Modular Assembly of 2-Aminoaniline Derivatives by Merging Hydroxylamine-Passerini and Hetero-Cope Rearrangement.

A metal-free three-component protocol that combines a hydroxylamine-Passerini reaction and hetero-Cope rearrangement was realized, which enables the modular assembly of a wide range of structurally new and interesting 2-aminoanilines bearing an α-hydroxyamide substructure.

The Chinese Herbal Formula Huoxiang Zhengqi Dropping Pills Prevents Acute Intestinal Injury Induced by Heatstroke by Increasing the Expression of Claudin-3 in Rats.

Intestinal injury has been regarded as an important causative factor for systemic inflammation during heatstroke, and maintaining intestinal integrity has been a potential target for the prevention of HS. Huoxiang Zhengqi Dropping Pills (HZPD) is a modern preparation of Huoxiang Zhengqi and widely used to prevent HS. The present study aims to explore the protective effect of HZDP on intestinal injury during heatstroke and analyze its potential pharmacodynamic basis. Male rats in the control and HS groups were given normal saline, and those in the HZDP groups were given HZDP (0.23, 0.46, and 0.92 g/kg) before induction of HS. Serum contents of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), intestinal fatty acid-binding protein (iFABP), and diamine oxidase (DAO) were determined using ELISA. Histopathology of intestinal injury was observed following H&E staining. The expression of claudin-3 was determined using western blot, immunohistochemistry, and immunofluorescence techniques. Moreover, network pharmacological tools were used to analyze the potential pharmacodynamic basis and the mechanism of HZDP. Treatment with HZDP significantly prolonged the time to reach Tc. Compared with the control group, the contents of TNF-α, IL-6, iFABP, and DAO in HS rats increased markedly. HZDP treatments reduced these levels significantly, and the effects in the middle dose group (0.46 g/kg) were most obvious. HZDP also attenuated intestinal injury and significantly reversed the decrease in claudin-3 expression. Bioinformatics analysis suggested that 35 active ingredients and 128 target genes of HZDP were screened from TCMSP and 93 target genes intersected with heatstroke target genes, which were considered potential therapeutic targets. TNF-α and IL-6 were the main inflammatory target genes of HZDP correlated with HS. These results indicated that HZDP effectively protected intestinal barrier function and prevented acute intestinal injury by increasing the expression of claudin-3 in rats, eventually improving heat resistance.

Self-limiting bidirectional positive feedback between P53 and P21 is involved in cardiac hypertrophy.

Pathological cardiac hypertrophy is an independent risk factor of cardiovascular diseases. Although the function of p53 and p21 in pathological cardiac hypertrophy have been studied, the relationship between them in cardiomyocytes is still unclear. By using specific adenoviruses and siRNAs to modulate p53 or p21 expression in neonatal rat ventricular myocytes (NRVMs), we found that both upregulated p53 and p21 expression induced hypertrophic responses, and they promote each other's expression. Overexpression of p53 aggravated the hypertrophic response of cardiomyocytes in vitro and in vivo, while knockdown of p21 diminished the hypertrophic responses induced by angiotensin Ⅱ and the increase of p53 expression. Additionally, Angiotensin Ⅱ treatment promoted the nuclear translocation of p21 in NRVMs. Notably, increased p53 expression alone did not promote p21 translocation to the nucleus. Together, these data suggest a self-limiting bidirectional positive feedback interaction between p53 and p21 during cardiac hypertrophy.

Cardiomyocytic FoxP3 is involved in Parkin-mediated mitophagy during cardiac remodeling and the regulatory role of triptolide.

Rationale: Forkhead/winged helix transcriptional factor P3 (FoxP3) is a well-studied transcription factor that maintains the activity of T cells, but whether cardiomyocytic FoxP3 participates in cardiac remodeling (CR) remains unclear. The present study was to investigate the role of cardiomyocytic FoxP3 in CR from the perspective of mitophagy. Methods: CR was induced by angiotensin II (AngII) in vitro, or by isoproterenol (Iso) in vivo using male C57 mice or FoxP3DTR mice. Histological changes were observed by hematoxylin-eosin and Masson staining. Molecular changes were detected by immunohistochemistry, immunofluorescence, immunoblotting, and real-time PCR. Mitophagy was shaped by transmission electron microscopy and co-localization. The mRNA expression was operated by siRNA or adeno associated virus (AAV). Molecular interactions were detected by co-localization, immunoprecipitation (IP), and chromatin IP. Results: The expression and nuclear translocation of cardiomyocytic FoxP3 were downregulated in CR, while they were upregulated after triptolide (TP) treatment. In left ventricle (LV) remodeling in mice, autophagy was activated continuously in the myocardium, and TP significantly attenuated it. AngII induced massive mitophagy characterized by the activation of autophagy regulatory protein 5 (Atg5)-dependent autophagic flux. Critically, Parkin was identified as the main adaptor mediated myocardial mitophagy and was responsible for the effect of TP. Moreover, FoxP3 was responsible for the downregulation of Parkin and inhibited AngII-induced cardiac mitophagy. We found that mitophagy increased significantly and the inhibition of TP treatment reversed completely in FoxP3-deficient LVs. Mechanistically, FoxP3 interacted with a motif located downstream of the activating transcription 4 (ATF4)-binding motif involved in the promoter of Parkin and hijacked free nuclear ATF4 to decrease Parkin mRNA expression in CR. Conclusion: Cardiomyocytic FoxP3 could negatively regulate Parkin-mediated mitophagy in CR, and restoring cardiomyocytic FoxP3 activity provided a cardioprotective strategy by inhibiting excessive cardiac mitophagy.

Effect of Triptolide on Temporal Expression of Cell Cycle Regulators During Cardiac Hypertrophy.

Adult mammalian cardiomyocytes may reenter the cell cycle and cause cardiac hypertrophy. Triptolide (TP) can regulate the expressions of various cell cycle regulators in cancer cells. However, its effects on cell cycle regulators during myocardial hypertrophy and mechanism are unclear. This study was designed to explore the profile of cell cycle of cardiomyocytes and the temporal expression of their regulators during cardiac hypertrophy, as well as the effects of TP. The hypertrophy models employed were neonatal rat ventricular myocytes (NRVMs) stimulated with angiotensin II (Ang II) for scheduled times (from 5 min to 48 h) in vitro and mice treated with isoprenaline (Iso) for from 1 to 21 days, respectively. TP was used in vitro at 1 µg/L and in vivo at 10 µg/kg. NRVMs were analyzed using flow cytometry to detect the cell cycle, and the expression levels of mRNA and protein of various cell cycle regulators were determined using real-time PCR and Western blot. It was found NRVM numbers in phases S and G2 increased, while that in the G1 phase decreased significantly after Ang II stimulation. The mRNA expression levels of p21 and p27 increased soon after stimulation, and thereafter, mRNA expression levels of all cell cycle factors showed a decreasing trend and reached their lowest levels in 1-3 h, except for cyclin-dependent kinase 1 (CDK1) and CDK4 mRNA. The mRNA expression levels of CDK1, p21, and p27 increased markedly after stimulation with Ang II for 24-48 h. In myocardium tissue, CDK and cyclin expression levels peaked in 3-7 days, followed by a decreasing trend, while those of p21 and p27 mRNA remained at a high level on day 21. Expression levels of all protein were consistent with the results of mRNA in NRVMs or mice. The influence of Ang II or Iso on protein expression was more obvious than that on mRNA. TP treatment effectively prevented the imbalance in the expression of cell cycle regulators in the hypertrophy model group. In Conclusion, an imbalance in the expression of cell cycle regulators occurs during cardiac hypertrophy, and triptolide corrects these abnormal expression levels and attenuates cardiac hypertrophy.

Iron-Catalyzed Radical Relay Enabling the Modular Synthesis of Fused Pyridines from Alkyne-Tethered Oximes and Alkenes.

We have rationally designed a new class of alkyne-tethered oximes and applied them in an unprecedented iron-catalyzed radical relay protocol for the rapid assembly of a wide array of structurally new and interesting fused pyridines. This method shows broad substrate scope and good functional-group tolerance and enabled the synthesis of several biologically active molecules. Furthermore, the fused pyridines could be diversely functionalized through various simple transformations, such as cyclization, C-H alkylation, and a click reaction. DFT calculation studies indicate that the reactions involve cascade 1,5-hydrogen atom transfer, 5-exo-dig radical addition, and cyclization processes. Moreover, preliminary biological investigations suggest that some of the fused pyridines exhibit good anti-inflammatory activity by restoring the imbalance of inflammatory homeostasis of macrophages in a lipopolysaccharide-induced model.

Dual Role of Triptolide in Interrupting the NLRP3 Inflammasome Pathway to Attenuate Cardiac Fibrosis.

In a previous paper, we reported that triptolide (TP), a commonly used immunomodulator, could attenuate cardiac hypertrophy. This present study aimed to further explore the inhibition of cardiac fibrosis by TP and the possible mechanism from the perspective of the NOD-like receptor protein 3 (NLRP3) inflammasome. Hematoxylin-eosin and Masson's staining, immunohistochemistry, and immunofluorescence were performed to observe cardiac fibrotic changes in mice and mouse cardiac fibroblasts (CFs). The Western blot, colocalization, and immunoprecipitation were applied to detect protein expression and interactions. Results suggested that TP dose-dependently inhibited cardiac fibrosis induced by isoproterenol and collagen production of CFs induced by angiotensin II. TP exhibited an antifibrotic effect via inhibiting activation of the NLRP3 inflammasome, which sequentially decreased IL-1ß maturation, myeloid differentiation factor 88 (MyD88)-related phosphorylation of c-Jun N-terminal kinase (JNK), extracellular regulated protein kinase 1/2 (ERK1/2), and TGF-ß1/Smad signaling, and ultimately resulted in less collagen production. Moreover, TP showed no antifibrotic effect in Nlrp3-knockout CFs. Notably, TP inhibited the expression of NLRP3 and apoptosis-associated speck-like proteins containing a caspase recruitment domain (ASC) as well as inflammasome assembly, by interrupting the NLRP3-ASC interaction to inhibit inflammasome activation. Finally, TP indeed inhibited the NLRP3-TGFß1-Smad pathway in vivo. Conclusively, TP was found to play a dual role in interrupting the activation of the NLRP3 inflammasome to attenuate cardiac fibrosis.

Cyclin-Dependent Kinase Inhibitor p21WAF1/CIP1 Facilitates the Development of Cardiac Hypertrophy.

BACKGROUND/AIMS: Adult cardiomyocytes can re-enter cell cycle as stimulated by prohypertrophic factors although they withdraw from cell cycle soon after birth. p21WAF1/CIP1, a cyclin-dependent kinase inhibitor, has been implicated in cardiac hypertrophy, however, its precise contribution to this process remains largely unclear. METHODS: The gene expression profile in left ventricle (LV) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats was determined using quantitative PCR array and verified by real-time PCR and Western blotting. Hypertrophic response of H9c2 cells and neonatal rat ventricular myocytes (NRVM) were induced by angiotensin II (1 µmol/L). Cardiac hypertrophy of mice was elicited by isoproterenol (ISO) infusion (40 mg/kg per day for 14 days). p21-adenovirus and p21-siRNA were employed to transfect NRVM, and sterigmatocystin (STE, 3 mg/kg, ip, qd) was used to inhibit p21 activity. mRNA and protein expression levels of α- and ß-myosin heavy chain (MHC), p21WAF1/CIP1, calcineurin (CaN) and atrial natriuretic peptide (ANP) were assayed by realtime PCR and WB, respectively. RESULTS: Sixteen genes showed two-fold or greater changes between SHR and WKY rats, in which the expression of p21WAF1/CIP1 was upregulated by 4.15-fold (P=0.002) and reversed by losartan. Surface area, protein content, mRNA and protein expressions of ß-MHC, ANP and p21WAF1/CIP1 in H9c2 cells treated with AngII elevated significantly compared with control group. p21-Ad transfection markedly increased the surface area and ß-MHC mRNA expression of normal NRVMs, and p21-siRNA transfection decreased them in AngII-treated NRVMs. STE treatment decreased HW/BW and cross-sectional area, expression levels of ß-MHC, ANP and p21 significantly in ISO-treated mice. CONCLUSION: Our findings suggest that p21 facilitates the development of cardiac hypertrophy, and regulating the expression of p21 may be an approach to attenuate hypertrophic growth of cardiomyocytes.

Triptolide Upregulates Myocardial Forkhead Helix Transcription Factor p3 Expression and Attenuates Cardiac Hypertrophy.

The forkhead/winged helix transcription factor (Fox) p3 can regulate the expression of various genes, and it has been reported that the transfer of Foxp3-positive T cells could ameliorate cardiac hypertrophy and fibrosis. Triptolide (TP) can elevate the expression of Foxp3, but its effects on cardiac hypertrophy remain unclear. In the present study, neonatal rat ventricular myocytes (NRVM) were isolated and stimulated with angiotensin II (1 µmol/L) to induce hypertrophic response. The expression of Foxp3 in NRVM was observed by using immunofluorescence assay. Fifty mice were randomly divided into five groups and received vehicle (control), isoproterenol (Iso, 5 mg/kg, s.c.), one of three doses of TP (10, 30, or 90 µg/kg, i.p.) for 14 days, respectively. The pathological morphology changes were observed after Hematoxylin and eosin, lectin and Masson's trichrome staining. The levels of serum brain natriuretic peptide (BNP) and troponin I were determined by enzyme-linked immunosorbent assay and chemiluminescence, respectively. The mRNA and protein expressions of α- myosin heavy chain (MHC), ß-MHC and Foxp3 were determined using real-time PCR and immunohistochemistry, respectively. It was shown that TP (1, 3, 10 µg/L) treatment significantly decreased cell size, mRNA and protein expression of ß-MHC, and upregulated Foxp3 expression in NRVM. TP also decreased heart weight index, left ventricular weight index and, improved myocardial injury and fibrosis; and decreased the cross-scetional area of the myocardium, serum cardiac troponin and BNP. Additionally, TP markedly reduced the mRNA and protein expression of myocardial ß-MHC and elevated the mRNA and protein expression of α-MHC and Foxp3 in a dose-dependent manner. In conclusion, TP can effectively ameliorate myocardial damage and inhibit cardiac hypertrophy, which is at least partly related to the elevation of Foxp3 expression in cardiomyocytes.

Artesunate enhances the antibacterial effect of {beta}-lactam antibiotics against Escherichia coli by increasing antibiotic accumulation via inhibition of the multidrug efflux pump system AcrAB-TolC.

OBJECTIVES: Occasionally, we found that artesunate enhanced the antibacterial effects of antibiotics in vitro. Therefore, the enhancement of various ß-lactam antibiotics by artesunate against Escherichia coli and the possible mechanism were investigated in the present study. METHODS: Antibacterial effects were observed using the serial 2-fold dilution method and dynamic bacterial growth. Daunomycin accumulation within E. coli was observed using fluorospectrophotometry and laser confocal scanning microscopy. AcrAB-TolC, AmpC and TEM-1 mRNA expression was observed using a PCR method. Antisense oligonucleotides (as-ODNs) targeting AcrB were designed and used to block AcrB gene expression within E. coli ATCC 35218. RESULTS: Although artesunate itself had no antibacterial ability, artesunate significantly increased the antibacterial effect of ß-lactam antibiotics against E. coli ATCC 35218 and an E. coli clinical strain. Artesunate increased daunomycin accumulation within E. coli ATCC 35218 in a dose-dependent manner and reduced the mRNA expression of AcrAB-TolC, an important multidrug efflux system for Gram-negative bacteria. The bacterial number was significantly reduced by as-ODN targeting AcrB, but did not further decrease after additional artesunate treatment. In contrast, artesunate lost its enhancement of ß-lactam antibiotics against E. coli AG100A, a strain lacking the gene encoding AcrAB, and artesunate did not increase daunomycin accumulation within E. coli AG100A. After the transformation of pET28a-AcrB into E. coli AG100A, artesunate regained enhancement of ß-lactam antibiotics. Furthermore, artesunate did not inhibit the expression of AmpC and TEM-1 mRNA. CONCLUSIONS: Artesunate enhances the antibacterial effect of various ß-lactam antibiotics against E. coli, which might be associated with the suppression of a major multidrug resistance system, AcrAB-TolC.