Identification of SaCas9 orthologs containing a conserved serine residue that determines simple NNGG PAM recognition.

Due to different nucleotide preferences at target sites, no single Cas9 is capable of editing all sequences. Thus, this highlights the need to establish a Cas9 repertoire covering all sequences for efficient genome editing. Cas9s with simple protospacer adjacent motif (PAM) requirements are particularly attractive to allow for a wide range of genome editing, but identification of such Cas9s from thousands of Cas9s in the public database is a challenge. We previously identified PAMs for 16 SaCas9 orthologs. Here, we compared the PAM-interacting (PI) domains in these orthologs and found that the serine residue corresponding to SaCas9 N986 was associated with the simple NNGG PAM requirement. Based on this discovery, we identified five additional SaCas9 orthologs that recognize the NNGG PAM. We further identified three amino acids that determined the NNGG PAM requirement of SaCas9. Finally, we engineered Sha2Cas9 and SpeCas9 to generate high-fidelity versions of Cas9s. Importantly, these natural and engineered Cas9s displayed high activities and distinct nucleotide preferences. Our study offers a new perspective to identify SaCas9 orthologs with NNGG PAM requirements, expanding the Cas9 repertoire.

Jmjd4 Facilitates Pkm2 Degradation in Cardiomyocytes and Is Protective Against Dilated Cardiomyopathy.

BACKGROUND: A large portion of idiopathic and familial dilated cardiomyopathy (DCM) cases have no obvious causal genetic variant. Although altered response to metabolic stress has been implicated, the molecular mechanisms underlying the pathogenesis of DCM remain elusive. The JMJD family proteins, initially identified as histone deacetylases, have been shown to be involved in many cardiovascular diseases. Despite their increasingly diverse functions, whether JMJD family members play a role in DCM remains unclear. METHODS: We examined Jmjd4 expression in patients with DCM, and conditionally deleted and overexpressed Jmjd4 in cardiomyocytes in vivo to investigate its role in DCM. RNA sequencing, metabolites profiling, and mass spectrometry were used to dissect the molecular mechanism of Jmjd4-regulating cardiac metabolism and hypertrophy. RESULTS: We found that expression of Jmjd4 is significantly decreased in hearts of patients with DCM. Induced cardiomyocyte-specific deletion of Jmjd4 led to spontaneous DCM with severely impaired mitochondrial respiration. Pkm2, the less active pyruvate kinase compared with Pkm1, which is normally absent in healthy adult cardiomyocytes but elevated in cardiomyopathy, was found to be drastically accumulated in hearts with Jmjd4 deleted. Jmjd4 was found mechanistically to interact with Hsp70 to mediate degradation of Pkm2 through chaperone-mediated autophagy, which is dependent on hydroxylation of K66 of Pkm2 by Jmjd4. By enhancing the enzymatic activity of the abundant but less active Pkm2, TEPP-46, a Pkm2 agonist, showed a significant therapeutic effect on DCM induced by Jmjd4 deficiency, and heart failure induced by pressure overload, as well. CONCLUSIONS: Our results identified a novel role of Jmjd4 in maintaining metabolic homeostasis in adult cardiomyocytes by degrading Pkm2 and suggest that Jmjd4 and Pkm2 may be therapeutically targeted to treat DCM, and other cardiac diseases with metabolic dysfunction, as well.

Guillain-Barre syndrome following scrub typhus: a case report and literature review.

BACKGROUND: Scrub typhus is an acute infectious disease caused by Orientia tsutsugamushi. Guillain-Barre syndrome (GBS) is an autoimmune-mediated peripheral neuropathy with a frequent history of prodromal infections, but GBS associated with scrub typhus is very rare. CASE PRESENTATION: We report a 51-year-old male patient who developed dysarthria and peripheral facial paralysis following the cure of scfrub typhus. CSF examination and electrophysiological findings suggested a diagnosis of GBS. After treatment with intravenous immunoglobulin, the patient's neurological condition improved rapidly. CONCLUSIONS: Scrub typhus infection is likely to be a potential predisposing factor in GBS, while scrub typhus-associated GBS has a favorable prognosis.

Promises and challenges of cardiac organoids.

Cardiovascular diseases are currently the main cause of death. The study of the pathogenesis and treatment of these diseases is still a major challenge. Traditional 2D cultured cells and animal models have certain limitations. Heart organoids as models can simulate the structure and function of the body, providing a new research strategy. This paper mainly discusses the development of organoids and their application in the study of the cardiac developmental process, drug screening and treatment of genetic and non-genetic diseases, concluding with their strengths and weaknesses.

MicroRNA-124a regulates the differentiation of bone marrow mesenchymal stem cells into neurons.

OBJECTIVE: This study investigated the effects of microRNA-124a on the differentiation of bone marrow mesenchymal stem cells (BMSCs) and its underlying mechanism. METHODS: Flow cytometry was used for isolation and identification of BMSCs. Real-time polymerase chain reaction (RT-PCR) was used to detect gene mRNA expression. Apoptosis was detected using Annexin V-FITC/PI Apoptosis Detection Kit. Cell proliferation ability was tested using Cell Counting Kit-8 (CCK-8). The differentiation of BMSCs into neuron inducers ß-thiol ethanol or baicalin formed the basis of the study. RESULTS: ß-thiol ethanol markedly suppressed the microRNA-124a expression of BMSCs, baicalin markedly induced the microRNA-124a expression of BMSCs and ß-thiol ethanol or baicalin promoted apoptosis and reduced the growth of BMSCs. Only the microRNA-124a inhibitor did not affect apoptosis or the differentiation of BMSCs, and it increased the effects of ß-thiol ethanol or baicalin on the apoptosis of BMSCs. CONCLUSION: ß-thiol ethanol and baicalin treatment could affect microRNA-124a expression in BMSCs. We demonstrated that microRNA-124a promoted the differentiation of BMSCs into neurons.

Disturbance of suprachiasmatic nucleus function improves cardiac repair after myocardial infarction by IGF2-mediated macrophage transition.

Suprachiasmatic nucleus (SCN) in mammals functions as the master circadian pacemaker that coordinates temporal organization of physiological processes with the environmental light/dark cycles. But the causative links between SCN and cardiovascular diseases, specifically the reparative responses after myocardial infarction (MI), remain largely unknown. In this study we disrupted mouse SCN function to investigate the role of SCN in cardiac dysfunction post-MI. Bilateral ablation of the SCN (SCNx) was generated in mice by electrical lesion; myocardial infarction was induced via ligation of the mid-left anterior descending artery (LAD); cardiac function was assessed using echocardiography. We showed that SCN ablation significantly alleviated MI-induced cardiac dysfunction and cardiac fibrosis, and promoted angiogenesis. RNA sequencing revealed differentially expressed genes in the heart of SCNx mice from D0 to D3 post-MI, which were functionally associated with the inflammatory response and cytokine-cytokine receptor interaction. Notably, the expression levels of insulin-like growth factor 2 (Igf2) in the heart and serum IGF2 concentration were significantly elevated in SCNx mice on D3 post-MI. Stimulation of murine peritoneal macrophages in vitro with serum isolated from SCNx mice on D3 post-MI accelerated the transition of anti-inflammatory macrophages, while antibody-mediated neutralization of IGF2 receptor blocked the macrophage transition toward the anti-inflammatory phenotype in vitro as well as the corresponding cardioprotective effects observed in SCNx mice post-MI. In addition, disruption of mouse SCN function by exposure to a desynchronizing condition (constant light) caused similar protective effects accompanied by elevated IGF2 expression on D3 post-MI. Finally, mice deficient in the circadian core clock genes (Ckm-cre; Bmal1f/f mice or Per1/2 double knockout) did not lead to increased serum IGF2 concentration and showed no protective roles in post-MI, suggesting that the cardioprotective effect observed in this study was mediated particularly by the SCN itself, but not by self-sustained molecular clock. Together, we demonstrate that inhibition of SCN function promotes Igf2 expression, which leads to macrophage transition and improves cardiac repair post-MI.

Antifungal Activity of Cadinane-Type Sesquiterpenes from Eupatorium adenophorum against Wood-Decaying Fungi.

The present study aimed to evaluate the antifungal activities of Eupatorium adenophorum against four strains of wood-decaying fungi, including Inonotus hispida, Inonotus obliquus, and Inonotus cuticularis. Bioguided isolation of the methanol extract of E. adenophorum by silica gel column chromatography and high-performance liquid chromatography afforded six cadinane-type sesquiterpenes. Their structures were identified by nuclear magnetic resonance and MS analyses. According to the antifungal results, the inhibition rate of the compound was between 59.85 % and 77.98 % at a concentration of 200 µg/mL. The EC50 values ranged from 74.5 to 187.4 µg/mL.

Comparison between the modified Blalock-Taussig shunt and right ventricular outflow tract stent in the palliative treatment for tetralogy of Fallot. / 改良Blalock-Taussigåˆ†æµæœ¯ä¸Žå³å¿ƒå®¤æµå‡ºé“æ”¯æž¶æ¤å ¥æœ¯å§‘æ¯æ€§æ²»ç–—æ³•æ´›å››è”ç—‡çš„æ¯”è¾ƒ.

OBJECTIVES: For patients with tetralogy of Fallot (TOF) who are not suitable candidates for primary corrective surgery or have a high surgical risk, transcatheter right ventricular outflow tract (RVOT) stent implantation is considered a safe and effective palliative intervention. This study aims to investigate the therapeutic outcomes of RVOT stent implantation in neonates and infants with TOF in comparison with the modified Blalock-Taussig shunt (mBTS) and to compare the impact of the 2 palliative interventions on arterial oxygen saturation and pulmonary artery development in pediatric patients. METHODS: Clinical data of 32 patients with TOF admitted to the Second Xiangya Hospital of Central South University from March 2011 to March 2021 were retrospectively collected. The patients were divided into an mBTS group (undergoing mBTS, n=15) and a stent implantation group (undergoing RVOT stenting, n=17) according to the surgical procedures. The 2 groups were assessed and compared in the surgical-related arterial oxygen saturation, postoperative complication rate, mortality rate, and re-intervention rate. The development of the patients' main pulmonary artery, right pulmonary artery, and left pulmonary artery was assessed by z-scores according to echocardiographic results. RESULTS: The children in the stent implantation group were younger and less weighed compared with the mBTS group (both P<0.05). Compared with the preoperative period, children in the stent implantation group had significantly higher arterial oxygen saturation [(75±17)% vs (96±3)%, P=0.026]; z-scores of pulmonary trunk [(-2.82±1.27) points vs (0.86±0.77) points, P=0.014], right pulmonary artery [(-1.88±0.59) points vs (-0.28±0.71) points, P=0.011], and left pulmonary artery [(-2.34±0.36) points vs (-1.67±0.36) points, P=0.036] were significantly increased. However, there were no significant differences in arterial oxygen saturation and pulmonary artery z-scores between pre- and post-mBTS procedures (all P>0.05). CONCLUSIONS: RVOT stent would have good surgical outcomes used in TOF patients with low weight and severe comorbidities. It also leads to an higher postoperative oxygen saturation and better promotion of pulmonary artery growth with RVOT stent compared to mBTS.

Atrial septal defect with a rare occupying lesion in heart.

BACKGROUND: Cardiac epicardium hemangiomas are exceedingly rare; however, they can cause significant hemodynamic impairment and large pericardial effusions. On rare occasion, cardiac tumors coexist with malformations of the heart. CASE PRESENTATION: We present the case of a 10-month-old female infant with a rare cardiac surface hemangioma coexisting with malformations of the heart. It revealed an atrial septal defect (ASD) coexisting with an abnormal occupying lesion with high echogenicity. It was 35*12*9 mm in size and was found in the anterior atrioventricular junction to the posterior atrioventricular junction at the bottom of the ventricular septum by transthoracic echocardiography. We performed surgical treatment of the atrial septal defect and performed biopsy with the occupying lesion. The histopathological examination reported a benign tumor as hemangioma. As far as we know, this is the first case in which cardiac surface hemangioma was found to coexist with an atrial septal defect. CONCLUSIONS: Cardiac epicardium hemangiomas is a rare solid tumor of the heart. If the mass is impossible to resect and does not cause hemodynamic impairment, only mass biopsy is possible.

Establishment of an in vitro safety assessment model for lipid-lowering drugs using same-origin human pluripotent stem cell-derived cardiomyocytes and endothelial cells.

Cardiovascular safety assessment is vital for drug development, yet human cardiovascular cell models are lacking. In vitro mass-generated human pluripotent stem cell (hPSC)-derived cardiovascular cells are a suitable cell model for preclinical cardiovascular safety evaluations. In this study, we established a preclinical toxicology model using same-origin hPSC-differentiated cardiomyocytes (hPSC-CMs) and endothelial cells (hPSC-ECs). For validation of this cell model, alirocumab, a human antibody against proprotein convertase subtilisin kexin type 9 (PCSK9), was selected as an emerging safe lipid-lowering drug; atorvastatin, a common statin (the most effective type of lipid-lowering drug), was used as a drug with reported side effects at high concentrations, while doxorubicin was chosen as a positive cardiotoxic drug. The cytotoxicity of these drugs was assessed using CCK8, ATP, and lactate dehydrogenase release assays at 24, 48, and 72 h. The influences of these drugs on cardiomyocyte electrophysiology were detected using the patch-clamp technique, while their effects on endothelial function were determined by tube formation and Dil-acetylated low-density lipoprotein (Dil-Ac-LDL) uptake assays. We showed that alirocumab did not affect the cell viability or cardiomyocyte electrophysiology in agreement with the clinical results. Atorvastatin (5-50 µM) dose-dependently decreased cardiovascular cell viability over time, and at a high concentration (50 µM, ~100 times the normal peak serum concentration in clinic), it affected the action potentials of hPSC-CMs and damaged tube formation and Dil-Ac-LDL uptake of hPSC-ECs. The results demonstrate that the established same-origin hPSC-derived cardiovascular cell model can be used to evaluate lipid-lowering drug safety in cardiovascular cells and allow highly accurate preclinical assessment of potential drugs.

The updated view on induced pluripotent stem cells for cardiovascular precision medicine.

Cardiovascular diseases have consistently been one of the leading causes of mortality, despite investigations by many scientists and clinicians. Animal models are versatile platforms to illustrate various mechanisms of different diseases, but are lacking in accurately portraying cardiovascular disease phenotypes. The advent of human pluripotent stem cells (PSCs) has led to much development in the construction of cardiovascular disease models. In this review, we provide a brief overview of the history and utilization of PSCs for cardiovascular precision medicine, including disease modeling, drug screening, and gene editing, and elaborate on the current updated research status of patient-specific induced pluripotent stem cell (iPSC)-based disease models for cardiac channelopathies, cardiomyopathies, and other cardiovascular diseases. Furthermore, we highlight the development of novel human iPSC-derived engineered heart tissues for cardiovascular disease modeling. Finally, we put forward our own views on the existing advantages and difficulties for moving forward in this field.

Differences in lipid homeostasis and membrane lipid unsaturation confer differential tolerance to low temperatures in two Cycas species.

BACKGROUND: C. panzhihuaensis is more tolerant to freezing than C. bifida but the mechanisms underlying the different freezing tolerance are unclear. Photosynthesis is one of the most temperature-sensitive processes. Lipids play important roles in membrane structure, signal transduction and energy storage, which are closely related to the stress responses of plants. In this study, the chlorophyll fluorescence parameters and lipid profiles of the two species were characterized to explore the changes in photosynthetic activity and lipid metabolism following low-temperature exposure and subsequent recovery. RESULTS: Photosynthetic activity significantly decreased in C. bifida with the decrease of temperatures and reached zero after recovery. Photosynthetic activity, however, was little affected in C. panzhihuaensis. The lipid composition of C. bifida was more affected by cold and freezing treatments than C. panzhihuaensis. Compared with the control, the proportions of all the lipid categories recovered to the original level in C. panzhihuaensis, but the proportions of most lipid categories changed significantly in C. bifida after 3 d of recovery. In particular, the glycerophospholipids and prenol lipids degraded severely during the recovery period of C. bifida. Changes in acyl chain length and double bond index (DBI) occurred in more lipid classes immediately after low-temperature exposure in C. panzhihuaensis compare with those in C. bifida. DBI of the total main membrane lipids of C. panzhihuaensis was significantly higher than that of C. bifida following all temperature treatments. CONCLUSIONS: The results of chlorophyll fluorescence parameters confirmed that the freezing tolerance of C. panzhihuaensis was greater than that of C. bifida. The lipid metabolism of the two species had differential responses to low temperatures. The homeostasis and plastic adjustment of lipid metabolism and the higher level of DBI of the main membrane lipids may contribute to the greater tolerance of C. panzhihuaensis to low temperatures.

Therapeutic mechanisms of mesenchymal stem cells in acute respiratory distress syndrome reveal potentials for Covid-19 treatment.

The mortality rate of critically ill patients with acute respiratory distress syndrome (ARDS) is 30.9% to 46.1%. The emergence of the coronavirus disease 2019 (Covid-19) has become a global issue with raising dire concerns. Patients with severe Covid-19 may progress toward ARDS. Mesenchymal stem cells (MSCs) can be derived from bone marrow, umbilical cord, adipose tissue and so on. The easy accessibility and low immunogenicity enable MSCs for allogeneic administration, and thus they were widely used in animal and clinical studies. Accumulating evidence suggests that mesenchymal stem cell infusion can ameliorate ARDS. However, the underlying mechanisms of MSCs need to be discussed. Recent studies showed MSCs can modulate immune/inflammatory cells, attenuate endoplasmic reticulum stress, and inhibit pulmonary fibrosis. The paracrine cytokines and exosomes may account for these beneficial effects. In this review, we summarize the therapeutic mechanisms of MSCs in ARDS, analyzed the most recent animal experiments and Covid-19 clinical trial results, discussed the adverse effects and prospects in the recent studies, and highlight the potential roles of MSC therapy for Covid-19 patients with ARDS.

Convergences of Life Sciences and Engineering in Understanding and Treating Heart Failure.

On March 1 and 2, 2018, the National Institutes of Health 2018 Progenitor Cell Translational Consortium, Cardiovascular Bioengineering Symposium, was held at the University of Alabama at Birmingham. Convergence of life sciences and engineering to advance the understanding and treatment of heart failure was the theme of the meeting. Over 150 attendees were present, and >40 scientists presented their latest work on engineering human functional myocardium for disease modeling, drug development, and heart failure research. The scientists, engineers, and physicians in the field of cardiovascular sciences met and discussed the most recent advances in their work and proposed future strategies for overcoming the major roadblocks of cardiovascular bioengineering and therapy. Particular emphasis was given for manipulation and using of stem/progenitor cells, biomaterials, and methods to provide molecular, chemical, and mechanical cues to cells to influence their identity and fate in vitro and in vivo. Collectively, these works are profoundly impacting and progressing toward deciphering the mechanisms and developing novel treatments for left ventricular dysfunction of failing hearts. Here, we present some important perspectives that emerged from this meeting.

The M310T mutation in the GATA4 gene is a novel pathogenic target of the familial atrial septal defect.

BACKGROUND: Although most cases of atrial septal defect (ASD) are sporadic, familial cases have been reported, which may be caused by mutation of transcription factor GATA binding protein 4 (GATA4). Herein we combined whole-exome sequencing and bioinformatics strategies to identify a novel mutation in GATA4 accounting for the etiology in a Chinese family with ASD. METHODS: We identified kindred spanning 3 generations in which 3 of 12 (25.0%) individuals had ASD. Punctilious records for the subjects included complete physical examination, transthoracic echocardiography, electrocardiograph and surgical confirming. Whole-exome capture and high-throughput sequencing were performed on the proband III.1. Sanger sequencing was used to validate the candidate variants, and segregation analyses were performed in the family members. RESULTS: Direct sequencing of GATA4 from the genomic DNA of family members identified a T-to-C transition at nucleotide 929 in exon 5 that predicted a methionine to threonine substitution at codon 310 (M310T) in the nuclear localization signal (NLS) region. Two affected members (II.2 and III.3) and the proband (III.1) who was recognized as a carrier exhibited this mutation, whereas the other unaffected family members or control individuals did not. More importantly, the mutation GATA4 (c.T929C: p.M310T) has not been reported previously in either familial or sporadic cases of congenital heart defects (CHD). CONCLUSIONS: We identified for the first time a novel M310T mutation in the GATA4 gene that is located in the NLS region and leads to family ASD with arrhythmias. However, the mechanism by which this pathogenic mutation contributes to the development of heart defect and tachyarrhythmias remains to be ascertained.

Application value of echocardiography in transthoracic punctural closure of postoperative residual ventricular septal defect of congenital heart disease. / è¶ å£°å¿ƒåŠ¨å›¾åœ¨ç»èƒ¸å£ç©¿åˆºæ²»ç–—å ˆå¤©æ€§å¿ƒè„ç— æœ¯åŽæ®‹ä½™å®¤é—´éš”ç¼ºæŸä¸­çš„åº”ç”¨ä»·å€¼.

OBJECTIVES: Residual ventricular septal defect (VSD) after congenital heart disease (CHD) is one of the major postoperative complications in cardiac surgery. At present, the commonly used clinical treatment methods for this complication are reoperation to redo surgical repair with cardiopulmonary bypass (CPB) and percutaneous transcatheter device closure, but these 2 methods have their own advantages and disadvantages. Transthoracic punctural closure of residual VSD is a feasible, safe, and novel technique for patients with residual VSD, which avoids not only the risk of difficulties in reoperation under another CPB due to thoracic adhesion, but also the risk of radiation exposure. Moreover, the operation is easier to handle due to short and direct operation path. This study aims to explore the role and value of echocardiography in transthoracic punctural closure of postoperative residual VSD of CHD. METHODS: A total of 25 patients, who were admitted in the Department of Cardiovascular Surgery, Second Xiangya Hospital, Central South University and accepted transthoracic punctural closure of postoperative residual VSD, were collected. The morphology of the residual VSD and the distance from tricuspid valve and aortic valve were assessed by trans-esophageal echocardiography (TEE) preoperatively, and the location of the punctural point and the direction of puncture were determined. The establishment of delivery track and releasing of occluder device were accurately guided by TEE intraoperatively. The position and morphology of the occluder device, residual shunt, aortic regurgitaion, and outflow obstruction were required close attention in immediately postoperative evaluation. If any dislocation or residual shunt was found, adjustments were needed immediately. Follow-ups were performed at 3-5 days, 1 month, 3 months, 6 months, and 1 year after operation. Occluder location, residual shunt, valvular function, and other complications were observed by transthoracic echocardiography (TTE) to assess the effect of the closure by occluder. Ventricular size and cardiac function were determined to evaluate the state of ventricular remodeling. In addition, cardiac rhythm was monitored by ECG periodically. RESULTS: Of the 25 patients underwent transthoracic punctural closure of postoperative residual VSD, except 1 double outlet right ventricle (DORV) and 1 tetralogy of fallot (TOF) postoperative patients failured and immediately received a thoracotomy surgery with CPB due to excessive size of residual defect and the irregular morphology, the rest 23 patients were successfully closed by the occluders (92.0%). Among the 23 occluders (diameters range from 5 mm to 10 mm), membrane symmetrical VSD occluders were applied to 17 cases, small-waist-large-edge VSD occluder was applied to 1 case, and eccentric VSD occluders were applied to 5 cases. TEE, applied immediately after occlusion, showed the satisfactory position and the shaping of the occluders. There were no residual shunts, no cardiac tamponade, no thrombosis and outflow obstruction. Two patients had small amounts of pericardial effusion. No newly emerging valve reflux was observed. After 3-48 months of observation, there was no device displacement, newly emerging valve reflux, and residual shunt. One case had incomplete right bundle branch block. CONCLUSIONS: Guided by TEE, transthoracic punctural closure of postoperative residual ventricular septal defect of CHD is safe and effective. This procedure has broadened the indications for the minimally invasive treatment of CHD and improved the technical system of the minimally invasive treatment of CHD. TEE which can provide accurate diagnosis and guide the whole process plays a decisive role in this operation technique.

CXADR-like membrane protein protects against heart injury by preventing excessive pyroptosis after myocardial infarction.

Myocardial infarction (MI) results in cardiomyocyte death and ultimately leads to heart failure. Pyroptosis is a type of the inflammatory programmed cell death that has been found in various diseased tissues. However, the role of pyroptosis in MI heart remains unknown. Here, we showed that CXADR-like membrane protein (CLMP) was involved in pyroptosis in the mouse MI heart. Our data showed that CLMP was strongly expressed in fibroblasts of the infarcted mouse hearts. The Clmp+/- mice showed more serious myocardial fibrosis and ventricular dysfunction post-MI than wild-type (Clmp+/+ ) mice, indicating a protective effect of the fibroblast-expressed CLMP against MI-induced heart damage. Transcriptome analyses by RNA sequencing indicated that Il-1ß mRNA was significantly increased in the MI heart of Clmp+/- mouse, which indicated a more serious inflammatory response. Meanwhile, cleaved caspase-1 and Gasdermin D were significantly increased in the Clmp+/- MI heart, which demonstrated enhanced pyroptosis in the Clmp knockdown heart. Further analysis revealed that the pyroptosis mainly occurred in cardiac fibroblasts (CFs). Compared to wild-type fibroblasts, Clmp+/- CFs showed more serious pyroptosis and inflammatory after LPS plus nigericin treatment. Collectively, our results indicate that CLMP participates in the pyroptotic and inflammatory response of CFs in MI heart. We have provided a novel pyroptotic insight into the ischaemic heart, which might hold substantial potential for the treatment of MI.

Lack of Cardiac Improvement After Cardiosphere-Derived Cell Transplantation in Aging Mouse Hearts.

RATIONALE: Aging is one of the most significant risk factors for cardiovascular diseases, and the incidence of myocardial ischemia increases dramatically with age. Some studies have reported that cardiosphere-derived cells (CDCs) could benefit the injured heart. Nevertheless, the convincing evidence on CDC-induced improvement of aging heart is still limited. OBJECTIVE: In this study, we tested whether the CDCs isolated from neonatal mice could benefit cardiac function in aging mice. METHODS AND RESULTS: We evaluated cardiac function of PBS- (n=15) and CDC-injected (n=19) aging mice. Echocardiography indicated that left ventricular (LV) ejection fraction (57.46%±3.57% versus 57.86%±2.44%) and LV fraction shortening (30.67%±2.41% versus 30.51%±1.78%) showed similar values in PBS- and CDC-injected mice. The diastolic wall thickness of LV was significantly increased after CDC injection, resulting in reduced diastolic LV volume. The pulse-wave Doppler and tissue Doppler imaging indicated that aging mice receiving PBS or CDC injection presented similar values of the peak early transmitral flow velocity, the peak late transmitral flow velocity, the ratio of the peak early transmitral flow velocity to the peak late transmitral flow velocity, and the ratio of the peak early transmitral flow velocity to the peak early diastolic mitral annular velocity, respectively. Pressure-volume loop experiment indicated that the LV end-diastolic pressure-volume relationship and end-systolic pressure-volume relationship were comparable in both PBS- and CDC-injected mice. Postmortem analysis of aging mouse hearts showed similar fibrotic degree in the 2 groups. In addition, the aging markers showed comparable expression levels in both PBS- and CDC-injected mice. The systemic aging performance measures, including exercise capacity, hair regrowth capacity, and inflammation, showed no significant improvement in CDC-injected mice. Finally, the telomere length was comparable between PBS- and CDC-injected mice. CONCLUSIONS: Together, these results indicate that CDCs do not improve heart function and systemic performances in aging mice.

MIR148A family regulates cardiomyocyte differentiation of human embryonic stem cells by inhibiting the DLL1-mediated NOTCH signaling pathway.

MicroRNAs (miRNAs), as a class of naturally occurring RNAs, play important roles in cardiac physiology and pathology. There are many miRNAs that show multifarious expression patterns during cardiomyocyte genesis. Here, we focused on the MIR148A family, which is composed of MIR148A, MIR148B and MIR152, and shares the same seed sequences. The expression levels of all MIR148A family members progressively increased during the differentiation of human embryonic stem cells (hESCs) into cardiomyocytes. The deletion of MIR148A family (MIR148A-TKO) resulted in a decreased proportion of cardiomyocytes after cardiac induction, which was restored by the ectopic expression of MIR148A family members. Transcriptome analyses indicated that the MIR148A family could partially repress paraxial mesodermal differentiation from primitive streak cells. In turn, these miRNAs promoted lateral mesoderm and cardiomyocyte differentiation. Furthermore, the NOTCH ligand Delta-like 1 (DLL1) was validated as the target gene of MIR148A family, and knockdown of DLL1 could promote the cardiomyocyte differentiation of MIR148A-TKO hESCs. Thus, our results demonstrate MIR148A family could promote cardiomyocyte differentiation by inhibiting undesired paraxial mesoderm lineage commitment, which improves our understanding on cardiomyocyte differentiation from hESCs.

Sodium butyrate ameliorates Corynebacterium pseudotuberculosis infection in RAW264.7 macrophages and C57BL/6 mice.

Corynebacterium pseudotuberculosis (CP) infection in livestock has become highly difficult to control. To decrease the incidence of CP infection, the supplementation of feed with non-antibiotic antibacterial substances is a potential approach. The aim of this study was to assess the effects of sodium butyrate (NaB), a potential alternative to antibiotics, on CP infection in RAW264.7 macrophages and C57BL/6 mice. Our data showed that NaB (2 mM) significantly ameliorated CPinfection in RAW264.7 macrophages and decreased the bacterial load in the spleens of infected mice. By real-time PCR, we found that NaB induced significant decreases in zinc-dependent superoxide dismutase (sodC) and tip protein C (spaC) expression in CP from infected-RAW264.7 cells and in phospholipase D (pld) and spaC expression in CP from the spleens of infected mice. NaB treatment significantly up-regulated cathelicidin-related antimicrobial peptide (cramp) expression in spleens of mice infected with CP. Furthermore, NaB alleviated histopathological changes in spleens of CP-infected mice. In conclusion, NaB ameliorated CP infection in RAW264.7 macrophages and C57BL/6 mice, and these effects may be related to the modulation of sodC, spaC, pld, and cramp expression.