Differentiation of C57/BL6 mice bone marrow mononuclear cells into early endothelial progenitors cells in different culture conditions

Endothelial progenitor cells in pregnancy-related diseases

Placental neovascularization plays a crucial role in fetomaternal circulation throughout pregnancy and is dysregulated in several pregnancy-related diseases, including preeclampsia, gestational diabetes mellitus, and fetal growth restriction. Endothelial progenitor cells (EPCs) are a heterogeneous population of cells that differentiate into mature endothelial cells, which influence vascular homeostasis, neovascularization, and endothelial repair. Since their discovery in 1997 by Asahara et al., the role of EPCs in vascular biology has garnered a lot of interest. However, although pregnancy-related conditions are associated with changes in the number and function of EPCs, the reported findings are conflicting. This review discusses the discovery, isolation, and classification of EPCs and highlights discrepancies between current studies. Overviews of how various diseases affect the numbers and functions of EPCs, the role of EPCs as biomarkers of pregnancy disorders, and the potential therapeutic applications involving EPCs are also provided.

Bone Marrow-Derived Mononuclear Cells in the Treatment of Neurological Diseases: Knowns and Unknowns

Bone marrow-derived mononuclear cells (BMMNCs) have been used for decades in preclinical and clinical studies to treat various neurological diseases. However, there is still a knowledge gap in the understanding of the underlying mechanisms of BMMNCs in the treatment of neurological diseases. In addition, prerequisite factors for the efficacy of BMMNC administration, such as the optimal route, dose, and number of administrations, remain unclear. In this review, we discuss known and unknown aspects of BMMNCs, including the cell harvesting, administration route and dose; mechanisms of action; and their applications in neurological diseases, including stroke, cerebral palsy, spinal cord injury, traumatic brain injury, amyotrophic lateral sclerosis, autism spectrum disorder, and epilepsy. Furthermore, recommendations on indications for BMMNC administration and the advantages and limitations of BMMNC applications for neurological diseases are discussed. BMMNCs in the treatment of neurological diseases. BMMNCs have been applied in several neurological diseases. Proposed mechanisms for the action of BMMNCs include homing, differentiation and paracrine effects (angiogenesis, neuroprotection, and anti-inflammation). Further studies should be performed to determine the optimal cell dose and administration route, the roles of BMMNC subtypes, and the indications for the use of BMMNCs in neurological conditions with and without genetic abnormalities.

Calcitonin Gene-Related Peptide Enhances Distraction Osteogenesis by Increasing Angiogenesis

Distraction osteogenesis (DO) is a well-established surgical technique for treating bone defect and limb lengthening. The major drawback of DO is the long treatment period as the external fixator has to be kept in place until consolidation is completed. Calcitonin gene-related peptide (CGRP) has been reported to promote angiogenesis by affecting endothelial progenitor cells (EPCs) in limb ischemia and wound healing. Thus, the goal of this study was to evaluate the angiogenic effect of exogenous CGRP on bone regeneration in a rat DO model. Exogenous CGRP was directly injected into the bone defect after each cycle of distraction in vivo. Microcomputed tomography, biomechanical test, and histological analysis were performed to assess the new bone formation. Angiography and immunofluorescence were performed to assess the formation of blood vessels. CD31⁺CD144⁺ EPCs in the bone defect were quantified with flow cytometry. In in vitro study, bone marrow stem cells (BMSCs) were used to investigate the effect of CGRP on EPCs production during endothelial differentiation. Our results showed that CGRP significantly promoted bone regeneration and vessel formation after consolidation. CGRP significantly increased the fraction of CD31⁺CD144⁺EPCs and the capillary density in the bone defect at the end of distraction phase. CGRP increased EPC population in the endothelial differentiation of BMSCs in vitro by activating PI3K/AKT signaling pathway. Furthermore, differentiated EPCs rapidly assembled into tube-like structures and promoted osteogenic differentiation of BMSCs. In conclusion, CGRP increased EPC population and promoted blood vessel formation and bone regeneration at the defect region in a DO model. Impact statement Distraction osteogenesis (DO) is a well-established surgical technique for limb lengthening and bone defect. The disadvantage of this technique is that external fixator is needed to be kept in place for about 12 months. This may result in increased risk of infection, financial burden, and negative psychological impacts. In this study, we have injected calcitonin gene-related peptide (CGRP) into the defect region after distraction and found that CGRP enhanced vessel formation and bone regeneration in a rat DO model. This suggests that a controlled delivery system for CGRP could be developed and applied clinically for accelerating bone regeneration in patients with DO.

Polygonatum sibiricum polysaccharide potentially attenuates diabetic retinal injury in a diabetic rat model

AIMS/INTRODUCTION

To investigate the protective effect of Polygonatum sibiricum polysaccharide (PSP) on the retina in diabetic rats.

MATERIALS AND METHODS

A total of 120 Sprague-Dawley rats were randomly divided into blank control, control model (meaning diabetes mellitus), and diabetes mellitus with PSP intervention of high, medium and low doses groups. The difference of retinal vascularization between groups was evaluated by fluorescein isothiocyanate-dextran perfusion. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining was used to assess apoptosis in the retinal ganglion cells; reverse transcriptase polymerase chain reaction and western blotting were utilized to evaluate the expression of Bcl2-associated X protein, B-cell lymphoma-2 factor, epidermal growth factor, p38 mitogen-activated protein kinases, transforming growth factor-β and vascular endothelial growth factor at the messenger ribonucleic acid and protein level.

RESULTS

Fluorescein isothiocyanate-dextran perfusion showed retinal vascular anomaly in diabetes mellitus rats, but vascular tortuosity and leakage were relatively alleviated after PSP intervention. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining showed numerous terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive retinal cells in the diabetes mellitus group, which then were reduced by PSP treatment. Reverse transcriptase polymerase chain reaction showed that PSP intervention decreased Bcl2-associated X protein, epidermal growth factor, p38 mitogen-activated protein kinases, vascular endothelial growth factor and transforming growth factor-β messenger ribonucleic acid expression, but increased B-cell lymphoma-2 factor messenger ribonucleic acid expression. Western blot showed that PSP intervention upregulated the expression of B-cell lymphoma-2 factor, and downregulated the expression of Bcl2-associated X protein, epidermal growth factor, p38 mitogen-activated protein kinases, vascular endothelial growth factor and transforming growth factor-β proteins.

CONCLUSIONS

Polygonatum sibiricum polysaccharide shows a protective effect against diabetes-induced retinal injury in a dose-dependent manner. The mechanism of action deserves further study and exploration.

Pathological Analysis of Cell Differentiation in Cholesterol Granulomas Experimentally Induced in Mice

In this study, cholesterin was implanted in the subcutaneous tissue in mice to induce the formation of cholesterol granuloma. Histological examination was carried out to determine the type and source of cells. The tissue surrounding the embedded cholesterin was examined histologically within the period of 6 months. Cell differentiation in cholesterol granulomas was investigated using ddY mice and GFP bone marrow transplanted mice. Cholesterin was embedded in mice subcutaneously and histopathological examination was carried out in a period of 6 months. Results showed that at 2 weeks, cholesterin was replaced partly by granulation tissues. The majority of cells in the granulation tissues were macrophages and foreign body giant cells and the center consists of small amount of fibroblasts, collagen fibers and capillaries. At 3 months, more granulation tissue was observed compared to 2 weeks. Similar cells were observed, however, there were more fibroblasts, collagen bundles and capillaries present compared to 2 weeks. At 6 months, the cholesterin was mostly substituted by fibrous tissues consisting mainly of fibroblasts and collagen fibers with some macrophages and foreign body giant cells. Specifically, the outer part of the tissue consists of fibroblasts, collagen bundles and capillaries and the inner portion is filled with collagen bundles. Immunohistochemistry revealed that macrophages and foreign body giant cells were positive to GFP and CD68 although the fibroblasts and capillaries in the outer portion of cholesterol granulomas were GFP negative. Some spindle shape fibroblasts were also GFP positive. Immunofluorescent double staining revealed that cells lining the blood vessels were both positive to GFP and CD31 indicating that those were endothelial cells and were actually derived from the transplanted bone marrow cells. The results suggest that macrophages, foreign body giant cells as well as fibroblasts and capillary endothelial cells are bone marrow derived mesenchymal cells.