PPR-DYW Protein EMP17 Is Required for Mitochondrial RNA Editing, Complex III Biogenesis, and Seed Development in Maize.

The conversion of cytidines to uridines (C-to-U) at specific sites in mitochondrial and plastid transcripts is a post-transcriptional processing event that is important to the expression of organellar genes. Pentatricopeptide repeat (PPR) proteins are involved in this process. In this study, we report the function of a previously uncharacterized PPR-DYW protein, Empty pericarp17 (EMP17), in the C-to-U editing and kernel development in maize. EMP17 is targeted to mitochondria. The loss-function of EMP17 arrests maize kernel development, abolishes the editing at ccmF C -799 and nad2-677 sites, and reduces the editing at ccmF C -906 and -966 sites. The absence of editing causes amino acid residue changes in CcmFC-267 (Ser to Pro) and Nad2-226 (Phe to Ser), respectively. As CcmFC functions in cytochrome c (Cytc) maturation, the amount of Cytc and Cytc 1 protein is drastically reduced in emp17, suggesting that the CcmFC-267 (Ser to Pro) change impairs the CcmFC function. As a result, the assembly of complex III is strikingly decreased in emp17. In contrast, the assembly of complex I appears less affected, suggesting that the Nad2-226 (Phe to Ser) change may have less impact on Nad2 function. Together, these results indicate that EMP17 is required for the C-to-U editing at several sites in mitochondrial transcripts, complex III biogenesis, and seed development in maize.

A right eye amaurosis patient with congenital absence of the internal carotid artery: A care compliant case report.

RATIONALE: Absence or hypoplasia of the internal carotid artery (ICA) are rare developmental anomalies. Usually, patients with ICA agenesis are asymptomatic due to collateral circulation, but they may present with seizures, headache, or transient ischemic attack. We report a patient with right ICA absence in whom "paroxysmal right eye amaurosis" was the main symptom. PATIENT CONCERNS: A 76-year-old male patient suffered from "paroxysmal right eye amaurosis for 3 years". Three years prior, the patient had suffered sudden one-minute right eye amaurosis without any obvious cause. The attack reoccurred 1-2 times/year until one week before admission when he experienced two sudden right eye amaurosis. DIAGNOSIS: Congenital absence of the right ICA was diagnosed. In this patient with congenital absence of the right ICA, the ipsilateral anterior cerebral artery (ACA) was compensated by the anterior communicating artery (ACOM), and the ipsilateral middle cerebral artery (MCA) emerged from the carotid siphon of the contralateral ICA. INTERVENTIONS: The patient was given antiplatelet treatment consisting of aspirin and atorvastatin after admission and instructed to maintain the treatment after discharge. OUTCOMES: No symptom onset was observed during follow-up. LESSONS: Here, we report the patient's clinical manifestations and imaging findings and analyze the cause of the condition to provide a clinical reference for the study of congenital absence of the ICA.

A comparison of sotagliflozin therapy for diabetes mellitus between week 24 with week 52 : A protocol for mixed treatment comparisons meta-analysis.

BACKGROUND: According to the centers for disease control and prevention, 14% of American adults have diabetes - 10% know it, and more than 4% go undiagnosed. Sotagliflozin is a new type of diabetes drug This study is to compare the efficacy of Sotagliflozin therapy for Diabetes Mellitus (DM) between week 24 with week 52. METHODS AND ANALYSIS: Through to October 2019, Web of Science, PubMed Database, Cochrane Library, EMBASE, Clinical Trials and CNKI will be searched to identify randomized controlled trials (RCTs) exploring SOTA therapy for DM. Strict screening and quality evaluation will be performed on the obtained literature independently by 2 researchers; outcome indexes will be extracted. The bias risk of the included studies will be evaluated based on Cochrane assessment tool. Meta-analysis will be performed on the data using Revman 5.3 software. We will provide practical and targeted results assessing the lost efficacy of SOTA therapy for DM from week 24 to week 52, to provide reference for clinicians. ETHICS AND DISSEMINATION: The stronger evidence about the lost efficacy of SOTA for DM from week 24 to week 52 will be provided for clinicians. TRIAL REGISTRATION NUMBER: PROSPERO CRD42019133027. STRENGTHS AND LIMITATIONS OF THIS STUDY: Whether the efficacy of SOTA could last for a long time is still inconclusive, high quality research is still lacking, and this study attempts to explore this issue; The efficacy of SOTA at different times will be compared by direct comparisons and indirect comparisons, this can lead to more accurate and reliable results; The quality of the included literatures are uneven, and some data might be estimated by calculation, which may affect the quality of this study.

Empty Pericarp21 encodes a novel PPR-DYW protein that is required for mitochondrial RNA editing at multiple sites, complexes I and V biogenesis, and seed development in maize.

C-to-U editing is an important event in post-transcriptional RNA processing, which converts a specific cytidine (C)-to-uridine (U) in transcripts of mitochondria and plastids. Typically, the pentatricopeptide repeat (PPR) protein, which specifies the target C residue by binding to its upstream sequence, is involved in the editing of one or a few sites. Here we report a novel PPR-DYW protein EMP21 that is associated with editing of 81 sites in maize. EMP21 is localized in mitochondria and loss of the EMP21 function severely inhibits the embryogenesis and endosperm development in maize. From a scan of 35 mitochondrial transcripts produced by the Emp21 loss-of-function mutant, the C-to-U editing was found to be abolished at five sites (nad7-77, atp1-1292, atp8-437, nad3-275 and rps4-870), while reduced at 76 sites in 21 transcripts. In most cases, the failure to editing resulted in the translation of an incorrect residue. In consequence, the mutant became deficient with respect to the assembly and activity of mitochondrial complexes I and V. As six of the decreased editing sites in emp21 overlap with the affected editing sites in emp5-1, and the editing efficiency at rpl16-458 showed a substantial reduction in the emp21-1 emp5-4 double mutant compared with the emp21-1 and emp5-4 single mutants, we explored their interaction. A yeast two hybrid assay suggested that EMP21 does not interact with EMP5, but both EMP21 and EMP5 interact with ZmMORF8. Together, these results indicate that EMP21 is a novel PPR-DYW protein required for the editing of ~17% of mitochondrial target Cs, and the editing process may involve an interaction between EMP21 and ZmMORF8 (and probably other proteins).

CYP2C19 polymorphism and antiplatelet effects of clopidogrel in Chinese stroke patients.

Recently published data indicate that CYP2C19*2 allele is the major determinant of metabolic bioactivation of clopidogrel and thereby variability of antiplatelet effect of clopidogrel in white or black patients undergoing elective coronary stent placement. The conclusion may not be fully generalized or extrapolated to the Chinese people due to significantly higher frequencies of the CYP2C19*2 or *3 variant alleles. We sought to investigate whether the CYP2C19*2 or *3 alleles affects platelet reactivity of clopidogrel in Chinese stroke patients. The study included 183 consecutive Chinese stroke patients after loading with clopidogrel 300 mg. Platelet function was assessed by adenosine diphosphate-induced (ADP 20 micromol/L) platelet aggregation and by light transmittance aggregometry (LTA) after seven 75-mg maintenance doses of clopidogrel before discharge. CYP2C19*2 or *3 genotypes were determined by time-of-flight mass spectrometer (MALDI/TOF-MS). In those patients who were carriers of 1 mutant allele (mutant heterozygotes, CYP2C19*1/*2 or *1/*3), ADP-induced maximum platelet aggregation (MPA) were significantly different compared with wild-type homozygous patients [37.2% (IQR, 19.6 to 50.5%) versus 23.6% (IQR, 14.0 to 35.4%), respectively; P=0.002]. In addition, in the patients who were carriers of 2 mutant allele (mutant homozygotes, CYP2C19*2/*2, *2/*3 or *3/*3,), MPA were also significantly different compared with wildtype homozygous patients [35.7% (IQR, 21.0 to 78.1%) versus 23.6% (IQR, 14.0 to 35.4%, respectively; P = 0.039]. By multivariable linear regression, CYP2C19*2 or *3 loss-of-function alleles were independently associated with ADP-induced MPA measurements (partial R2 = 0.138, P = 0.001). CYP2C19*2 or *3 allele does link to increased MPA and clopidogrel response.