Quality-Quantity Control Culture Enhances Vasculogenesis and Wound Healing Efficacy of Human Diabetic Peripheral Blood CD34+ Cells

The quality and quantity media-cultured mononuclear cell transplantation is safe and effective in ischemic hindlimb mouse model

Objective

This study was conducted to investigate in vitro proangiogenic and anti-inflammatory phenotypes and functions and the in vivo efficacy and safety of quality and quantity (QQ) media-cultured mononuclear cells (MNCs) compared with standard cultured MNCs from the peripheral blood of patients with chronic limb-threatening ischemia (CLTI) with atherosclerotic risk factors.

Methods

Peripheral blood MNCs (PBMNCs) from patients with CLTI were cultured in QQ culture media or standard culture media. Phenotypic analysis of progenitor cells (CD34+CD133+), M2 macrophages (CD206+), and inactivated T regulatory cells (CD4+CD25+CD127+), colony-forming assay, and tube formation assay of QQ media-cultured MNCs (QQMNCs) and PBMNCs, were conducted. Intramuscular transplantation of QQMNCs or PBMNCs was performed in the ischemic hindlimb model. The clinical appearance of ischemic limbs was observed, and blood flow in ischemic limbs was measured using a laser Doppler perfusion imager. Outcomes were compared between the QQMNC and PBMNC groups.

Results

Twenty patients with CLTI were included. The mean percentages of CD34+ cells, CD133+ cells, CD34+CD133+ progenitor cells, CD206+ cells, colony-forming cells, and tube formation were significantly higher in the QQMNCs. The mean percentage of CD4+CD25+CD127+ cells was significantly lower in QQMNC. The colony-forming unit count and Dil-acetylated low-density lipoprotein uptake were significantly greater in QQMNCs. The clinical appearance of post-QQMNC-injected limbs was less severe than the appearance of post-PBMNC-injected limbs. Limb perfusion was significantly better in the QQMNCs.

Conclusions

Proangiogenic and anti-inflammatory phenotypes of MNCs cultured in QQ culture media were reproducible. Intramuscular QQMNC transplantation was safe and resulted in better reperfusion of ischemic hindlimbs compared with PBMNCs.

Therapeutic application of regeneration-associated cells: a novel source of regenerative medicine

Chronic diseases with comorbidities or associated risk factors may impair the function of regenerative cells and the regenerative microenvironment. Following this consideration, the vasculogenic conditioning culture (VCC) method was developed to boost the regenerative microenvironment to achieve regeneration-associated cells (RACs), which contain vasculogenic endothelial progenitor cells (EPCs) and anti-inflammatory/anti-immunity cells. Preclinical and clinical studies demonstrate that RAC transplantation is a safe and convenient cell population for promoting ischemic tissue recovery based on its strong vasculogenicity and functionality. The outputs of the scientific reports reviewed in the present study shed light on the fact that RAC transplantation is efficient in curing various diseases. Here, we compactly highlight the universal features of RACs and the latest progress in their translation toward clinics.

Hematopoietic Stem Cells in Wound Healing Response

Significance: Emerging evidence has shown a link between the status of hematopoietic stem cells (HSCs) and wound healing responses. Thus, better understanding HSCs will contribute to further advances in wound healing research. Recent Advances: Myeloid cells such as neutrophils and monocyte-derived macrophages are critical players in the process of wound healing. HSCs actively respond to wound injury and other tissue insults, including infection and produce the effector myeloid cells, and a failing of the HSC response can result in impaired wound healing. Technological advances such as transcriptome at single-cell resolution, epigenetics, three-dimensional imaging, transgenic animals, and animal models, have provided novel concepts of myeloid generation (myelopoiesis) from HSCs, and have revealed cell-intrinsic and -extrinsic mechanisms that can impact HSC functions in the context of health conditions. Critical Issues: The newer concepts include-the programmed cellular fate at a differentiation stage that is used to be considered as the multilineage, the signaling pathways that can activate HSCs directly and indirectly, the mechanisms that can deteriorate HSCs, the roles and remodeling of the surrounding environment for HSCs and their progenitors (the niche). Future Directions: The researches on HSCs, which produce blood cells, should contribute to the development of blood biomarkers predicting a risk of chronic wounds, which may transform clinical practice of wound care with precision medicine for patients at high risk of poor healing.

Homing of mRNA-Modified Endothelial Progenitor Cells to Inflamed Endothelium

Endothelial progenitor cells (EPCs) are one of the most important stem cells for the neovascularization of tissues damaged by ischemic diseases such as myocardial infarction, ischemic stroke, or critical limb ischemia. However, their low homing efficiency in the treatment of ischemic tissues limits their potential clinical applications. The use of synthetic messenger RNA (mRNA) for cell engineering represents a novel and promising technology for the modulation of cell behavior and tissue regeneration. To improve the therapeutic potential of EPCs, in this study, murine EPCs were engineered with synthetic mRNAs encoding C-X-C chemokine receptor 4 (CXCR4) and P-selectin glycoprotein ligand 1 (PSGL-1) to increase the homing and migration efficiency of EPCs to inflamed endothelium. Flow cytometric measurements revealed that the transfection of EPCs with CXCR4 and PSGL-1 mRNA resulted in increased expressions of CXCR4 and PSGL-1 on the cell surface compared with the unmodified EPCs. The transfection of EPCs with mRNAs did not affect cell viability. CXCR4-mRNA-modified EPCs showed significantly higher migration potential than unmodified cells in a chemotactic migration assay. The binding strength of the EPCs to inflamed endothelium was determined with single-cell atomic force microscopy (AFM). This showed that the mRNA-modified EPCs required a three-fold higher detachment force to be released from the TNF-α-activated endothelium than unmodified EPCs. Furthermore, in a dynamic flow model, significantly increased binding of the mRNA-modified EPCs to inflamed endothelium was detected. This study showed that the engineering of EPCs with homing factors encoding synthetic mRNAs increases the homing and migration potentials of these stem cells to inflamed endothelium. Thus, this strategy represents a promising strategy to increase the therapeutic potential of EPCs for the treatment of ischemic tissues.

Stem and Somatic Cell Monotherapy for the Treatment of Diabetic Foot Ulcers: Review of Clinical Studies and Mechanisms of Action

Diabetic foot ulcer (DFU) is one of the most severe complications of diabetes mellitus, often resulting in a limb amputation. A cell-based therapy is a highly promising approach for an effective DFU treatment. However, there is no consensus regarding the most effective cell type for DFU treatment. Various cell types contribute to chronic wound healing via different mechanisms. For example, application of keratinocytes can stimulate migration of native keratinocytes from the wound edge, while mesenchymal stem cells can correct limb ischemia. To assess the effectiveness of a certain cell type, it should be administered as a monotherapy without other substances and procedures that have additional therapeutic effects. In the present review, we described therapeutic effects of various cells and provided an overview of clinical studies in which stem and somatic cell-based therapy was administered as a monotherapy. Topical application of somatic cells contributes to DFU healing only, while injection of mesenchymal stem cells and mononuclear cells can break a pathophysiological chain leading from insufficient blood supply to DFU development. At the same time, the systemic use of mesenchymal stem cells carries greater risks. Undoubtedly, cell therapy is a potent tool for the treatment of DFU. However, it is vital to conduct further high-quality clinical research to determine the most effective cell type, dosage and way of administration for DFU treatment. Ischemia, neuropathy and neuro-ischemia are underlying factors of diabetic foot ulcer. Stem and somatic cells monotherapy can improve chronic wound healing via different mechanisms.

Phase I/IIa Feasibility Trial of Autologous Quality- and Quantity-Cultured Peripheral Blood Mononuclear Cell Therapy for Non-Healing Extremity Ulcers

Non-healing wounds are among the main causes of morbidity and mortality. We recently described a novel, serum-free ex vivo expansion system, the quantity and quality culture system (QQc), which uses peripheral blood mononuclear cells (PBMNCs) for effective and noninvasive regeneration of tissue and vasculature in murine and porcine models. In this prospective clinical study, we investigated the safety and efficacy of QQ-cultured peripheral blood mononuclear cell (MNC-QQ) therapy for chronic non-healing ischemic extremity wounds. Peripheral blood was collected from 9 patients with 10 chronic (>1 month) non-healing wounds (8 males, 1 female; 64-74 years) corresponding to ischemic extremity ulcers. PBMNCs were isolated and cultured using QQc. Within a 20-cm area surrounding the ulcer, 2 × 107 cells were injected under local anesthesia. Wound healing was monitored photometrically every 2 weeks. The primary endpoint was safety, whereas the secondary endpoint was efficacy at 12-week post-injection. All patients remained ambulant, and no deaths, other serious adverse events, or major amputations were observed for 12 weeks after cell transplantation. Six of the 10 cases showed complete wound closure with an average wound closure rate of 73.2% ± 40.1% at 12 weeks. MNC-QQ therapy increased vascular perfusion, skin perfusion pressure, and decreased pain intensity in all patients. These results indicate the feasibility and safety of MNC-QQ therapy in patients with chronic non-healing ischemic extremity wounds. As the therapy involves transplanting highly vasculogenic cells obtained from a small blood sample, it may be an effective and highly vasculogenic strategy for limb salvage.

Novel culture media enhances mononuclear cells from patients with chronic limb-threatening ischemia to increase vasculogenesis and anti-inflammatory effect

Background

Quality and Quantity culture media (QQ culture media) was reported to enhance vasculogenesis and angiogenesis function of mononuclear cells (MNCs) from healthy volunteers. In this study, MNCs from chronic limb-threatening ischemia (CLTI) patients were cultured in QQ culture media, and then investigated for angiogenesis-related phenotype and function.

Methods

Patients aged ≥ 18 years with CLTI caused by atherosclerosis of the lower extremities were prospectively recruited at Siriraj Hospital (Bangkok, Thailand) during July 2017–December 2018. Peripheral blood mononuclear cells (PBMNCs) were isolated from peripheral blood. PBMNCs were cultured in either QQ culture media or standard culture media. The number of CD34+CD133+ cells, CD206+ cells, CD4+CD25+CD127+ cells, colony formation assay, and human umbilical vein endothelial cell (HUVEC) tube formation assay in MNCs were compared between those cultured in QQ culture media and those cultured in standard culture media.

Results

Thirty-nine patients were included with a mean age of 69 ± 11 years. Diabetes mellitus was found in 25 (64%) patients. The percentage of CD34+CD133+ progenitor cells in MNCs cultured in QQ culture media and in MNCs cultured in standard culture media was 4.91 ± 5.30% and 0.40 ± 0.46%, respectively (p < 0.0001). The percentage of CD206+ cells in MNCs cultured in QQ culture media and in MNCs cultured in standard culture media was 19.31 ± 11.42% and 4.40 ± 2.54%, respectively (p < 0.0001). The percentage of inactive population of T regulatory cells (CD4+CD25+CD127+ cells) in MNCs cultured in standard culture media and in MNCs cultured in QQ culture media was 14.5 ± 10.68% and 1.84 ± 1.37%, respectively (p < 0.0001). The total number of colony-forming units from MNCs cultured in QQ culture media and in MNCs cultured in standard culture media was 8.86 ± 8.35 of 2 × 10⁵ cells/dish, and 0.58 ± 1.05 of 2 × 10⁵ cells/dish, respectively (p < 0.0001). The mean intensity of Dil-Ac-LDL uptake that incorporated into the HUVEC forming tube was 1.37 ± 0.88 in MNCs cultured in QQ culture media, and 0.78 ± 0.41 in MNCs cultured in standard culture media. (p < 0.0003).

Conclusions

MNCs from CLTI patients that were cultured in QQ culture media had a significantly higher number of CD34+CD133+ cells and anti-inflammatory cells, and higher angiogenesis-related function compared to MNCs cultured in standard culture media.

Quality and Quantity-Cultured Human Mononuclear Cells Improve Human Fat Graft Vascularization and Survival in an In Vivo Murine Experimental Model

BACKGROUND

Fat graft ischemia impedes us from having satisfying long-term results. The quality and quantity culture is a 1-week cell culture that increases the vasculogenic potential of peripheral blood mononuclear cells (PBMNC). This in vivo murine model investigates whether enrichment with quality and quantity-cultured human mononuclear cells (MNC-QQ) improves the vascularization in the human fat graft and whether this decreases the tissue loss.

METHODS

Human adipose tissue, PBMNC, MNC-QQ, and stromal vascular fraction were prepared. First, PBMNC, MNC-QQ, and stromal vascular fraction were compared in vitro for vasculogenic potential by endothelial progenitor cell colony-forming and culture assays. Second, 0.25-g fat grafts were created with 1 × 106 PBMNC (n = 16), 1 × 106 MNC-QQ (n = 16), 1 × 106 stromal vascular fraction (n = 16), or phosphate-buffered saline as control (n = 16) before grafting in BALB/c nude mice. Grafts were analyzed for weight persistence, vessel formation by CD31 immunohistochemistry, and angiogenic markers by quantitative polymerase chain reaction.

RESULTS

MNC-QQ develop more definitive endothelial progenitor cell colonies and more functional endothelial progenitor cells compared to PBMNC and stromal vascular fraction. Weight persistence after 7 weeks was significantly higher in grafts with MNC-QQ (89.8 ± 3.5 percent) or stromal vascular fraction (90.1 ± 4.2 percent) compared with control (70.4 ± 6.3 percent; p < 0.05). MNC-QQ-enriched grafts had the highest vessel density (96.6 ± 6.5 vessels/mm2; control, 70.4 ± 5.6 vessels/mm2; p < 0.05). MNC-QQ exerted a direct vasculogenic effect through vascular integration and a potential paracrine vascular endothelial growth factor-mediated effect.

CONCLUSION

Quality and quantity-cultured human mononuclear cells containing endothelial progenitor cells stimulate fat graft vascularization and enhance graft survival in a rodent recipient.

Regenerative Potential of DPSCs and Revascularization: Direct, Paracrine or Autocrine Effect?

A new source of mesenchymal stem cells has recently been discovered, the so-called dental pulp derived stem cells (DPSCs) which therefore could represent potentially tools for regenerative medicine. DPSC originate from the neural crest and are physiologically involved in dentin homeostasis; moreover, they contribute to bone remodeling and differentiation into several tissues including cartilage, bone, adipose and nervous tissues. DPSCs have also been shown to influence the angiogenesis process, for example through the release of secretory factors or by differentiating into vascular and/or perivascular cells. Angiogenesis, that has a pivotal role in tissue regeneration and repair, is defined as the formation of new vessels from preexisting vessels and is mediated by mutual and reciprocal interactions between endothelial cells and perivascular cells. It is also known that co-cultures of perivascular and endothelial cells (ECs) can form a vascular network in vitro and also in vivo. Since DPSCs seem to have characteristics similar to pericytes, understanding the possible mechanism of interaction between DPSCs and ECs during neo-angiogenesis is dramatically important for the development of advanced clinical application in the field of regeneration.

Quality and quantity culture effectively restores functional and proliferative capacities of endothelial progenitor cell in end-stage renal disease patients

BACKGROUND

Endothelial cell dysfunction plays the crucial role in initiation and propagation of obstructive arteriosclerosis which ultimately causes arterial obstructive syndrome. Additionally, severe endothelial progenitor cells (EPC) dysfunction is always found in those of end-stage renal disease (ESRD) patients. This study tested the hypothesis that a novel method, named "quality and quantity (QQ) culture", could successfully improve the EPC proliferation and function in ESRD patients.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMNCs) were isolated from age-matched control subjects (i.e., normal renal function) (group 1) and ESRD patients (group 2), followed by culture in either conventional EPC culture for one month or in QQ culture for 7 days, respectively. The result showed that as compared to the conventional EPC culture method, the EPC population and M2-like population/ratio (M2/M1) were significantly enriched in QQ culture both in groups 1 and 2 (all p < 0.001), but these parameters did not differ between the groups. As compared with conventional EPC culture, the angiogenesis capacity and colony formation were significantly increased in QQ culture (all p < 0.001), but they showed no difference between groups 1 and 2. In RAW264.7 macrophages treated by liposaccharide, the gene expressions and ELISA findings of pro-inflammatory cytokines (IL-1β/IL-6/TGF-β) and inflammatory mediator (iNOS) were significantly reduced in QQ culture than in conventional EPC culture in groups 1 and 2 (all p < 0.001), but they showed no difference between the groups.

CONCLUSIONS

This study demonstrated that QQ culture enhanced number, proliferation, and angiogenesis of EPCs and anti-inflammatory capacity in ESRD patients.

Ex vivo conditioning of peripheral blood mononuclear cells of diabetic patients promotes vasculogenic wound healing

The quality and quantity of endothelial progenitor cells (EPCs) are impaired in patients with diabetes mellitus patients, leading to reduced tissue repair during autologous EPC therapy. This study aimed to address the limitations of the previously described serum-free Quantity and Quality Control Culture System (QQc) using CD34+ cells by investigating the therapeutic potential of a novel mononuclear cell (MNC)-QQ. MNCs were isolated from 50 mL of peripheral blood of patients with diabetes mellitus and healthy volunteers (n = 13 each) and subjected to QQc for 7 days in serum-free expansion media with VEGF, Flt-3 ligand, TPO, IL-6, and SCF. The vascular regeneration capability of MNC-QQ cells pre- or post-QQc was evaluated with an EPC colony-forming assay, FACS, EPC culture, tube formation assay, and quantitative real time PCR. For in vivo assessment, 1 × 10⁴ pre- and post-MNC-QQc cells from diabetic donors were injected into a murine wound-healing model using Balb/c nude mice. The percentage of wound closure and angio-vasculogenesis was then assessed. This study revealed vasculogenic, anti-inflammatory, and wound-healing effects of MNC-QQ therapy in both in vitro and in vivo models. This system addresses the low efficiency and efficacy of the current naïve MNC therapy for wound-healing in diabetic patients. As this technique requires a simple blood draw, isolation, and peripheral blood MNC suspension culture for only a week, it can be used as a simple and effective outpatient-based vascular and regenerative therapy for patients with diabetes mellitus.

Experimental Study on the Effect of Allogeneic Endothelial Progenitor Cells on Wound Healing in Diabetic Mice

Endothelial progenitor cells (EPCs) are involved in the neovascularization in traumatic and ischemic sites, but EPCs are "detained" in bone marrow under diabetic conditions, which results in reduction of the number of EPCs and their biological activity in peripheral blood. Based on our previous study to mobilize autologous bone marrow EPCs by administering AMD3100+G-CSF to realize the optimal effect, our present study is aimed at exploring the effects of transplanting EPCs locally in a wound model of diabetic mice. First, we prepared and identified EPCs, and the biological functions and molecular characteristics were compared between EPCs from DB/+ and DB/DB mice. Then, we performed full-thickness skin resection in DB/DB mice and tested the effect of local transplantation of EPCs on skin wound healing. The wound healing process was recorded using digital photographs. The animals were sacrificed on postoperative days 7, 14, and 17 for histological and molecular analysis. Our results showed that DB/+ EPCs were biologically more active than those of DB/DB EPCs. When compared with the control group, local transplantation of EPCs accelerated wound healing in DB/DB mice by promoting wound granulation tissue formation, angiogenesis, and collagen fiber deposition, but there was no significant difference in wound healing between DB/+ EPCs and DB/DB EPCs transplanted into the wound. Furthermore, local transplantation of EPCs promoted the expression of SDF-1, CXCR4, and VEGF. We speculated that EPC transplantation may promote wound healing through the SDF-1/CXCR4 axis. This point is worth exploring further. Present data are of considerable significance because they raise the possibility of promoting wound healing by isolating autologous EPCs from the patient, which provides a new approach for the clinical treatment of diabetic wounds in the future.

Differences of Angiogenesis Factors in Tumor and Diabetes Mellitus

Angiogenesis, as a process occurring under the regulation of a variety of factors, is one of the important ways of vascular development. It coexists in a variety of pathological and physiological processes. Now a large number of studies have proved that tumor growth, metastasis, and various vascular complications of diabetes are closely related to angiogenesis, and an increasing number of studies have shown that there are many common factors between the two. But angiogenesis is the opposite of the two: it is enhanced in tumors and suppressed in diabetes. Therefore, this review discusses the causes of the phenomenon from the expression of various factors affecting angiogenesis in these two diseases and their effects on angiogenesis in the relevant microenvironment, as well as the application status of these factors or cells as therapeutic targets in the treatment of these two diseases.

Delivery of Human Stromal Vascular Fraction Cells on Nanofibrillar Scaffolds for Treatment of Peripheral Arterial Disease

Cell therapy for treatment of peripheral arterial disease (PAD) is a promising approach but is limited by poor cell survival when cells are delivered using saline. The objective of this study was to examine the feasibility of aligned nanofibrillar scaffolds as a vehicle for the delivery of human stromal vascular fraction (SVF), and then to assess the efficacy of the cell-seeded scaffolds in a murine model of PAD. Flow cytometric analysis was performed to characterize the phenotype of SVF cells from freshly isolated lipoaspirate, as well as after attachment onto aligned nanofibrillar scaffolds. Flow cytometry results demonstrated that the SVF consisted of 33.1 ± 9.6% CD45⁺ cells, a small fraction of CD45^–/CD31⁺ (4.5 ± 3.1%) and 45.4 ± 20.0% of CD45^–/CD31^–/CD34⁺ cells. Although the subpopulations of SVF did not change significantly after attachment to the aligned nanofibrillar scaffolds, protein secretion of vascular endothelial growth factor (VEGF) significantly increased by six-fold, compared to SVF cultured in suspension. Importantly, when SVF-seeded scaffolds were transplanted into immunodeficient mice with induced hindlimb ischemia, the cell-seeded scaffolds induced a significant higher mean perfusion ratio after 14 days, compared to cells delivered using saline. Together, these results show that aligned nanofibrillar scaffolds promoted cellular attachment, enhanced the secretion of VEGF from attached SVF cells, and their implantation with attached SVF cells stimulated blood perfusion recovery. These findings have important therapeutic implications for the treatment of PAD using SVF.

microRNA-381-3p Confers Protection Against Ischemic Stroke Through Promoting Angiogenesis and Inhibiting Inflammation by Suppressing Cebpb and Map3k8

Ischemic stroke is a serious disease with limited prevention methods, and various genes and microRNAs (miRNAs) have been found to be dysregulated in the pathogenesis of this disease. This study aims to explore the potential role of miR-381-3p in ischemic stroke, along with its underlying mechanism. A mouse model of ischemic stroke was developed using middle cerebral artery occlusion. Next, the expression of mitogen-activated protein kinase kinase kinase 8 (Map3k8) and CCAAT enhancer binding protein beta (Cebpb) was determined by RT-qPCR. Gain- and loss-of-function approaches were applied to analyze the effects of miR-381-3p, Cebpb and Map3k8 on the biological functions of endothelial progenitor cells (EPCs) with the involvement of the tumor necrosis factor-α (TNF-α) signaling pathway. In addition, dual luciferase reporter gene assay was performed for the analysis of the relationship among miR-381-3p, Map3k8 and Cebpb. Further, rescue experiment was performed with the help of JNK/p38 specific agonist, Anisomycin. Map3k8 and Cebpb were highly expressed in ischemic stroke. Loss-of-function of Map3k8 or Cebpb in EPCs contributed to accelerated proliferation, migration and angiogenesis of EPCs. Next, miR-381-3p downregulated the expression of its two target genes, Map3k8 and Cebpb. miR-381-3p overexpression promoted angiogenesis of EPCs, and inhibited inflammation, which could be reversed by restoration of Map3k8 or Cebpb. Additionally, silencing Map3k8 or Cebpb inhibited the activation of TNF-α signaling pathway. Furthermore, Anisomycin treatment could enhance inflammation and inhibit angiogenesis. Taken together, miR-381-3p downregulates Map3k8 and Cebpb to protect against ischemic stroke, broadening our understanding of the pathogenesis of ischemic stroke.

Hyperbaric oxygen facilitates the effect of endothelial progenitor cell therapy on improving outcome of rat critical limb ischemia

We tested the hypothesis that hyperbaric oxygen (HBO) (100% oxygen/2.4 atmospheres) facilitated the effect of autologous endothelial progenitor cell (EPC) therapy on restoring the blood flow in rat critical-limb ischemia (CLI). Adult-male-SD rats (n = 8/each group) were categorized into group 1 [sham control (SC)], group 2 (CLI-treated with culture medium), group 3 [CLI-intermittent HBO (3 h/day for 5 consecutive days after CLI), group 4 (CLI-EPC/2.0 × 10⁶ cells), and group 5 (CLI-HBO-EPC). By day 5 after CLI, flow cytometry showed that the circulating EPC (Sca-1/CD31+/C-kit/CD31+/CD34+) levels were highest in group 5 and lowest in group 2 (all P < 0.001). By day 14, laser Doppler demonstrated that the ratio of blood flow (i.e., CLI to normal hind-limb) was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3 and 4 (all P < 0.0001). The protein expressions of endothelial-cell biomarkers (CD31/vWF/eNOS), and numbers of endothelial-cell markers (CD31+/vWF+) and small vessels exhibited a similar pattern to blood-flow ratio among five groups, whereas the angiogenesis parameters in protein (CXCR4/SDF-1α/HIF-1α/VEGF) and cellular (HIF-1α/SDF-1α/CXCR4+) levels were progressively increased from groups 1 to 5 (all P < 0.0001). The protein expression of apoptotic (mitochondrial-Bax/cleaved-capspase-3/PARP), fibrotic (p-Smad3/TGF-ß) and mitochondrial-damaged (cytosolic-cytochrome C) exhibited an opposite pattern, whereas the protein expressions of anti-fibrotic (BMP-2/p-Smad1/5) and mitochondrial integrity (mitochondrial-cytochrome C) exhibited an identical pattern of ratio of blood flow among the five groups (all P < 0.0001). Combined HBO-EPC therapy is superior to either one alone in improving ischemia in rodent CLI.

Predictors of responders to mononuclear stem cell-based therapeutic angiogenesis for no-option critical limb ischemia

Background

Although the mononuclear cell (MNC) transplantation could theoretically induce therapeutic angiogenesis in the patients with no-option critical limb ischemia (NO-CLI), the clinical responses to this approach are inconsistent among different clinical trials. The purpose of this study was to identify the prognostic factors of responders and develop a predictive nomogram to guide patient selection.

Methods

We retrospectively reviewed a consecutive NO-CLI cohort who received peripheral blood-derived transplantation in our center. The patients who survived and achieved complete remission of CLI at 6 months post-transplantation were defined as responders. Logistic regression models were used to screen and identify the prognostic factors based on which predictive nomogram was developed. A receiver operating characteristic (ROC) curve and a calibration curve were drawn to determine the discrimination level and predictive accuracy.

Results

The study ultimately enrolled 103 patients, including 58 responders and 45 non-responders. Based on the multivariate regression analysis, age ≥ 50 years (odds ratio [OR] 0.201, P = 0.004), blood fibrinogen > 4 g/L (OR 0.176, P = 0.003), arterial occlusion above the knee/elbow (OR 0.232, P = 0.010), the transcutaneous pressure of oxygen (TcPO₂) (OR 1.062, P = 0.006), and the Log total transplanted CD34⁺ cell count (OR 3.506, P = 0.046) were identified as independent prognostic factors of the responders in the nomogram. An area under the ROC curve of 0.851 indicated good discrimination, and the calibration curve of the predicted probability showed optimal agreement with that of the observed probability.

Conclusions

Age, blood fibrinogen, arterial occlusion level, TcPO₂, and the total transplanted CD34⁺ cell count were independent prognostic factors of the responders. A nomogram with high discrimination and accuracy was developed to provide individualized predictions.

Trail registration

ChiCTR, ChiCTR1800019401. Registered 9 November 2018—Retrospectively registered

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1117-5) contains supplementary material, which is available to authorized users.

Regeneration-associated cells improve recovery from myocardial infarction through enhanced vasculogenesis, anti-inflammation, and cardiomyogenesis

Background

Considering the impaired function of regenerative cells in myocardial infarction (MI) patients with comorbidities and associated risk factors, cell therapy to enhance the regenerative microenvironment was designed using regeneration-associated cells (RACs), including endothelial progenitor cells (EPCs) and anti-inflammatory cells.

Methods

RACs were prepared by quality and quantity control culture of blood mononuclear cells (QQMNCs). Peripheral blood mononuclear cells (PBMNCs) were isolated from Lewis rats and conditioned for 5 days using a medium containing stem cell factors, thrombopoietin, Flt-3 ligand, vascular endothelial growth factor, and interleukin-6 to generate QQMNCs.

Results

A 5.3-fold increase in the definitive colony-forming EPCs and vasculogenic EPCs was observed, in comparison to naïve PBMNCs. QQMNCs were enriched with EPCs (28.9-fold, P<0.0019) and M2 macrophages (160.3-fold, P<0.0002). Genes involved in angiogenesis (angpt1, angpt2, and vegfb), stem/progenitors (c-kit and sca-1), and anti-inflammation (arg-1, erg-2, tgfb, and foxp3) were upregulated in QQMNCs. For in vivo experiments, cells were administered into syngeneic rat models of MI. QQMNC-transplanted group (QQ-Tx) preserved cardiac function and fraction shortening 28 days post-MI in comparison with PBMNCs-transplanted (PB-Tx) (P<0.0001) and Control (P<0.0008) groups. QQ-Tx showed enhanced angiogenesis and reduced interstitial left ventricular fibrosis, along with a decrease in neutrophils and an increase in M2 macrophages in the acute phase of MI. Cell tracing studies revealed that intravenously administered QQMNCs preferentially homed to ischemic tissues via blood circulation. QQ-Tx showed markedly upregulated early cardiac transcriptional cofactors (Nkx2-5, 29.8-fold, and Gata-4, 5.2-fold) as well as c-kit (4.5-fold) while these markers were downregulated in PB-Tx. In QQ-Tx animals, de novo blood vessels formed a “Biological Bypass”, observed macroscopically and microscopically, while PB-Tx and Control-Tx groups showed severe fibrotic adhesion to the surrounding tissues, but no epicardial blood vessels.

Conclusion

QQMNCs conferred potent angiogenic and anti-inflammatory properties to the regenerative microenvironment, enhancing myocardiogenesis and functional recovery of rat MI hearts.