Inhibition of mitochondrial cytochrome c release and suppression of caspases by gamma-tocotrienol prevent apoptosis and delay aging in stress-induced premature senescence of skin fibroblasts

Effects of tocotrienol on aging skin: A systematic review

The skin is the largest organ of the body that protects from mechanical, thermal, and physical injury. However, the function and appearance of skin visibly degenerates with age due to its frequent exposure to harmful effects of the environment, including ultraviolet irradiation and hazardous substances, in addition to the progression of oxidative stress in aging. These factors result in phenotypic changes in the skin, including wrinkling, pigmentation, reduced elasticity, and hydration during aging. Many natural antioxidant compounds have been studied extensively to reverse the signs of aging skin. Tocotrienols are a subfamily of vitamin E with potent antioxidant activity. Therefore, supplementation with vitamin E in the form of tocotrienol may efficiently protect skin from aging. In this review, the effects of tocotrienol on skin health, including pigmentation, moisture, and wrinkles during aging and UV exposure, were systematically evaluated based on a literature search of the PubMed and Scopus databases. The present data showed that tocotrienols protect the skin from inflammation, UV radiation and melanin accumulation. As the therapeutic value of tocotrienols grows, the potential of these vitamin E analogs to the skin requires further investigation.

A Link between Mitochondrial Dysregulation and Idiopathic Autism Spectrum Disorder (ASD): Alterations in Mitochondrial Respiratory Capacity and Membrane Potential

Autism spectrum disorder (ASD) is a neurological disorder triggered by various factors through complex mechanisms. Research has been done to elucidate the potential etiologic mechanisms in ASD, but no single cause has been confirmed. The involvement of oxidative stress is correlated with ASD and possibly affects mitochondrial function. This study aimed to elucidate the link between mitochondrial dysregulation and idiopathic ASD by focusing on mitochondrial respiratory capacity and membrane potential. Our findings showed that mitochondrial function in the energy metabolism pathway was significantly dysregulated in a lymphoblastoid cell line (LCL) derived from an autistic child (ALCL). Respiratory capacities of oxidative phosphorylation (OXPHOS), electron transfer of the Complex I and Complex II linked pathways, membrane potential, and Complex IV activity of the ALCL were analyzed and compared with control cell lines derived from a developmentally normal non-autistic sibling (NALCL). All experiments were performed using high-resolution respirometry. Respiratory capacities of OXPHOS, electron transfer of the Complex I- and Complex II-linked pathways, and Complex IV activity of the ALCL were significantly higher compared to healthy controls. Mitochondrial membrane potential was also significantly higher, measured in the Complex II-linked pathway during LEAK respiration and OXPHOS. These results indicate the abnormalities in mitochondrial respiratory control linking mitochondrial function with autism. Correlating mitochondrial dysfunction and autism is important for a better understanding of ASD pathogenesis in order to produce effective interventions.

γ-Tocotrienol Protects against Mitochondrial Dysfunction, Energy Deficits, Morphological Damage, and Decreases in Renal Functions after Renal Ischemia

Ischemia-induced mitochondrial dysfunction and ATP depletion in the kidney result in disruption of primary functions and acute injury of the kidney. This study tested whether γ-tocotrienol (GTT), a member of the vitamin E family, protects mitochondrial function, reduces ATP deficits, and improves renal functions and survival after ischemia/reperfusion injury. Vehicle or GTT (200 mg/kg) were administered to mice 12 h before bilateral kidney ischemia, and endpoints were assessed at different timepoints of reperfusion. GTT treatment reduced decreases in state 3 respiration and accelerated recovery of this function after ischemia. GTT prevented decreases in activities of complexes I and III of the respiratory chain, and blocked ischemia-induced decreases in F₀F₁-ATPase activity and ATP content in renal cortical tissue. GTT improved renal morphology at 72 h after ischemia, reduced numbers of necrotic proximal tubular and inflammatory cells, and enhanced tubular regeneration. GTT treatment ameliorated increases in plasma creatinine levels and accelerated recovery of creatinine levels after ischemia. Lastly, 89% of mice receiving GTT and 70% of those receiving vehicle survived ischemia. Conclusions: Our data show novel observations that GTT administration improves mitochondrial respiration, prevents ATP deficits, promotes tubular regeneration, ameliorates decreases in renal functions, and increases survival after acute kidney injury in mice.

Mitigation of late cardiovascular effects of oxygen ion radiation by γ-tocotrienol in a mouse model

PURPOSE

While there is concern about degenerative tissue effects of exposure to space radiation during deep-space missions, there are no pharmacological countermeasures against these adverse effects. γ-Tocotrienol (GT3) is a natural form of vitamin E that has anti-oxidant properties, modifies cholesterol metabolism, and has anti-inflammatory and endothelial cell protective properties. The purpose of this study was to test whether GT3 could mitigate cardiovascular effects of oxygen ion (¹⁶O) irradiation in a mouse model.

MATERIALS AND METHODS

Male C57BL/6 J mice were exposed to whole-body ¹⁶O (600 MeV/n) irradiation (0.26-0.33 Gy/min) at doses of 0 or 0.25 Gy at 6 months of age and were followed up to 9 months after irradiation. Animals were administered GT3 (50 mg/kg/day s.c.) or vehicle, on Monday - Friday starting on day 3 after irradiation for a total of 16 administrations. Ultrasonography was used to measure in vivo cardiac function and blood flow parameters. Cardiac tissue remodeling and inflammatory infiltration were assessed with histology and immunoblot analysis at 2 weeks, 3 and 9 months after radiation.

RESULTS

GT3 mitigated the effects of ¹⁶O radiation on cardiac function, the expression of a collagen type III peptide, and markers of mast cells, T-cells and monocytes/macrophages in the left ventricle.

CONCLUSIONS

GT3 may be a potential countermeasure against late degenerative tissue effects of high-linear energy transfer radiation in the heart.

Acetylshikonin Induces Apoptosis in Human Colorectal Cancer HCT-15 and LoVo Cells via Nuclear Translocation of FOXO3 and ROS Level Elevation

Acetylshikonin, a naphthoquinone, is a pigment compound derived from Arnebia sp., which is known for its anti-inflammatory potential. However, its anticarcinogenic effect has not been well investigated. Thus, in this study, we focused on investigating its apoptotic effects against HCT-15 and LoVo cells, which are human colorectal cancer cells. MTT assay, cell counting assay, and colony formation assay have shown acetylshikonin treatment induced cytotoxic and antiproliferative effects against colorectal cancer cells in a dose- and time-dependent manner. DNA fragmentation was observed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Also, the increase of subG1 phase in cell cycle arrest assay and early/late apoptotic rates in annexin V/propidium iodide (PI) double staining assay was observed, which indicates an apoptotic potential of acetylshikonin against colorectal cancer cells. 2′,7′-Dichlorofluorescin diacetate (DCF-DA) staining was used to evaluate reactive oxygen species (ROS) generation in acetylshikonin-treated colorectal cancer cells. Fluorescence-activated cell sorting (FACS) analysis showed that acetylshikonin induced an increase in reactive oxygen species (ROS) levels and apoptotic rate in a dose- and time-dependent manner in HCT-15 and LoVo cells. In contrast, cotreatment with N-acetyl cysteine (NAC) has reduced ROS generation and antiproliferative effects in colorectal cancer cells. Western blotting analysis showed that acetylshikonin treatment induced increase of cleaved PARP, γH2AX, FOXO3, Bax, Bim, Bad, p21, p27, and active forms of caspase-3, caspase-7, caspase-9, caspase-6, and caspase-8 protein levels, while those of inactive forms were decreased. Also, the expressions of pAkt, Bcl-2, Bcl-xL, peroxiredoxin, and thioredoxin 1 were decreased. Furthermore, western blotting analysis of cytoplasmic and nuclear fractionated proteins showed that acetylshikonin treatment induced the nuclear translocation of FOXO3, which might result from DNA damage by the increased intracellular ROS level. This study represents apoptotic potential of acetylshikonin against colorectal cancer cells via translocation of FOXO3 to the nucleus and upregulation of ROS generation.

Reduction of senescence-associated beta-galactosidase activity by vitamin E in human fibroblasts depends on subjects' age and cell passage number

Cell senescence is due to the permanent cell cycle arrest that occurs as a result of the inherent limited replicative capacity toward the Hayflick limit (replicative senescence), or in response to various stressors (stress-induced premature senescence, SIPS). With the acquisition of the senescence-associated secretory phenotype (SASP), cells release several molecules (cytokines, proteases, lipids), and express the senescence-associated beta-galactosidase (SA-β-Gal). Here we tested whether vitamin E affects SA-β-Gal in an in vitro model of cell ageing. Skin fibroblasts from human subjects of different age (1, 13, 29, 59, and 88 years old) were cultured until they reached replicative senescence. At different passages (Passages 2, 9, 13, and 16), these cells were treated with vitamin E for 24 hr. Vitamin E reduced SA-β-Gal in all cells at passage 16, but at earlier passage numbers it reduced SA-β-Gal only in cells isolated from the oldest subjects. Therefore, short time treatment with vitamin E decreases SA-β-Gal in cells both from young and old subjects when reaching replicative senescence; but in cells isolated from older subjects, a decrease in SA-β-Gal by vitamin E occurs also at earlier passage numbers. The possible role of downregulation of CD36 by vitamin E, a scavenger receptor essential for initiation of senescence and SASP, is discussed.

Neuroprotection of GLP-1/GIP receptor agonist via inhibition of mitochondrial stress by AKT/JNK pathway in a Parkinson's disease model

OBJECTIVES

To investigate the effect of glucagon-like peptide-1 (GLP-1) receptor and glucose dependent insulinotrophic polypeptide (GIP) receptor dual agonist DA-JC4 on alleviating Parkinson's disease (PD) and unveil related cellular mechanisms.

METHODS

Rotenone was injected to generate a rat PD model, on which the effect of DA-JC4 on motor functions was evaluated by rotational behavioral assay and open field test. The survival of dopaminergic neurons was analyzed, in addition to assays for mitochondrial stress and quantification of neurotransmitter levels using high performance liquid chromatography (HPLC). In cultured hippocampal neurons, the effect of DA-JC4 on mitochondrial stress and related cellular mechanism was analyzed by Flow cytometry, western blotting and reactive oxygen species (ROS).

RESULTS

DA-JC4 significantly improved motor functions in PD rats, and elevated levels of major neurotransmitters. By histological analysis, DA-JC4 protected dopaminergic neurons from rotenone-induced cell death, which was associated with reduced mitochondrial stress. Experiments in cultured rat hippocampal neurons validated the neuroprotective role of DA-JC4 against cell apoptosis and mitochondrial stress induced by rotenone. The protective effect of DA-JC4 was later found to be dependent on AKT/JNK signal pathway, as treatment using AKT inhibitor or JNK activator abolished such effects.

CONCLUSION

Our results showed that the dual agonist of GLP-1/GIP receptor could ameliorate motor dysfunctions of PD by protecting dopaminergic neurons which was mediated by relieved mitochondrial stress and apoptosis via AKT/JNK signal pathway.

Intravenous leiomyomatosis is inclined to a solid entity different from uterine leiomyoma based on RNA-seq analysis with RT-qPCR validation

Introduction

Intravenous leiomyomatosis (IVL) is currently regarded as a special variant of the common uterine leiomyoma (LM). Though IVL shows a similar histological morphology to LM, IVL is characterized by unique intravenous growth patterns and low‐grade malignant potential, which are quite different from LM. There are currently few studies underlying the molecular alterations of IVL, though this information is important for understanding the pathogenesis of the disease, and for identifying potential biomarkers.

Method

We carried out a high‐throughput whole transcriptome sequencing of tumor and normal tissue samples from five IVL patients and five LM patients and compared the differentially expressed genes (DEGs) between IVL and leiomyoma. We performed multiple different enrichment and target analyses, and the expression of selected DEGs was validated using RT‐qPCR in formalin‐fixed samples.

Results

Our study identified substantial different genes and pathways between IVL and LM, and functional enrichment analyses found several important pathways, such as angiogenesis and antiapoptosis pathways, as well as important related genes, including SH2D2A, VASH2, ADAM8, GATA2, TNF, and the lncRNA GATA6‐AS1, as being significantly different between IVL and LM (P = .0024, P = .0195, P = .0212, P = .0435, P = .0401, and P = .0246, respectively). CXCL8, LIF, CDKN2A, BCL2A1, COL2A1, IGF1, and HMGA2 were also differently expressed between IVL and LM groups, but showed no statistical difference (P = .2409, P = .1773, P = .0596, P = .2737, P = .1553, P = .1045, and P = .1847, respectively) due to the large differences among individuals. Furthermore, RT‐qPCR results for five selected DEGs in IVL tissues and adjacent nontumor tissues were mainly consistent with our sequencing results.

Conclusion

Our results indicated that IVL may be a solid entity that is unique and different from LM, proving consistent with previous studies. Furthermore, we identified DEGs, particularly within angiogenesis and antiapoptosis pathway‐related genes that may play crucial roles in the development and pathogenesis of IVL and may be potential specific biomarkers.

Effect of antioxidants on the H2O2-induced premature senescence of human fibroblasts

The study was aimed at evaluation of the role of secondary oxidative stress in the stress-induced premature senescence (SIPS) of human fibroblasts induced by H₂O₂. Two fibroblast lines were used: lung MRC-5 and ear H8F2p25LM fibroblasts. The lines differed considerably in sensitivity to H₂O₂ (IC₅₀ of 528 and 33.5 μM, respectively). The cells were exposed to H₂O₂ concentrations corresponding to IC₅₀ and after 24 h supplemented with a range of antioxidants. Most of antioxidants studied slightly augmented the survival of fibroblasts at single concentrations or in a narrow concentration range, but the results were not consistent among the cell lines. Chosen antioxidants (4-amino-TEMPO, curcumin, caffeic acid and p-coumaric acid) did not restore the level of glutathione decreased by H₂O₂. Hydrogen peroxide treatment did not induce secondary production of H₂O₂ and even decreased it, decreased mitochondrial potential in both cell lines and induced changes in the mitochondrial mass inconsistent between the lines. Antioxidant protected mitochondrial potential only in H8F2p25LM cells, but attenuated changes in mitochondrial mass. These results speak against the intermediacy of secondary oxidative stress in the SIPS induced by H₂O₂ and suggest that the small protective action of antioxidants is due to their effects on mitochondria.

Genotoxic and cytotoxic alterations induced by environmentally-relevant concentrations of amoxicillin in blood cells of Cyprinus carpio

Amoxicillin (AMX) is a pharmaceutical widely employed in human and veterinary medicine worldwide. Its wide production and use has led to this pharmaceutical being released into the environment in concentrations that range from ng L^-1 to μg L^-1. Previous studies have demonstrated that this antibiotic generates toxic effects, amongst which alterations to embryonic development and oxidative stress in aquatic organisms, is noteworthy. Nonetheless, it is necessary to characterize the risks that this pharmaceutical represents for species of economic interest such as Cyprinus carpio, in a more precise manner. The aim of this work was to demonstrate if AMX, at environmentally-relevant concentrations, is capable of inducing genotoxic/cytotoxic alterations in C. carpio. In order to evaluate genotoxicity, the comet assay and micronucleus test were used; in order to determine cytotoxic effects, caspase-3 activity and the TUNEL assay were carried out. The results showed that the effects of the biomarkers had their maximum at 72 h; considering the DNA damage in the comet assay, 0.039 μg L^-1 resulted in a 29% increase compared to control, and 1.67 μg L^-1 caused a 40% increase; micronucleus frequency increased by 205% in C1 and by 311% in C2 when compared to control; compared to control, caspase-3 activity increased 262% in C1 and 787% in C2; for the TUNEL assay, DNA fragmentation increased by 86% in C1 and 120% in C2 compared to control. The results showed that environmentally-relevant concentrations, AMX was capable of generating DNA damage and cytotoxic effects in blood cells of the common carp.

Cellular and viral miRNA expression in polyomavirus BK infection

Polyomavirus BK (BKV) is an important pathogen in kidney transplant patients. Regulation of BKV encoded microRNAs (miRNAs) is not well understood. Therefore, tubular epithelial cells infected with BKV were examined for changes in small RNA expression. The observed changes were further evaluated by real-time PCR and RNA-seq analysis of renal allograft biopsies. BKV-miR-B1-5p and BKV-miR-B1-3p showed a 1000-fold increase over 12 days but did not prevent cell lysis. Downregulation of host miR-10b and miR-30a could be confirmed on all three platforms evaluated. Whereas, the BKV genome expressed more 3p than 5p miRNA species, the reverse was true for the human genome. Decreased expression of TP53INP2, and increased expression of BCL2A1, IL-6, IL8 and other proinflammatory cytokines were shown in biopsies with BKV nephropathy. No change in expression was seen in miR-10a dependent expression of NKG2D ligands ULBP3, MICA, or MICB. In conclusion, BKV infection results in regulation of cellular genes regulated by and possibly amenable to therapies targeting miR-10 and miR-30.

Vitamin E: Regulatory Role on Signal Transduction

Vitamin E modulates signal transduction pathways by several molecular mechanisms. As a hydrophobic molecule located mainly in membranes it contributes together with other lipids to the physical and structural characteristics such as membrane stability, curvature, fluidity, and the organization into microdomains (lipid rafts). By acting as the main lipid-soluble antioxidant, it protects other lipids such as mono- and poly-unsaturated fatty acids (MUFA and PUFA, respectively) against chemical reactions with reactive oxygen and nitrogen species (ROS and RNS, respectively) and prevents membrane destabilization and cellular dysfunction. In cells, vitamin E affects signaling in redox-dependent and redox-independent molecular mechanisms by influencing the activity of enzymes and receptors involved in modulating specific signal transduction and gene expression pathways. By protecting and preventing depletion of MUFA and PUFA it indirectly enables regulatory effects that are mediated by the numerous lipid mediators derived from these lipids. In recent years, some vitamin E metabolites have been observed to affect signal transduction and gene expression and their relevance for the regulatory function of vitamin E is beginning to be elucidated. In particular, the modulation of the CD36/FAT scavenger receptor/fatty acids transporter by vitamin E may influence many cellular signaling pathways relevant for lipid homeostasis, inflammation, survival/apoptosis, angiogenesis, tumorigenesis, neurodegeneration, and senescence. Thus, vitamin E has an important role in modulating signal transduction and gene expression pathways relevant for its uptake, distribution, metabolism, and molecular action that when impaired affect physiological and patho-physiological cellular functions relevant for the prevention of a number of diseases. © 2018 IUBMB Life, 71(4):456-478, 2019.

Fluoride-induced oxidative stress and apoptosis are involved in the reducing of oocytes development potential in mice

The present study was conducted to investigate the mechanisms of excessive-fluoride-induced reduction of oocyte development potential in mice. The development morphology of oocyte and the changes of pathomorphology in ovary were observed. The protein expression levels of apoptosis factors, including Bax, Bcl-2, casepase-3, casepase-9 and cytochrome c, and the mRNA expression levels of antioxidant enzymes, including SOD1, GSH-Px1, CAT and inducible nitric oxide synthase were measured by Western blot and real-time PCR, respectively. DNA damage in the ovary was analysed by single cell gel electrophoresis and TUNEL staining. Results indicated that the structure and function of ovarian cells were seriously damaged, followed, the development potential of oocyte was reduced by excessive fluoride. The expression levels of apoptosis factors were up-regulated and antioxidant enzymes were significantly down-regulated. Meanwhile, the contents of ROS, MDA, NO and iNOS were significantly increased. Whereas, the activities of SOD1, GSH-Px1 and CAT was significantly decreased compared with the control group. Simultaneously, the results of DNA analysis indicated that the tail length and tailing ratio of ovarian cells were significantly increased in the fluoride group. In summary, the results provided compelling evidence that excessive fluoride intake can reduce the development potential of oocyte by inducing oxidative stress and apoptosis in the ovary of female mice.

Reduction of oxidative-nitrosative stress underlies anticataract effect of topically applied tocotrienol in streptozotocin-induced diabetic rats

Cataract, a leading cause of blindness, is of special concern in diabetics as it occurs at earlier onset. Polyol accumulation and increased oxidative-nitrosative stress in cataractogenesis are associated with NFκB activation, iNOS expression, ATP depletion, loss of ATPase functions, calpain activation and proteolysis of soluble to insoluble proteins. Tocotrienol was previously shown to reduce lens oxidative stress and inhibit cataractogenesis in galactose-fed rats. In current study, we investigated anticataract effects of topical tocotrienol and possible mechanisms involved in streptozotocin-induced diabetic rats. Diabetes was induced in Sprague Dawley rats by intraperitoneal injection of streptozotocin. Diabetic rats were treated with vehicle (DV) or tocotrienol (DT). A third group consists of normal, non-diabetic rats were treated with vehicle (NV). All treatments were given topically, bilaterally, twice daily for 8 weeks with weekly slit lamp monitoring. Subsequently, rats were euthanized and lenses were subjected to estimation of polyol accumulation, oxidative-nitrosative stress, NFκB activation, iNOS expression, ATP levels, ATPase activities, calpain activity and total protein levels. Cataract progression was delayed from the fifth week onwards in DT with lower mean of cataract stages compared to DV group (p<0.01) despite persistent hyperglycemia. Reduced cataractogenesis in DT group was accompanied with lower aldose reductase activity and sorbitol level compared to DV group (p<0.01). DT group also showed reduced NFκB activation, lower iNOS expression and reduced oxidative-nitrosative stress compared to DV group. Lenticular ATP and ATPase and calpain 2 activities in DT group were restored to normal. Consequently, soluble to insoluble protein ratio in DT group was higher compared to DV (p<0.05). In conclusion, preventive effect of topical tocotrienol on development of cataract in STZ-induced diabetic rats could be attributed to reduced lens aldose reductase activity, polyol levels and oxidative-nitrosative stress. These effects of tocotrienol invlove reduced NFκB activation, lower iNOS expression, restoration of ATP level, ATPase activities, calpain activity and lens protein levels.

Application of an Image Cytometry Protocol for Cellular and Mitochondrial Phenotyping on Fibroblasts from Patients with Inherited Disorders

Cellular phenotyping of human dermal fibroblasts (HDFs) from patients with inherited diseases provides invaluable information for diagnosis, disease aetiology, prognosis and assessing of treatment options. Here we present a cell phenotyping protocol using image cytometry that combines measurements of crucial cellular and mitochondrial parameters: (1) cell number and viability, (2) thiol redox status (TRS), (3) mitochondrial membrane potential (MMP) and (4) mitochondrial superoxide levels (MSLs). With our protocol, cell viability, TRS and MMP can be measured in one small cell sample and MSL on a parallel one. We analysed HDFs from healthy individuals after treatment with various concentrations of hydrogen peroxide (H2O2) for different intervals, to mimic the physiological effects of oxidative stress. Our results show that cell number, viability, TRS and MMP decreased, while MSL increased both in a time- and concentration-dependent manner. To assess the use of our protocol for analysis of HDFs from patients with inherited diseases, we analysed HDFs from two patients with very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD), one with a severe clinical phenotype and one with a mild one. HDFs from both patients displayed increased MSL without H2O2 treatment. Treatment with H2O2 revealed significant differences in MMP and MSL between HDFs from the mild and the severe patient. Our results establish the capacity of our protocol for fast analysis of cellular and mitochondrial parameters by image cytometry in HDFs from patients with inherited metabolic diseases.

Adipose-Derived Mesenchymal Stem Cells Transplantation Alleviates Renal Injury in Streptozotocin-Induced Diabetic Nephropathy

Previous studies have illustrated that bone marrow-derived mesenchymal stem cell (BMMSC) transplantation has therapeutic effects on diabetes and can prevent mice from renal damage and diabetic nephropathy (DN). Moreover, adipose-derived MSCs possess similar characteristics to BMMSCs. We investigated the effect of ADMSC transplantation on streptozotocin (STZ)-induced renal injury. Diabetes was induced in rats by STZ injection. After ADMSC treatment, renal histological changes and cell apoptosis were evaluated as were the expression of apoptosis-related proteins, Wnt/β-catenin pathway members, and klotho levels. We found that ADMSCs improved renal histological changes. Next, NRK-52E cells were exposed to normal glucose (NG; 5.5 mM glucose plus 24.5 mM mannitol)/high glucose (HG) or ADMSCs, and then measured for changes in the aforementioned proteins. Similarly, changes in these proteins were also determined following transient transfection of klotho siRNA. We found that both ADMSC transplantation and co-incubation reduced the rate of cellular apoptosis, decreased Bax and Wnt/β-catenin levels, and elevated Bcl-2 and klotho levels. Interestingly, klotho knockdown reversed the effects of ADMSCs on the expression of apoptosis-related proteins and Wnt/β-catenin pathway members. Taken together, ADMSCs transplantation might attenuate renal injury in DN via activating klotho and inhibiting the Wnt/β-catenin pathway. This study may provide evidence for the treatment of DN using ADMSCs.

A tocotrienol-enriched formulation protects against radiation-induced changes in cardiac mitochondria without modifying late cardiac function or structure

Radiation-induced heart disease (RIHD) is a common and sometimes severe late side effect of radiation therapy for intrathoracic and chest wall tumors. We have previously shown that local heart irradiation in a rat model caused prolonged changes in mitochondrial respiration and increased susceptibility to mitochondrial permeability transition pore (mPTP) opening. Because tocotrienols are known to protect against oxidative stress-induced mitochondrial dysfunction, in this study, we examined the effects of tocotrienols on radiation-induced alterations in mitochondria, and structural and functional manifestations of RIHD. Male Sprague-Dawley rats received image-guided localized X irradiation to the heart to a total dose of 21 Gy. Twenty-four hours before irradiation, rats received a tocotrienol-enriched formulation or vehicle by oral gavage. Mitochondrial function and mitochondrial membrane parameters were studied at 2 weeks and 28 weeks after irradiation. In addition, cardiac function and histology were examined at 28 weeks. A single oral dose of the tocotrienol-enriched formulation preserved Bax/Bcl2 ratios and prevented mPTP opening and radiation-induced alterations in succinate-driven mitochondrial respiration. Nevertheless, the late effects of local heart irradiation pertaining to myocardial function and structure were not modified. Our studies suggest that a single dose of tocotrienols protects against radiation-induced mitochondrial changes, but these effects are not sufficient against long-term alterations in cardiac function or remodeling.

Reversal of myoblast aging by tocotrienol rich fraction posttreatment

Skeletal muscle satellite cells are heavily involved in the regeneration of skeletal muscle in response to the aging-related deterioration of the skeletal muscle mass, strength, and regenerative capacity, termed as sarcopenia. This study focused on the effect of tocotrienol rich fraction (TRF) on regenerative capacity of myoblasts in stress-induced premature senescence (SIPS). The myoblasts was grouped as young control, SIPS-induced, TRF control, TRF pretreatment, and TRF posttreatment. Optimum dose of TRF, morphological observation, activity of senescence-associated β-galactosidase (SA-β-galactosidase), and cell proliferation were determined. 50 μg/mL TRF treatment exhibited the highest cell proliferation capacity. SIPS-induced myoblasts exhibit large flattened cells and prominent intermediate filaments (senescent-like morphology). The activity of SA-β-galactosidase was significantly increased, but the proliferation capacity was significantly reduced as compared to young control. The activity of SA-β-galactosidase was significantly reduced and cell proliferation was significantly increased in the posttreatment group whereas there was no significant difference in SA-β-galactosidase activity and proliferation capacity of pretreatment group as compared to SIPS-induced myoblasts. Based on the data, we hypothesized that TRF may reverse the myoblasts aging through replenishing the regenerative capacity of the cells. However, further investigation on the mechanism of TRF in reversing the myoblast aging is needed.