Deferoxamine preconditioning to restore impaired HIF-1α-mediated angiogenic mechanisms in adipose-derived stem cells from STZ-induced type 1 diabetic rats

Metformin as a Modulator of Autophagy and Hypoxia Responses in the Enhancement of Wound Healing in Diabetic Rats

The molecular mechanisms underlying delayed wound repair in diabetes involve dysregulation of key cellular processes, including autophagy and hypoxia response pathways. Herein, we investigated the role of topical metformin, an established anti-diabetic drug with potential autophagy-inducing properties, in improving wound healing outcomes under hypoxic conditions. Full-thickness skin wounds were created in streptozotocin-induced diabetic rats, and tissue samples were collected at regular intervals for molecular and histological analysis. The expression levels of autophagy markers LC3B and Beclin-1 were evaluated via immunohistochemistry and qRT-PCR, while the amount of AMP-activated protein kinase (AMPK) and hypoxia-inducible factor-1α (HIF-1α) were determined via ELISA. Our results demonstrated that metformin administration resulted in the upregulation of LC3B and Beclin-1 in the wound bed, suggesting induction of autophagy in response to the treatment. Mechanistically, metformin treatment also led to the increased amount of AMPK, a critical regulator of cellular energy homeostasis, and a subsequent reduction in HIF-1α amount under hypoxic conditions. In conclusion, our findings demonstrate that metformin promotes wound healing in diabetes mellitus by enhancing autophagy through AMPK activation and modulating HIF-1α amount in a hypoxic microenvironment. This study offers a new therapeutic approach by shedding light on the potential benefits of metformin as adjunctive therapy in diabetic wound management.

Translational Challenges in Drug Therapy and Delivery Systems for Treating Chronic Lower Extremity Wounds

Despite several promising preclinical studies performed over the past two decades, there remains a paucity of market-approved drugs to treat chronic lower extremity wounds in humans. This translational gap challenges our understanding of human chronic lower extremity wounds and the design of wound treatments. Current targeted drug treatments and delivery systems for lower extremity wounds rely heavily on preclinical animal models meant to mimic human chronic wounds. However, there are several key differences between animal preclinical wound models and the human chronic wound microenvironment, which can impact the design of targeted drug treatments and delivery systems. To explore these differences, this review delves into recent new drug technologies and delivery systems designed to address the chronic wound microenvironment. It also highlights preclinical models used to test drug treatments specific for the wound microenvironments of lower extremity diabetic, venous, ischemic, and burn wounds. We further discuss key differences between preclinical wound models and human chronic wounds that may impact successful translational drug treatment design.

Mechanism of damage of HIF-1 signaling in chronic diabetic foot ulcers and its related therapeutic perspectives

Diabetic foot ulcer (DFU) is a chronic complication of diabetes. Wound healing in patients with DFU is generally very slow, with a high recurrence rate even after the ulcer healed. The DFU remains a major clinical challenge due to a lack of understanding of its pathogenesis. Given the significant impact of DFU on patient health and medical costs, enhancing our understanding of pathophysiological alterations and wound healing in DFU is critical. A growing body of research has shown that impaired activation of the HIF-1 pathway in diabetics, which weakens HIF-1 mediated responses to hypoxia and leads to down-regulation of its downstream target genes, leading to incurable diabetic foot ulcers. By analyzing and summarizing the literature in recent years, this review summarizes the mechanism of HIF-1 signaling pathway damage in the development of DFU, analyzes and compares the application of PHD inhibitors, VHL inhibitors, biomaterials and stem cell therapy in chronic wounds of diabetes, and proposes a new treatment scheme mediated by participation in the HIF-1 signaling pathway, which provides new ideas for the treatment of DFU.

Mitochondrial Metabolism and EV Cargo of Endothelial Cells Is Affected in Presence of EVs Derived from MSCs on Which HIF Is Activated

Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) have attracted growing interest as a possible novel therapeutic agent for the management of different cardiovascular diseases (CVDs). Hypoxia significantly enhances the secretion of angiogenic mediators from MSCs as well as sEVs. The iron-chelating deferoxamine mesylate (DFO) is a stabilizer of hypoxia-inducible factor 1 and consequently used as a substitute for environmental hypoxia. The improved regenerative potential of DFO-treated MSCs has been attributed to the increased release of angiogenic factors, but whether this effect is also mediated by the secreted sEVs has not yet been investigated. In this study, we treated adipose-derived stem cells (ASCs) with a nontoxic dose of DFO to harvest sEVs (DFO-sEVs). Human umbilical vein endothelial cells (HUVECs) treated with DFO-sEVs underwent mRNA sequencing and miRNA profiling of sEV cargo (HUVEC-sEVs). The transcriptomes revealed the upregulation of mitochondrial genes linked to oxidative phosphorylation. Functional enrichment analysis on miRNAs of HUVEC-sEVs showed a connection with the signaling pathways of cell proliferation and angiogenesis. In conclusion, mesenchymal cells treated with DFO release sEVs that induce in the recipient endothelial cells molecular pathways and biological processes strongly linked to proliferation and angiogenesis.

Losartan enhances the suppressive effect of pirfenidone on the bleomycin-induced epithelial-mesenchymal transition and oxidative stress in A549 cell line

Objectives

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease. Despite the promising anti-fibrotic effect, the toleration of pirfenidone (PFD) by the patients in full dose is low. Combination therapy is a method for enhancing the therapeutic efficiency of PFD and decreasing its dose. Therefore, the present study evaluated the effect of a combination of losartan (LOS) and PFD on oxidative stress parameters and the epithelial-mesenchymal transition (EMT) process induced by bleomycin (BLM) in human lung adenocarcinoma A549 cells.

Materials and Methods

The non-toxic concentrations of BLM, LOS, and PFD were assessed by the MTT assay. Malondialdehyde (MDA) and anti-oxidant enzyme activity including catalase (CAT) and superoxide dismutase (SOD) were assessed after co-treatment. Migration and western blot assays were used to evaluate EMT in BLM-exposed A549 after single or combined treatments.

Results

The combination treatment exhibited a remarkable decrease in cellular migration compared with both single and BLM-exposed groups. Furthermore, the combination treatment significantly improved cellular anti-oxidant markers compared with the BLM-treated group. Moreover, combined therapy markedly increased epithelial markers while decreasing mesenchymal markers.

Conclusion

This in vitro study revealed that the combination of PFD with LOS might be more protective in pulmonary fibrosis (PF) than single therapy because of its greater efficacy in regulating the EMT process and oxidative stress. The current results might offer a promising therapeutic strategy for the future clinical therapy of lung fibrosis.

Boosting therapeutic efficacy of mesenchymal stem cells in pulmonary fibrosis: The role of genetic modification and preconditioning strategies

Pulmonary fibrosis (PF) is the end stage of severe lung diseases, in which the lung parenchyma is replaced by fibrous scar tissue. The result is a remarkable reduction in pulmonary compliance, which may lead to respiratory failure and even death. Idiopathic pulmonary fibrosis (IPF) is the most prevalent form of PF, with no reasonable etiology. However, some factors are believed to be behind the etiology of PF, including prolonged administration of several medications (e.g., bleomycin and amiodarone), environmental contaminant exposure (e.g., gases, asbestos, and silica), and certain systemic diseases (e.g., systemic lupus erythematosus). Despite significant developments in the diagnostic approach to PF in the last few years, efforts to find more effective treatments remain challenging. With their immunomodulatory, anti-inflammatory, and anti-fibrotic properties, stem cells may provide a promising approach for treating a broad spectrum of fibrotic conditions. However, they may lose their biological functions after long-term in vitro culture or exposure to harsh in vivo situations. To overcome these limitations, numerous modification techniques, such as genetic modification, preconditioning, and optimization of cultivation methods for stem cell therapy, have been adopted. Herein, we summarize the previous investigations that have been designed to assess the effects of stem cell preconditioning or genetic modification on the regenerative capacity of stem cells in PF.

Chelating the valley of death: Deferoxamine's path from bench to wound clinic

There is undisputable benefit in translating basic science research concretely into clinical practice, and yet, the vast majority of therapies and treatments fail to achieve approval. The rift between basic research and approved treatment continues to grow, and in cases where a drug is granted approval, the average time from initiation of human trials to regulatory marketing authorization spans almost a decade. Albeit with these hurdles, recent research with deferoxamine (DFO) bodes significant promise as a potential treatment for chronic, radiation-induced soft tissue injury. DFO was originally approved by the Food and Drug Administration (FDA) in 1968 for the treatment of iron overload. However, investigators more recently have posited that its angiogenic and antioxidant properties could be beneficial in treating the hypovascular and reactive-oxygen species-rich tissues seen in chronic wounds and radiation-induced fibrosis (RIF). Small animal experiments of various chronic wound and RIF models confirmed that treatment with DFO improved blood flow and collagen ultrastructure. With a well-established safety profile, and now a strong foundation of basic scientific research that supports its potential use in chronic wounds and RIF, we believe that the next steps required for DFO to achieve FDA marketing approval will include large animal studies and, if those prove successful, human clinical trials. Though these milestones remain, the extensive research thus far leaves hope for DFO to bridge the gap between bench and wound clinic in the near future.

Secretome from human adipose-derived mesenchymal stem cells promotes blood vessel formation and pericyte coverage in experimental skin repair

Human adipose tissue-derived stem cells (hASC) secretome display various therapeutically relevant effects in regenerative medicine, such as induction of angiogenesis and tissue repair. The benefits of hASC secretome are primarily orchestrated by trophic factors that mediate autocrine and paracrine effects in host cells. However, the composition and the innate characteristics of hASC secretome can be highly variable depending on the culture conditions. Here, we evaluated the combined effect of serum-free media and hypoxia preconditioning on the hASCs secretome composition and biological effects on angiogenesis and wound healing. The hASCs were cultured in serum-free media under normoxic (NCM) or hypoxic (HCM) preconditioning. The proteomic profile showed that pro- and anti-antiangiogenic factors were detected in NCM and HCM secretomes. In vitro studies demonstrated that hASCs secretomes enhanced endothelial proliferation, survival, migration, in vitro tube formation, and in vivo Matrigel plug angiogenesis. In a full-thickness skin-wound mouse model, injection of either NCM or HCM significantly accelerated the wound healing. Finally, hASC secretomes were potent in increasing endothelial density and vascular coverage of resident pericytes expressing NG2 and nestin to the lesion site, potentially contributing to blood vessel maturation. Overall, our data suggest that serum-free media or hypoxic preconditioning enhances the vascular regenerative effects of hASC secretome in a preclinical wound healing model.

Guiding stem cells for cutaneous repair

The significance of mesenchymal stem cells (MSCs) for tissue repair and regeneration is widely recognized. The pleiotropic nature of MSCs is demonstrated by their potential for proliferation and differentiation, and paracrine secretions, thereby making them ideal candidates for cell replacement therapy. Tissue resident MSCs are engaged in homeostasis under normal wear and tear. However, stem cell therapy may be applicable if damage cannot be repaired by normal homeostatic mechanisms. The safety of MSCs has been clearly established in clinical trials but their efficacy remains questionable. The efficacy of MSCs depends on several factors, such as their viability, functional status in terms of secretome secretions, and the in-vivo scenario after transplantation. The performance of MSCs is regulated by their micro-environmental conditions and cues. The so-called MSC niche comprises physical, chemical, and biological components, which play key roles in determining the fate of MSCs. MSCs scaled up for transplantation purposes comprise a disorganized mass of cells, which needs to be directed to perform the required function. Thus, MSCs need to be directed toward an expected target activity in human patients. This review focuses on the various methods that can be used to guide stem cells for cutaneous repair.

Angiogenic Effect of a Nanoniosomal Deferoxamine-Loaded Poly(vinyl alcohol)-Egg White Film as a Promising Wound Dressing

Owing to the noticeable increase in the number of patients with impaired wound healing capabilities, developing bioactive wound dressings with supportive physicomechanical and biological properties for clinical wound management has attracted much more attention nowadays. In this regard, engineered dressings with angiogenesis potential are vital for accelerated tissue regeneration. In the current study, nanoniosomal deferoxamine (DFO)-loaded transparent films of egg white-poly(vinyl alcohol) (PVA/EW/ND) were successfully fabricated at three different PVA/EW ratios (1:0, 1:1, and 1:1.5 wt/wt %) through the thin film hydration and solvent casting methods. The developed films' characterizations were carried out using scanning electron microscopy, Fourier transform infrared spectroscopy analysis, uniaxial tensile strength, water uptake, water vapor transmission rate, in vitro degradation, and drug release. The results demonstrated that the various weight ratios of PVA/EW have a significant effect on the microscopic morphology, equilibrium swelling, degradation, and mechanical properties of the films. The drug release profile exhibited a sustained release of DFO with controlled burst-lag phases resembling the Korsmeyer-Peppas pattern. The cytotoxicity and adhesion analysis using human dermal fibroblasts displays the biocompatibility of the developed PVA/EW/ND films and the formation of cellular colonies on the surface. The in vitro angiogenic capability of the developed films evaluated by the scratch wound assay and microbead-assisted tube formation study showed a significant increase in the rate of migration of human umbilical vein endothelial cells and in the number of tube-like structures. Therefore, the achieved results suggest that the presented PVA/EW/ND film has promising potential for effective wound healing applications.

DFO treatment protects against depression-like behaviors and cognitive impairment in CUMS mice

Depression has several negative effects on emotion as well as learning and memory abilities. Previous studies showed that depression could exacerbate inflammation, which in turn further aggravated depression. Deferoxamine (DFO) is a chelating agent binding iron and aluminium, and is clinically applied to treat acute ion poisoning and hemochromatosis. Researches showed that it could reduce inflammation via increasing the expression of hypoxia-inducible factor-1alpha (HIF-1α). Here, we established a chronic unpredictable mild stress (CUMS) model to investigate whether DFO exerted a neuroprotective function in depression. The results demonstrated that CUMS (4 weeks) effectively induced depression-like behaviors in mice based on sucrose preference test (SPT), forced swim test (FST), tail suspension test (TST), open field test (OFT), and elevated plus-maze test (EPT). It also brought cognitive deficits based on Morris water maze (MWM) test and the impairment of synaptic plasticity based on in vivo electrophysiological recordings. Additionally, CUMS exposure significantly decreased the expression of hippocampal synapse related proteins and the spine density of neurons in the DG region, accompanied by increasing the expression of hippocampal inflammatory cytokines, and promoted the activation of microglia in the hippocampus. The expression of HIF-1α was down-regulated as expected. However, DFO distinctly reversed the CUMS-induced impairments. The mechanism is associated with the DFO inhibition of inflammation by upregulating HIF-1 expression, thereby alleviating a series of pathology changes. Together, these findings suggest that DFO likely plays a protective role in cognitive impairments and synaptic plasticity deficits resulting from depression.

Applications of tetrahedral DNA nanostructures in wound repair and tissue regeneration

Tetrahedral DNA nanostructures (TDNs) are molecules with a pyramidal structure formed by folding four single strands of DNA based on the principle of base pairing. Although DNA has polyanionic properties, the special spatial structure of TDNs allows them to penetrate the cell membrane without the aid of transfection agents in a caveolin-dependent manner and enables them to participate in the regulation of cellular processes without obvious toxic side effects. Because of their stable spatial structure, TDNs resist the limitations imposed by nuclease activity and innate immune responses to DNA. In addition, TDNs have good editability and biocompatibility, giving them great advantages for biomedical applications. Previous studies have found that TDNs have a variety of biological properties, including promoting cell migration, proliferation and differentiation, as well as having anti-inflammatory, antioxidant, anti-infective and immune regulation capabilities. Moreover, we confirmed that TDNs can promote the regeneration and repair of skin, blood vessels, muscles and bone tissues. Based on these findings, we believe that TDNs have broad prospects for application in wound repair and regeneration. This article reviews recent progress in TDN research and its applications.

Resveratrol Enhances Wound Healing in Type 1 Diabetes Mellitus by Promoting the Expression of Extracellular Vesicle-Carried MicroRNA-129 Derived from Mesenchymal Stem Cells

Recent studies have shown the promotive effect of resveratrol on wound healing. This study aims to explore the underlying molecular mechanism of resveratrol in type 1 diabetes mellitus (T1DM) through microRNA (miR)-129-containing extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) based on in silico analysis. The rat model of T1DM was established by intraperitoneal injection of sodium citrate containing streptozotocin, and the wound was made around the deep fascia. Rat MSCs were isolated and treated with resveratrol (SRT501), and the corresponding EVs (SRT501-EVs) were isolated, where the expression of miR-129 was determined. By performing function experiments, the effect of SRT501-EVs and miR-129 on the biological functions of human umbilical vein endothelial cells (HUVECs) was determined. Finally, the binding relationship between miR-129 and tumor necrosis factor receptor-associated factor 6 (TRAF6) was also determined by the dual-luciferase reporter gene assay. miR-129 was shown as a candidate related to both resveratrol and wound healing in T1DM. SRT501-EVs promoted the skin wound healing of T1DM rats and also further improved the proliferative, migratory, and tube formation potentials of HUVECs. Resveratrol inhibited the expression of TRAF6 in HUVECs stimulated by MSC-conditioned medium and promoted the transfer of miR-129 via EVs, while TRAF6 was confirmed as a target gene of miR-129. Furthermore, inhibition of miR-129 attenuated the proangiogenic effect of resveratrol on HUVECs. Resveratrol exerts promotive role in wound healing in T1DM through downregulation of TRAF6 via MSC-EV-carried miR-129, suggesting a regulatory network involved in the wound healing process in T1DM.

Impact of insulin producing cells derived from adipose tissue mesenchymal stem cells on testicular dysfunction of diabetic rats

The present study is to clarify the effect of insulin-producing cells (IPCs) derived from adipose tissue mesenchymal stem cells (AT-MSCs) on diabetic-induced impairments as the abnormalities of testicular tissues, oxidative stress of testes, and defects of spermatogenesis. Diabetes was stimulated by streptozotocin (STZ) injection in male adult Sprague Dawley (SD) rats. Diabetes was confirmed by taking two highly consecutive fasting blood sugar readings; more than 300 mg/dl; within one week. Five million of IPCs derived from AT-MSCs; encased in TheraCyte capsule; were then directly transplanted (one implant for each rat) subcutaneously in diabetic rats. Implants were maintained for 3 months and the fasting blood sugar of the transplanted rats was observed every month. At the end of the experiment; serum testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were also estimated. The sperm parameters (count, motility, and abnormality) were recorded. In testicular tissue; GPX4, Bcl2, and Bax levels were evaluated, while oxidative stress and antioxidant enzymes activities were measured in the testes homogenate. Also, histopathological alterations were examined in the testes cross-section. In the results, it was found that IPCs treatment enhanced the serum testosterone, FSH, and LH levels. Diabetic-induced impairments in the sperm parameters were noticeably improved post-IPCs transplantation in the diabetic rats. Moreover, the treatment improved the diabetic-associated testicular oxidative stress. Also, it was recognized that the Bax expression decreased, while, GPX4 and Bcl2 expression increased in the treated rats. Meanwhile, the abnormalities showed in the histopathological studies of the hyperglycemic rat's testes were attenuated post-treatment. So, IPCs transplantation improved diabetes and consequently protected against hyperglycemia-induced testicular damages.

Translational insights into stem cell preconditioning: From molecular mechanisms to preclinical applications

Cell-based therapy (CBT) is a revolutionary approach for curing a variety of degenerative diseases. Stem cell-based regenerative medicine is a novel strategy for treating tissue damages regarding stem cells unique properties such as differentiation potential, paracrine impacts, and self-renewal ability. However, the current cell-based treatments encounter considerable challenges to be translated into clinical practice, including low cell survival, migration, and differentiation rate of transplanted stem cells. The poor stem cell therapy outcomes mainly originate from the unfavorable condition of damaged tissues for transplanted stem cells. The promising method of preconditioning improves cell resistance against the host environment's stress by imposing certain conditions similar to the harsh microenvironment of the damaged tissues on the transplanted stem cells. Various pharmacological, biological, and physical inducers are able to establish preconditioning. In addition to their known pharmacological effects on tissues and cells, these preconditioning agents improve cell biological aspects such as cell survival, proliferation, differentiation, migration, immunomodulation, paracrine impacts, and angiogenesis. This review focuses on different protocols and inducers of preconditioning along with underlying molecular mechanisms of their effects on stem cell behavior. Moreover, preclinical applications of preconditioned stem cells in various damaged organs such as heart, lung, brain, bone, cartilage, liver, and kidney are discussed with prospects of their translation into the clinic.

Adipose-Derived Stem Cell Conditioned Medium and Wound Healing: A Systematic Review

Adipose-derived stem cells (ASCs) have been growing in popularity for their potential in wound healing and tissue engineering. Stem cell therapies are limited in application, with the need to maintain cell viability and function as well as safety concerns. It has been increasingly reported that the effects of ASCs are predominantly attributable to the paracrine effects of the secreted factors, which can be collected in conditioned medium (CM). The goal of this systematic review is to investigate the effects on wound healing of CM collected from ASC culture. Original articles relevant to ASC-CM and wound healing (in vitro: dermal fibroblast, epidermal keratinocytes and their equivalent cell lines; in vivo: full-thickness wound models) were included. The agreement level of selections between two investigators were calculated by the kappa scores. And the information concerning to the publications, CM preparation and its application and effects were extracted and reported in a systematic way and summarized in tables. In total, 121 publications were initially identified through a search of the PubMed/MEDLINE database with a specific search algorithm, and 36 articles were ultimately included after two screenings. Nineteen were in vitro studies that met the search criteria and 17 were in vivo studies with or without in vitro data. In summary, based on the included articles, treatment with ASC conditioned medium (ASC-CM), to a large extent, resulted in positive effects on wound healing in vitro and in vivo. Modulation of the culture conditions of ASCs producing the CM, including hypoxic conditions, alternative substrates, medium supplementation, as well as genetic modification of cells, favorably promoted the effects of ASC-CM. Finally, a discussion of the future perspectives and therapeutic potential of ASC-CM, which also addresses the limitations of the field, is presented. A limitation of the evidence is the inconsistency in CM preparation methods among included articles. In conclusion, ASC-CM is a promising novel cell-free therapy for wound healing in regenerative medicine and warrants further exploration.

Conditioned Medium of Adipose-Derived Mesenchymal Stem Cells as a Promising Candidate to Protect High Glucose-Induced Injury in Cultured C28I2 Chondrocytes

Purpose: The aim of this study was to evaluate the protective effect of conditioned medium derived from human adipose mesenchymal stem cells (CM-hADSCs) on C28I2 chondrocytes against oxidative stress and mitochondrial apoptosis induced by high glucose (HG).

Methods: C28I2 cells were pre-treated with CM-hADSCs for 24 hours followed by HG exposure (75 mM) for 48 hours. MTT assay was used to assess the cell viability. Reactive oxygen species (ROS) and lipid peroxidation were determined by 2,7-dichlorofluorescein diacetate (DCFHDA) and thiobarbituric acid reactive substances (TBARS) assays, respectively. Expressions of glutathione peroxidase 3 (GPX 3), heme oxygenase-1 (HO-1), and NAD(P)H quinone dehydrogenase 1 (NQO1) were analyzed by RT-PCR. Finally, western blot analysis was used to measure Bax, Bcl-2, cleaved caspase-3, and Nrf-2 expression at protein levels.

Results: CM-hADSCs pretreatment mitigated the cytotoxic effect of HG on C28I2 viability. Treatment also markedly reduced the levels of ROS, lipid peroxidation, and augmented the expression of HO-1, NQO1, and GPx3 genes in HG-exposed group. CM-ADSCs enhanced Nrf-2 protein expression and reduced mitochondrial apoptosis through reducing Bax/Bcl-2 ratio and Caspase-3 activation.

Conclusion: MSCs, probably through its paracrine effects, declined the deleterious effect of HG on chondrocytes. Hence, therapies based on MSCs secretomes appear to be a promising therapeutic approaches to prevent joint complications in diabetic patients.

Autologous platelet-rich plasma repairs burn wound and reduces burn pain in rats

OBJECTIVE

To investigate the effects of autologous platelet-rich plasma (PRP) on burn wound and burn pain in rats.

METHODS

Rats were treated with high-temperature copper rod to induce skin burn. During treatment, the wound area of rats was recorded on days 0, 3, 7, 10, 14 and healing rates were calculated. After 14-day treatment, the paw withdrawal mechanical threshold (PWMT) as well as paw withdrawal thermal latency (PWTL) were measured. In addition, CD31 expression in burn wound was detected by Immunohistochemistry. The contents of TNF-α and IL-1β in wound tissues were detected by ELISA. Moreover, the mRNA and protein expression levels of VEGF, MMP-9 and TGF-β1 in wound tissues were detected by RT-qPCR together with Western blot.

RESULTS

Burn wound of rats in the PRP group gradually got better with a decreased wound area. Compared with the NS group, the wound area of the PRP group was significantly reduced and the healing rate was significantly increased. Meanwhile, PWMT of the rats in the PRP group was obviously increased compared with the NS group. Compared with the NS group, the rate of CD31-positive cells in the wound tissue of burned rats was increased; while the contents of TNF-α and IL-1β were significantly decreased after a subcutaneous injection of PRP. In addition, the mRNA and protein expression levels of VEGF, MMP-9 and TGF-β1 in the wound tissue of rats from PRP group were evidently increased.

CONCLUSION

Autologous platelet-rich plasma not only shortened the healing time, but also relieved the burn pain.

Hippocampal ornithine decarboxylase/spermidine pathway mediates H2S-alleviated cognitive impairment in diabetic rats: Involving enhancment of hippocampal autophagic flux

Introduction

We have previously demonstrated the antagonistic role of hydrogen sulfide (H2S) in the cognitive dysfunction of streptozotocin (STZ)-induced diabetic rats. It has been confirmed that the impaired hippocampal autophagic flux has a key role in the pathogenesis of cognitive impairment and that ornithine decarboxylase (ODC)/spermidine (Spd) pathway plays an important role in the formation of memory by promoting autophagic flux.

Objectives

To investigate the roles of hippocampal ODC/Spd pathway and autophagic flux in H2S-attenuated cognitive impairment in STZ-induced diabetic rats.

Methods

Cognitive function is judged by the novel objective recognition task (NOR), the Y-maze, and the Morris water maze (MWM) tests. The ODC/Spd pathway in hippocampus was evaluated using the expression of ODC detected by western blot and the level of Spd assayed by GC-MS. Autophagic flux was assessed using the expressions of Beclin-1, LC3II/I, and P62 detected by western blot, and the number of autophagosomes observed by transmission electron microscope.

Results

Sodium hydrosulfide (NaHS, a donor of H2S) markedly improved the autophagic flux in the hippocampus of STZ-exposed rats, as evidenced by a decrease in the number of autophagosomes as wells as downregulations in the expressions of LC3-II, Beclin-1, and P62 in the hippocampus of cotreatment with NaHS and STZ rats. NaHS also up-regulated the expression of ODC and the level of Spd in the hippocampus of STZ-induced diabetic rats. Furthermore, inhibited hippocampal ODC/Spd pathway by difluoromethylornithine (DFMO) markedly reversed the protections of NaHS against the hippocampal autophagic flux impairment as well as the cognitive dysfunction in STZ-exposed rats.

Conclusion

These findings indicated that improving hippocampal autophagic flux plays a key role in H2S-attenuated cognitive impairment in STZ-induced diabetic rats, as results of up-regulating hippocampal ODC/Spd pathway.

Skin wound healing assisted by angiogenic targeted tissue engineering: A comprehensive review of bioengineered approaches

Skin injuries and in particular, chronic wounds, are one of the major prevalent medical problems, worldwide. Due to the pivotal role of angiogenesis in tissue regeneration, impaired angiogenesis can cause several complications during the wound healing process and skin regeneration. Therefore, induction or promotion of angiogenesis can be considered as a promising approach to accelerate wound healing. This article presents a comprehensive overview of current and emerging angiogenesis induction methods applied in several studies for skin regeneration, which are classified into the cell, growth factor, scaffold, and biological/chemical compound-based strategies. In addition, the advantages and disadvantages of these angiogenic strategies along with related research examples are discussed in order to demonstrate their potential in the treatment of wounds.

Investigating The Alterations of Oxidative Stress Status, Antioxidant Defense Mechanisms, MAP Kinase and Mitochondrial Apoptotic Pathway in Adipose-Derived Mesenchymal Stem Cells from STZ Diabetic Rats

Objective

This study aimed to investigate the reliability of diabetic adipose-derived stem cells (ADSCs) for autologous cell-based therapies by exploring the functionality of signalling pathways involved in regulating oxidative stress and apoptosis.

Materials and Methods

In this experimental study, ADSCs were isolated from streptozotocin (STZ)-induced diabetic rats (dADSCs) and normal rats (nADSCs). The colonies derived from dADSCs and nADSCs were compared by colony-forming unit (CFU) assay. Reactive oxygen species (ROS) formation and total antioxidant power (TAP) were also measured. Furthermore, the expression of antioxidant enzymes, including catalase (Cat), superoxide dismutase (Sod)-1 and -3, glutathione peroxidase (Gpx)-1, -3 and -4 was measured at mRNA level by semi-quantitative reverse transcriptase polymerase chain reaction assay. The expression of Bax, Bcl2, caspase-3, total and phosphorylated c-Jun N-terminal kinase (JNK) and P38 Mitogen-Activated Protein Kinase (MAPK) at protein level was analyzed by western blotting.

Results

The results of this study indicated that viability and plating efficiency of dADSCs were significantly lower than those of nADSCs. ROS generation and TAP level were respectively higher and lower in dADSCs. The gene expression of antioxidant enzymes, including Cat, Sod-1, Gpx-3 and Gpx-4 in dADSCs was significantly greater than that in nADSCs. However, Sod-3 and Gpx-1 mRNA levels were decreased in dADSCs. Moreover, Bax/Bcl-2 protein ratio, caspase-3 protein expression and phosphorylation of JNK and P38 proteins were increased in dADSCs compared to nADSCs.

Conclusion

Taken together, diabetes might impair the cellular functions of dADSCs as candidates for autologous cell- based therapies. This impairment seems to be mediated by JNK, P38 MAPKs, and mitochondria pathway of apoptosis and partly by disruption of antioxidant capacity.

Protective effect of hydralazine on a cellular model of Parkinson’s disease: a possible role of hypoxia-inducible factor (HIF)-1α

Parkinson’s disease (PD) is a neurodegenerative disease accompanied by a low expression level of cerebral hypoxia-inducible factor (HIF-1α). Hence, activating the hypoxia-signaling pathway may be a favorable therapeutic approach for curing PD. This study explored the efficacy of hydralazine, a well-known antihypertensive agent, for restoring the impaired HIF-1 signaling in PD, with the aid of 6-hydroxydopamine (6-OHDA)-exposed SH-SY5Y cells. The cytotoxicity of hydralazine and 6-OHDA on the SH-SY5Y cells were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and apoptosis detection assays. The activities of malondialdehyde, nitric oxide (NO), ferric reducing antioxidant power (FRAP), and superoxide dismutase (SOD) were also measured. Expression levels of HIF-1α and its downstream genes at the protein level were assessed by Western blotting. Hydralazine showed no toxic effects on SH-SY5Y cells, at the concentration of ≤50 μmol/L. Hydralazine decreased the levels of apoptosis, malondialdehyde, and NO, and increased the activities of FRAP and SOD in cells exposed to 6-OHDA. Furthermore, hydralazine up-regulated the protein expression levels of HIF-1α, vascular endothelial growth factor, tyrosine hydroxylase, and dopamine transporter in the cells also exposed to 6-OHDA, by comparison with the cells exposed to 6-OHDA alone. In summary, hydralazine priming could attenuate the deleterious effects of 6-OHDA on SH-SY5Y cells by increasing cellular antioxidant capacity, as well as the protein levels of HIF-1α and its downstream target genes.

The efficacy of a traditional medicine preparation on second-degree burn wounds in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Lime Salve (L.S) has been well documented from the 9th to the 19th century AD by traditional Iranian medicine (TIM) as an effective remedy for burn healing.

AIM OF THE STUDY

The present study was undertaken to evaluate the healing effect and related underlying mechanisms of Lime Salve in a model of deep second-degree thermal burn in male Wistar rats.

MATERIALS AND METHOD

L.S was made up of a combination of refined calcium hydroxide powder, beeswax and sesame oil and its quality control was assessed. A deep second-degree burn was created by a hot plate in 48 male Wistar rats. Afterwards, they were randomly divided into four groups including normal saline (C group), L.S (T group), basement of formulation composed of beeswax and sesame oil (B group) and silver sulfadiazine (S group). On days 5, 10, 17 and 24, the wounds were digitally photographed by a camera and after sacrifice of the rats, skin samples were obtained for performing qRT-PCR, immunohistochemistry staining and histological examination.

RESULTS

L.S prominently augmented the wound closure rate, neovascularization on day 10 and collagen formation on days 17 and 24 in comparison with the C group. Furthermore, the Salve-exposed specimens showed a significant higher epithelialization during the experiment with a peak on day 24. qRT-PCR also showed that on day 10, VEGF and TGF-β1 genes were significantly higher in the T group as compared with the C group. Also, MMP-9 and MMP-2 genes had a significant peak of expression on day 17 and rapid reduction of expression on day 24. Expression levels of IL-6 and TNF-α genes peaked on day 10 in the T group, followed by a progressive reduction until the end of the examination.

CONCLUSION

L.S could effectively accelerate the healing process of deep second-degree burn wounds and therefore, it may be recommended as a promising topical medication for treating burn wounds in the future clinical trials.

Diabetes-induced glucolipotoxicity impairs wound healing ability of adipose-derived stem cells-through the miR-1248/CITED2/HIF-1α pathway

Despite being an attractive cell type for mesenchymal stem cell (MSC) transplantation therapy for wound healing, human adipose-derived stem cells (hADSCs) from diabetes mellitus (DM) patients result in remarkable retention of stem cell activity due to diabetes-induced glucolipotoxicity. We explored the effect of diabetes and medium containing AGEs on the cell activity, phenotype, multipotency, angiogenic potential, and the therapeutic effect of hADSCs. Then, miRNA-1248 was selected by miRNA microarray analysis to further study the core molecular pathways that regulate the wound healing ability of hADSCs. hADSCs isolated from DM patients or cultured in medium containing AGEs in vitro exhibited decreased effectiveness in stem cell therapy. The expression of miRNA-1248 was decreased in the hADSCs of DM patients and hence failed to positively regulate stem cell activity, differentiation functions, and angiogenesis promotion effect. This concomitantly increased the expression of CITED2, an inhibitor of HIF-1α, thus influencing growth factors that promote angiogenesis, cellular proliferation, and wound healing. Overall, our data demonstrated that the glucolipotoxicity-impaired wound healing ability of hADSCs might occur through the miR-1248/CITED2/HIF-1α pathway. MiRNA-1248 may have potential to be used as a novel therapeutic target for wound healing in DM patients or restoring the wound healing ability of diabetic hADSCs.

The evaluation of VEGF and HIF-1α gene polymorphisms and multiple sclerosis susceptibility

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disease that leads to myelin sheath destruction. Hypoxia-inducible factor 1 (HIF-1) has several roles in cells, such as inducing inflammation and angiogenesis. Recently, several lines of evidence have indicated the role of the hypoxia response and the HIF-1 signaling pathway in an autoimmune disease such as MS. The present study aimed to evaluate the effects of HIF-1α gene polymorphisms and vascular endothelial growth factor (VEGF) (as a major target gene of HIF-1α) gene polymorphism on MS susceptibility.

METHODS

In total, 150 MS patients and 150 healthy age- and gender-matched people as a control group participated in the present study. The polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping.

RESULTS

The results obtained showed that the CC genotype of the VEGF rs699947 polymorphism was significantly higher in the case group than in the control group (p = 0.004). Also, we showed a significant relationship between the VEGF rs699947 polymorphism and MS in a dominant inheritance model (p = 0.005). Regarding the VEGF rs699947 polymorphism allelic distribution, the C allele frequency was significantly higher in the control group than in the case group (71.3% versus 61%, respectively, p = 0.009) and decreased the MS susceptibility by 1.6-fold (odds ratio = 1.6, 95% confidence interval = 1.2-2.2). There was no significant difference between the two groups with respect to HIF-1α rs11549465 genotypic distribution. The HIF-1α C111A polymorphism was non-polymorphic in our study population, except in the case group where nine subjects carried the CA genotype.

CONCLUSIONS

We show a significant association between VEGF rs60047 polymorphism and MS susceptibility. However, our results do not show a significant association between MS and HIF-1α polymorphisms.

Iron Chelation as a Potential Therapeutic Strategy for AKI Prevention

AKI remains a major public health concern. Despite years of investigation, no intervention has been demonstrated to reliably prevent AKI in humans. Thus, development of novel therapeutic targets is urgently needed. An important role of iron in the pathophysiology of AKI has been recognized for over three decades. When present in excess and in nonphysiologic labile forms, iron is toxic to the kidneys and multiple other organs, whereas iron chelation is protective across a broad spectrum of insults. In humans, small studies have investigated iron chelation as a novel therapeutic strategy for prevention of AKI and extrarenal acute organ injury, and have demonstrated encouraging initial results. In this review, we examine the existing data on iron chelation for AKI prevention in both animal models and human studies. We discuss practical considerations for future clinical trials of AKI prevention using iron chelators, including selection of the ideal clinical setting, patient population, iron chelating agent, and dosing regimen. Finally, we compare the key differences among the currently available iron chelators, including pharmacokinetics, routes of administration, and adverse effects.

Deferoxamine: An Angiogenic and Antioxidant Molecule for Tissue Regeneration

Deferoxamine (DFO) has been in use for half a century as a Food and Drug Administration-approved iron chelator, but recent studies indicate a variety of properties that could expand this drug's application into the fields of tissue and regenerative engineering. DFO has been implicated as an angiogenic agent in studies on ischemia, wound healing, and bone regeneration because of its ability to upregulate hypoxia-inducible factor-1 alpha (HIF-1α) and other key downstream angiogenic factors. DFO has also demonstrated antioxidant capabilities unrelated to its iron-chelating properties, making it a potential modulator of the oxidative stress involved in the inflammation response. Together, these properties make DFO a potential bioactive molecule to promote wound healing and enhance tissue integration of biomaterials in vivo. Impact Statement Deferoxamine (DFO) is approved by the Food and Drug Administration as an iron chelator and is been used to treat iron overload. Recent studies indicate that DFO may have important applications in the growing field of tissue regeneration because of its unique properties of downregulating inflammation while promoting vascularization, thereby enhancing wound healing in vivo.

Diabetes impairs the angiogenic capacity of human adipose-derived stem cells by reducing the CD271+ subpopulation in adipose tissue

Type 2 diabetes mellitus is an important risk factor for cardiovascular diseases (CVDs). Therapeutic angiogenesis using adipose-derived stem cells (ADSCs) is attractive for CVD therapy. However, although it would be critical for ADSC application on CVD therapy, whether and how diabetes impairs human ADSC therapeutic potential is still uncertain. In this study, we aimed to investigate the impact of diabetes on the angiogenic potential of ADSCs in patients with CVDs, with special focus on stemness-related genes and cellular alteration of ADSCs. We established cultured ADSCs from diabetic (DM-ADSCs) and non-diabetic patients (nonDM-ADSCs) with CVDs. DM-ADSCs demonstrated limited proliferative capacity and reduced paracrine capacity of VEGF, with lower expression of the stemness gene SOX2. Angiogenic capacity and ADSC engraftment were assessed using xenograft experiments in a hindlimb ischemia model of athymic nude mice. Consistent with the results of in vitro assays, DM-ADSCs did not rescue limb ischemia. In contrast, nonDM-ADSCs induced neovascularization with enhanced engraftment. To elucidate the mechanism underlying these ADSC changes, we compared the surface marker profiles of freshly isolated ADSCs obtained from diabetic and non-diabetic patients by flow cytometry. Among studied subsets, the CD34⁺CD31^-CD271⁺ subpopulation was reduced in the adipose tissues of diabetic patients. In addition, SOX2 expression and proliferative capacity were considerably reduced in nonDM-ADSCs derived from the stromal vascular fraction (SVF) with depletion of CD271⁺ cells (p < 0.01). Our observations elucidated that reduced CD271⁺ subpopulation is critical for the impairment of ADSCs in diabetic patients. Further investigations on the CD271⁺ subset of ADSCs might provide novel insights into the mechanisms and solutions for diabetes-related ADSC dysfunction in cell therapy.

Harnessing the secretome of adipose-derived stem cells in the treatment of ischemic heart diseases

Adipose-derived stem cells (ASCs) are promising therapeutic cells for ischemic heart diseases, due to the ease and efficiency of acquisition, the potential of myocardial lineage differentiation, and the paracrine effects. Recently, many researchers have claimed that the ASC-based myocardial repair is mainly attributed to its paracrine effects, including the anti-apoptosis, pro-angiogenesis, anti-inflammation effects, and the inhibition of fibrosis, rather than the direct differentiation into cardiovascular lineage cells. However, the usage of ASCs comes with the problems of low cardiac retention and survival after transplantation, like other stem cells, which compromises the effectiveness of the therapy. To overcome these drawbacks, researchers have proposed various strategies for improving survival rate and ensuring sustained paracrine secretion. They also investigated the safety and efficacy of phase I and II clinical trials of ASC-based therapy for cardiovascular diseases. In this review, we will discuss the characterization and paracrine effects of ASCs on myocardial repair, followed by the strategies for stimulating the paracrine secretion of ASCs, and finally their clinical usage.

[Experimental study on the effect of desferrioxamine on targeted homing and angiogenesis of bone marrow mesenchymal stem cells]

Objective

To investigate whether desferrioxamine (DFO) can enhance the homing of bone marrow mesenchymal stem cells (BMSCs) and improve neovascularization in random flaps of rats.

Methods

BMSCs and fibroblasts (FB) of luciferase transgenic Lewis rats were isolated and cultured. Forty 4-week-old Lewis male rats were used to form a 10 cm×3 cm rectangular flap on their back. The experimental animals were randomly divided into 4 groups with 10 rats in each group: in group A, 200 μL PBS were injected through retrobulbar venous plexus; in group B, 200 μL FB with a concentration of 1×10 ⁶ cells/mL were injected; in group C, 200 μL BMSCs with a concentration of 1×10 ⁶ cells/mL were injected; in group D, cells transplantation was the same as that in group C, after cells transplantation, DFO [100 mg/(kg·d)] were injected intraperitoneally for 7 days. On the 7th day after operation, the survival rate of flaps in each group was observed and calculated; the blood perfusion was observed by laser speckle imaging. Bioluminescence imaging was used to detect the distribution of transplanted cells in rats at 30 minutes and 1, 4, 7, and 14 days after operation. Immunofluorescence staining was performed at 7 days after operation to observe CD31 staining and count capillary density under 200-fold visual field and to detect the expressions of stromal cell derived factor 1 (SDF-1), epidermal growth factor (EGF), fibroblast growth factor (FGF), and Ki67. Transplanted BMSCs were labeled with luciferase antibody and observed by immunofluorescence staining whether they participated in the repair of injured tissues.

Results

The necrosis boundary of ischemic flaps in each group was clear at 7 days after operation. The survival rate of flaps in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). Laser speckle imaging showed that the blood perfusion units of flaps in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). Bioluminescence imaging showed that BMSCs gradually migrated to the ischemia and hypoxia area and eventually distributed to the ischemic tissues. The photon signal of group D was significantly stronger than that of other groups at 14 days after operation ( P<0.05). CD31 immunofluorescence staining showed that capillary density in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). The expressions of SDF-1, EGF, FGF, and Ki67 in groups C and D were significantly stronger than those in groups A and B, and in group D than in group C. Luciferase-labeled BMSCs were expressed in the elastic layer of arteries, capillaries, and hair follicles at 7 days after transplantation.

Conclusion

DFO can enhance the migration and homing of BMSCs to the hypoxic area of random flap, accelerate the differentiation of BMSCs in ischemic tissue, and improve the neovascularization of ischemic tissue.

Angiogenin production in response to hypoxia and l-mimosine in periodontal fibroblasts

BACKGROUND

A major mediator of angiogenesis is angiogenin, which is expressed in the early phase of healing in oral tissue engineering strategies. It is unclear how angiogenin is regulated in the periodontal tissue. The objective of this study was to reveal the regulation of angiogenin in response to hypoxia and the hypoxia mimetic agent l-mimosine in periodontal fibroblasts.

METHODS

Human fibroblasts of the periodontal ligament (PDLF) and the gingiva (GF) in monolayer and spheroid cultures were exposed to hypoxia or l-mimosine. The production of angiogenin was evaluated at mRNA and protein levels with reverse transcription quantitative polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Echinomycin, an inhibitor of hypoxia-inducible factor (HIF)-1 activity, was used to test the involvement of HIF-1.

RESULTS

Our data show that hypoxia and l-mimosine can increase angiogenin mRNA and protein levels in PDLF monolayer cultures. In GF monolayer cultures, we found an increase of angiogenin at the mRNA level in response to hypoxia. The increase of angiogenin can be blocked by inhibition of HIF-1 signaling via echinomycin. In PDLF and GF spheroid cultures, the impact of hypoxia and l-mimosine did not reach the level of significance.

CONCLUSION

Hypoxia and the hypoxia mimetic agent l-mimosine can increase the production of angiogenin via HIF-1 signaling in PDLF monolayer cultures but not in spheroid cultures. GF were less sensitive to the impact of hypoxia and l-mimosine. Overall, these results suggest a link between hypoxia, HIF-1 signaling and angiogenin in the periodontium.

Neuroprotective Role of Hypothermia in Hypoxic-ischemic Brain Injury: Combined Therapies using Estrogen

Hypoxic-ischemic brain injury is a complex network of factors, which is mainly characterized by a decrease in levels of oxygen concentration and blood flow, which lead to an inefficient supply of nutrients to the brain. Hypoxic-ischemic brain injury can be found in perinatal asphyxia and ischemic-stroke, which represent one of the main causes of mortality and morbidity in children and adults worldwide. Therefore, knowledge of underlying mechanisms triggering these insults may help establish neuroprotective treatments. Selective Estrogen Receptor Modulators and Selective Tissue Estrogenic Activity Regulators exert several neuroprotective effects, including a decrease of reactive oxygen species, maintenance of cell viability, mitochondrial survival, among others. However, these strategies represent a traditional approach of targeting a single factor of pathology without satisfactory results. Hence, combined therapies, such as the administration of therapeutic hypothermia with a complementary neuroprotective agent, constitute a promising alternative. In this sense, the present review summarizes the underlying mechanisms of hypoxic-ischemic brain injury and compiles several neuroprotective strategies, including Selective Estrogen Receptor Modulators and Selective Tissue Estrogenic Activity Regulators, which represent putative agents for combined therapies with therapeutic hypothermia.

A fibrinous and allogeneic fibroblast-enriched membrane as a biocompatible material can improve diabetic wound healing

The novel fibroblast-loaded fibrin membrane was prepared to promote diabetic wound healing.

Nucleic acids and analogs for bone regeneration

With the incidence of different bone diseases increasing, effective therapies are needed that coordinate a combination of various technologies and biological materials. Bone tissue engineering has also been considered as a promising strategy to repair various bone defects. Therefore, different biological materials that can promote stem cell proliferation, migration, and osteoblastic differentiation to accelerate bone tissue regeneration and repair have also become the focus of research in multiple fields. Stem cell therapy, biomaterial scaffolds, and biological growth factors have shown potential for bone tissue engineering; however, off-target effects and cytotoxicity have limited their clinical use. The application of nucleic acids (deoxyribonucleic acid or ribonucleic acid) and nucleic acid analogs (peptide nucleic acids or locked nucleic acids), which are designed based on foreign genes or with special structures, can be taken up by target cells to exert different effects such as modulating protein expression, replacing a missing gene, or targeting specific gens or proteins. Due to some drawbacks, nucleic acids and nucleic acid analogs are combined with various delivery systems to exert enhanced effects, but current studies of these molecules have not yet satisfied clinical requirements. In-depth studies of nucleic acid or nucleic acid analog delivery systems have been performed, with a particular focus on bone tissue regeneration and repair. In this review, we mainly introduce delivery systems for nucleic acids and nucleic acid analogs and their applications in bone repair and regeneration. At the same time, the application of conventional scaffold materials for the delivery of nucleic acids and nucleic acid analogs is also discussed.

Used with an appropriate delivery system, nucleic acids and nucleic acid analogs have excellent potential for bone repair and regeneration. Owing to various challenges with bone tissue regeneration, current research is largely focused on gene therapy, which employs genes to treat or prevent disease, and such new materials as nucleic acids (DNA and RNA) and nucleic acid analogs (compounds structurally similar to naturally occurring nucleic acids). A team headed by Yunfeng Lin at Sichuan University, China conducted a review of delivery systems for nucleic acids and nucleic acid analogs and their application in bone repair and regeneration. The authors identified the use of biomaterial scaffolds (which mimic living tissue) as one of the most important research areas for gene therapy, and that strategy has proven effective with all types of bone regeneration and repair.

Effect of saxagliptin on the expression of HIF-1α in the liver of diabetic rats with fatty liver

The present study was designed to establish a rat model of type 2 diabetes mellitus (T2DM) complicated with fatty liver and to detect the expression of hypoxia-inducible factor-1α (HIF-1α) in liver tissue during the treatment with saxagliptin. Eighty male Wistar rats were randomly divided into two groups. One group was fed with high fat diet to establish T2DM model (n=40), and the other group was fed normally to serve as the control group (n=40). Successfully established rat T2DM models were randomly divided into two groups: The treatment group that received intraperitoneal injection of saxagliptin solution and the other the model group with normal breeding. Blood glucose, blood lipid, liver function and the expression of HIF-1α in liver tissue were detected. Levels of blood glucose in model treatment group were significantly higher than those in the control group (p<0.05). Levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT) in model and treatment group were significantly higher than those in control group (p<0.05), but were significantly reduced with the prolonged treatment (p<0.05). Levels of TC, TG, LDL-C, HDL-C, AST, ALT and GGT and expression level of HIF-1α were significantly higher in the model group than in control group before 3 weeks of treatment (p<0.05), but no significant differences were found after 3 weeks of treatment (p>0.05). Expression level of HIF-1α was decreased with the prolonged treatment, and no significant difference in expression level of HIF-1α was found 3 weeks after treatment (p>0.05). In conclusion, HIF-1α is highly expressed in rats with T2DM and fatty liver. Saxagliptin can effectively improve blood glucose, blood lipid and liver function and reduce the protein expression of HIF-1α in diabetic rats with fatty liver.

Conditioned Medium from Human Umbilical Vein Endothelial Cells Promotes Proliferation, Migration, Invasion and Angiogenesis of Adipose Derived Stem Cells

Preeclampsia (PE) is a pregnancy-specific hypertensive complication, closely related to endothelial dysfunction. Adipose derived stem cells (ADSCs) have the capacity to differentiate into endothelial cells for vascular repair. Therefore, we hypothesized that induced endothelial differentiation of ADSCs might hold great potential for the treatment of PE. In this study, the primary ADSCs and human umbilical vein endothelial cells (HUVECs) were isolated by the collagenase digestion method. The supernatant of HUVECs was collected from the first generation of cells. Then, ADSCs were divided into two groups: ADSCs alone group and induced ADSCs (iADSCs) group. In iADSCs group, ADSCs were induced by HUVECs conditioned medium and ADSCs special culture medium at a ratio of 1:1 over a two-week period. In order to identify the endothelial characteristics of iADSCs, CD31 and CD34 were examined by flow cytometry. The proliferation, migration, invasion and angiogenesis assays were employed to compare the bioactivity of iADSCs and ADSCs. Furthermore, The levels of angiogenic related factors including vascular endothelial growth factor (VEGF) and placenta growth factor (P1GF) were detected by RT-PCR and Western blotting. Results showed conditioned medium from HUVECs promoted ADSCs proliferation, migration, invasion and angiogenesis. In addition, the levels of VEGF and P1GF were significantly enhanced in iADSCs group. This study uncovered the iADSCs application potential in the therapy and intervention of PE.

Concise Review: Optimized Strategies for Stem Cell-Based Therapy in Myocardial Repair: Clinical Translatability and Potential Limitation

Ischemic heart diseases (IHDs) remain major public health problems with high rates of morbidity and mortality worldwide. Despite significant advances, current therapeutic approaches are unable to rescue the extensive and irreversible loss of cardiomyocytes caused by severe ischemia. Over the past 16 years, stem cell-based therapy has been recognized as an innovative strategy for cardiac repair/regeneration and functional recovery after IHDs. Although substantial preclinical animal studies using a variety of stem/progenitor cells have shown promising results, there is a tremendous degree of skepticism in the clinical community as many stem cell trials do not confer any beneficial effects. How to accelerate stem cell-based therapy toward successful clinical application attracts considerate attention. However, many important issues need to be fully addressed. In this Review, we have described and compared the effects of different types of stem cells with their dose, delivery routes, and timing that have been routinely tested in recent preclinical and clinical findings. We have also discussed the potential mechanisms of action of stem cells, and explored the role and underlying regulatory components of stem cell-derived secretomes/exosomes in myocardial repair. Furthermore, we have critically reviewed the different strategies for optimizing both donor stem cells and the target cardiac microenvironments to enhance the engraftment and efficacy of stem cells, highlighting their clinical translatability and potential limitation. Stem Cells 2018;36:482-500.

Ternary complex of plasmid DNA with NLS-Mu-Mu protein and cationic niosome for biocompatible and efficient gene delivery: a comparative study with protamine and lipofectamine

Non-viral gene delivery methods are considered due to safety and simplicity in human gene therapy. Since the use of cationic peptide and niosome represent a promising approach for gene delivery purposes we used recombinant fusion protein and cationic niosome as a gene carrier. A multi-domain fusion protein including nuclear localization motif (NLS) and two DNA-binding (Mu) domains, namely NLS-Mu-Mu (NMM) has been designed, cloned and expressed in E. coli DE3 strain. Afterward, the interested protein was purified by affinity chromatography. Binary vectors based on protein/DNA and ternary vectors based on protein/DNA/niosome were prepared. Protamine was used as a control. DNA condensing properties of NMM and protamine were evaluated by various experiments. Furthermore, we examined cytotoxicity, hemolysis and transfection potential of the binary and ternary complexes in HEK293T and MCF-7 cell lines. Protamine and Lipofectamine™2000 were used as positive controls, correspondingly. The recombinant NMM was expressed and purified successfully and DNA was condensed efficiently at charge ratios that were not harmful to cells. Peptidoplexes showed transfection efficiency (TE) but ternary complexes had higher TE. Additionally, NMM ternary complex was more efficient compared to protamine ternary vectors. Our results showed that niosomal ternary vector of NMM is a promising non-viral gene carrier to achieve an effective and safe carrier system for gene therapy.

Cytoprotective effects of endothelin-1 on mesenchymal stem cells: an in vitro study

Stem cell-based therapies is a promising approach for regenerative therapy in various diseases. Some obstacles remain to be solved before clinical application of the cell therapy is realized, including increasing the survival of transplanted stem cells, reducing loss of transplanted cells, and maintaining adequate vascular supply. Recently, stem cell preconditioning with chemical and pharmacological agents has been shown to increase therapeutic efficacy. The present study investigated the effect of endothelin-1 (ET-1) on survival, angiogenesis, and migration of mesenchymal stem cells (MSCs), in vitro. MSCs were treated with various concentrations of ET-1 and the expression of cyclooxygenase-2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), C-C chemokine receptor type 2 (CCR2), vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2), angiopoietin-4 (Ang-4) and matrix metalloproteinase-2 (MMP-2) were examined. Caspase 3 activity and prostaglandin E2 (PGE2) were determined by ELISA assay. MSCs migration and tube formation potential were assessed using scratch test and three dimensional vessel formation assay. ET-1 enhanced the MSCs viability. In ET-1- treated MSCs, expression of COX-2, HIF-1, CXCR4, CCR2, VEGF, Ang-2, Ang-4 and MMP-2 were increased compared to control groups. Elevation of all these genes were reversed by celecoxib (50 μmol/L), a selective COX-2 inhibitor. PGE2 generation, MSCs migration and tube formation were enhanced by ET-1 conditioning, whereas caspase-3 activity was reduced in these cells, compared to the control group. The results presented here reveal that preconditioning of MSCs with ET-1 has strong cytoprotective effects through activation of survival signalling molecules and trophic factors.

Synergistic effect of human Bone Morphogenic Protein-2 and Mesenchymal Stromal Cells on chronic wounds through hypoxia-inducible factor-1 α induction

Chronic skin ulcers and burns require advanced treatments. Mesenchymal Stromal Cells (MSCs) are effective in treating these pathologies. Bone Morphogenic Protein-2 (BMP-2) is known to enhance angiogenesis. We investigated whether recombinant human hBMP-2 potentiates the effect of MSCs on wound healing. Severe ulceration was induced in rats by irradiation and treated by co-infusion of MSCs with hBMP-2 into the ulcerated area which accelerated wound healing. Potentiation of the effect of MSCs by hBMP-2 on endothelial repair improved skin healing. HBMP-2 and MSCs synergistically, in a supra additive or enhanced manner, renewed tissue structures, resulting in normalization of the epidermis, hair follicles, sebaceous glands, collagen fibre density, and blood vessels. Co-localization of MSCs with CD31 + cells suggests recruitment of endothelial cells at the site of injection. HBMP-2 and MSCs enhanced angiogenesis and induced micro-vessel formation in the dermis where hair follicles were regenerated. HBMP-2 acts by causing hypoxia-inducible factor-1 α (HIF-1α) expression which impacts endothelial tube formation and skin repair. This effect is abolished by siRNA. These results propose that new strategies adding cytokines to MSCs should be evaluated for treating radiation-induced dermatitis, burns, and chronic ulcers in humans.

Effect of tetrahedral DNA nanostructures on osteogenic differentiation of mesenchymal stem cells via activation of the Wnt/β-catenin signaling pathway

Adipose-derived stem cells (ADSCs) are considered to be ideal stem cell sources for bone regeneration owing to their ability to differentiate into osteo-like cells. Therefore, they have attracted increasing attention in recent years. Tetrahedral DNA nanostructures (TDNs), a new type of DNA-based biomaterials, have shown great potential for biomedical applications. In the present work, we aimed to investigate the role played by TDNs in osteogenic differentiation and proliferation of ADSCs and tried to explore if the canonical Wnt signal pathway could be the vital biological mechanism driving these cellular responses. Upon exposure to TDNs, ADSCs proliferation and osteogenic differentiation were significantly enhanced, accompanied by the up-regulation of genes correlated with the Wnt/β-catenin pathway. In conclusion, our results indicate that TDNs are crucial regulators of the increase in osteogenic potential and ADSCs proliferation, and this noteworthy discovery could provide a promising novel approach toward ADSCs-based bone defect regeneration.

New insights into the ameliorative effects of ferulic acid in pathophysiological conditions

Ferulic acid, a natural phytochemical has gained importance as a potential therapeutic agent by virtue of its easy commercial availability, low cost and minimal side-effects. It is a derivative of curcumin and possesses the necessary pharmacokinetic properties to be retained in the general circulation for several hours. The therapeutic effects of ferulic acid are mediated through its antioxidant and anti-inflammatory properties. It exhibits different biological activities such as anti-inflammatory, anti-apoptotic, anti-carcinogenic, anti-diabetic, hepatoprotective, cardioprotective, neuroprotective actions, etc. The current review addresses its therapeutic effects under different pathophysiological conditions (eg. cancer, cardiomyopathy, skin disorders, brain disorders, viral infections, diabetes etc.).

All-trans retinoic acid preconditioning enhances proliferation, angiogenesis and migration of mesenchymal stem cell in vitro and enhances wound repair in vivo

OBJECTIVES

Stem cell therapy is considered to be a suitable alternative in treatment of a number of diseases. However, there are challenges in their clinical application in cell therapy, such as to reduce survival and loss of transplanted stem cells. It seems that chemical and pharmacological preconditioning enhances their therapeutic efficacy. In this study, we investigated effects of all-trans retinoic acid (ATRA) on survival, angiogenesis and migration of mesenchymal stem cells (MSCs) in vitro and in a wound-healing model.

MATERIALS AND METHODS

MSCs were treated with a variety of concentrations of ATRA, and mRNA expression of cyclo-oxygenase-2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), C-C chemokine receptor type 2 (CCR2), vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) and Ang-4 were examined by qRT-PCR. Prostaglandin E2 (PGE2) levels were measured using an ELISA kit and MSC angiogenic potential was evaluated using three-dimensional tube formation assay. Finally, benefit of ATRA-treated MSCs in wound healing was determined with a rat excisional wound model.

RESULTS

In ATRA-treated MSCs, expressions of COX-2, HIF-1, CXCR4, CCR2, VEGF, Ang-2 and Ang-4 increased compared to control groups. Overexpression of the related genes was reversed by celecoxib, a selective COX-2 inhibitor. Tube formation and in vivo wound healing of ATRA-treated MSCs were also significantly enhanced compared to untreated MSCs.

CONCLUSION

Pre-conditioning of MSCs with ATRA increased efficacy of cell therapy by activation of survival signalling pathways, trophic factors and release of pro-angiogenic molecules.

Changes in physical and chemical properties of niosome membrane induced by cholesterol: a promising approach for niosome bilayer intervention

Recently, the self-assembly property of nonionic surfactants has been utilized to create vesicles as alternatives to liposomes.

Notch Signaling Pathway Regulates Angiogenesis via Endothelial Cell in 3D Co-Culture Model

This study aimed to investigate the role of Notch signaling pathway for angiogenesis in a three-dimensional (3D) collagen gel model with co-culture of adipose-derived stromal cells (ASCs) and endothelial cells (ECs). A 3D collagen gel model was established in vitro by implanting both ASCs from green fluorescent protein-labeled mouse and ECs from red fluorescent protein-labeled mouse, and the phenomena of angiogenesis with Notch signaling inducer Jagged1, inhibitor DAPT and PBS, respectively were observed by confocal laser scanning microscopy. Semi-quantitative PCR and immunofluorescent staining were conducted to detect expressions of angiogenesis-related genes and proteins. Angiogenesis in the co-culture gels was promoted by Jagged1 treatment while attenuated by DAPT treatment, compared to control group. In co-culture system of ASCs and ECs, the gene expressions of VEGFA, VEGFB, Notch1, Notch2, Hes1, Hey1, VEGFR1,and the protein expression of VEGFA, VEGFB, Notch1, Hes1, Hey1 were increased by Jagged1 treatment and decreased by DAPT treatment in ECs. And the result of VEGFR3 was the opposite. However, the same results did not appear completely in ASCs. These results revealed the VEGFA/B-Notch1/2-Hes1/Hey1- VEGFR1/3 signal axis played an important role in angiogenesis when ASCs and ECs were co-cultured in a 3D collagen gel model. J. Cell. Physiol. 232: 1548-1558, 2017. © 2016 Wiley Periodicals, Inc.