fusion was analyzed by flow cytometry and fluorescence microscopy. These MSCs were also transplanted in rat model of myocardial infarction (MI) and changes at tissue level and cardiac function were assessed by histological analysis and echocardiography, respectively.

RESULTS

Co-culture of IL-7 transfected MSCs and CMs showed significantly higher (P < 0.01) number of fused cells as compared to normal MSCs. Histological analysis of hearts transplanted with IL-7 transfected MSCs showed significant reduction (P < 0.001) in infarct size and better preservation (P < 0.001) of left ventricular wall thickness as compared to normal MSCs. Presence of cardiac-specific proteins, α-actinin, and troponin-T showed that the transplanted MSCs were differentiated into cardiomyocytes. Echocardiographic recordings of the experimental group transplanted with transfected MSCs showed significant increase in the ejection fraction and fractional shortening (P < 0.01), and decrease in diastolic and systolic left ventricular internal diameters (P < 0.001) and end systolic and diastolic volumes (P < 0.01 and P < 0.001, respectively).

CONCLUSION

Interleukin-7 is able to enhance the fusogenic properties of MSCs and improve cardiac function. This improvement may be attributed to the supportive action of IL-7 on cell proliferation and cell survival contributing to the regeneration of damaged myocardium.

Visceral Injuries in Patients with Blunt and Penetrating Abdominal Trauma Presenting to a Tertiary Care Facility in Karachi, Pakistan

Introduction

Abdominal injuries are responsible for 10% of the mortalities due to trauma. Delays in early diagnosis or misdiagnoses are two major reasons for the mortality and morbidity associated with abdominal trauma. The objectives of this study were to determine the frequency of visceral injuries in patients with abdominal trauma and compare the frequency of visceral injuries in patients with blunt and penetrating abdominal trauma.

Methods

We conducted a cross-sectional study from May 2016 to May 2018 of patients presenting to the emergency department (ED) at Jinnah Postgraduate Medical Center in Karachi, Pakistan. Patients were 12 to 65 years old and presented within 24 hours of abdominal trauma. We recorded the type of abdominal visceral injuries, such as liver, spleen, intestine, stomach, mesentery, and pancreas.

Results

The mean patient age was 31 ±13 years. Penetrating trauma was found in most patients (n=72, 51%). Liver injuries were found in 37 patients (26.4%), spleen injuries in 29 patient (20.7%), stomach injuries in eight patients (5.7%), intestine injuries in 67 patients (47.9%), mesentery injuries in 21 patients (15%), and pancreas injuries in nine patients (6.4%). The type of abdominal trauma was found significantly associated with liver injury (p-value 0.021), and intestine injury (p-value <0.001).

Conclusion

Penetrating trauma (51.4%) was more common than blunt trauma (48.5%), and intestines are the most commonly affected by penetrating and blunt trauma injuries (70.1% and 47.8%, respectively). The liver is the most commonly affected (42.85%) in blunt trauma injuries, followed by the spleen (28.5%). The appropriate authorities should consider this information when instituting public health and safety initiatives.

Epac-Rap1-activated mesenchymal stem cells improve cardiac function in rat model of myocardial infarction

INTRODUCTION

Rap1, a member of Ras superfamily of small GTP-binding proteins, is involved in cardiovascular biology in numerous ways. It is an evolutionary conserved regulator of adhesion, polarity, differentiation and growth.

AIMS

Our aim was to analyze Rap1-activated rat bone marrow mesenchymal stem cells (MSCs) for their potential role in adhesion and cardiac differentiation.

METHODS

Myocardial infarction (MI) was produced in Sprague Dawley (SD) rats through occlusion of the left anterior descending coronary artery. MSCs were treated with 8-pCPT-2'-O-Me-cAMP (CPT) to activate Rap1. Normal (untreated) and CPT-treated MSCs were transplanted through intramyocardial injection in respective groups. Cardiac function was assessed by echocardiography at 2 and 4 weeks after cell transplantation. Histological analysis was performed to observe changes at tissue level.

RESULTS

Homing of CPT-treated MSCs was significantly (***P<.001) higher as compared to normal MSCs in the infarcted hearts. This may be due to increase in the gene expression of some of the cell adhesion molecules as evident by qRT-PCR analysis. Significant (***P<.001) improvement in the restoration of heart function in terms of left ventricular diastolic and systolic internal diameters (LVIDd, LVIDs), % ejection fraction, % fraction shortening and end-systolic and end-diastolic volumes were observed in CPT-treated MSCs as compared to the MI model. Histological analyses showed significant (***P<.001) reduction in scar formation in the CPT-treated group. Differentiation of treated MSCs into functional cardiomyocytes was evident through immunohistochemical staining. LV wall thickness was also preserved significantly (***P<.001). Blood vessel formation was more pronounced in CPT-treated group although both cell therapy groups showed significant increase as compared to MI model.

CONCLUSION

Our findings showed that pharmacological activation of Epac-Rap1 improves cardiac function through better survival, adhesion and differentiation of transplanted cells. Transplantation of these MSCs in the infarct area restored functional myocardium.

Conditioned media trans-differentiate mature fibroblasts into pancreatic beta-like cells

AIM

The study was carried out to evaluate the role of preconditioning strategies on the trans-differentiation of mature fibroblasts (NIH3T3 cells) into insulin producing β-cells.

METHODS

The NIH3T3 cells were treated with dexamethasone (5μM) and pancreatic extract (0.05 and 0.4mg/mL) separately or in combination. The treated cells were analyzed for the morphological changes, and expression of pancreatic genes and proteins by phase contrast microscopy, RT-PCR and flow cytometry/immunocytochemistry, respectively.

RESULTS

Treatment of mature fibroblasts with different combinations of dexamethasone and pancreatic extract in the form of conditioned media resulted in comparable morphological changes and expression of certain pancreatic genes and proteins; however, their expression varied with each treatment. Most prominent effect was observed in case of combined treatment which resulted in significant increase (p<0.001) in gene expression levels of insulin, MafA, and Ngn3. Variable pattern was observed in insulin, MafA, Ngn3 and Sca1 expressions at the protein level.

CONCLUSION

It is concluded from this study that preconditioning of NIH3T3 cells with conditioned media containing different combinations of dexamethasone and pancreatic extract can induce trans-differentiation of these cells into pancreatic β-like cells. The conditioned media however, need to be optimized. The study may offer the possibility of improved regeneration of mature cell type that could serve as a future therapeutic option for diabetes.

Preconditioning of mesenchymal stem cells with 2,4-dinitrophenol improves cardiac function in infarcted rats

AIMS

The aim of this study is to determine if preconditioning of bone marrow derived mesenchymal stem cells (MSCs) with 2,4-dinitrophenol (DNP) improves survival of transplanted stem cells in a rat model of myocardial infarction (MI), and to asses if this strategy has measurable impact on cardiac function.

MAIN METHODS

MSCs were preconditioned with DNP. In vitro cell adhesion assay and qRT-PCR were performed to analyze the expression of genes involved in cardiomyogenesis, cell adhesion and angiogenesis. MI was produced by occlusion of left anterior descending coronary artery. One million cells were transplanted by intramyocardial injection into the infarcted myocardium. Echocardiography was performed after two and four weeks of cellular transplantation. Hearts were harvested after four weeks and processed for histological analysis.

KEY FINDINGS

DNP treated MSCs adhered to the surface more (p<0.001) as compared to the normal MSCs. Gene expression levels were significantly upregulated in case of DNP treatment. The number of viable MSCs was more (p<0.001) in animals that received DNP treated MSCs, leading to significant improvement in cardiac function. Histological analysis revealed significant reduction in scar formation (p<0.001), maintenance of left ventricular wall thickness (p<0.001), and increased angiogenesis (p<0.01).

SIGNIFICANCE

The study evidenced for the first time that MSCs preconditioned with DNP improved cardiac function after transplantation. This can be attributed to improved survival, homing, adhesion, and cardiomyogenic and angiogenic differentiation of DNP treated MSCs in vivo.

Abstract 367: Combined Effect of Dinitrophenol Preconditioning and Jagged-1 Over-expression in Mesenchymal Stem Cells Improved Cardiomyogenesis and Angiogenesis in Rat Model of Myocardial Infarction

Cardiac regeneration following myocardial infarction (MI) largely depends on angiogenesis; an important physiological response that allows the heart to recover. Mesenchymal stem cells (MSCs) can be utilized as a source for cardiac regeneration and angiogenesis using various preconditioning strategies. We investigated the role of cardiomyogenic and angiogenic growth factors combined with preconditioning of MSCs using 2, 4, dinitrophenol (DNP). MSCs were isolated from rat bone marrow and treated with DNP; an uncoupler of oxidative phosphorylation. Based on our earlier report in which we showed that DNP treatment affect the expression of cardiomyogenic and angiogenic factors after different re-oxygenation periods, we selected jagged 1 (Jag1), neuropilin1 (Nrp1), TATA box 20 (Tbx20), and myogenin (Myo) to transfect MSCs. Rat MI models were developed through ligation of left anterior descending coronary artery and confirmed through echocardiographic evaluation 4 weeks post MI. The study was divided into different groups which include control; MI model; and MI groups that received untreated, DNP-treated, transfected-MSCs using the above mentioned growth factors and transfected and DNP-treated MSCs. Functional performance of the hearts was analyzed through echocardiography while regeneration of cardiomyocytes and angiogenesis were observed through histological examination. Significant (p<0.05) improvement in the heart function was observed in case of all treatment groups when compared with the normal MSCs. Histological examination of the heart sections 4 weeks post MI showed that MSCs home towards the site of injury. Most prominent result was observed in case of Jag1-transfected and DNP treated MSCs with heart function comparable to that of the control group. Cardiac regeneration and newly developed blood vessels were prominent in the tissue sections. Significant reduction (p<0.05) in the infarct size was also observed as compared to that in case of Myo, Tbx20 and Nrp1 groups. It is, therefore, concluded that Jag1-transfected MSCs can be a suitable angiogenic factor to be used in combination with DNP for preconditioning of MSCs for future regenerative therapy for cardiomyogenesis.

Promoting effect of small molecules in cardiomyogenic and neurogenic differentiation of rat bone marrow-derived mesenchymal stem cells

Small molecules, growth factors, and cytokines have been used to induce differentiation of stem cells into different lineages. Similarly, demethylating agents can trigger differentiation in adult stem cells. Here, we investigated the in vitro differentiation of rat bone marrow mesenchymal stem cells (MSCs) into cardiomyocytes by a demethylating agent, zebularine, as well as neuronal-like cells by β-mercaptoethanol in a growth factor or cytokines-free media. Isolated bone marrow-derived MSCs cultured in Dulbecco's Modified Eagle's Medium exhibited a fibroblast-like morphology. These cells expressed positive markers for CD29, CD44, and CD117 and were negative for CD34 and CD45. After treatment with 1 μM zebularine for 24 hours, the MSCs formed myotube-like structures after 10 days in culture. Expression of cardiac-specific genes showed that treated MSCs expressed significantly higher levels of cardiac troponin-T, Nkx2.5, and GATA-4 compared with untreated cells. Immunocytochemical analysis showed that differentiated cells also expressed cardiac proteins, GATA-4, Nkx 2.5, and cardiac troponin-T. For neuronal differentiation, MSCs were treated with 1 and 10 mM β-mercaptoethanol overnight for 3 hours in complete and serum-free Dulbecco's Modified Eagle's Medium, respectively. Following overnight treatment, neuron-like cells with axonal and dendritic-like projections originating from the cell body toward the neighboring cells were observed in the culture. The mRNA expression of neuronal-specific markers, Map2, Nefl, Tau, and Nestin, was significantly higher, indicating that the treated cells differentiated into neuronal-like cells. Immunostaining showed that differentiated cells were positive for the neuronal markers Flk, Nef, Nestin, and β-tubulin.

Hypoxic stress and IL-7 gene overexpression enhance the fusion potential of rat bone marrow mesenchymal stem cells with bovine renal epithelial cells

Transplantation of mesenchymal stem cells (MSCs) has been shown to enhance the improvement in kidney function following injury. However, the poor survival and grafting of the stem cells to the site of injury has restricted their therapeutic efficacy. Accelerated regeneration potential of MSCs has been observed when they were exposed to hypoxic stress or genetic modulation by various cytokines and growth factors. These preconditioning strategies may stimulate endogenous mechanisms resulting in multiple cellular responses. In this study, we used IL-7 gene to transfect MSCs. IL-7 is a hematopoietic growth factor that plays an important role in cell survival, proliferation, and differentiation. MSCs were also subjected to hypoxic stress for 8 and 24 h. These preconditioned MSCs were co-cultured with cisplatin-treated injured Mardin-Darby bovine kidney (MDBK) cells and their fusion potential was analyzed. Flow cytometry of fluorescently labeled preconditioned MSCs and injured MDBK cells revealed evidence of significant (P < 0.001) cell fusion compared to that of the normal MSCs. In addition, we also observed improved migration ability of these preconditioned MSCs in the in vitro wound healing assay, as compared to the normal MSCs. We conclude that hypoxic stress and IL-7 overexpression can enhance the renal regeneration potential of MSCs. This study would help in designing more potent therapeutic strategy in which preconditioned MSCs can be used for renal regeneration.

Correlates of emotional intelligence: results from a multi-institutional study among undergraduate medical students

BACKGROUND

Emotional Intelligence (EI) is the ability to deal with your own and others emotions. Medical students are inducted into medical schools on the basis of their academic achievement. Professionally, however, their success rate is variable and may depend on their interpersonal relationships. EI is thought to be significant in achieving good interpersonal relationships and success in life and career. Therefore, it is important to measure EI and understand its correlates in an undergraduate medical student population.

AIM

The objective of study was to investigate the relationship between the EI of medical students and their academic achievement (based on cumulative grade point average [CGPA]), age, gender and year of study.

METHODS

A cross-sectional survey design was used. The SSREIS and demographic survey were administered in the three medical schools in Saudi Arabia from April to May 2012.

RESULTS

The response rate was 30%. For the Optimism subscale, the mean score was M = 3.79, SD ± 0.54 (α = 0.82), for Awareness-of-emotion subscale M = 3.94, SD ± 0.57 (α = 0.72) and for Use-of-emotion subscale M = 3.92, SD ± 0.54 (α = 0.63). Multiple regression showed a significant positive correlation between CGPA and the EI of medical students (r = 0.246, p = 0.000) on the Optimism subscale. No correlation was seen between CGPA and Awareness of Emotions and Use of Emotions subscales. No relationship was seen for the other independent variables.

CONCLUSION

The current study demonstrates that CGPA is the only significant predictor, indicating that Optimism tends to be higher for students with a higher CPGA. None of the other independent variables (age, year of study, gender) showed a significant relationship.

Clinical skills assessment: comparison of student and examiner assessment in an objective structured clinical examination

BACKGROUND

Learning of basic clinical skills is introduced in Years 1 and 2 of the MBBS Program; the Aga Khan University, Pakistan, through a structured Clinical Skills Teaching program. Acquisition of competence in performing these skills is assessed through use of the Objective Structured Clinical Examination (OSCE). Self-assessment is defined broadly as the involvement of learners in judging whether or not learner-identified standards have been met.

OBJECTIVE

Compared Year 2 students' self-assessment of clinical skills with examiners' assessment of performance in an OSCE using a standard rating scale.

METHODS

A self-assessment questionnaire was completed by all Year 2 students immediately after the OSCE. Students assessed their performance at three stations, using a performance rating scale. Examiners observed and evaluated the students during history-taking and physical examination using the same rating scale.

RESULTS

There were significant positive correlations between examiners' assessments of performance and students' self-assessed ratings in taking consent, obtaining demographic information, history of presenting problems and summarization. Significant differences were observed in pre-procedural skills, comment on prostate, liver palpation percussion and spleen percussion.

CONCLUSIONS

Findings highlight the strengths and weaknesses in clinical competence at the end of Year 2 and provide a direction to improve the gaps in the Clinical Skills Teaching program.

Outcome of adult umbilical cord blood transplant patients admitted to a medical intensive care unit

Umbilical cord blood transplant (UCBT) has emerged as an alternate source of stem cells for transplantation in patients with hematologic malignancies. However, outcomes of adult UCBT patients requiring ICU admission remain unknown. In order to identify predictors of ICU transfer and mortality in UCBT patients, the course and outcome of all adult (> or = 16 years old) patients who underwent UCBT between 1 January 1998 and 31 December 2003 at University Hospitals of Cleveland were analyzed. Forty-four patients underwent UCBT during the study period and 25 (57%) required ICU transfer. Use of a myeloablative preparative regimen was a significant predictor of ICU transfer (P = 0.03). An infusion of higher numbers of nucleated cells was protective from ICU transfer (P = 0.05). For those patients transferred to the ICU, mortality was 72%. The univariate predictors of mortality, at the time of ICU admission were a high APACHE III score (P = 0.0004), use of vasopressors (P = 0.03), and a low platelet count (P = 0.03). We conclude that transfer of UCBT patients to an ICU may be predicted by their preparative regimen, while ICU mortality may be predicted by physiologic parameters upon admission.

Transfer of the hematopoietic stem cell transplant patient to the intensive care unit: does it really matter?

We critically reviewed published English language literature and concluded that from 1998 onward the survival of hematopoietic stem cell transplant (SCT) patients who experienced intensive care unit (ICU) transfer has improved. The factors associated with increased mortality during ICU stay included increased patient age, allogeneic transplant, intubation/mechanical ventilation, multiorgan system failure (MOSF), presumed/documented infection, graft-versus-host disease, and higher APACHE and O-PRISM score at ICU transfer. This encouraging outcome trend reflects evolving advances such as use of recombinant hematopoietic growth factors, use of mobilized blood cells rather than marrow, protective strategies for acute lung injury and early goal-directed therapy for sepsis syndrome. Patient selection bias (which patients were transferred and which were not sent to an ICU) also plays a role in ICU survival rates. New strategies to improve upon SCT patient outcome include use of a scoring system to predict mortality, better therapies for MOSF and integration of ICU components and multispecialist involvement earlier in the clinical course to prevent severe complications such as respiratory failure. SCT recipients comprise a heterogeneous group; to further advance this field, prospective multicenter trials involving larger populations from many centers are needed to reduce the biases of retrospective and single-center reports.

Direct current cardioversion does not cause cardiac damage: evidence from cardiac troponin T estimation

AIM

To determine whether elective direct current (dc) cardioversion of atrial fibrillation/flutter causes myocardial damage.

METHODS AND RESULTS

Cardiac troponin T and creatine kinase were estimated 20-28 hours after dc cardioversion in 51 patients who received dc shocks for elective cardioversion of chronic atrial fibrillation/flutter. Although creatine kinase was raised in 44 patients, cardiac troponin T was undetectable in all patients.

CONCLUSION

Cardiac damage does not occur as a result of cardioversion.