Identification of a Hippocampus-to-Zona Incerta Projection involved in Motor Learning.

Motor learning (ML), which plays a fundamental role in growth and physical rehabilitation, involves different stages of learning and memory processes through different brain regions. However, the neural mechanisms that underlie ML are not sufficiently understood. Here, a previously unreported neuronal projection from the dorsal hippocampus (dHPC) to the zona incerta (ZI) involved in the regulation of ML behaviors is identified. Using recombinant adeno-associated virus, the projections to the ZI are surprisingly identified as originating from the dorsal dentate gyrus (DG) and CA1 subregions of the dHPC. Furthermore, projection-specific chemogenetic and optogenetic manipulation reveals that the projections from the dorsal CA1 to the ZI play key roles in the acquisition and consolidation of ML behaviors, whereas the projections from the dorsal DG to the ZI mediate the retrieval/retention of ML behaviors. The results reveal new projections from the dorsal DG and dorsal CA1 to the ZI involved in the regulation of ML and provide insight into the stages over which this regulation occurs.

Overexpressed ski efficiently promotes neurorestoration, increases neuronal regeneration, and reduces astrogliosis after traumatic brain injury.

Traumatic brain injury (TBI) survivors suffer from long-term disability and neuropsychiatric sequelae due to irreparable brain tissue destruction. However, there are still few efficient therapies to promote neurorestoration in damaged brain tissue. This study aimed to investigate whether the pro-oncogenic gene ski can promote neurorestoration after TBI. We established a ski-overexpressing experimental TBI mouse model using adenovirus-mediated overexpression through immediate injection after injury. Hematoxylin-eosin staining, MRI-based 3D lesion volume reconstruction, neurobehavioral tests, and analyses of neuronal regeneration and astrogliosis were used to assess neurorestorative efficiency. The effects of ski overexpression on the proliferation of cultured immature neurons and astrocytes were evaluated using imaging flow cytometry. The Ski protein level increased in the perilesional region at 3 days post injury. ski overexpression further elevated Ski protein levels up to 14 days post injury. Lesion volume was attenuated by approximately 36-55% after ski overexpression, with better neurobehavioral recovery, more newborn immature and mature neurons, and less astrogliosis in the perilesional region. Imaging flow cytometry results showed that ski overexpression elevated the proliferation rate of immature neurons and reduced the proliferation rate of astrocytes. These results show that ski can be considered a novel neurorestoration-related gene that effectively promotes neurorestoration, facilitates neuronal regeneration, and reduces astrogliosis after TBI.

Construction of quality evaluation strategy for Chinese medicine based on ambient mass spectrometry / 中国中药杂志

Quality is the guarantee for the clinical safety and effectiveness of Chinese medicine. Accurate quality evaluation is the key to the standardization and modernization of Chinese medicine. Efforts have been made in improving Chinese medicine quality and strengthening the quality and safety supervision in China, but rapid and accurate quality evaluation of complex Chinese medicine samples is still a challenge. On the basis of the development of ambient mass spectrometry and the application in quality evaluation of complex Chinese medicine systems in recent years, the authors developed the multi-scenario Chinese medicine quality evaluation strategies. A systematic methodology was proposed in specific areas such as real-time monitoring of the quality of complex Chinese medicine decoction system, rapid toxicity grading of compound Chinese patent medicine, and evaluation of bulk medicinals of Chinese patent medicine. Allowing multi-scenario analysis of Chinese medicine, it is expected to provide universal research ideas and technical methods for rapid and accurate quality evaluation of Chinese medicine and boost the high-quality development of Chinese medicine industry.

Research progress on identification methods of growth years of traditional Chinese medicinal materials / 中国中药杂志

The growth years of traditional Chinese medicinal materials are closely related to their quality, which directly affects the efficacy and safety of clinical medication. Therefore, it is particularly important to establish an identification method for the growth years of traditional Chinese medicinal materials. In this review, the identification methods for the growth years of traditional Chinese medicinal materials were summarized systematically, and were divided into four types according to the identification principles and methods: traditional identification, molecular identification, physical/chemical identification, and integrated identification. Relying on rich experience, objective molecular markers, various physical/chemical methods and integrated identification techniques(including infrared spectroscopy, nuclear magnetic resonance spectroscopy, high performance liquid chromatography, gas chromatography, mass spectrometry, bionic identification technology and their tandem technologies, etc.), the differences of characters or chemical fingerprints were compared in depth. The growth years of traditional Chinese medicinal materials were quickly identified or predicted by the appearance and characters, the whole fingerprint information or the content of specific chemical markers, and their content ratios. Through the case analysis of mature varieties, we intend to promote the establishment of a perfect technology system for the identification of the growth years of traditional Chinese medicinal materials, and to provide a reference for other perennial herbal materials, finally resulting in the accurate and precise quality control of traditional Chinese medicinal materials.

NLRC3 silencing accelerates the invasion of hepatocellular carcinoma cell via IL-6/JAK2/STAT3 pathway activation.

Nucleotide-binding domain, leucine-rich repeat family with a caspase activation and recruitment domain 3 (NLRC3) participates in both immunity and cancer. The aim of this study was to determine the role of NLRC3 in human hepatocellular carcinoma (HCC) and the underlying mechanisms. We collected human liver tissues from nonalcoholic steatohepatitis (NASH), HCC, and adjacent normal tissues to characterize the pattern of NLRC3 expression by real-time quantitative polymerase chain reaction and immunohistochemistry. Then, we used the HCC cell line, HuH-7, transfected with small interfering RNA to silence the NLRC3 expression. 5-Ethynyl-2'-deoxyuridine assay, scratch assay, and transwell invasion assay were used for assessing proliferation, migration, and invasion, respectively. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were conducted to assess cell apoptosis. The expression of NLRC3 was reduced in human HCC tissues, compared with normal liver and nonalcoholic steatohepatitis tissues. After knocking down of NLRC3, the proliferation, migration, and invasion were increased in HuH-7 cells. And flow cytometry and TUNEL assay showed that HuH-7 cell apoptosis was suppressed after NLRC3 knockdown. As for the underlying mechanisms, knockdown of NLRC3 in HuH-7 cells was associated with the activation of Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) pathway under interleukin-6 (IL-6) stimulation. NLRC3 expression was downregulated in human HCC tissues. NLRC3 silencing in HuH-7 cells can promote the proliferation, migration, and invasion of hepatocellular carcinoma cells. JAK2/STAT3 pathway activation induced by IL-6 may be the underlying mechanism for HCC when NLRC3 expression is silenced. And the invasion of HuH-7 cells was partially suppressed by the STAT3 specific inhibitor (cryptotanshinone). Therefore, NLRC3 may play a significant role in HCC and might be a therapeutic target for the treatment of HCC.

A2A R inhibition in alleviating spatial recognition memory impairment after TBI is associated with improvement in autophagic flux in RSC.

Spatial recognition memory impairment is an important complication after traumatic brain injury (TBI). We previously found that spatial recognition memory impairment can be alleviated in adenosine A2A receptor knockout (A2A R KO) mice after TBI, but the mechanism remains unclear. In the current study, we used manganese-enhanced magnetic resonance imaging and the Y-maze test to determine whether the electrical activity of neurons in the retrosplenial cortex (RSC) was reduced and spatial recognition memory was impaired in wild-type (WT) mice after moderate TBI. Furthermore, spatial recognition memory was damaged by optogenetically inhibiting the electrical activity of RSC neurons in WT mice. Additionally, the electrical activity of RSC neurons was significantly increased and spatial recognition memory impairment was reduced in A2A R KO mice after moderate TBI. Specific inhibition of A2A R in the ipsilateral RSC alleviated the impairment in spatial recognition memory in WT mice. In addition, A2A R KO improved autophagic flux in the ipsilateral RSC after injury. In primary cultured neurons, activation of A2A R reduced lysosomal-associated membrane protein 1 and cathepsin D (CTSD) levels, increased phosphorylated protein kinase A and phosphorylated extracellular signal-regulated kinase 2 levels, reduced transcription factor EB (TFEB) nuclear localization and impaired autophagic flux. These results suggest that the impairment of spatial recognition memory after TBI may be associated with impaired autophagic flux in the RSC and that A2A R activation may reduce lysosomal biogenesis through the PKA/ERK2/TFEB pathway to impair autophagic flux.

Expression of a short antibody heavy chain peptide effectively antagonizes adenosine 2A receptor in vitro and in vivo.

BACKGROUND: Adenosine 2A receptor (A2AR) is involved in many physiological and pathological functions and serves as an important drug target. Inhibition of A2AR may alleviate symptoms associated with a variety of neuropsychiatric disorders. However, the currently used A2AR antagonists have specificity limitations. RESEARCH DESIGN AND METHODS: A Fab fragment (Fab2838) of an A2AR mouse monoclonal antibody can specifically bind to A2AR to form a complex and inhibit the activity of its receptor. We constructed the vector AntiA2AR, a small-molecule peptide that binds to and inhibits A2AR based on Fab2838. RESULTS: Experiments in HEK293T cells showed that peptide AntiA2AR of 29 peptides was the most effective among the synthesized peptides in inhibiting the A2AR downstream signal cAMP/PKA/CREB. In neurons, the AntiA2AR reversed the calcium flow change induced by the A2AR agonist CGS21680 (1 µM). Furthermore, AntiA2AR expression in the mice striatum weakened the p-PKA/p-CREB signal, enhanced locomotor abilities and increased time spent in the center area in the home-cage observation experiment and increased anxiolytic behavior in the elevated-plus maze test. CONCLUSIONS: Antagonistic peptide AntiA2AR can effectively block the A2AR signaling pathway. This provides a new strategy for the specific inhibition of A2AR and provides information needed for drug development.

CTRP5-Overexpression Attenuated Ischemia-Reperfusion Associated Heart Injuries and Improved Infarction Induced Heart Failure.

Aims: C1q/tumor necrosis factor (TNF)-related protein 5 (CTRP5) belongs to the C1q/TNF-α related protein family and regulates glucose, lipid metabolism, and inflammation production. However, the roles of CTRP5 in ischemia/reperfusion (I/R) associated with cardiac injuries and heart failure (HF) needs to be elaborated. This study aimed to investigate the roles of CTRP5 in I/R associated cardiac injuries and heart failure. Materials and Methods: Adeno-associated virus serum type 9 （AAV9）vectors were established for CTRP5 overexpression in a mouse heart (AAV9-CTRP5 mouse). AAV9-CTRP5, AMPKα2 global knock out （AMPKα2-/-）and AAV9-CTRP5+ AMPKα2-/- mice were used to establish cardiac I/R or infarction associated HF models to investigate the roles and mechanisms of CTRP5 in vivo. Isolated neonatal rat cardiomyocytes (NRCMS) transfected with or without CTRP5 adenovirus were used to establish a hypoxia/reoxygenation (H/O) model to study the roles and mechanisms of CTRP5 in vitro. Key Findings: CTRP5 was up-regulated after MI but was quickly down-regulated. CTRP5 overexpression significantly decreased I/R induced IA/AAR and cardiomyocyte apoptosis, and attenuated infarction area, and improved cardiac functions. Mechanistically, CTRP5 overexpression markedly increased AMPKα2 and ACC phosphorylation and PGC1-α expression but inhibited mTORC1 phosphorylation. In in vitro experiments, CTRP5 overexpression could also enhance AMPKα2 and ACC phosphorylation and protect against H/O induced cardiomyocytes apoptosis. Finally, we showed that CTPR5 overexpression could not protect against I/R associated cardiac injuries and HF in AMPKα2-/- mice. Significance: CTRP5 overexpression protected against I/R induced mouse cardiac injuries and attenuated myocardial infarction induced cardiac dysfunction by activating the AMPKαsignaling pathway.

Seminal plasma miR-210-3p induces spermatogenic cell apoptosis by activating caspase-3 in patients with varicocele.

The aim of this study was to investigate the role of seminal plasma miR-210-3p in the impairment of semen quality caused by varicocele. This study included 102 patients whose semen quality was normal when they were diagnosed with varicocele. A 2-year follow-up for included patients was performed, and they were divided into Group A (semen quality became abnormal) and Group B (semen quality remained normal) according to the results of semen analysis during the follow-up. Semen parameters and seminal plasma miR-210-3p expression were investigated by semen analysis and quantitative real-time polymerase chain reaction, respectively. In vitro experiments with GC-2 cells were performed to explore the role of miR-210-3p in spermatogenic cells. The results of quantitative real-time polymerase chain reaction showed that the level of seminal plasma miR-210-3p in Group A was higher than that in Group B both after 2-year follow-up and when they were diagnosed with varicocele (both P < 0.01). Apoptosis and proliferation assays showed that miR-210-3p induces apoptosis of spermatogenic cells by promoting caspase-3 activation. In conclusion, our study indicated that seminal plasma miR-210-3p induces spermatogenic cell apoptosis by activating caspase-3 in patients with varicocele. Seminal plasma miR-210-3p may be a potential biomarker for predicting impaired semen quality caused by varicocele.

Design and application of quality standard of Dao-di herbs / 中国中药杂志

Dao-di herbs, which are widely recognized as medicinal materials with a high quality and good efficacy in clinic, are now facing the dilemma of absence of standard. This study focused on a pivotal scientific problem of design and application of quality standard of Dao-di herbs, and systematically illustrated the general rules for the quality standard of Dao-di herbs involving "four rules, six core contents, and three key methods". The quality standard of Dao-di herbs shall be fully based on literatures as well as habitat, planting/breeding, processing, characters, chemical-pharmacological/toxic data. The common requirements for the quality standard of Dao-di herbs contain "clear source, explicit origin, rational indicator, gradable quality, and multiple detection methods". Notably, traditional experiences and modern techniques, quality tracing management system, "quality determination by distinguishing characters" method, rapid detection technology, effective/toxic substances control method, were comprehensively applied in this standard to purse the objectification, automation, and intellectualization of detection technology. Appearance characters, chemical components, and bioactive parameters, unified effective/toxic indicators, quality markers, and pharmacopeial control indicators and reasonable ranges were included in rigorous quality standards for Dao-di herbs. Besides, simple grading method shall be developed to guide the implementation of "high quality-high price" policy. Eventually, the new quality standards for Dao-di herbs will lead international standards and promote the high-quality development of Dao-di herbs.

Limitation standard of toxic aconitines in proprietary Chinese medicines using on-line extraction electrospray ionization mass spectrometry

Development of rapid analytical methods and establishment of toxic component limitation standards are of great importance in quality control of traditional Chinese medicine. Herein, an on-line extraction electrospray ionization mass spectrometry (oEESI-MS) coupled with a novel whole process integral quantification strategy was developed and applied to direct determination of nine key aconitine-type alkaloids in 20 proprietary Chinese medicines (APCMs). Multi-type dosage forms (, tablets, capsules, pills, granules, and liquid preparation) of APCM could be determined directly with excellent versatility. The strategy has the characteristics of high throughput, good tolerance of matrix interference, small amount of sample (∼0.5 mg) and reagent (∼240 μL) consumption, and short analysis time for single sample (<15 min). The results were proved to be credible by high performance liquid chromatography-mass spectrometry (LC-MS) and electrospray ionization mass spectrometry, respectively. Moreover, the limitation standard for the toxic aconitines in 20 APCMs was established based on the holistic weight toxicity (HWT) evaluation and the severally, and turned out that HWT-based toxicity evaluation results were closer to the real clinical applications. Hence, a more accurate and reliable APCM toxicity limitation was established and expected to play an important guiding role in clinics. The current study extended the power of ambient MS as a method for the direct quantification of molecules in complex samples, which is commonly required in pharmaceutical analysis, food safety control, public security, and many other disciplines.

Herbal Textual Research on Qizhu / 中国实验方剂学杂志

Qizhu, the dried rhizome of Atractylodes macrocephala in Compositae family, is the representative wild variety of Atractylodis Macrocephalae Rhizoma (Baizhu) with modern excellent quality. Through textual research of materia medica works and modern studies, the medication methods between Qizhu and ancient Baizhu were systematically compared. Focusing on seven key issues, this paper systematically summarized the medicinal history, characters, cultivation and other related contents of Qizhu, in order to provide a basis of Qizhu in the recovery and development of its own Daodi-status, and further serve the industrial development of this herb. The name, harvesting time, processing method and other issues had undergone a relatively complicated evolution process. At present, acknowledged points are as following：①The distribution areas of Qizhu include southern areas of the Yangtze River in Anhui province and its surrounding regions. ②Harvesting time is late October. ③Qizhu can be dried in the shade or micro-hot dried after being wrapped with absorbent paper, later it can be divided into two commercial specifications. ④In addition to cutting, there is still a lack of other processing methods. ⑤The superior characters of Qizhu contain white, less oil, fragrant smell and sweet taste and so on. ⑥The history of Qizhu as a genuine medicinal material can be traced back to the Ming dynasty.

Exosomes Derived from TIMP2-Modified Human Umbilical Cord Mesenchymal Stem Cells Enhance the Repair Effect in Rat Model with Myocardial Infarction Possibly by the Akt/Sfrp2 Pathway.

Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) are a promising new therapeutic option for myocardial infarction (MI). The tissue matrix metalloproteinase inhibitor 2, also known as TIMP2, is a member of the tissue inhibitor family of metalloproteinases. Since TIMP2-mediated inhibition of matrix metalloproteinases (MMPs) is a key determinant of post-MI remodeling, we analyzed the therapeutic effects of exosomes derived from TIMP2-overexpressing hucMSCs (huc-exoTIMP2) on the MI rat model. The huc-exoTIMP2 significantly improved in vivo cardiac function as measured by echocardiography and promoted angiogenesis in MI injury. It also restricted extracellular matrix (ECM) remodeling, as indicated by the reduced collagen deposition. In addition, huc-exoTIMP2 administration increased the in situ expression of the antiapoptotic Bcl-2 and decreased that of the proapoptotic Bax and pro-caspase-9 in the infracted myocardium. Meanwhile, huc-exoTIMP2 upregulated superoxide dismutase (SOD) as well as glutathione (GSH) and decreased the malondialdehyde (MDA) level in MI models. In vitro huc-exoTIMP2 pretreatment could inhibit H2O2-mediated H9C2-cardiomyocyte apoptosis and promote human umbilical vein endothelial cell (HUVEC) proliferation, migration, and tube formation, as well as decrease TGFß-induced MMP2, MMP9, and α-SMA secretion by cardiac fibroblasts (CFs). Besides that, huc-exoTIMP2 pretreatment also increased the expression of Akt phosphorylation in the infarcted myocardium, which may relate to a high level of secreted frizzled-related protein 2 (Sfrp2) in huc-exoTIMP2, indicating a mechanistic basis of its action. Importantly, Sfrp2 knockdown in huc-exoTIMP2 abrogated the protective effects. Taken together, huc-exoTIMP2 improved cardiac function by alleviating MI-induced oxidative stress and ECM remodeling, partly via the Akt/Sfrp2 pathway.

Research advancement in mechanisms of processing and compatibility for detoxication of Aconitums / 中国中药杂志

Aconitums,represented by Aconite Radix,Aconiti Lateralis Radix Praeparata and Aconiti Kusnezoffh Folium,is a kind of traditional Chinese medicine with a long medicinal history in China. They possess the significant toxicity and therapeutic effects simultaneously. Their potent effects of rescuing from dying,curing rheumatism,anti-inflammation,and analgesia make Aconitums highly regarded by physicians and pharmacists of various dynasties. However,countless poisoning cases caused by an irrational use of Aconitums were reported. In case of improper application and exceeding the therapeutic window,the acute cardiotoxicity and neurotoxicity would be caused,seriously threatening health and even life of the users. Therefore,the clinical application of Aconitums is limited to some extent. To avoid its toxicity and ensure the safety of medicinal use,Aconitums is usually used in a form of its processed products instead of the crude herbs,or combined with some other traditional Chinese medicines in a normal prescription. A proper processing and compatibility method can detoxicate its severe toxicity,reduce the adverse reactions,and also significantly broaden the indications and application range of Aconitums. This provides a guarantee for the secondary exploitation and utilization of Aconitums. In this paper,the traditional processing methods of Aconitums,along with the modern advancement were reviewed,and the mechanisms of detoxification by processing and compatibility were also illuminated. The physical detoxification mode and chemical detoxification mode were found as two main detoxification ways for Aconitums. In particular,the detoxification by hydrolysis,ion-pair,and saponification were three main means. The mechanisms illustrated in this paper can be a reference to the development of modern processing method and a guidance for appropriate use of Aconitums in clinical application.

Hyperoside Suppresses Lipopolysaccharide-induced Inflammation and Apoptosis in Human Umbilical Vein Endothelial Cells.

Finding the novel drug from the effective components of traditional Chinese herbal medicine is a hotspot of the modern pharmacological research. Hyperoside (HYP) belongs to flavonoid glycosides, and it has various properties, such as anti-inflammation, anti-spasm, anti-diuretic, antitussive, lowering blood pressure, and lowering cholesterol effects as well as protective effects for the cardiac and cerebral blood vessels. The purpose of this study was to investigate the effects of HYP on inflammatory and apoptotic responses in vascular endothelial cells stimulated by lipopolysaccharide (LPS) and further to identify the possible mechanisms underlying these effects. In our study, human umbilical vein endothelial cells (HUVECs) were stimulated with 1 µg/mL LPS in the presence or absence of HYP (10, 20 and 50 µmol/L). Our results indicated that HYP alone exerted no cytotoxicity on HUVECs, while it had an up-regulatory effect on the viability of HUVECs induced by LPS in a dose-dependent manner; increased mRNA expression of IL-1ß, IL-6, TNFα and iNOS induced by LPS was attenuated after treatment with HYP both in a dose-and time-dependent manner; LPS-induced HUVECs apoptosis and cleaved-caspase 8, 9, 3 were all significantly reduced by HYP. Furthermore, the possible pathway involved in apoptosis and inflammation by HYP was detected, and the results showed that when treated with HYP, LPS-induced mitochondrial membrane instability was significantly inhibited through up-regulation of Bcl-2 and down-regulation of Bax. Furthermore, the expression of TLR4 and the phosphorylation of IκBα and p65 in LPS-treated cells were blocked by HYP. Our results suggested that HYP treatment prevented HUVECs from LPSinduced inflammation and apoptosis responses, which might be mediated by inhibiting TLR4/NFκB pathway.

Comparison of various lipid parameters in association of target organ damage: a cohort study.

BACKGROUND: Recommendations of non-HDL amplification varied from different guidelines. We aim to test the relationships between various lipid parameters and target organ damage (TOD) including aortic stiffness, peripheral arterial disease and chronic kidney disease in a community-based elderly cohort. METHODS: 1599 (aged 71.4 ± 6.1 years) participants were recruited. Eight lipid parameters, including total cholesterol (TC), triglycerides (TG), LDL-C, HDL-C, non-HDL-C, TC/HDL ratio, TG/HDL ratio and LDL/HDL ratio, together with other plasma biomarkers like creatinine were measured. Pulse wave velocity (PWV) was measured by the SphygmoCor device, and ankle-brachial index (ABI) was assessed by Omron VP-1000 device. RESULTS: Four individual lipid parameters (TC, TG, LDL-C and HDL-C) significantly correlated with most, but not all, TOD indices. Meanwhile, 4 combined lipid parameters, namely non-HDL-C, TC/HDL, TG/HDL and LCL/HDL, significantly correlated with all TOD (P ≤ 0.033). In multiple linear regression analyses, 4 combined lipid parameters also significantly associated with TOD (P ≤ 0.027), while none of individual lipid parameters significantly associated with all TOD indices. In multiple logistic regression analyses, only non-HDLC and TC/HDL significantly associated with TOD (P ≤ 0.039), and other lipid parameters did not significantly associate with TOD. CONCLUSION: In an elderly community sample, non-HDLC and TC/HDLC were better associated with TOD than other lipid parameters. This finding should be considered in future clinical lipid-lowing therapy. TRIAL REGISTRATION: This trial was retrospectively registered in ClinicalTrials.gov (No. NCT02368938 , registered on 15 Feb 2015).

Pathogenic mechanism of a catecholaminergic polymorphic ventricular tachycardia causing-mutation in cardiac calcium release channel RyR2.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a condition that is characterized by an abnormal heart rhythm in response to physical or emotional stress. The majority CPVT patients carry mutations in the RYR2 gene that encodes the calcium release channel/ryanodine receptor (RyR2) in cardiomyocytes. The pathogenic mechanisms that account for the clinical phenotypes of CPVT are still elusive. We have identified a de novo mutation, A165D, from a CPVT patient. We found that CPVT phenotypes are recapitulated in A165D knock-in mice. The mutant RyR2 channels enhanced sarcoplasmic reticulum Ca2+ release, triggered delayed afterdepolarization in cardiomyocytes. Structural analysis revealed that the A165D mutation is located in a loop that is involved in inter-subunit interactions in the RyR2 tetrameric structure, it disrupted conformational stability of the RyR2, which favored a closed-to-open state transition, resulting in a leaky channel. The loop also harbors several other CPVT mutations, which suggests a common pathogenic molecular mechanism of CPVT-causing mutations. Our data illustrated disease-relevant functional defects and provide a deeper mechanistic understanding of a life-threatening cardiac arrhythmia.

Diosgenin Protects Rats from Myocardial Inflammatory Injury Induced by Ischemia-Reperfusion.

BACKGROUND Diosgenin, a phytosteroid sapogenin, has anti-inflammatory properties shown to reduce myocardial ischemia-reperfusion injury (MIRI). However, the specific mechanism by which this is achieved is not clear. This study investigated the protective effects of diosgenin on myocardial ischemia/reperfusion (I/R) and the potential anti-inflammatory mechanisms. MATERIAL AND METHODS Healthy adult male SD rats, body weight (b.w.) 250-280 g, were used to model ischemia-reperfusion injury (IRI) and were administered diosgenin (50 mg/kg and 100 mg/kg b.w.) intragastrically for 4 consecutive weeks before surgery. The left anterior descending artery (LAD) was ligated to induce myocardial ischemia for 30 min and reperfusion for 30 min, 60 min, and 120 min while relevant indicators were detected. RESULTS Both 50 mg and 100 mg diosgenin oral administration increased left ventricular developed pressure (LVDP) and maximum changing rate of ventricular pressure (±dp/dtmax), decreased left ventricular end-diastolic pressure (LVEDP), and myocardial enzyme markers. TTC staining suggested that diosgenin reduced myocardial infarct size in the rat model. Pathological results showed that myocardial ischemia and inflammation were alleviated by diosgenin. In addition, the increased expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß) in serum, and myeloperoxidase (MPO) in myocardium were significantly suppressed by diosgenin administration. Diosgenin further inhibited the phosphorylation of transcription factor NF-κB and modulated the expression of downstream inflammatory cytokines by regulating the activation of p38-MAPK and JNK pathways. CONCLUSIONS Results demonstrate diosgenin plays an anti-inflammatory role in the protection of MIRI through regulation of p38-MAPK and JNK pathways and phosphorylation of NF-κB.