Curcumin-induced heme oxygenase-1 expression prevents H2O2-induced cell death in wild type and heme oxygenase-2 knockout adipose-derived mesenchymal stem cells

Iron-Related Genes and Proteins in Mesenchymal Stem Cell Detection and Therapy

Mesenchymal stem cells (MSCs) are located in various tissues of the body. These cells exhibit regenerative and reparative properties, which makes them highly valuable for cell-based therapy. Despite this, majority of MSC-related studies remain to be translated for regular clinical use. This is partly because there are methodical challenges in pre-administration MSC labelling, post-administration detection and tracking of cells, and in retention of maximal therapeutic potential in-vivo. This calls for exploration of alternative or adjunctive approaches that would enable better detection of transplanted MSCs via non-invasive methods and enhance MSC therapeutic potential in-vivo. Interestingly, these attributes have been demonstrated by some iron-related genes and proteins.Accordingly, this unique forward-looking article integrates the apparently distinct fields of iron metabolism and MSC biology, and reviews the utility of iron-related genes and iron-related proteins in facilitating MSC detection and therapy, respectively. Effects of genetic overexpression of the iron-related proteins ferritin, transferrin receptor-1 and MagA in MSCs and their utilisation as reporter genes for improving MSC detection in-vivo are critically evaluated. In addition, the beneficial effects of the iron chelator deferoxamine and the iron-related proteins haem oxygenase-1, lipocalin-2, lactoferrin, bone morphogenetic protein-2 and hepcidin in enhancing MSC therapeutics are highlighted with the consequent intracellular alterations in MSCs. This review aims to inform both regenerative and translational medicine. It can aid in formulating better methodical approaches that will improve, complement, or provide alternatives to the current pre-transplantation MSC labelling procedures, and enhance MSC detection or augment the post-transplantation MSC therapeutic potential.

Curcumin preconditioned mesenchymal stem cells derived exosomes transplantation ameliorate and protect against non- alcoholic steatohepatitis by regulation the expression of key genes of inflammation and oxidative stress

BACKGROUND

Mesenchymal stem cells (MSCs) derived exosomes (MSCs/Exo) is considered a new strategy in cell free regenerative therapy. Curcumin preconditioning of MSCs reported to improve the anti- inflammatory and immunomodulatory properties of MSCs. We investigated the efficacy of exosome (Exo) obtained from curcumin-preconditioned MSCs (MSCs/Exo-Cur) vs. MSC/Exo without curcumin to ameliorate and prevent recurrence of non-alcoholic fatty liver (NASH) disease.

METHODS AND RESULTS

In-vivo, methionine/choline-deficient diet (MCD) induced mice non-alcoholic fatty liver disease (NASH) were injected with MSCs/Exo without curcumin or MSCs/Exo-Cur with curcumin. We found that mice treated with MSCs/Exo-Cur had significantly ameliorated steatosis, inflammation, as evaluated by the reduced fibrosis in histopathological examination, decreased the serum level of liver enzymes (p < 0.001), liver triglycerides (TG) (p < 0.001) and cholesterol (Ch) (p < 0.001) and increased the lipid peroxidation (p < 0.001) compared to MSCs/Exo-treated mice. These effects remained for 3 months after treatment in MSCs/Exo-Cur-treated mice while features of NASH returned in MSCs/Exo-treated group. In vitro, HepG2 cells were cultured with palmitic acid (PA) and treated with MSCs/Exo or MSCs/Exo-Cur: the MSCs/Exo-Cur exposure reversed the lipotoxic effect from 4.5 to 1.7 fold vs 4.0 fold in MSCs/Exo and oxidative stress in PA-treated HepG2 cells (p < 0.001). We found that MSCs/Exo-Cur regulated the key markers of inflammatory and oxidative stress, genes responsible for fibrogenesis of the liver, key genes of lipid synthesis and transport . Interestingly, MSCs/Exo-Cur significantly down regulated the ASK-JNK-BAX genes involved in mitochondrial stress and apoptosis compared to MSCs/Exo (p < 0.001).

CONCLUSION

Our study indicated that exosomes derived from curcumin preconditioned MSCs were able to ameliorate and protect against recurrence of NASH and regulated inflammatory, oxidative stress and mitochondrial-dependent apoptosis ASK-JNK-BAX genes.

Role of curcumin and its nanoformulations in the treatment of neurological diseases through the effects on stem cells

Curcumin from turmeric is a natural phenolic compound with a promising potential to regulate fundamental processes involved in neurological diseases, including inflammation, oxidative stress, protein aggregation, and apoptosis at the molecular level. In this regard, employing nanoformulation can improve curcumin efficiency by reducing its limitations, such as low bioavailability. Besides curcumin, growing data suggest that stem cells are a noteworthy candidate for neurodegenerative disorders therapy due to their anti-inflammatory, anti-oxidative, and neuronal-differentiation properties, which result in neuroprotection. Curcumin and stem cells have similar neurogenic features and can be co-administered in a cell-drug delivery system to achieve better combination therapeutic outcomes for neurological diseases. Based on the evidence, curcumin can induce the neuroprotective activity of stem cells by modulating their related signalling pathways. The present review is about the role of curcumin and its nanoformulations in the improvement of neurological diseases alone and through the effect on different categories of stem cells by discussing the underlying mechanisms to provide a roadmap for future investigations.

The dual role of heme oxygenase in regulating apoptosis in the nervous system of Drosophila melanogaster

Accumulating evidence from mammalian studies suggests the dual-faced character of heme oxygenase (HO) in oxidative stress-dependent neurodegeneration. The present study aimed to investigate both neuroprotective and neurotoxic effects of heme oxygenase after the ho gene chronic overexpression or silencing in neurons of Drosophila melanogaster. Our results showed early deaths and behavioral defects after pan-neuronal ho overexpression, while survival and climbing in a strain with pan-neuronal ho silencing were similar over time with its parental controls. We also found that HO can be pro-apoptotic or anti-apoptotic under different conditions. In young (7-day-old) flies, both the cell death activator gene (hid) expression and the initiator caspase Dronc activity increased in heads of flies when ho expression was changed. In addition, various expression levels of ho produced cell-specific degeneration. Dopaminergic (DA) neurons and retina photoreceptors are particularly vulnerable to changes in ho expression. In older (30-day-old) flies, we did not detect any further increase in hid expression or enhanced degeneration, however, we still observed high activity of the initiator caspase. In addition, we used curcumin to further show the involvement of neuronal HO in the regulation of apoptosis. Under normal conditions, curcumin induced both the expression of ho and hid, which was reversed after exposure to high-temperature stress and when supplemented in flies with ho silencing. These results indicate that neuronal HO regulates apoptosis and this process depends on ho expression level, age of flies, and cell type.

Cartilaginous Metabolomics Reveals the Biochemical-Niche Fate Control of Bone Marrow-Derived Stem Cells

Joint disorders have become a global health issue with the growth of the aging population. Screening small active molecules targeting chondrogenic differentiation of bone marrow-derived stem cells (BMSCs) is of urgency. In this study, microfracture was employed to create a regenerative niche in rabbits (n = 9). Cartilage samples were collected four weeks post-surgery. Microfracture-caused morphological (n = 3) and metabolic (n = 6) changes were detected. Non-targeted metabolomic analysis revealed that there were 96 differentially expressed metabolites (DEMs) enriched in 70 pathways involved in anti-inflammation, lipid metabolism, signaling transduction, etc. Among the metabolites, docosapentaenoic acid 22n-3 (DPA) and ursodeoxycholic acid (UDCA) functionally facilitated cartilage defect healing, i.e., increasing the vitality and adaptation of the BMSCs, chondrogenic differentiation, and chondrocyte functionality. Our findings firstly reveal the differences in metabolomic activities between the normal and regenerated cartilages and provide a list of endogenous biomolecules potentially involved in the biochemical-niche fate control for chondrogenic differentiation of BMSCs. Ultimately, the biomolecules may serve as anti-aging supplements for chondrocyte renewal or as drug candidates for cartilage regenerative medicine.

Potential pre-activation strategies for improving therapeutic efficacy of mesenchymal stem cells: current status and future prospects

Mesenchymal stem cell (MSC)-based therapy has been considered as a promising approach targeting a variety of intractable diseases due to remarkable multiple effect of MSCs, such as multilineage differentiation, immunomodulatory property, and pro-regenerative capacity. However, poor engraftment, low survival rate of transplanted MSC, and impaired donor-MSC potency under host age/disease result in unsatisfactory therapeutic outcomes. Enhancement strategies, including genetic manipulation, pre-activation, and modification of culture method, have been investigated to generate highly functional MSC, and approaches for MSC pre-activation are highlighted. In this review, we summarized the current approaches of MSC pre-activation and further classified, analysed the scientific principles and main characteristics of these manipulations, and described the pros and cons of individual pre-activation strategies. We also discuss the specialized tactics to solve the challenges in this promising field so that it improves MSC therapeutic functions to serve patients better.

HO-1 in Bone Biology: Potential Therapeutic Strategies for Osteoporosis

Osteoporosis is a prevalent bone disorder characterized by bone mass reduction and deterioration of bone microarchitecture leading to bone fragility and fracture risk. In recent decades, knowledge regarding the etiological mechanisms emphasizes that inflammation, oxidative stress and senescence of bone cells contribute to the development of osteoporosis. Studies have demonstrated that heme oxygenase 1 (HO-1), an inducible enzyme catalyzing heme degradation, exhibits anti-inflammatory, anti-oxidative stress and anti-apoptosis properties. Emerging evidence has revealed that HO-1 is critical in the maintenance of bone homeostasis, making HO-1 a potential target for osteoporosis treatment. In this Review, we aim to provide an introduction to current knowledge of HO-1 biology and its regulation, focusing specifically on its roles in bone homeostasis and osteoporosis. We also examine the potential of HO-1-based pharmacological therapeutics for osteoporosis and issues faced during clinical translation.

Regulation of Heme Oxygenase and Its Cross-Talks with Apoptosis and Autophagy under Different Conditions in Drosophila

Heme oxygenase (HO) is one of the cytoprotective enzymes that can mitigate the effects of oxidative stress. Here, we found that the ho mRNA level oscillates in the brain of Drosophila melanogaster with two minima at the beginning of the day and night. This rhythm was partly masked by light as its pattern changed in constant darkness (DD). It followed a similar trend in the clock mutant per⁰¹ under light/dark regime (LD12:12); however, differences between time points were not statistically significant. In older flies (20 days old), the rhythm was vanished; however, 15 days of curcumin feeding restored this rhythm with an elevated ho mRNA level at all time points studied. In addition, flies exposed to paraquat had higher ho expression in the brain, but only at a specific time of the day which can be a protective response of the brain against stress. These findings suggest that the expression of ho in the fly’s brain is regulated by the circadian clock, light, age, exposure to stress, and the presence of exogenous antioxidants. We also found that HO cross-talks with apoptosis and autophagy under different conditions. Induction of neuronal ho was accompanied by increased transcription of apoptosis and autophagy-related genes. However, this trend changed after exposure to curcumin and paraquat. Our results suggest that HO is involved in the control of apoptotic and autophagic key processes protecting the brain against oxidative damage.

Curcumin preconditioning enhances the efficacy of adipose-derived mesenchymal stem cells to accelerate healing of burn wounds

Background

Following recent findings from our group that curcumin preconditioning augments the therapeutic efficacy of adipose-derived stem cells in the healing of diabetic wounds in rats, we aimed to investigate the regenerative effects of curcumin preconditioned adipose-derived mesenchymal stem cells (ASCs) for better recovery of acid inflicted burns in this study.

Methods

ASCs were preconditioned with 5 μM curcumin for 24 hours and assessed for proliferation, migration, paracrine release potential and gene expression comparative to naïve ASCs. Subsequently, the healing capacity of curcumin preconditioned ASCs (Cur-ASCs) versus naïve ASCs was examined using acidic wounds in rats. For this, acid inflicted burns of 20 mm in diameter were made on the back of male Wistar rats. Then, 2 × 10⁶ cells of Cur-ASCs and naïve ASCs were intradermally injected in the wound periphery (n = 6) for comparison with an untreated saline control. Post-transplantation, wounds were macroscopically analysed and photographed to evaluate the percentage of wound closure and period of re-epithelization. Healed wound biopsies were excised and used for histological evaluation and expression analysis of wound healing markers at molecular level by quantitative PCR and western blotting.

Results

We found that Cur-ASCs exhibited greater proliferation, migration and paracrine potential in vitro. Further, Cur-ASCs showed more effective recovery than naïve ASCs as exhibited by gross morphology, faster wound closure and earlier re-epithelialization. Masson’s trichrome and hematoxylin and eosin staining demonstrated the improved architecture of the healing burns, as evidenced by reduced infiltration of inflammatory cells, compact collagen and marked granulation in Cur-ASC treated rats. Corroborating these findings, molecular assessment showed significantly reduced expressions of pro-inflammatory factors (interleukin-1 beta, interleukin-6, tumor necrosis factor alpha) a with striking upsurge of an oxidative marker (superoxide dismutase 1), pro-angiogenic factors (vascular endothelial growth factor, hepatocyte growth factor, hypoxia-inducible factor-1 alpha) and collagen markers (transforming growth factor beta 1, fibroblast growth factor-2, collagen type 1 alpha 1), verifying that Cur-ASCs modulate the regulation of pro-inflammatory and healing markers at burn sites.

Conclusions

Treatment with Cur-ASCs resulted in faster re-epithelization of acid inflicted burns compared to the treatment with naïve ASCs. Based on observed findings, we suggest the transplantation of Cur-ASCs is a valuable therapy for the potent clinical management of acidic burns.

Curcumin Mitigates AFB1-Induced Hepatic Toxicity by Triggering Cattle Antioxidant and Anti-inflammatory Pathways: A Whole Transcriptomic In Vitro Study

Aflatoxin B1 (AFB1) toxicity in livestock and human beings is a major economic and health concern. Natural polyphenolic substances with antioxidant properties have proven to be effective in ameliorating AFB1-induced toxicity. Here we assessed the potential anti-AFB1 activity of curcumin (pure curcumin, C, and curcumin from Curcuma longa, CL) in a bovine fetal hepatocyte-derived cell line (BFH12). First, we measured viability of cells exposed to AFB1 in presence or absence of curcumin treatment. Then, we explored all the transcriptional changes occurring in AFB1-exposed cells cotreated with curcumin. Results demonstrated that curcumin is effective in reducing AFB1-induced toxicity, decreasing cells mortality by approximately 30%. C and CL induced similar transcriptional changes in BFH12 exposed to AFB1, yet C treatment resulted in a larger number of significant genes compared to CL. The mitigating effects of curcuminoids towards AFB1 toxicity were mainly related to molecular pathways associated with antioxidant and anti-inflammatory response, cancer, and drug metabolism. Investigating mRNA changes induced by curcumin in cattle BFH12 cells exposed to AFB1 will help us to better characterize possible tools to reduce its consequences in this susceptible and economically important food-producing species.

Cannabinoid-Induced Autophagy and Heme Oxygenase-1 Determine the Fate of Adipose Tissue-Derived Mesenchymal Stem Cells under Stressful Conditions

The administration of adipose tissue-derived mesenchymal stem cells (ADMSCs) represents a promising therapeutic option after myocardial ischemia or myocardial infarction. However, their potential is reduced due to the high post-transplant cell mortality probably caused by oxidative stress and mitogen-deficient microenvironments. To identify protection strategies for ADMSCs, this study investigated the influence of the non-psychoactive phytocannabinoid cannabidiol (CBD) and the endocannabinoid analogue R(+)-methanandamide (MA) on the induction of heme oxygenase-1 (HO-1) and autophagy under serum-free conditions. At a concentration of 3 µM, CBD induced an upregulation of HO-1 mRNA and protein within 6 h, whereas for MA only a late and comparatively lower increase in the HO-1 protein could be detected after 48 h. In addition, both cannabinoids induced time- and concentration-dependent increases in LC3A/B-II protein, a marker of autophagy, and in metabolic activity. A participation of several cannabinoid-binding receptors in the effect on metabolic activity and HO-1 was excluded. Similarly, knockdown of HO-1 by siRNA or inhibition of HO-1 activity by tin protoporphyrin IX (SnPPIX) had no effect on CBD-induced autophagy and metabolic activity. On the other hand, the inhibition of autophagy by bafilomycin A₁ led to a significant decrease in cannabinoid-induced metabolic activity and to an increase in apoptosis. Under these circumstances, a significant induction of HO-1 expression after 24 h could also be demonstrated for MA. Remarkably, inhibition of HO-1 by SnPPIX under conditions of autophagy deficit led to a significant reversal of apoptosis in cannabinoid-treated cells. In conclusion, the investigated cannabinoids increase metabolic viability of ADMSCs under serum-free conditions by inducing HO-1-independent autophagy but contribute to apoptosis under conditions of additional autophagy deficit via an HO-1-dependent pathway.

CXCL12-CXCR4 Interplay Facilitates Palatal Osteogenesis in Mice

Cranial neural crest cells (CNCCs), identified by expression of transcription factor Sox9, migrate to the first branchial arch and undergo proliferation and differentiation to form the cartilage and bone structures of the orofacial region, including the palatal bone. Sox9 promotes osteogenic differentiation and stimulates CXCL12-CXCR4 chemokine-receptor signaling, which elevates alkaline phosphatase (ALP)-activity in osteoblasts to initiate bone mineralization. Disintegration of the midline epithelial seam (MES) is crucial for palatal fusion. Since we earlier demonstrated chemokine-receptor mediated signaling by the MES, we hypothesized that chemokine CXCL12 is expressed by the disintegrating MES to promote the formation of an osteogenic center by CXCR4-positive osteoblasts. Disturbed migration of CNCCs by excess oxidative and inflammatory stress is associated with increased risk of cleft lip and palate (CLP). The cytoprotective heme oxygenase (HO) enzymes are powerful guardians harnessing injurious oxidative and inflammatory stressors and enhances osteogenic ALP-activity. By contrast, abrogation of HO-1 or HO-2 expression promotes pregnancy pathologies. We postulate that Sox9, CXCR4, and HO-1 are expressed in the ALP-activity positive osteogenic regions within the CNCCs-derived palatal mesenchyme. To investigate these hypotheses, we studied expression of Sox9, CXCL12, CXCR4, and HO-1 in relation to palatal osteogenesis between E15 and E16 using (immuno)histochemical staining of coronal palatal sections in wild-type (wt) mice. In addition, the effects of abrogated HO-2 expression in HO-2 KO mice and inhibited HO-1 and HO-2 activity by administrating HO-enzyme activity inhibitor SnMP at E11 in wt mice were investigated at E15 or E16 following palatal fusion. Overexpression of Sox9, CXCL12, CXCR4, and HO-1 was detected in the ALP-activity positive osteogenic regions within the palatal mesenchyme. Overexpression of Sox9 and CXCL12 by the disintegrating MES was detected. Neither palatal fusion nor MES disintegration seemed affected by either HO-2 abrogation or inhibition of HO-activity. Sox9 progenitors seem important to maintain the CXCR4-positive osteoblast pool to drive osteogenesis. Sox9 expression may facilitate MES disintegration and palatal fusion by promoting epithelial-to-mesenchymal transformation (EMT). CXCL12 expression by the MES and the palatal mesenchyme may promote osteogenic differentiation to create osteogenic centers. This study provides novel evidence that CXCL12-CXCR4 interplay facilitates palatal osteogenesis and palatal fusion in mice.

Cytoprotective effects of antioxidant supplementation on mesenchymal stem cell therapy

Mesenchymal stem cells (MSCs) are earmarked as perfect candidates for cell therapy and tissue engineering due to their capacity to differentiate into different cell types. However, their potential for application in regenerative medicine declines when the levels of the reactive oxygen and nitrogen species (RONS) increase from the physiological levels, a phenomenon which is at least inevitable in ex vivo cultures and air-exposed damaged tissues. Increased levels of RONS can alter the patterns of osteogenic and adipogenic differentiation and inhibit proliferation, as well. Besides, oxidative stress enhances senescence and cell death, thus lowering the success rates of the MSC engraftment. Hence, in this review, we have selected some representatives of antioxidants and newly emerged nano antioxidants in three main categories, including chemical compounds, biometabolites, and protein precursors/proteins, which are proved to be effective in the treatment of MSCs. We will focus on how antioxidants can be applied to optimize the clinical usage of the MSCs and their associated signaling pathways. We have also reviewed several paralleled properties of some antioxidants and nano antioxidants which can be simultaneously used in real-time imaging, scaffolding techniques, and other applications in addition to their primary antioxidative function.

[Research progress in mesenchymal stem cells modified by Heme oxygenase 1]

Objective

To review the literature reports on research progress of Heme oxygenase 1 (HO-1) modified mesenchymal stem cells (MSCs).

Methods

The significance, effects, and related mechanism of HO-1 modification of MSCs were summarized by consulting the related literatures and reports of HO-1 modification of MSCs.

Results

HO-1 modification of MSCs has important research value. It can effectively enhance the anti-oxidative stress and anti-apoptotic properties of MSCs in complex internal environment after transplantation into vivo. It can also effectively enhance the immune regulation function of MSCs. It can improve the anti-injury, repair, and immune regulation effect of MSCs in various disease models and research fields.

Conclusion

The basic research of HO-1 modified MSCs has made remarkable progress, which is expected to be applied in clinical trials and provide theoretical basis and reference value for stem cell therapy.

Tissue engineering strategies combining molecular targets against inflammation and fibrosis, and umbilical cord blood stem cells to improve hampered muscle and skin regeneration following cleft repair

Cleft lip with or without cleft palate is a congenital deformity that occurs in about 1 of 700 newborns, affecting the dentition, bone, skin, muscles and mucosa in the orofacial region. A cleft can give rise to problems with maxillofacial growth, dental development, speech, and eating, and can also cause hearing impairment. Surgical repair of the lip may lead to impaired regeneration of muscle and skin, fibrosis, and scar formation. This may result in hampered facial growth and dental development affecting oral function and lip and nose esthetics. Therefore, secondary surgery to correct the scar is often indicated. We will discuss the molecular and cellular pathways involved in facial and lip myogenesis, muscle anatomy in the normal and cleft lip, and complications following surgery. The aim of this review is to outline a novel molecular and cellular strategy to improve musculature and skin regeneration and to reduce scar formation following cleft repair. Orofacial clefting can be diagnosed in the fetus through prenatal ultrasound screening and allows planning for the harvesting of umbilical cord blood stem cells upon birth. Tissue engineering techniques using these cord blood stem cells and molecular targeting of inflammation and fibrosis during surgery may promote tissue regeneration. We expect that this novel strategy improves both muscle and skin regeneration, resulting in better function and esthetics after cleft repair.

Fluorescence properties of curcumin-loaded nanoparticles for cell tracking

BACKGROUND

Posttransplant cell tracking, via stem cell labeling, is a crucial strategy for monitoring and maximizing benefits of cell-based therapies. The structures and functionalities of polysaccharides, proteins, and lipids allow their utilization in nanotechnology systems.

MATERIALS AND METHODS

In the present study, we analyzed the potential benefit of curcumin-loaded nanoparticles (NPC) using Vero cells (in vitro) and NPC-labeled adipose-derived mesenchymal stem cells (NPC-ADMSCs) (in vivo) in myocardial infarction and sciatic nerve crush preclinical models. Thereafter, transplantation, histological examination, real time imaging, and assessment of tissue regeneration were done.

RESULTS

Transplanted NPC-ADMSCs were clearly identified and revealed potential benefit when used in cell tracking.

CONCLUSION

This approach may have broad applications in modeling labeled transplanted cells and in developing improved stem cell therapeutic strategies.

Spatholobus suberectus Ameliorates Diabetes-Induced Renal Damage by Suppressing Advanced Glycation End Products in db/db Mice

Spatholobus suberectus (SS) is a medicinal herb commonly used in Asia to treat anemia, menoxenia and rheumatism. However, its effect of diabetes-induced renal damage and mechanisms of action against advanced glycation end-products (AGEs) are unclear. In this study, we evaluated the effects of SS on diabetes-induced renal damage and explored the possible underlying mechanisms using db/db type 2 diabetes mice. db/db mice were administered SS extract (50 mg/kg) orally for 6 weeks. SS-treated group did not change body weight, blood glucose and glycated hemoglobin (HbA1c) levels. However, SS treatment reversed diabetes-induced dyslipidemia and urinary albumin/creatinine ratio in db/db mice. Moreover, SS administration showed significantly increased protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which is a transcription factor for antioxidant enzyme. SS significantly upregulated glyoxalase 1 (Glo1) and NADPH quinine oxidoreductase 1 (NQO1) expression but reduced CML accumulation and downregulated receptor for AGEs (RAGE). Furthermore, SS showed significant decrease of periodic acid⁻Schiff (PAS)-positive staining and AGEs accumulation in histological and immunohistochemical analyses of kidney tissues. Taken together, we concluded that SS ameliorated the renal damage by inhibiting diabetes-induced glucotoxicity, dyslipidemia and oxidative stress, through the Nrf2/antioxidant responsive element (ARE) stress-response system.

Potential Non-neoplastic Applications for Polyphenols in Stem Cell Utilization

While polyphenols may have important effects on pluripotential stem cells that make them noteworthy as potential antineoplastic agents, their action on stem cells may portend other health benefits, such as treatments for cardiovascular and neurocognitive disorders. Resveratrol, the beststudied polyphenol, has been found to enable stem cells to differentiate into cardiomyocytes, neurons, osteocytes, and pancreatic beta cells, as well as facilitating augmentation of stem cell populations and protecting them from toxic injury. Curcumin protects mesenchymal stem cells from toxicity, and prevents them from facilitating chondrocytic hypertrophy. Quercetin enabled osteocytic and pancreatic beta cell differentiation, and protected neuronal stem cells from injury. Epigallocatechin gallate prevented damage to osteocyte precursors and averted differentiation into undesirable adipocytes. Genistein facilitated osteogenesis while preventing adipogenesis. Several other polyphenols, daidzein, caffeic and chlorogenic acid, kaempferol, and piceatannol, protect stems cells from reactive oxygen species and foster stem cells differentiation away from adipocytic and toward osteocytic lineages. Further research should better elucidate the pharmacokinetic profiles of each polyphenol, explore novel delivery systems, and expand investigation beyond rodent models to additional species.

Thermosensitive biomimetic polyisocyanopeptide hydrogels may facilitate wound repair

Changing wound dressings inflicts pain and may disrupt wound repair. Novel synthetic thermosensitive hydrogels based on polyisocyanopeptide (PIC) offer a solution. These gels are liquid below 16 °C and form gels beyond room temperature. The architecture and mechanical properties of PIC gels closely resemble collagen and fibrin, and include the characteristic stiffening response at high strains. Considering the reversible thermo-responsive behavior, we postulate that PIC gels are easy to apply and remove, and facilitate healing without eliciting foreign body responses or excessive inflammation. Biocompatibility may be higher in RGD-peptide-functionalized PIC gels due to enhanced cell binding capabilities. Full-thickness dorsal skin wounds in mice were compared to wounds treated with PIC gel and PIC-RGD gel for 3 and 7 days. No foreign body reactions and similar wound closure rates were found in all groups. The level of macrophages, myofibroblasts, epithelial migration, collagen expression, and blood vessels did not significantly differ from controls. Surprisingly, granulocyte populations in the wound decreased significantly in the PIC gel-treated groups, likely because foreign bacteria could not penetrate the gel. RGD-peptides did not further improve any effect observed for PIC. The absence of adverse effects, ease of application, and the possibilities for bio-functionalization make the biomimetic PIC hydrogels suitable for development into wound dressings.

Cytoprotective role of vitamin E in porcine adipose-tissue-derived mesenchymal stem cells against hydrogen-peroxide-induced oxidative stress

Survival of mesenchymal stem cells (MSCs) against oxidative stress and inflammation is vital for effective stem cell therapy. The reactive oxygen species (ROS) result in apoptosis and release of inflammatory mediators. Adipose-derived stem cells (ASCs) have shown promise for stem cell therapy owing to their anti-inflammatory and anti-oxidant activity. Previously, we showed the benefits of vitamin E against hydrogen peroxide (H₂O₂)-induced oxidative stress in rat bone marrow-derived MSCs. In this study, we aim to evaluate the effect of vitamin E treatment on porcine adipose-derived mesenchymal stem cells (pASCs) against H₂O₂-induced oxidative stress. The oxidative stress was induced by treating pASCs with 500 μM H₂O₂ with or without vitamin E. Viability of pASCs is enhanced after vitamin E treatment. In addition, reduced cellular toxicity, total NO level, PGE₂ production and caspase-3 activity were observed after vitamin E treatment. Gene expression analysis of vitamin E-treated pASCs showed down-regulated expression for the genes associated with oxidative stress and apoptosis, viz., NOS2, Casp3, p53, BAX, MDM2, NFκB, HIF1α and VEGF-A genes. On the other hand, expression of anti-apoptotic and survival genes was up-regulated, viz., BCL2, BCL2L1 and MCL1. Furthermore, phosphorylation of Akt was attenuated following vitamin E treatment. The findings of this study may help in developing effective stem cell therapy for the diseases characterized by the oxidative stress and inflammation.

Mechanisms of curcumin-induced gastroprotection against ethanol-induced gastric mucosal lesions

BACKGROUND

Curcumin, a pleiotropic substance used for centuries in traditional medicine, exhibits antioxidant, anti-inflammatory and antiproliferative efficacy against various tumours, but the role of curcumin in gastroprotection is little studied. We determined the effect of curcumin against gastric haemorrhagic lesions induced by 75% ethanol and alterations in gastric blood flow (GBF) in rats with cyclooxygenase-1 (COX-1) and COX-2 activity inhibited by indomethacin, SC-560 or rofecoxib, inhibited NO-synthase activity, capsaicin denervation and blockade of TRPV1 receptors by capsazepine.

METHODS

One hour after ethanol administration, the gastric mucosal lesions were assessed by planimetry, the GBF was examined by H2 gas clearance, plasma gastrin was determined by radioimmunoassay, and the gastric mucosal mRNA expression of Cdx-2, HIF-1α, HO-1 and SOD 2 was analysed by RT-PCR.

RESULTS

Curcumin, in a dose-dependent manner, reduced ethanol-induced gastric lesions and significantly increased GBF and plasma gastrin levels. Curcumin-induced protection was completely reversed by indomethacin and SC-560, and significantly attenuated by rofecoxib, L-NNA, capsaicin denervation and capsazepine. Curcumin downregulated Cdx-2 and Hif-1α mRNA expression and upregulated HO-1 and SOD 2, and these effects were reversed by L-NNA and further restored by co-treatment of L-NNA with L-arginine.

CONCLUSIONS

Curcumin-induced protection against ethanol damage involves endogenous PG, NO, gastrin and CGRP released from sensory nerves due to activation of the vanilloid TRPV1 receptor. This protective effect can be attributed to the inhibition of HIF-1α and Cdx-2 expression and the activation of HO-1 and SOD 2 expression.

Curcumin increases cholesterol efflux via heme oxygenase‑1‑mediated ABCA1 and SR‑BI expression in macrophages

Curcumin, which is an extract from a traditional Chinese medicine, has previously been demonstrated to exhibit an anti‑atherosclerotic effect, which is closely associated with an increase in cholesterol efflux. However, it is unclear as to whether the increased effect is mediated by heme oxygenase (HO)‑1. Macrophages were treated with different concentrations of curcumin, HO‑1 inhibitor and small interfering (si)RNA in different experiments. Analysis of protein expression was conducted via western blotting. mRNA expression levels were measured using reverse transcription‑polymerase chain reaction. Antioxidant response element (ARE)‑driven promoter activity was measured by a dual‑luciferase reporter assay. The cholesterol efflux analysis was performed by fluorescence‑labelled cholesterol (NBD) using a multi‑label counter. In the present study, the results indicated that curcumin increased the cholesterol efflux from macrophages. Additionally, curcumin significantly upregulated HO‑1 expression. The HO‑1 inhibitor (zinc protoporphyrin) partly blocked this effect. Curcumin also promoted scavenger receptor class B type I (SR‑BI) and ATP‑binding cassette transporter A1 (ABCA1) expression. HO‑1 small interfering (si)RNA partly abolished the increased SR‑BI and ABCA1 expression induced by curcumin. Furthermore, the nuclear factor, erythroid 2 like 2 (Nrf2) expression in the nucleus was dose‑dependently increased by curcumin. Nrf2 siRNA successfully inhibited the curcumin‑induced HO‑1 expression. Curcumin significantly increased Nrf2‑driven luciferase activity. Overall, these data indicated that curcumin activates the Nrf2‑ARE signaling pathway and upregulates HO‑1 expression, which mediates SR‑BI and ABCA1 expression and thereby increases cholesterol efflux.

[The role of glutathione in steroid induced bone marrow mesenchymal stem cells dysfunction]

Objective

To investigate the protective effect of the antioxidant glutathione (GSH) on the steroid-induced imbalance between osteogenesis and adipogenesis in human bone marrow mesenchymal stem cells (BMSCs).

Methods

The BMSCs were isolated from the proximal femur bone marrow from 3 patients of femoral neck fracture and were separated, cultured, and purificated by density gradient centrifugation and adherent wall method in vitro. The third generation BMSCs were divided into 5 groups: group A, BMSCs (1×10 ⁵ cells/mL); group B, BMSCs (1×10 ⁵ cells/mL)+10 μmol/L dexamethasone; group C, BMSCs (1×10 ⁵ cells/mL)+10 μmol/L dexamethasone+5 μmol/L GSH; group D, BMSCs (1×10 ⁵ cells/mL)+10 μmol/L dexamethasone+10 μmol/L GSH; group E, BMSCs (1×10 ⁵ cells/mL)+10 μmol/L dexamethasone+50 μmol/L GSH. After cultured for 7 days, the reactive oxygen species expression was detected by flow cytometry; the superoxide dismutase (SOD) and Catalase mRNA expressions were determined by RT-PCR; the peroxisome proliferator-activated receptors γ (PPAR-γ), CCAAT/enhancer-binding family of proteins (C/EBP), Runx2, and alkaline phosphatase (ALP) mRNA expressions were evaluated by real-time fluorescence quantitative PCR. After cultured for 21 days, Oil red O staining was used to observe the adipogenesis differentiation of cells, and the expressions of related proteins were detected by Western blot.

Results

The reactive oxygen species expression in group B was obviously higher than in the other groups, in group C than in groups A, D, and E, and in groups D, E than in group A, all showing significant differences between groups ( P<0.05); but there was no significant difference between groups D and E ( P>0.05). The oil red O staining positive cells in group B were obviously more than the other groups, and groups C, D, E, and A decreased sequentially, the absorbance ( A) values had significant differences between groups ( P<0.05). RT-PCR detection showed that the relative expressions of SOD and Catalase mRNA in group B were significantly lower than those in the other groups, while in group C than in groups A, D, and E ( P<0.05), but there was no significant difference among groups A, D, and E ( P>0.05). Real-time fluorescence quantitative PCR detection showed that the relative expressions of PPAR-γ and C/EBP mRNA in group B were significantly higher than those in the other groups, while in group C than in groups A, D, and E, and in groups D, E than in group A ( P<0.05); but there was no significant difference between groups D and E ( P>0.05). The relative expressions of Runx2 and ALP mRNA in group B were significantly lower than those in the other groups, while in group C than in groups A, D, and E, and in groups D, E than in group A ( P<0.05); but there was no significant difference between groups D and E ( P>0.05). Western blot detection showed that the relative expression of PPAR-γ and C/EBP protein in group B was significantly higher than those in the other groups, and groups C, D, E, and A decreased sequentially, all showing significant differences between groups ( P<0.05). The relative expression of Runx2 and ALP protein in group B was significantly lower than those in the other groups, and groups C, D, E, and A increased sequentially, all showing significant differences between groups ( P<0.05).

Conclusions

GSH can inhibit the adipogenesis differentiation and enhance the osteogenic differentiation of human BMSCs by reducing the intracellular reactive oxygen species level; and in a certain range, the higher the concentration of GSH, the more obvious the effect is.

Gelatin positively regulates the immunosuppressive capabilities of adipose-derived mesenchymal stem cells

This characteristics of adipose-derived mesenchymal stem cells (Ad-MSCs) can be selectively enhanced by altering the culture environment. We evaluated the effects of gelatin on Ad-MSCs when used in combination with culture media. Ad-MSCs were initially cultured in 0%, 0.5%, 1%, 2%, and 4% gelatin in Dulbecco's modified Eagle's medium (DMEM) to evaluate cell proliferation. This expression of inflammatory, antiinflammatory, antioxidant, and osteogenic markers was then assessed by rtPCR in Ad-MSCs cultured in 0.5% gelatin in DMEM (GMSCs), and without gelatin (MSCs), for 5 and 10 days. We found that 0.5% gelatin significantly increased the proliferation rate of Ad-MSCs after 24 h of incubation, up until 72 h. GMSCs had upregulated IL-10, VEGF, and HO-1 after 5 and 10 days of incubation, while IL-6 and TNF-α were upregulated after 5 days and then significantly decreased after 10 days of incubation. The osteogenic factors BMP-7, AXIN, and β-catenin were significantly upregulated in GMSCs after 5 and 10 days. Notably, there was 5- to 8-fold higher expression of BMP-7 in GMSCs than in MSCs. We conclude that culture medium containing 0.5% gelatin enhances the proliferation rate, induces immunosuppression, and activates BMP-7 and the wnt/AXIN/β-catenin pathway in Ad-MSCs.

Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study

Curcumin has been shown to exert potential antitumor activity in vitro and in vivo involved in multiple signaling pathways. However, the application of curcumin is still limited because of its poor hydrophilicity and low bio-availability. In the present study, we investigated the therapeutic effects of a novel and water soluble bis(hydroxymethyl) alkanoate curcuminoid derivative, MTH-3, on human breast adenocarcinoma MDA-MB-231 cells. This study investigated the effect of MTH-3 on cell viability, cell cycle and induction of autophagy and apoptosis in MDA-MB-231 cells. After 24-h treatment with MTH-3, a concentration-dependent decrease in MDA-MB-231 cell viability was observed, and the IC₅₀ value was 5.37±1.22 μM. MTH-3 significantly triggered G₂/M phase arrest and apoptosis in MDA-MB-231 cells. Within a 24-h treatment, MTH-3 decreased the CDK1 activity by decreasing CDK1 and cyclin B1 protein levels. MTH-3-induced apoptosis was further confirmed by morphological assessment and Annexin V/PI staining assay. Induction of apoptosis caused by MTH-3 was accompanied by an apparent increase of DR3, DR5 and FADD and, as well as a marked decrease of Bcl-2 and Bcl-xL protein expression. MTH-3 also decreased the protein levels of Ero1, PDI, PERK and calnexin, as well as increased the expression of IRE1α, CHOP and Bip that consequently led to ER stress and MDA-MB-231 cell apoptosis. In addition, MTH-3-treated cells were involved in the autophagic process and cleavage of LC3B was observed. MTH-3 enhanced the protein levels of LC3B, Atg5, Atg7, Atg12, p62 and Beclin-1 in MDA-MB-231 cells. Finally, DNA microarray was carried out to investigate the level changes of gene expression modulated by MTH-3 in MDA-MB-231 cells. Taken together, our results suggest that MTH-3 might be a novel therapeutic agent for the treatment of triple-negative breast cancer in the near future.

Effects of Remote Ischemic Preconditioning on Heme Oxygenase-1 Expression and Cutaneous Wound Repair

Skin wounds may lead to scar formation and impaired functionality. Remote ischemic preconditioning (RIPC) can induce the anti-inflammatory enzyme heme oxygenase-1 (HO-1) and protect against tissue injury. We aim to improve cutaneous wound repair by RIPC treatment via induction of HO-1. RIPC was applied to HO-1-luc transgenic mice and HO-1 promoter activity and mRNA expression in skin and several other organs were determined in real-time. In parallel, RIPC was applied directly or 24h prior to excisional wounding in mice to investigate the early and late protective effects of RIPC on cutaneous wound repair, respectively. HO-1 promoter activity was significantly induced on the dorsal side and locally in the kidneys following RIPC treatment. Next, we investigated the origin of this RIPC-induced HO-1 promoter activity and demonstrated increased mRNA in the ligated muscle, heart and kidneys, but not in the skin. RIPC did not change HO-1 mRNA and protein levels in the wound 7 days after cutaneous injury. Both early and late RIPC did not accelerate wound closure nor affect collagen deposition. RIPC induces HO-1 expression in several organs, but not the skin, and did not improve excisional wound repair, suggesting that the skin is insensitive to RIPC-mediated protection.

Anti-inflammatory signaling: the point of convergence for medical gases in neuroprotection against ischemic stroke

Recent studies suggest that a variety of medical gases confer neuroprotective effects against cerebral ischemia, extending function beyond their regular clinical applications. The mechanisms underlying ischemic neuroprotection afforded by medical gases have been intensively studied over the past two decades. A number of signaling pathways have been proposed, among which anti-inflammatory signaling has been proven to be critical. Pursuit of the role for anti-inflammatory signaling may shed new light on the translational application of medical gas-afforded neuroprotection.

Mechanisms underlying the antiapoptotic and anti-inflammatory effects of monotropein in hydrogen peroxide-treated osteoblasts

Monotropein, the primary iridoid glycoside isolated from Morindacitrifolia, has been previously reported to possess potent antioxidant and antiosteoporotic properties. However, there is no direct evidence correlating the antiosteoporotic effect of monotropein with its observed antioxidant capacity, and the molecular mechanisms involved in mediating these processes remain unclear. Therefore, the aim of the present study was to investigate the protective effects of monotropein against oxidative stress in osteoblasts and the mechanisms involved in mediating this process. Osteoblast viability was evaluated using the MTT assay. The mitochondrial membrane potential and reactive oxygen species were detected by flow cytometry analyses. Western blotting and enzyme‑linked immunosorbent assays were performed to detect protein expression levels. A significant reduction in osteoblast viability was observed at 24 h following exposure to various concentrations (100‑1,000 µM) of H2O2 compared with untreated osteoblasts. The cytotoxic effect of H2O2 was notably reversed when osteoblasts were pretreated with 1‑10 µg/ml monotropein. Pretreatment with 1-10 µg/ml monotropein increased the mitochondrial membrane potential and reduced the generation of reactive oxygen species in osteoblasts following exposure to H2O2. In addition, the H2O2‑induced increase in apoptotic markers (caspase-3 and caspase-9) and H2O2-induced reduction in sirtuin 1 levels were significantly reversed following pretreatment of cells with monotropein. Furthermore, monotropein significantly reduced H2O2‑induced stimulation of NF‑κB expression, in addition to the expression of a number of proinflammatory mediators. These results indicate that monotropein suppresses apoptosis and the inflammatory response in H2O2‑induced osteoblasts through the activation of the mitochondrial apoptotic signaling pathway and inhibition of the NF‑κB signaling pathway.

Potentiation of hydrogen peroxide toxicity: From catalase inhibition to stable DNA-iron complexes

Hydrogen peroxide (H₂O₂) is unique among general toxins, because it is stable in abiotic environments at ambient temperature and neutral pH, yet rapidly kills any type of cells by producing highly-reactive hydroxyl radicals. This life-specific reactivity follows the distribution of soluble iron, Fe(II) (which combines with H₂O₂ to form the famous Fenton's reagent),Fe(II) is concentrated inside cells, but is virtually absent outside them. Because of the immediate danger of H₂O₂, all cells have powerful H₂O₂ scavengers, the equally famous catalases, which enable cells to survive thousand-fold higher concentrations of H₂O₂ and, in combination with adequate movement of H₂O₂ across membranes, make the killing H₂O₂ concentrations virtually impractical to generate in vivo. And yet, low concentrations of H₂O₂ are somehow used as an efficient biological weapon. Here we review several examples of how cells potentiate H₂O₂ toxicity with other chemicals. At first, these potentiators were thought to simply inhibit catalases, but recent findings with cyanide suggest that potentiators mostly promote the other side of Fenton's reaction, recruiting iron from cell depots into stable DNA-iron complexes that, in the presence of elevated H₂O₂, efficiently break duplex DNA, pulverizing the chromosome. This multifaceted potentiation of H₂O₂ toxicity results in robust and efficient killing.

Mechanical Stress Changes the Complex Interplay Between HO-1, Inflammation and Fibrosis, During Excisional Wound Repair

Mechanical stress following surgery or injury can promote pathological wound healing and fibrosis, and lead to functional loss and esthetic problems. Splinted excisional wounds can be used as a model for inducing mechanical stress. The cytoprotective enzyme heme oxygenase-1 (HO-1) is thought to orchestrate the defense against inflammatory and oxidative insults that drive fibrosis. Here, we investigated the activation of the HO-1 system in a splinted and non-splinted full-thickness excisional wound model using HO-1-luc transgenic mice. Effects of splinting on wound closure, HO-1 promoter activity, and markers of inflammation and fibrosis were assessed. After seven days, splinted wounds were more than three times larger than non-splinted wounds, demonstrating a delay in wound closure. HO-1 promoter activity rapidly decreased following removal of the (epi)dermis, but was induced in both splinted and non-splinted wounds during skin repair. Splinting induced more HO-1 gene expression in 7-day wounds; however, HO-1 protein expression remained lower in the epidermis, likely due to lower numbers of keratinocytes in the re-epithelialization tissue. Higher numbers of F4/80-positive macrophages, αSMA-positive myofibroblasts, and increased levels of the inflammatory genes IL-1β, TNF-α, and COX-2 were present in 7-day splinted wounds. Surprisingly, mRNA expression of newly formed collagen (type III) was lower in 7-day wounds after splinting, whereas, VEGF and MMP-9 were increased. In summary, these data demonstrate that splinting delays cutaneous wound closure and HO-1 protein induction. The pro-inflammatory environment following splinting may facilitate higher myofibroblast numbers and increase the risk of fibrosis and scar formation. Therefore, inducing HO-1 activity against mechanical stress-induced inflammation and fibrosis may be an interesting strategy to prevent negative effects of surgery on growth and function in patients with orofacial clefts or in patients with burns.