Thrombospondin 1 and Reelin act through Vldlr to regulate cardiac growth and repair.

Adult mammalian cardiomyocytes have minimal cell cycle capacity, which leads to poor regeneration after cardiac injury such as myocardial infarction. Many positive regulators of cardiomyocyte cell cycle and cardioprotective signals have been identified, but extracellular signals that suppress cardiomyocyte proliferation are poorly understood. We profiled receptors enriched in postnatal cardiomyocytes, and found that very-low-density-lipoprotein receptor (Vldlr) inhibits neonatal cardiomyocyte cell cycle. Paradoxically, Reelin, the well-known Vldlr ligand, expressed in cardiac Schwann cells and lymphatic endothelial cells, promotes neonatal cardiomyocyte proliferation. Thrombospondin1 (TSP-1), another ligand of Vldlr highly expressed in adult heart, was then found to inhibit cardiomyocyte proliferation through Vldlr, and may contribute to Vldlr's overall repression on proliferation. Mechanistically, Rac1 and subsequent Yap phosphorylation and nucleus translocation mediate the regulation of the cardiomyocyte cell cycle by TSP-1/Reelin-Vldlr signaling. Importantly, Reln mutant neonatal mice displayed impaired cardiomyocyte proliferation and cardiac regeneration after apical resection, while cardiac-specific Thbs1 deletion and cardiomyocyte-specific Vldlr deletion promote cardiomyocyte proliferation and are cardioprotective after myocardial infarction. Our results identified a novel role of Vldlr in consolidating extracellular signals to regulate cardiomyocyte cell cycle activity and survival, and the overall suppressive TSP-1-Vldlr signal may contribute to the poor cardiac repair capacity of adult mammals.

Improved Sleep Affects Epigastric Pain in Functional Dyspepsia by Reducing the Levels of Inflammatory Mediators.

INTRODUCTION: The pathogenesis of epigastric pain in functional dyspepsia (FD) is complex. The study aims to explore the effect of sleep improvement on this symptom. METHODS: In total, 120 patients with FD-associated epigastric pain and insomnia were randomly divided into experimental and control groups using the envelope method. After applying the exclusion criteria, 107 patients were enrolled in the experimental (56 patients) and control (51 patients) groups. Insomnia was graded according to the Pittsburgh Sleep Quality Index (PSQI). In the experimental group, eszopiclone 3 mg, eszopiclone 3 mg + estazolam 1 mg, and eszopiclone 3 mg + estazolam 2 mg were given to patients with mild, moderate, and severe insomnia, respectively. In the control group, patients were given 1, 2, or 3 tablets of vitamin B complex. Patient sleep quality was monitored with Sleepthing. Epigastric pain was evaluated with a Numeric Rating Scale. The serum levels of IL-1ß, IL-6, IL-8, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay. Pain scores, sleep parameters, and serum levels of inflammatory mediators were compared before and after treatment. RESULTS: After treatment, the pain scores, sleep parameters, and TNF-α and IL-6 levels in the experimental group were significantly lower than those in the control group (p < 0.05). PSQI insomnia scores were significantly associated with pain scores, IL-6, and TNF-α (p < 0.05) but not in IL-8 and IL-1ß levels (p > 0.05) among the three groups. CONCLUSIONS: Improving sleep with eszopiclone and/or estazolam alleviates FD-associated epigastric pain, possibly by inhibiting related downstream transmission pathways and reducing the release of inflammatory mediators.

Extracellular vesicles derived from human bone marrow mesenchymal stem cells protect rats against acute myocardial infarction-induced heart failure.

Extracellular vesicles (EVs) derived from human bone marrow mesenchymal stem cells (BMSCs) are suggested to promote angiogenesis in a rat model of acute myocardial infarction (AMI). This study aimed to explore the underlying mechanism of BMSCs-EVs in AMI-induced heart failure (HF). BMSCs were isolated and verified, and EVs were purified and identified. After establishment of AMI-induced HF models, rats were treated with BMSCs-EVs and/or overexpressing (ov)/knocking down (kd) bone morphogenetic protein 2 (BMP2). Cardiac function, myocardial histopathological changes, angiogenesis, and vascular regeneration density were measured. Levels of pro-angiogenesis factors and cardiomyocyte apoptosis were detected. The viability and angiogenesis of hypoxic human umbilical vein endothelial cells (HUVECs) were measured. After BMSCs-EV treatment, the cardiac function of HF rats was improved, myocardial fibrosis and inflammatory cell infiltration were decreased, angiogenesis was increased, and cardiomyocyte apoptosis was inhibited. BMP2 was significantly upregulated in the myocardium. Ov-BMP2-BMSCs-EVs alleviated myocardial fibrosis and inflammatory cell infiltration, and promoted angiogenesis of HF rats, and improved the activity and angiogenesis of hypoxic HUVECs, while kd-BMP2-BMSCs-EVs showed limited protection against AMI-induced HF. BMSCs-EVs deliver BMP2 to promote angiogenesis and improve cardiac function of HF rats.

Synthesis and Evaluation of Bakuchiol Derivatives as Potent Anti-inflammatory Agents in Vitro and in Vivo.

Bakuchiol, a prenylated phenolic monoterpene derived from the fruit of Psoralen corylifolia L. (Buguzhi), is widely used to treat tumors, viruses, inflammation, and bacterial infections. In this study, we designed and synthesized 30 bakuchiol derivatives to identify new anti-inflammatory drugs. The anti-inflammatory activities of the derivatives were screened using lipopolysaccharide-induced RAW264.7 cells. To evaluate the anti-inflammatory activity of the compounds, we measured nitric oxide (NO), interleukin-6, and tumor necrosis factor-α production. Based on the screening results, compound 7a displayed more pronounced activity than bakuchiol and celecoxib. Furthermore, the mechanistic studies indicated that 7a inhibited pro-inflammatory cytokine release, which was correlated with activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway and blockade of the nuclear factor-κB/mitogen-activated protein kinase signaling pathway. The in vivo anti-inflammatory activity in zebrafish indicated that 7a inhibited NO and reactive oxygen species production in a dose-dependent manner. These results indicate that 7a is a potential candidate for development as an anti-inflammatory agent.

Correcting mitochondrial fusion by manipulating mitofusin conformations.

Mitochondria are dynamic organelles that exchange contents and undergo remodelling during cyclic fusion and fission. Genetic mutations in MFN2 (the gene encoding mitofusin 2) interrupt mitochondrial fusion and cause the untreatable neurodegenerative condition Charcot-Marie-Tooth disease type 2A (CMT2A). It has not yet been possible to directly modulate mitochondrial fusion, in part because the structural basis of mitofusin function is not completely understood. Here we show that mitofusins adopt either a fusion-constrained or a fusion-permissive molecular conformation, directed by specific intramolecular binding interactions, and demonstrate that mitofusin-dependent mitochondrial fusion can be regulated in mouse cells by targeting these conformational transitions. On the basis of this model, we engineered a cell-permeant minipeptide to destabilize the fusion-constrained conformation of mitofusin and promote the fusion-permissive conformation, reversing mitochondrial abnormalities in cultured fibroblasts and neurons that harbour CMT2A-associated genetic defects. The relationship between the conformational plasticity of mitofusin 2 and mitochondrial dynamism reveals a central mechanism that regulates mitochondrial fusion, the manipulation of which can correct mitochondrial pathology triggered by defective or imbalanced mitochondrial dynamics.

Discovery of Novel 3,4-Dihydro-2(1H)-Quinolinone Sulfonamide Derivatives as New Tubulin Polymerization Inhibitors with Anti-Cancer Activity.

In this paper, a small series of novel quinoline sulfonamide derivatives was synthesized, and their structure of the target compounds were confirmed by 1H NMR and MS. The screening of the news target compounds' in vitro cytotoxic activities against tumor cell lines by the MTT method was performed. Among them, compound D13 (N-(4-methoxybenzyl)-2-oxo-N-(3,4,5-trimethoxyphenyl)-1,2,3,4-tetrahydroquinoline-6-sulfonamide exhibited the strongest inhibitory effect on the proliferation of HeLa (IC50: 1.34 µM), and this value correlated well with the inhibitory activities of the compound against tubulin polymerization (IC50: 6.74 µM). In summary, a new type of quinoline-sulfonamide derivative with tubulin polymerization inhibitory activity was discovered, and it can be used as a lead compound for further modification.

Mitoflash generated at the Qo site of mitochondrial Complex III.

The previous research has shown that mitochondrial flash (mitoflash) genesis are functionally and mechanistically integrated with mitochondrial electron transport chain (ETC) energy metabolism. However, the response of mitoflash to superoxide is not entirely consistent with the response of MitoSOX Red. The generation mechanism of mitoflash is still unclear. Here, we investigated mitoflash activities, using the different combinations of ETC substrates and inhibitors, in permeabilized cardiomyocytes or hearts. We found that blocking the complete electron flow, from Complex I to IV, with any one of ETC inhibitors including rotenone (Rot), antimycin A (AntA), myxothiazol (Myxo), stigmatellin, and sodium cyanide, will lead to the abolishment of mitoflashes triggered by substrates in adult permeabilized cardiomyocytes. However, Myxo boosted mitoflashes triggered by the reverse electron of N,N,N',N'-tetramethyl-p-phenylenediamine/ascorbate. Moreover, Rot and AntA furtherly enhanced mitoflash activity rather than depressed it, suggesting that mitoflashes generated at the Complex III Qo site. Meanwhile, the inhibition of Complex III protein expression resulted in the activity of Complex III decrease, which decreased mitoflash frequency. The function defect (no change of protein level) of the Qo site of Complex III in aging hearts augmented mitoflash generation confirmed the Qo site function was critical to mitoflash genesis. Thus, our results indicate that mitoflash detected by circularly permuted yellow fluorescent protein is generated at the Qo site of Complex III.

Mitochondrial fusion mediated by fusion promotion and fission inhibition directs adult mouse heart function toward a different direction.

Mitochondrial fusion and fission are essential for heart function. Abrogating mitochondrial dynamism leads to cardiomyopathy. Excessive mitochondrial fragmentation is involved in most heart diseases, thus enhancing mitochondrial fusion will be a potential therapeutic strategy. To understand the effects of promoting mitochondrial fusion in adult cardiac, we investigated mice hearts, and cultured murine embryonic fibroblasts (MEFs), in which mitofusin 2 (Mfn2) overexpressed or dynamin-related protein 1 (Drp1) was abrogated concomitantly forcing mitochondrial fusion. Parallel studies revealed that fission-defective Drp1 knockout hearts and MEFs evoked stronger mitochondrial enlargement, enhanced mitophagy with mitochondrial volume decrease and increased mitochondrial calcium uptake, superoxide production, and permeability transition pore opening, contributed to cardiomyocyte apoptosis and dilated cardiomyopathy. Mfn2 overexpression in the adult heart is comparable with the control except for slight mitochondrial enlargement and mitochondrial volume increase, but without mitophagy induction. Moreover, Mfn2 overexpression increases mitochondrial biogenesis and fusion could protect against mitochondrial fragmentation and Drp1 deletion evoking mitophagy in MEFs. Our findings indicate that mitochondrial fusion provoked by fusion promotion and fission inhibition direct the different fate of heart, Mfn2 upregulation other than Drp1 downregulation well maintains heart mitochondrial function is a more safe strategy for correcting excessive mitochondrial fragmentation in hearts.

Discovery and evaluation of novel synthetic 5-alkyl-4-oxo-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinoxaline-1-carbox-amide derivatives as anti-inflammatory agents.

To develop novel anti-inflammatory agents, a series of 5-alkyl-4-oxo-4,5-dihydro-[1, 2, 4]triazolo[4,3-a]quinoxaline-1-carboxamide derivatives were designed, synthesised, and evaluated for anti-inflammatory effects using RAW264.7 cells. Structures of the synthesised compounds were determined using 1H NMR, 13 C NMR, and HRMS. All the compounds were screened for anti-inflammatory activity based on their inhibitory effects against LPS-induced NO release. Among them, 5-(3,4,5-trimethoxybenzyl)-4-oxo-4,5-dihydro-[1, 2, 4]triazolo[4,3-a]quinoxaline-1-carboxamide (6p) showed the highest anti-inflammatory activity and inhibited NO release more potently than the lead compound D1. Further studies revealed that compound 6p reduced the levels of NO, TNF-α, and IL-6, and that its anti-inflammatory activity involves the inhibition of COX-2 and iNOS and downregulation of the mitogen-activated protein kinases (MAPK) signal pathway. Notably, compound 6p displayed more prominent anti-inflammatory activity than D1 and the positive control ibuprofen in the in vivo acute inflammatory model. Overall, these findings indicate that compound 6p is a therapeutic candidate for the treatment of inflammation.

Comparative study on isolation and mitochondrial function of adult mouse and rat cardiomyocytes.

BACKGROUND: Cultured adult mouse and rat cardiomyocytes are the best and low-cost cell model for cardiac cellular physiology, pathology, drug toxicity screening, and intervention. The functions of mouse cardiomyocytes decline faster than rat cardiomyocytes in culture conditions. However, little is known about the difference of mitochondrial function between cultured mouse and rat myocytes. METHODS AND RESULTS: A large number of adult mouse and rat cardiomyocytes were comparative isolated using a simple perfusion system. Cardiomyocytes mitochondrial functions were measured after 2 h, 1 day, 2 days, 3 days, and 4 days culture by monitoring mitoflashes. We found that the mitochondrial function of mouse myocytes was remarkedly declined on the third day. Then, we focused on the third day cultured mouse and rat myocytes, comparatively analyzing the respiration function and superoxide generation stimulated by pyruvate/malate/ADP and the mitochondrial permeability transition pore (mPTP) opening induction. Mouse myocytes showed lower respiration and mitoflash activity, but without the change of maximum uncoupled respiration when compared with rat myocytes. Although the response to superoxide production stimulated by respiration substrates was slower than rat myocytes, the basal superoxide generation is faster than the rat. The faster mitochondrial reactive oxygen species (ROS) generation of mouse myocytes upon laser stimulation triggered the faster mPTP opening compared with the rat. Finally, antioxidant MitoTEMPO pretreatment preserved the mitochondrial function of mouse myocytes on the third day. CONCLUSIONS: The mitochondrial function and stability are different between cultured mouse and rat cardiac myocytes beyond 3 days even though they both belong to Muridae. Mitochondrial ROS impairs the mitochondrial functions of mouse cardiomyocytes on the third day. Suppressing superoxide maintained the mitochondrial function of mouse myocytes on the third day.

Synthesis and biological evaluation of ursolic acid derivatives bearing triazole moieties as potential anti-Toxoplasma gondii agents.

Ursolic acid (UA), a plant-derived compound, has many properties beneficial to health. In the present study, we synthesised three series of novel UA derivatives and evaluated their anti-Toxoplasma gondii activity both in vitro and in vivo. Most derivatives exhibited an improved anti-T. gondii activity in vitro when compared with UA (parent compound), whereas compound 3d exhibited the most potent anti-T. gondii activity in vivo. Spiramycin served as the positive control. Additionally, determination of biochemical parameters, including the liver and spleen indexes, indicated compound 3d to effectively reduce hepatotoxicity and significantly enhance anti-oxidative effects, as compared with UA. Furthermore, our molecular docking study indicated compound 3d to possess a strong binding affinity for T. gondii calcium-dependent protein kinase 1 (TgCDPK1). Based on these findings, we conclude that compound 3d, a derivative of UA, could act as a potential inhibitor of TgCDPK1.

Heart specific knockout of Ndufs4 ameliorates ischemia reperfusion injury.

RATIONALE: Ischemic heart disease (IHD) is a leading cause of mortality. The most effective intervention for IHD is reperfusion, which ironically causes ischemia reperfusion (I/R) injury mainly due to oxidative stress-induced cardiomyocyte death. The exact mechanism and site of reactive oxygen species (ROS) generation during I/R injury remain elusive. OBJECTIVE: We aim to test the hypothesis that Complex I-mediated forward and reverse electron flows are the major source of ROS in I/R injury of the heart. METHODS AND RESULTS: We used a genetic model of mitochondrial Complex I deficiency, in which a Complex I assembling subunit, Ndufs4 was knocked out in the heart (Ndufs4H-/-). The Langendorff perfused Ndufs4H-/- hearts exhibited significantly reduced infarct size (45.3 ±â€¯5.5% in wild type vs 20.9 ±â€¯8.1% in Ndufs4H-/-), recovered contractile function, and maintained mitochondrial membrane potential after no flow ischemia and subsequent reperfusion. In cultured adult cardiomyocytes from Ndufs4H-/- mice, I/R mimetic treatments caused minimal cell death. Reintroducing Ndufs4 in Ndufs4H-/- cardiomyocytes abolished the protection. Mitochondrial NADH declined much slower in Ndufs4H-/- cardiomyocytes during reperfusion suggesting decreased forward electron flow. Mitochondrial flashes, a marker for mitochondrial respiration, were inhibited in Ndufs4H-/- cardiomyocytes at baseline and during I/R, which was accompanied by preserved aconitase activity suggesting lack of oxidative damage. Finally, pharmacological blockade of forward and reverse electron flow at Complex I inhibited I/R-induced cell death. CONCLUSIONS: These results provide the first genetic evidence supporting the central role of mitochondrial Complex I in I/R injury of mouse heart. The study also suggests that both forward and reverse electron flows underlie oxidative cardiomyocyte death during reperfusion.

Comprehensive Circular RNA Profiling Reveals the Regulatory Role of the CircRNA-0067835/miR-155 Pathway in Temporal Lobe Epilepsy.

BACKGROUND/AIMS: Temporal lobe epilepsy (TLE) is the most common form of adult localization-related epilepsy that is accompanied by progressive etiopathology and high incidences of drug resistance. Circular RNAs (circRNAs) play important roles in fine-tuning gene expression, however, the expression profile and clinical significance of circRNAs in TLE remains unknown. METHODS: Circular RNA microarray was conducted to identify TLE-related circRNAs. CCK8 assays and flow cytometric assays were conducted to clarify the role of circRNA in TLE in vitro. Bioinformatics analysis and in vitro experiments were conducted to clarify the mechanism of circRNA-mediated gene regulation in TLE cell. RESULTS: 586 differentially expressed circRNAs were identified between TLE and the control tissues. The expression of circRNA-0067835 was significantly down-regulated in tissues and plasma from TLE patients. Lower circRNA-0067835 correlated to increased seizure frequency, HS, and higher Engel's score. Overexpression of circRNA-0067835 observably decreased SH-SY5Y cell proliferation by causing G1 arrest and promoting apoptosis. Bioinformatics online programs predicted that circRNA-0067835 acted as miR-155 sponge to regulate FOXO3a expression, which was validated using luciferase reporter assay. CONCLUSION: Our experiments showed that circRNA-0067835 regulated refractory epilepsy progression by acting as a sponge of miR-155 to promote FOXO3a expression, indicating that circRNA-0067835 may serve as a potential therapeutic target for patients with TLE.

Mitoflash lights single mitochondrial dynamics events in mature cardiomyocytes.

Mitochondria, the powerhouse of eukaryotic cells, are highly dynamic organelle. Mitochondrial fission, fusion, kissing and contraction have been reported over and over again in non-static cells, such as fibroblast, with tubular mitochondrial networks. Even though the fluorescence propagation among mitochondria of mature cardiomyocytes had been captured using mitochondrial matrix targeted photoactivatable GFP (PAGFP) or MitoDendra proteins, there are no direct evidence that single real time mitochondrial dynamics events exist in mature cardiomyocytes with ball-like mitochondria. Here we first time revealed the visualizable single mitochondrial dynamics events in adult mature cardiomyocytes by the mitochondrial flash (mitoflash). We found fission, fusion, contraction and kissing were accompanied by a mitoflash event. Metabolism could increase mitochondrial contraction. Fusion and Kissing mediated inter-mitochondrial communication with higher frequency than fission. These results demonstrate that mitochondria of static mature cardiomyocytes are undergoing the rare, but real dynamics change.

Synthesis and characterisation of (Z)-styrylbenzene derivatives as potential selective anticancer agents.

To identify anticancer agents with high potency and low toxicity, a series of (Z)-styrylbenzene derivatives were synthesised and evaluated for anticancer activities using a panel of nine cancer cell lines and two noncancerous cell lines. Most derivatives exhibited significant anti-proliferative activities against five cancer cell lines, including MGC-803 and BEL-7402. (Z)-3-(p-Tolyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile (6h) showed a strong inhibitory effect on MGC-803 cells (IC50 < 0.01 µM) and exhibited stronger anti-proliferative activity than taxol (IC50 < 0.06 ± 0.01 µM). The IC50 value of 6h in L-02 cells was 10,000-fold higher than in MGC-803 cells. Compound 6h inhibited proliferation of BEL-7402 cells by arresting at the G2/M phase through up-regulation of cyclin B1 expression, down-regulation of cyclin A and D1 expression, and induction of apoptosis. In addition, 6h inhibited the migration of BEL-7402 cells and the formation of cell colonies.

Design and synthesis of novel oridonin analogues as potent anticancer agents.

To identify anticancer agents with higher potency and lower toxicity, a series of oridonin derivatives with substituted benzene moieties at the C17 position were designed, synthesised, and evaluated for their antiproliferative properties. Most of the derivatives exhibited antiproliferative effects against AGS, MGC803, Bel7402, HCT116, A549, and HeLa cells. Compound 2p (IC50 = 1.05 µM) exhibited the most potent antiproliferative activity against HCT116 cells; it was more potent than oridonin (IC50 = 6.84 µM) and 5-fluorouracil (5-FU) (IC50 = 24.80 µM). The IC50 value of 2p in L02 cells was 6.5-fold higher than that in HCT116 cells. Overall, it exhibited better selective antiproliferative activity and specificity than oridonin and 5-FU. Furthermore, compound 2p arrested HCT116 cells at the G2 phase of the cell cycle and increased the percentage of apoptotic cells to a greater extent than oridonin.

Identification and prognostic value of anterior gradient protein 2 expression in breast cancer based on tissue microarray.

Breast cancer has attracted substantial attention as one of the major cancers causing death in women. It is crucial to find potential biomarkers of prognostic value in breast cancer. In this study, the expression pattern of anterior gradient protein 2 in breast cancer was identified based on the main molecular subgroups. Through analysis of 69 samples from the Gene Expression Omnibus database, we found that anterior gradient protein 2 expression was significantly higher in non-triple-negative breast cancer tissues compared with normal tissues and triple-negative breast cancer tissues (p < 0.05). The data from a total of 622 patients from The Cancer Genome Atlas were analysed. The data from The Cancer Genome Atlas and results from quantitative reverse transcription polymerase chain reaction also verified the anterior gradient protein 2 expression pattern. Furthermore, we performed immunohistochemical analysis. The quantification results revealed that anterior gradient protein 2 is highly expressed in non-triple-negative breast cancer (grade 3 excluded) and grade 1 + 2 (triple-negative breast cancer excluded) tumours compared with normal tissues. Anterior gradient protein 2 was significantly highly expressed in non-triple-negative breast cancer (grade 3 excluded) and non-triple-negative breast cancer tissues compared with triple-negative breast cancer tissues (p < 0.01). In addition, anterior gradient protein 2 was significantly highly expressed in grade 1 + 2 (triple-negative breast cancer excluded) and grade 1 + 2 tissues compared with grade 3 tissues (p < 0.05). Analysis by Fisher's exact test revealed that anterior gradient protein 2 expression was significantly associated with histologic type, histological grade, oestrogen status and progesterone status. Univariate analysis of clinicopathological variables showed that anterior gradient protein 2 expression, tumour size and lymph node status were significantly correlated with overall survival in patients with grade 1 and 2 tumours. Cox multivariate analysis revealed anterior gradient protein 2 as a putative independent indicator of unfavourable outcomes (p = 0.031). All these data clearly showed that anterior gradient protein 2 is highly expressed in breast cancer and can be regarded as a putative biomarker for breast cancer prognosis.

Interdependence of Parkin-Mediated Mitophagy and Mitochondrial Fission in Adult Mouse Hearts.

RATIONALE: The role of Parkin in hearts is unclear. Germ-line Parkin knockout mice have normal hearts, but Parkin is protective in cardiac ischemia. Parkin-mediated mitophagy is reportedly either irrelevant, or a major factor, in the lethal cardiomyopathy evoked by cardiac myocyte-specific interruption of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission. OBJECTIVE: To understand the role of Parkin-mediated mitophagy in normal and mitochondrial fission-defective adult mouse hearts. METHODS AND RESULTS: Parkin mRNA and protein were present at low levels in normal mouse hearts, but were upregulated after cardiac myocyte-directed Drp1 gene deletion in adult mice. Alone, forced cardiac myocyte Parkin overexpression activated mitophagy without adverse effects. Likewise, cardiac myocyte-specific Parkin deletion evoked no adult cardiac phenotype, revealing no essential function for, and tolerance of, Parkin-mediated mitophagy in normal hearts. Concomitant conditional Parkin deletion with Drp1 ablation in adult mouse hearts prevented Parkin upregulation in mitochondria of fission-defective hearts, also increasing 6-week survival, improving ventricular ejection performance, mitigating adverse cardiac remodeling, and decreasing cardiac myocyte necrosis and replacement fibrosis. Underlying the Parkin knockout rescue was suppression of Drp1-induced hyper-mitophagy, assessed as ubiquitination of mitochondrial proteins and mitochondrial association of autophagosomal p62/sequestosome 1 (SQSTM1) and processed microtubule-associated protein 1 light chain 3 (LC3-II). Consequently, mitochondrial content of Drp1-deficient hearts was preserved. Parkin deletion did not alter characteristic mitochondrial enlargement of Drp1-deficient cardiac myocytes. CONCLUSIONS: Parkin is rare in normal hearts and dispensable for constitutive mitophagic quality control. Ablating Drp1 in adult mouse cardiac myocytes not only interrupts mitochondrial fission, but also markedly upregulates Parkin, thus provoking mitophagic mitochondrial depletion that contributes to the lethal cardiomyopathy.

Design, synthesis, anti-inflammatory activity, and molecular docking studies of perimidine derivatives containing triazole.

We report here the design, synthesis, and anti-inflammatory activities of a series of perimidine derivatives containing triazole (5a-s). The chemical structures of the synthesized compounds have been assigned on the basis of IR, 1H NMR, 13C NMR, and HRMS spectral analyses. The anti-inflammatory properties of the synthesized perimidine derivatives were evaluated in a lipopolysaccharide (LPS)-stimulated inflammation model. Among the tested compounds, compound 7-(3-methylbenzyl)-7H-[1,2,4]triazolo[4,3-a]perimidine (hereafter referred to as 5h) and compound 7-(2-fluorobenzyl)-7H-[1,2,4]triazolo[4,3-a]perimidine (hereafter referred to as 5n) caused a reduction in the levels of the pro-inflammatory cytokines-tumor necrosis factor (TNF)-α and interleukin (IL)-6-in RAW264.7 cells. The anti-inflammatory potential of compounds 5h and 5n was also evaluated in vivo in a xylene-induced ear inflammation model. Compound 5n showed the most potent anti-inflammatory activity with an inhibition of 49.26% at a dose of 50mg/kg. This activity is more potent than that of the reference drug ibuprofen (28.13%), and slightly less than that of indometacin (49.36%). To further elucidate the mechanisms underlying these inhibitory effects, LPS-induced nuclear factor-κB (NF-κB) activation and mitogen-activated protein kinase (MAPK) phosphorylation were studied. The results of western blotting showed that the extract obtained from compound 5n inhibited NF-κB (p65) activation and MAPK (extracellular signal-regulated kinase (ERK) and p38) phosphorylation in a dose-dependent manner. Moreover, the results of a docking study of compound 5n into the COX-2 binding site revealed that its mechanism was possibly similar to that of naproxen, a COX-2 inhibitor. The effect of compound 5n on COX-2 antibody was showed it could significantly inhibit COX-2 activity.