ADT-OH synergistically enhanced the antitumor activity of celecoxib in human colorectal cancer cells.

BACKGROUND: Colorectal cancer is one of the most prevalent cancers in the world, but the research on its prevention, early diagnosis and treatment is still a major challenge in clinical oncology. Thus, there is a pressing requirement to find effective strategies to improve the survival of colon cancer patients. METHODS: Celecoxib has been accounted to be an effective antitumor drug, but may exhibit significant side effects. In recent studies, 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADT-OH), one of the most commonly used reagents for the synthesis of sustained-release H2 S donors, has also been reported to inhibit cancer progression by affecting processes such as cell cycle, angiogenesis, and apoptosis. Therefore, we evaluated the therapeutic effect of the combination of ADT-OH and celecoxib on colorectal cancer through in vitro and in vivo, hoping to achieve better therapeutic effect and reduce the effect of celecoxib on gastric injury through exogenous administration of H2 S. RESULTS: Our results demonstrated that ADT-OH combined with celecoxib synergistically inhibited the proliferation and migration ability of human colorectal cancer HCT116 cells, altered cell cycle and cytoskeleton, increased intracellular reactive oxygen species (ROS), and promoted cell apoptosis. Noteworthy, in vivo studies also indicated the excellent antitumor therapeutic effect of the combination therapy without apparent toxicity. CONCLUSIONS: In general, our results provide a reasonable combination strategy of low-dose ADT-OH and celecoxib in the preclinical application of colorectal cancer.

CY-09 Alleviates the Depression-like Behaviors via Inhibiting NLRP3 Inflammasome-Mediated Neuroinflammation in Lipopolysaccharide-Induced Mice.

Depression is a serious mental illness, mainly characterized as large mood swings and sleep, diet, and cognitive function disorders. NLPR3, one of the inflammasomes that can be activated by a variety of stimuli to promote the maturation and secretion of pro-inflammatory cytokines, has been considered to be involved in the pathophysiology of depression. In this study, the putative role of CY-09, a selective and direct inhibitor of NLRP3, was evaluated in the lipopolysaccharide (LPS)-induced mice. The results of the study indicated that CY-09 significantly decreased the levels of NLRP3 in the hippocampus of LPS-induced mice. In addition, CY-09 increased the sucrose preference and shortened the immobility time in LPS-induced mice, suggesting the antidepressant-like effects of inhibiting NLRP3 inflammasome. Biochemical analysis showed that LPS significantly activated the NLRP3/ASC/cytokine signaling pathway and caused microglial activation, while CY-09 prevented the changes. Moreover, CY-09 increased the brain-derived neurotrophic factor (BDNF) only in microglia but not in the whole hippocampus. Meanwhile, CY-09 did not promote neurogenesis in the hippocampus of LPS mice. In conclusion, the results of the study showed that the antidepressant-like effects of NLRP3 inhibitor CY-09 were mediated by alleviating neuroinflammation in microglia and independent of the neurotrophic function in the hippocampus.

Mitochondrial dysfunction and potential mitochondrial protectant treatments in tendinopathy.

Tendinopathy is a common musculoskeletal condition that affects a wide range of patients, including athletes, laborers, and older patients. Tendinopathy is often characterized by pain, swelling, and impaired performance and function. The etiology of tendinopathy is multifactorial, including both intrinsic and extrinsic mechanisms. Various treatment strategies have been described, but outcomes are often variable, as tendons have poor intrinsic healing potential compared with other tissues. Therefore, several novel targets for tendon regeneration have been identified and are being explored. Mitochondria are organelles that generate adenosine triphosphate, and they are considered to be the power generators of the cell. Recently, mitochondrial dysfunction verified by increased reactive oxygen species (ROS), decreased superoxide dismutase activity, cristae disorganization, and decreased number of mitochondria has been identified as a mechanism that may contribute to tendinopathy. This has provided new insights for studying tendinopathy pathogenesis and potential treatments via antioxidant, metabolic modulation, or ROS inhibition. In this review, we present the current understanding of mitochondrial dysfunction in tendinopathy. The review summarizes the potential mechanism by which mitochondrial dysfunction contributes to the development of tendinopathy, as well as the potential therapeutic benefits of mitochondrial protectants in the treatment of tendinopathy.

Anticonvulsant Effectiveness and Neurotoxicity Profile of 4-butyl-5-[(4-chloro-2-methylphenoxy)methyl]-2,4-dihydro-3H-1,2,4-triazole-3-thione (TPL-16) in Mice.

Protective (antiseizure) effects of 4-butyl-5-[(4-chloro-2-methylphenoxy)-methyl]-2,4-dihydro-3H-1,2,4-triazole-3-thione (TPL-16) and acute neurotoxic effects were determined in the tonic-clonic seizure model and rotarod test in mice. The interaction profile of four classic antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) with TPL-16 was also determined in the tonic-clonic seizure model in mice. The protective effects of TPL-16 from tonic-clonic seizures (as ED50 values) and acute neurotoxic effects of TPL-16 (as TD50 values) were determined in 4 pretreatment times (15, 30, 60 and 120 min after its i.p. administration), in adult male albino Swiss mice. The interaction profile of TPL-16 with carbamazepine, phenobarbital, phenytoin and valproate in the tonic-clonic seizure model was determined with isobolographic analysis. Total concentrations of carbamazepine, phenobarbital, phenytoin and valproate were measured in the mouse brain homogenates. The candidate for novel antiepileptic drug (TPL-16) administered separately 15 min before experiments, has a beneficial profile with protective index (as ratio of TD50 and ED50 values) amounting to 5.58. The combination of TPL-16 with valproate produced synergistic interaction in the tonic-clonic seizure model in mice. The combinations of TPL-16 with carbamazepine, phenobarbital and phenytoin produced additive interaction in terms of protection from tonic-clonic seizures in mice. None of the total brain concentrations of classic AEDs were changed significantly after TPL-16 administration in mice. Synergistic interaction for TPL-16 with valproate and the additive interaction for TPL-16 with carbamazepine, phenobarbital and phenytoin in the tonic-clonic seizures in mice allows for recommending TPL-16 as the promising drug for further experimental and clinical testing.

Nrf2 activation ameliorates mechanical allodynia in paclitaxel-induced neuropathic pain.

Paclitaxel-induced neuropathic pain (PINP) is refractory to currently used analgesics. Previous studies show a pivotal role of oxidative stress in PINP. Because the nuclear factor erythroid-2-related factor 2 (Nrf2) has been considered as the critical regulator of endogenous antioxidant defense, we here explored whether activation of Nrf2 could attenuate PINP. A rat model of PINP was established by intraperitoneal injection of paclitaxel (2 mg/kg) every other day with a final cumulative dose of 8 mg/kg. Hind paw withdrawal thresholds (PWTs) in response to von Frey filament stimuli were used to assess mechanical allodynia. We showed that a single dose of Nrf2 activator, oltipraz (10, 50, and 100 mg/kg), dose-dependently attenuated established mechanical allodynia, whereas repeated injection of oltipraz (100 mg· kg-1· d-1, i.p. from d 14 to d 18) almost abolished the mechanical allodynia in PINP rats. The antinociceptive effect of oltipraz was blocked by pre-injection of Nrf2 inhibitor trigonelline (20 mg/kg, i.p.). Early treatment with oltipraz (100 mg· kg-1· d-1, i.p. from d 0 to d 6) failed to prevent the development of the PINP, but delayed its onset. Western blot and immunofluorescence analysis revealed that the expression levels of Nrf2 and HO-1 were significantly upregulated in the spinal cord of PINP rats. Repeated injection of oltipraz caused further elevation of the expression levels of Nrf2 and HO-1 in the spinal cord of PINP rats, which was reversed by pre-injection of trigonelline. These results demonstrate that oltipraz ameliorates PINP via activating Nrf2/HO-1-signaling pathway in the spinal cord.

Design, Synthesis and Biological Activity of Some 4, 5-Disubstituted-2, 4- Dihydro-3H-1, 2, 4- Triazole-3-Thione Derivatives.

BACKGROUND: In the present study, 4, 5-disubstituted triazol-3-thione derivatives were synthesized and evaluated for anticonvulsant activity along with neurotoxicity determination. MATERIALS AND METHODS: The synthesized compounds were characterized using FTIR, 1H-NMR and MS. The anticonvulsant activity was assessed by Maximal Electroshock (MES) test and subcutaneous Pentylenetetrazole (scPTZ) tests and neurotoxicity was assessed by rotarod test. Docking was also performed to study the interactions of compounds with LYS329 residue of gamma amino butyric acid aminotransferase (GABA-AT) using Autodock 4.2 software. RESULTS: The compounds 7a and 9a with significant pharmacological activity were also found to interact with LYS329 residue of GABA-AT by H-bond with a docking score of -5.92 kcal/mol (Ki = 41.99 µM) and -5.87 kcal/mol (Ki = 49.83 µM) respectively. CONCLUSION: Most of the compounds were found to be active in MES test but only seven showed protection in scPTZ test.

Enantiomer of the novel flexible heteroarotinoid, SL-1-09, blocks cell cycle progression in breast cancer cells.

Flexible heteroarotinoids (Flex-Hets) are compounds with promising anti-cancer activities. SHetA2, a first-generation Flex-Het, has been shown to inhibit the growth of cervical, head and neck, kidney, lung, ovarian, prostate, and breast cancers. However, SHetA2's high lipophilicity, limited selectivity, low oral bioavailability, and complicated synthesis has led to the development of second-generation compounds, such as 1-(1-(naphthalen-1-yl)ethyl)-3-(4-nitrophenyl) thiourea or SL-1-09. Results from our lab show that SL-1-09 exhibits anti-cancer activities against ERα+ and ERα- breast cancer cells at micromolar concentrations. SL-1-09 is a mixture of two enantiomers, R and S. The objective of this study was to further analyze these enantiomers to determine their individual anti-cancer activities. Cell cycle analysis demonstrated that the percentage of cells in S-phase is reduced significantly when breast cancer cell lines MCF-7, T47D and MDA-MB-453 cells are treated with 5.0 µM of the S enantiomer. Consistent with this finding, treatment of these cells with the S enantiomer resulted in lower expression levels of cell cycle proteins. Overall, our data indicate that the S enantiomer shows greater growth inhibitory effects than the R form against ERα+ (MCF7 and T47D) and ERα- (MDA-MB-453) breast cancer cells, suggesting that the activity observed in SL-1-09 is most likely due to the ability of the S enantiomer to block cell cycle progression.

The Matrine Derivate MASM Inhibits Recruitment of Gr1hi Monocyte and Alleviates Liver Injury.

BACKGROUNDS: (6aS, 10S, 11aR, 11bR, 11cS)-10-methylaminododecahydro-3a, 7a-diaza-benzo (de) anthracene-8-thione (MASM), a novel derivative of matrine, exhibits better anti-inflammatory activity. This study was designed to evaluate the protective effect of MASM on acute and chronic liver injuries and explore the possible mechanisms. METHODS: Acute and chronic liver injury models were established by the CCl4 intraperitoneal injection and the protective effect of MASM was assessed by biochemical and histological examination. The infiltration of different monocyte subsets into the liver was characterized and analyzed by flow cytometry. The in vitro effect of MASM on liver nonparenchymal cells was evaluated by real-time PCR and transwell chemotaxis assays. RESULTS: Administration of MASM markedly attenuated acute liver injury and liver fibrosis induced by CCl4 injection. Meanwhile, the infiltrations of Gr1hi monocytes in injured livers and induced hepatic expression of monocyte chemoattractant protein-1 (MCP-1) were greatly inhibited. Cellular experiments demonstrated that MASM not only decreased the expression of MCP-1 but also inhibited its chemotactic activity. CONCLUSIONS: This study demonstrates that the protective effect of MASM on liver injury could be contributed to the suppression of Gr1hi monocyte infiltration to the liver and the inhibition of MCP-1 production and activity. These findings provide new insights into the protective role of MASM in liver injury.

Inhibition of HtrA2 alleviated dextran sulfate sodium (DSS)-induced colitis by preventing necroptosis of intestinal epithelial cells.

Necroptosis of intestinal epithelial cells has been indicated to play an important role in the pathogenesis of inflammatory bowel disease (IBD). The identification of dysregulated proteins that can regulate necroptosis in dextran sulfate sodium (DSS)-induced colitis is the key to the rational design of therapeutic strategies for colitis. Through tandem mass tag (TMT)-based quantitative proteomics, HtrA2 was found to be downregulated in the colon of DSS-treated mice. UCF-101, a specific serine protease inhibitor of HtrA2, significantly alleviated DSS-induced colitis as indicated by prevention of body weight loss and decreased mortality. UCF-101 decreased DSS-induced colonic inflammation, prevented intestinal barrier function loss and inhibited necroptosis of intestinal epithelial cells. In vitro, UCF-101 or silencing of HtrA2 decreased necroptosis of HT-29 and L929 cells. UCF-101 decreased phosphorylation of RIPK1 and subsequent phosphorylation of RIPK3 and MLKL during necroptosis. Upon necroptotic stimulation, HtrA2 translocated from mitochondria to cytosol. HtrA2 directly interacted with RIPK1 and promoted its degradation during a specific time phase of necroptosis. Our findings highlight the importance of HtrA2 in regulating colitis by modulation of necroptosis and suggest HtrA2 as an attractive target for anti-colitis treatment.

The Mitochondria-Targeted H2S-Donor AP39 in a Murine Model of Combined Hemorrhagic Shock and Blunt Chest Trauma.

Hemorrhagic shock (HS) accounts for 30% to 40% of trauma-induced mortality, which is due to multi-organ-failure subsequent to systemic hyper-inflammation, triggered by hypoxemia and tissue ischemia. The slow-releasing, mitochondria-targeted H2S donor AP39 exerted beneficial effects in several models of ischemia-reperfusion injury and acute inflammation. Therefore, we tested the effects of AP39-treatment in a murine model of combined blunt chest trauma (TxT) and HS with subsequent resuscitation. METHODS: After blast wave-induced TxT or sham procedure, anesthetized and instrumented mice underwent 1 h of hemorrhage followed by 4 h of resuscitation comprising an i.v. bolus injection of 100 or 10 nmol kg AP39 or vehicle, retransfusion of shed blood, fluid resuscitation, and norepinephrine. Lung mechanics and gas exchange were assessed together with hemodynamics, metabolism, and acid-base status. Blood and tissue samples were analyzed for cytokine and chemokine levels, western blot, immunohistochemistry, mitochondrial oxygen consumption (JO2), and histological changes. RESULTS: High dose AP39 attenuated systemic inflammation and reduced the expression of inducible nitric oxide synthase (iNOS) and IκBα expression in lung tissue. In the combined trauma group (TxT + HS), animals treated with high dose AP39 presented with the lowest mean arterial pressure and thus highest norepinephrine requirements and higher mortality. Low dose AP39 had no effects on hemodynamics, leading to unchanged norepinephrine requirements and mortality rates. CONCLUSION: AP39 is a systemic anti-inflammatory agent. In our model of trauma with HS, there may be a narrow dosing and timing window due to its potent vasodilatory properties, which might result in or contribute to aggravation of circulatory shock-related hypotension.

5-(4-Hydroxyphenyl)-3H-1,2-dithiole-3-thione-based fibrates as potential hypolipidemic and hepatoprotective agents.

Hypolipidemic effects of the newly synthesized 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione-based fibrates were evaluated in Triton WR-1339 and high-fat diet (HFD)-induced hyperlipidemic mice. Preliminary screening of all the synthesized compounds was done by using an acute model (Triton WR-1339 model), in which compound 6 shown more significant antidyslipidemic activity than fenofibrate (FF). The compound 6 was also found to reduce serum triglyceride (TG), total cholesterol (TC) and low density lipoprotein cholesterin (LDL) in HFD-induced hyperlipidemic mice. Moreover, compound 6 displayed hepatoprotective effect, a significant amelioration in hepatic indices (AST and ALT) toxicity was observed and the histological examination showed that compound 6 inhibited the development of hepatic lipid accumulation and ameliorated the damage in hepatic tissue compared to model mice. Additional effects such as the potent antioxidant and anti-inflammatory action confirmed and reinforced the efficacy of compound 6 as a new agent of dual-effect hypolipidemic and hepatoprotective activities.

Circular RNA­MTO1 suppresses breast cancer cell viability and reverses monastrol resistance through regulating the TRAF4/Eg5 axis.

Circular RNAs (circRNAs), a class of endogenous RNAs, have emerged as an enigmatic class of genes. However, little is known about their value in the progression and chemoresistance of cancers. The present study sought to determine the expression profiles and potential modulatory role of circRNAs on breast cancer cell viability and monastrol resistance. Monastrol-resistant cell lines were established by exposing breast cancer cells to increasing concentrations of monastrol. A human circRNA microarray was used to search for dysregulated circRNAs in monastrol-resistant cells, then circRNA­MTO1 (hsa­circRNA-007874) was validated as a circRNA that exhibited elevated expression levels in monastrol-resistant cells. Mechanistic investigations suggested that upregulation of circRNA­MTO1 suppressed cell viability, promoted monastrol-induced cell cytotoxicity and reversed monastrol resistance. Subsequently, Eg5 was identified as the functional target of circRNA­MTO1, and MTO1 inhibited Eg5 protein level but not mRNA level. By treating with protein synthesis inhibitor cycloheximide (CHX), it was revealed that MTO1 did not affect the protein stability of Eg5. RNA-pull down experiments followed by mass spectrometry revealed that MTO1 interacted with tumor necrosis factor receptor associated factor 4 (TRAF4), and sequester TRAF4 from activating Eg5 translation, thereby inhibiting the Eg5 protein level. Taken together, the data reveal a regulatory mechanism by circRNA­MTO1 to control cell viability and monastrol resistance in breast cancer cells.

Dithiolethiones: a privileged pharmacophore for anticancer therapy and chemoprevention.

Dithiolethiones are five-membered sulfur-containing cyclic scaffolds that exhibit antioxidative, anti-inflammatory, antithrombic and chemotherapeutic activities. Dithiolethiones display the chemopreventive and cytoprotective effects by activating the antioxidant response element and mounting the transcription of cytoprotective phase II enzymatic machinery. In addition, several classes of dithiolethiones efficiently modulate the activities of proteins that play crucial roles in normal and cancer cells, including glutathione S-transferase, cyclooxygenases and master regulator NF-κB. The present paper summarizes synthetic aspects, pharmacological potentials and biological attributes of dithiolethiones and its derivatives. Additionally, this review concludes with a discussion on how the current state-of-the-art technologies may help in defining a structure-activity relationship of dithiolethiones, thereby facilitating the design and synthesis of potent drug candidates.

Dithiolethione ACDT suppresses neuroinflammation and ameliorates disease severity in experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is an autoimmune disorder characterized by the central nervous system (CNS) infiltration of myelin-specific pathogenic T cells followed by brain inflammation in association with demyelination. Similarly, experimental autoimmune encephalomyelitis (EAE), the animal model of MS, also exhibits increased CNS infiltration of pathogenic T cells, including Th1 and Th17, leading to detrimental effects of neuroinflammation and demyelination. We previously reported that 3H-1,2-dithiole-3-thione (D3T), the structurally-simplest of the sulfur-containing dithiolethiones, exerted a promising therapeutic effect in EAE. In the current study we report that 5-Amino-3-thioxo-3H-(1,2)dithiole-4-carboxylic acid ethyl ester (ACDT), a substituted derivative of D3T, exhibits anti-inflammatory properties in EAE. ACDT, administered post immunization, delayed disease onset and reduced disease severity in chronic C57BL/6 EAE, and ACDT, administered during disease remission, suppressed disease relapse in relapsing-remitting SJL/J EAE. Further analysis of the cellular and molecular mechanisms underlying the protective effects of ACDT in EAE revealed that ACDT inhibited pathogenic T cell infiltration, suppressed microglia activation, repressed neurotoxic A1 astrocyte generation, lessened blood-brain barrier disruption, and diminished MMP3/9 production in the CNS of EAE. In summary, we demonstrate that ACDT suppresses neuroinflammation and ameliorates disease severity in EAE through multiple cellular mechanisms. Our findings suggest the potential of developing ACDT as a novel therapeutic agent for the treatment of MS/EAE.

Synthetic lethality in DNA repair network: A novel avenue in targeted cancer therapy and combination therapeutics.

Synthetic lethality refers to a lethal phenotype that results from the simultaneous disruptions of two genes, while the disruption of either gene alone is viable. Many DNA double strand break repair (DSBR) genes have synthetic lethal relationships with oncogenes and tumor suppressor genes, which can be exploited for targeted cancer therapy, an approach referred to as combination therapy. DNA double-strand breaks (DSBs) are one of the most toxic lesions to a cell and can be repaired by non-homologous end joining (NHEJ) or homologous recombination (HR). HR and NHEJ genes are particularly attractive targets for cancer therapy because these genes have altered expression patterns in cancer cells when compared with normal cells and these genetic abnormalities can be targeted for selectively killing cancer cells. Here, we review recent advances in the development of small molecule inhibitors against HR and NHEJ genes to induce synthetic lethality and address the future directions and clinical relevance of this approach. © 2017 IUBMB Life, 69(12):929-937, 2017.

Synthesis and characterization of new 1-hydroxy-2-pyridinethione derivatives: Their lead complexes and efficacy in the treatment of acute lead poisoning in rats.

A number of new mono- and dihydroxypyridinethione ligands have been synthesized via reaction of dimethylamine and amino acid esters with the active amide obtained from the reaction of 1-hydroxy-2-pyridinethione-4-carboxylic acid (1) and 1,1'-carbonyldiimidazole in DMF. Moreover, the lead complexes of these new ligands were also prepared. Structures of the newly synthesized compounds have been confirmed by different spectroscopic methods such as IR, 1H NMR, and 13C NMR, and by elemental analysis. The effect of these synthesized ligands on the excretion of lead, iron, and zinc, and their distribution in kidneys, liver, and bones in acutely intoxicated rats was investigated and results, for lead, were compared with those of the known drug meso-2,3-dimercaptosuccinic acid (DMSA). Results obtained revealed that compound 5 exhibits remarkable ability in total fecal and urinary excretion of lead and was superior to DMSA. In addition, results show that the concentration of lead in soft tissues and bones was lower in rats treated with HTPL than those treated with DMSA. Furthermore, the concentration of lead in liver tissues obtained from sub-chronic lead-intoxicated rats treated with HTPL was lower than those treated with DMSA and calcium disodium ethylenediaminetetraacetic acid (CaNa2EDTA).

Design and discovery of novel monastrol-1,3,5-triazines as potent anti-breast cancer agent via attenuating Epidermal Growth Factor Receptor tyrosine kinase.

A novel series of hybrid analogues of monastrol-1,3,5-triazine were designed and developed via one-pot synthesis using Bi(NO3)3 as a catalyst. Entire compounds were evaluated for their anticancer activity against HeLa (cervical cancer), MCF-7 (breast cancer), HL-60 (Human promyelocytic leukemia), HepG2 (Hepatocellular carcinoma) and MCF 12A (normal epithelial breast cell line) using MTT assay, where they showed highest inhibitory activity against MCF-7. The molecules were also found to be non-toxic to MCF 12A cells. These molecules showed considerable inhibitory percentage against Epidermal Growth Factor Receptor tyrosine kinase (EGFR-TK), in in-vitro assay. Molecular docking study was carried out on the analogs and reference compound (Erlotinib) into the ATP binding site of EGFR-TK domain (PDB ID:1M17) to elucidate vital structural residues necessary for bioactivity. The effect of most active compound 7l was also estimated in-vivo in DMBA induced mammary tumor in female Sprague-Dawley rats. The effect of anti-breast cancer effect of 7l was quantified on the basis of tumour incidence, body weight and tumor volume in DMBA-induced rats. Its effect on biochemical parameters, such as antioxidant status (SOD, CAT, GPX and GSH) and lipid peroxidation was also studied. The compound 7l showed inhibition of EGFR downstream signalling in the western blot analysis.

3H-1,2-Dithiole-3-thione as a novel therapeutic agent for the treatment of ischemic stroke through Nrf2 defense pathway.

Cerebral ischemic stroke accounts for more than 80% of all stroke cases. During cerebral ischemia, reactive oxygen species produced in brain tissue induce oxidative stress and inflammatory responses. D3T, the simplest compound of the cyclic, sulfur-containing dithiolethiones, is found in cruciferous vegetables and has been reported to induce antioxidant genes and glutathione biosynthesis through activation of Nrf2. In addition to antioxidant activity, D3T was also reported to possess anti-inflammatory effects. In this study, we evaluated the therapeutic potential of D3T for the treatment of ischemic stroke and investigated the mechanisms underlying the protective effects of D3T in ischemic stroke. Mice subjected to transient middle cerebral artery occlusion/reperfusion (tMCAO/R) were administered with vehicle or D3T to evaluate the effect of D3T in cerebral brain injury. We observed D3T reduced infarct size, decreased brain edema, lessened blood-brain barrier disruption, and ameliorated neurological deficits. Further investigation revealed D3T suppressed microglia (MG) activation and inhibited peripheral inflammatory immune cell infiltration of CNS in the ischemic brain. The protective effect of D3T in ischemic stroke is mediated through Nrf2 induction as D3T-attenuated brain injury was abolished in Nrf2 deficient mice subjected to tMCAO/R. In addition, in vitro results indicate the induction of Nrf2 by D3T is required for its suppressive effect on MG activation and cytokine production. In summary, we demonstrate for the first time that D3T confers protection against ischemic stroke, which is mediated through suppression of MG activation and inhibition of CNS peripheral cell infiltration, and that the protective effect of D3T in ischemic stroke is dependent on the activation of Nrf2.

AP39, a Mitochondria-Targeted Hydrogen Sulfide Donor, Supports Cellular Bioenergetics and Protects against Alzheimer's Disease by Preserving Mitochondrial Function in APP/PS1 Mice and Neurons.

Increasing evidence suggests that mitochondrial functions are altered in AD and play an important role in AD pathogenesis. It has been established that H2S homeostasis is balanced in AD. The emerging mitochondrial roles of H2S include antioxidation, antiapoptosis, and the modulation of cellular bioenergetics. Here, using primary neurons from the well-characterized APP/PS1 transgenic mouse model, we studied the effects of AP39 (a newly synthesized mitochondrially targeted H2S donor) on mitochondrial function. AP39 increased intracellular H2S levels, mainly in mitochondrial regions. AP39 exerted dose-dependent effects on mitochondrial activity in APP/PS1 neurons, including increased cellular bioenergy metabolism and cell viability at low concentrations (25-100 nM) and decreased energy production and cell viability at a high concentration (250 nM). Furthermore, AP39 (100 nM) increased ATP levels, protected mitochondrial DNA, and decreased ROS generation. AP39 regulated mitochondrial dynamics, shifting from fission toward fusion. After 6 weeks, AP39 administration to APP/PS1 mice significantly ameliorated their spatial memory deficits in the Morris water maze and NORT and reduced Aß deposition in their brains. Additionally, AP39 inhibited brain atrophy in APP/PS1 mice. Based on these results, AP39 was proposed as a promising drug candidate for AD treatment, and its anti-AD mechanism may involve protection against mitochondrial damage.

Medical Functions of Hydrogen Sulfide.

Hydrogen sulfide (H(2)S) is a gasomediator synthesized from L- and D-cysteine in various tissues. It is involved in a number of physiological and pathological processes. H(2)S exhibits antiatherosclerotic, vasodilator, and proangiogenic properties, and protects the kidney and heart from damage following ischemia/reperfusion injury. H(2)S donors may be natural or synthetic, and may be used for the safe treatment of a wide range of diseases. This review article summarizes the current state of knowledge of the therapeutic function of H(2)S.