Ubiquitin-induced RNF168 condensation promotes DNA double-strand break repair.

Rapid accumulation of repair factors at DNA double-strand breaks (DSBs) is essential for DSB repair. Several factors involved in DSB repair have been found undergoing liquid-liquid phase separation (LLPS) at DSB sites to facilitate DNA repair. RNF168, a RING-type E3 ubiquitin ligase, catalyzes H2A.X ubiquitination for recruiting DNA repair factors. Yet, whether RNF168 undergoes LLPS at DSB sites remains unclear. Here, we identified K63-linked polyubiquitin-triggered RNF168 condensation which further promoted RNF168-mediated DSB repair. RNF168 formed liquid-like condensates upon irradiation in the nucleus while purified RNF168 protein also condensed in vitro. An intrinsically disordered region containing amino acids 460-550 was identified as the essential domain for RNF168 condensation. Interestingly, LLPS of RNF168 was significantly enhanced by K63-linked polyubiquitin chains, and LLPS largely enhanced the RNF168-mediated H2A.X ubiquitination, suggesting a positive feedback loop to facilitate RNF168 rapid accumulation and its catalytic activity. Functionally, LLPS deficiency of RNF168 resulted in delayed recruitment of 53BP1 and BRCA1 and subsequent impairment in DSB repair. Taken together, our finding demonstrates the pivotal effect of LLPS in RNF168-mediated DSB repair.

IP3R2-mediated Ca2+ release promotes LPS-induced cardiomyocyte pyroptosis via the activation of NLRP3/Caspase-1/GSDMD pathway.

Pyroptosis plays a crucial role in sepsis, and the abnormal handling of myocyte calcium (Ca2+) has been associated with cardiomyocyte pyroptosis. Specifically, the inositol 1,4,5-trisphosphate receptor type 2 (IP3R2) is a Ca2+ release channel in the endoplasmic reticulum (ER). However, the specific role of IP3R2 in sepsis-induced cardiomyopathy (SIC) has not yet been determined. Thus, this study aimed to investigate the underlying mechanism by which IP3R2 channel-mediated Ca2+ signaling contributes to lipopolysaccharide (LPS)-induced cardiac pyroptosis. The SIC model was established in rats by intraperitoneal injection of LPS (10 mg/kg). Cardiac dysfunction was assessed using echocardiography, and the protein expression of relevant signaling pathways was analyzed using ELISA, RT-qPCR, and western blot. Small interfering RNAs (siRNA) and an inhibitor were used to explore the role of IP3R2 in neonatal rat cardiomyocytes (NRCMs) stimulated by LPS in vitro. LPS-induced NLRP3 overexpression and GSDMD-mediated pyroptosis in the rats' heart. Treatment with the NLRP3 inhibitor MCC950 alleviated LPS-induced cardiomyocyte pyroptosis. Furthermore, LPS increased ATP-induced intracellular Ca2+ release and IP3R2 expression in NRCMs. Inhibiting IP3R activity with xestospongin C (XeC) or knocking down IP3R2 reversed LPS-induced intracellular Ca2+ release. Additionally, inhibiting IP3R2 reversed LPS-induced pyroptosis by suppressing the NLRP3/Caspase-1/GSDMD pathway. We also found that ER stress and IP3R2-mediated Ca2+ release mutually regulated each other, contributing to cardiomyocyte pyroptosis. IP3R2 promotes NLRP3-mediated pyroptosis by regulating ER Ca2+ release, and the mutual regulation of IP3R2 and ER stress further promotes LPS-induced pyroptosis in cardiomyocytes.

Phase separation in DNA double-strand break response.

DNA double-strand break (DSB) is the most dangerous type of DNA damage, which may lead to cell death or oncogenic mutations. Homologous recombination (HR) and nonhomologous end-joining (NHEJ) are two typical DSB repair mechanisms. Recently, many studies have revealed that liquid-liquid phase separation (LLPS) plays a pivotal role in DSB repair and response. Through LLPS, the crucial biomolecules are quickly recruited to damaged sites with a high concentration to ensure DNA repair is conducted quickly and efficiently, which facilitates DSB repair factors activating downstream proteins or transmitting signals. In addition, the dysregulation of the DSB repair factor's phase separation has been reported to promote the development of a variety of diseases. This review not only provides a comprehensive overview of the emerging roles of LLPS in the repair of DSB but also sheds light on the regulatory patterns of phase separation in relation to the DNA damage response (DDR).

Contribution of ADD3 and the HLA Genes to Biliary Atresia Risk in Chinese.

Nonsyndromic biliary atresia (BA) is a rare polygenic disease, with autoimmunity, virus infection and inflammation thought to play roles in its pathogenesis. We conducted a genome-wide association study in 336 nonsyndromic BA infants and 8900 controls. Our results validated the association of rs17095355 in ADD3 with BA risk (odds ratio (OR) = 1.70, 95% confidence interval (95% CI) = 1.49-1.99; p = 4.07 × 10-11). An eQTL analysis revealed that the risk allele of rs17095355 was associated with increased expression of ADD3. Single-cell RNA-sequencing data and immunofluorescence analysis revealed that ADD3 was moderately expressed in cholangiocytes and weakly expressed in hepatocytes. Immuno-fluorescent staining showed abnormal deposition of ADD3 in the cytoplasm of BA hepatocytes. No ADD3 auto-antibody was observed in the plasma of BA infants. In the HLA gene region, no variants achieved genome-wide significance. HLA-DQB1 residue Ala57 is the most significant residue in the MHC region (OR = 1.44, 95% CI = 1.20-1.74; p = 1.23 × 10-4), and HLA-DQB1 was aberrantly expressed in the bile duct cells. GWAS stratified by cytomegalovirus (CMV) IgM status in 87 CMV IgM (+) BA cases versus 141 CMV IgM (-) BA cases did not yield genome-wide significant associations. These findings support the notion that common variants of ADD3 account for BA risk. The HLA genes might have a minimal role in the genetic predisposition of BA due to the weak association signal. CMV IgM (+) BA patients might not have different genetic risk factor profiles compared to CMV IgM (-) subtype.

Association analysis and functional follow-up identified common variants of JAG1 accounting for risk to biliary atresia.

Background: Biliary atresia (BA) is a destructive, obliterative cholangiopathy characterized by progressive fibro-inflammatory disorder and obliteration of intra- and extrahepatic bile ducts. The Jagged1 (JAG1) gene mutations have been found in some isolated BA cases. We aim to explore the association of common variants in JAG1 with isolated BA risk in the Chinese Han population. Methods: We genotyped 31 tag single nucleotide polymorphisms covering the JAG1 gene region in 333 BA patients and 1,665 healthy controls from the Chinese population, and performed case-control association analysis. The expression patterns of JAG1 homologs were investigated in zebrafish embryos, and the roles of jag1a and jag1b in biliary development were examined by morpholino knockdown in zebrafish. Results: Single nucleotide polymorphisms rs6077861 [P Allelic = 1.74 × 10-4, odds ratio = 1.78, 95% confidence interval: 1.31-2.40] and rs3748478 (P Allelic = 5.77 × 10-4, odds ratio = 1.39, 95% confidence interval: 1.15-1.67) located in the intron region of JAG1 showed significant associations with BA susceptibility. The JAG1 homologs, jag1a and jag1b genes were expressed in the developing hepatobiliary duct of zebrafish, especially at 72 and 96 h postfertilization. Knockdown of both jag1a and jag1b led to poor biliary secretion, sparse intrahepatic bile duct network and smaller or no gallbladders compared with control embryos in the zebrafish model. Conclusion: Common genetic variants of JAG1 were associated with BA susceptibility. Knockdown of JAG1 homologs led to defective intrahepatic and extrahepatic bile ducts in zebrafish. These results suggest that JAG1 might be implicated in the etiology of BA.

Exploiting E3 ubiquitin ligases to reeducate the tumor microenvironment for cancer therapy.

Tumor development relies on a complex and aberrant tissue environment in which cancer cells receive the necessary nutrients for growth, survive through immune escape, and acquire mesenchymal properties that mediate invasion and metastasis. Stromal cells and soluble mediators in the tumor microenvironment (TME) exhibit characteristic anti-inflammatory and protumorigenic activities. Ubiquitination, which is an essential and reversible posttranscriptional modification, plays a vital role in modulating the stability, activity and localization of modified proteins through an enzymatic cascade. This review was motivated by accumulating evidence that a series of E3 ligases and deubiquitinases (DUBs) finely target multiple signaling pathways, transcription factors and key enzymes to govern the functions of almost all components of the TME. In this review, we systematically summarize the key substrate proteins involved in the formation of the TME and the E3 ligases and DUBs that recognize these proteins. In addition, several promising techniques for targeted protein degradation by hijacking the intracellular E3 ubiquitin-ligase machinery are introduced.

Mettl3-mediated m6A modification of Fgf16 restricts cardiomyocyte proliferation during heart regeneration.

Cardiovascular disease is the leading cause of death worldwide due to the inability of adult heart to regenerate after injury. N6-methyladenosine (m6A) methylation catalyzed by the enzyme methyltransferase-like 3 (Mettl3) plays an important role in various physiological and pathological bioprocesses. However, the role of m6A in heart regeneration remains largely unclear. To study m6A function in heart regeneration, we modulated Mettl3 expression in vitro and in vivo. Knockdown of Mettl3 significantly increased the proliferation of cardiomyocytes and accelerated heart regeneration following heart injury in neonatal and adult mice. However, Mettl3 overexpression decreased cardiomyocyte proliferation and suppressed heart regeneration in postnatal mice. Conjoint analysis of methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq identified Fgf16 as a downstream target of Mettl3-mediated m6A modification during postnatal heart regeneration. RIP-qPCR and luciferase reporter assays revealed that Mettl3 negatively regulates Fgf16 mRNA expression in an m6A-Ythdf2-dependent manner. The silencing of Fgf16 suppressed the proliferation of cardiomyocytes. However, the overexpression of ΔFgf16, in which the m6A consensus sequence was mutated, significantly increased cardiomyocyte proliferation and accelerated heart regeneration in postnatal mice compared with wild-type Fgf16. Our data demonstrate that Mettl3 post-transcriptionally reduces Fgf16 mRNA levels through an m6A-Ythdf2-dependen pathway, thereby controlling cardiomyocyte proliferation and heart regeneration.

Cardiovascular diseases are one of the world's biggest killers. Even for patients who survive a heart attack, recovery can be difficult. This is because ­ unlike some amphibians and fish ­ humans lack the ability to produce enough new heart muscle cells to replace damaged tissue after a heart injury. In other words, the human heart cannot repair itself. Molecules known as messenger RNA (mRNA) carry the 'instructions' from the DNA inside the cell nucleus to its protein-making machinery in the cytoplasm of the cell. These messenger molecules can also be altered by different enzymes that attach or remove chemical groups. These modifications can change the stability of the mRNA, or even 'silence' it altogether by stopping it from interacting with the protein-making machinery, thus halting production of the protein it encodes. For example, a protein called Mettl3 can attach a methyl group to a specific part of the mRNA, causing a reversible mRNA modification known as m⁶A. This type of alteration has been shown to play a role in many conditions, including heart disease, but it has been unclear whether m⁶A could also be important for the regeneration of heart tissue. To find out more, Jiang, Liu, Chen et al. studied heart injury in mice of various ages. Newborn mice can regenerate their heart muscle for a short time, but adult mice lack this ability, which makes them a useful model to study heart disease. Analyses of the proteins and mRNAs in mouse heart cells confirmed that both Mettl3 and m⁶A-modified mRNAs were present. The amount of each also increased with age. Next, experiments in genetically manipulated mice revealed that removing Mettl3 greatly improved tissue repair after heart injury in both newborn and adult mice. In contrast, mouse hearts that produced abnormally high quantities of Mettl3 were unable to regenerate ­ even if the mice were young. Moreover, a detailed analysis of gene activity revealed that Mettl3 was suppressing heart regeneration by decreasing the production of a growth-promoting protein called FGF16. These results reveal a key biological mechanism controlling the heart's ability to repair itself after injury. In the future, Jiang et al. hope that Mettl3 can be harnessed for new, effective therapies to promote heart regeneration in patients suffering from heart disease.

Novel insights into the SPOP E3 ubiquitin ligase: From the regulation of molecular mechanisms to tumorigenesis.

Ubiquitin-mediated protein degradation is the primary biological process by which protein abundance is regulated and protein homeostasis is maintained in eukaryotic cells. Speckle-type pox virus and zinc finger (POZ) protein (SPOP) is a typical substrate adaptor of the Cullin 3-RING ligase (CRL3) family; it serves as a bridge between the Cullin 3 (Cul3) scaffold protein and its substrates. In recent years, SPOP has received increasing attention because of its versatility in its regulatory pathways and the diversity of tumor types involved. Mechanistically, SPOP substrates are involved in a wide range of biological processes, and abnormalities in SPOP function perturb downstream biological processes and promote tumorigenesis. Additionally, liquid-liquid phase separation (LLPS), a potential mechanism of membraneless organelle formation, was recently found to mediate the self-triggered colocalization of substrates with higher-order oligomers of SPOP. Herein, we summarize the structure of SPOP and the specific mechanisms by which it mediates the efficient ubiquitination of substrates. Additionally, we review the biological functions of SPOP, the regulation of SPOP expression, the role of SPOP in tumorigenesis and its therapeutic value.

Transcriptional regulation and ubiquitination-dependent regulation of HnRNPK oncogenic function in prostate tumorigenesis.

BACKGROUND: Heterogeneous nuclear ribonucleoprotein K (HnRNPK) is a nucleic acid-binding protein that regulates diverse biological events. Pathologically, HnRNPK proteins are frequently overexpressed and clinically correlated with poor prognosis in various types of human cancers and are therefore pursued as attractive therapeutic targets for select patients. However, both the transcriptional regulation and degradation of HnRNPK in prostate cancer remain poorly understood. METHODS: qRT-PCR was used to detect the expression of HnRNPK mRNA and miRNA; Immunoblots and immunohistochemical assays were used to determine the levels of HnRNPK and other proteins. Flow cytometry was used to investigate cell cycle stage. MTS and clonogenic assays were used to investigate cell proliferation. Immunoprecipitation was used to analyse the interaction between SPOP and HnRNPK. A prostate carcinoma xenograft mouse model was used to detect the in vivo effects of HnRNPK and miRNA. RESULTS: In the present study, we noted that HnRNPK emerged as an important player in the carcinogenesis process of prostate cancer. miR-206 and miR-613 suppressed HnRNPK expression by targeting its 3'-UTR in PrCa cell lines in which HnRNPK is overexpressed. To explore the potential biological function, proliferation and colony formation of PrCa cells in vitro and tumor growth in vivo were also dramatically suppressed upon reintroduction of miR-206/miR-613. We have further provided evidence that Cullin 3 SPOP is a novel upstream E3 ubiquitin ligase complex that governs HnRNPK protein stability and oncogenic functions by promoting the degradation of HnRNPK in polyubiquitination-dependent proteolysis in the prostate cancer setting. Moreover, prostate cancer-associated SPOP mutants fail to interact with and promote the destruction of HnRNPK proteins. CONCLUSION: Our findings reveal new posttranscriptional and posttranslational modification mechanisms of HnRNPK regulation via miR-206/miR-613 and SPOP, respectively. More importantly, given the critical oncogenic role of HnRNPK and the high frequency of SPOP mutations in prostate cancer, our results provide a molecular rationale for the clinical investigation of novel strategies to combat prostate cancer based on SPOP genetic status.

Outcomes of redo-isolated tricuspid valve surgery after left-sided valve surgery.

OBJECTIVES: To compare early and long-term outcomes of redo-isolated tricuspid surgery (RITS) after left-sided valve surgery. METHODS: We retrospectively reviewed 173 patients who underwent RITS for severe tricuspid regurgitation after previous left-sided valve surgery from January 1999 to December 2019. Patients were divided into two groups: RITS by median sternotomy (m-RITS; n = 78) and totally endoscopic approach (e-RITS; n = 95). Perioperative outcomes and follow-up results were analyzed. RESULTS: There were 19 (11%) in-hospital deaths (14.1% in m-RITS and 8.4% in e-RITS, p = .234) that decreased from 16.7% (1999-2014) to 6.9% (2015-2019) (p = .044). Tricuspid valve replacement (odds ratio [OR] = 4.989, 95% confidence interval [CI]: 1.133-29.790, p = .041) and NYHA function class IV (OR = 9.611, 95% CI: 2.102-43.954, p = .004) were independent risk factors for in-hospital mortality. The overall 1-, 5-, 10-, and 15-year survival rates were 97.2% (95% CI: 94.5%-99.9%), 80.3% (95% CI: 71.7%-88.9%), 59.2% (95% CI: 43.5%-75.5%), and 49.3% (95% CI: 27.2%-71.4%), respectively. CONCLUSION: Patients undergoing RITS carry a high risk of early mortality. There was no significant difference in early mortality or long-term survival between the endoscopy and median sternotomy, whereas the endoscopy approach was associated with shorter intensive care unit stays and fewer reoperations. Repair resulted in lower surgical mortality than replacement with acceptable residual tricuspid regurgitation.

Association Analysis of Variants of DSCAM and BACE2 With Hirschsprung Disease Susceptibility in Han Chinese and Functional Evaluation in Zebrafish.

Hirschsprung disease (HSCR) has a higher incidence in children with Down syndrome (DS), which makes trisomy 21 a predisposing factor to HSCR. DSCAM and BACE2 are close together on the HSCR-associated critical region of chromosome 21. Common variants of DSCAM and rare variants of BACE2 were implicated to be associated with sporadic HSCR. However, the submucosal neuron defect of DS mouse model could not be rescued by normalization of Dscam. We aimed to explore the contribution of DSCAM and BACE2 to the development of the enteric nervous system (ENS) and HSCR susceptibility. We genotyped 133 tag single-nucleotide polymorphisms (SNPs) in DSCAM and BACE2 gene region in 420 HSCR patients and 1,665 controls of Han Chinese. Expression of DSCAM and BACE2 homologs was investigated in the developing gut of zebrafish. Overexpression and knockdown of the homologs were performed in zebrafish to investigate their roles in the development of ENS. Two DSCAM SNPs, rs430255 (P Addtive = 0.0052, OR = 1.36, 95% CI: 1.10-1.68) and rs2837756 (P Addtive = 0.0091, OR = 1.23, 95% CI: 1.05-1.43), showed suggestive association with HSCR risk. Common variants in BACE2 were not associated with HSCR risk. We observed dscama, dscamb, and bace2 expression in the developing gut of zebrafish. Knockdown of dscama, dscamb, and bace2 caused a reduction of enteric neurons in the hindgut of zebrafish. Overexpression of DSCAM and bace2 had no effects on neuron number in the hindgut of zebrafish. Our results suggested that common variation of DSCAM contributed to HSCR risk in Han Chinese. The dysfunction of both dscams and bace2 caused defects in enteric neuron, indicating that DSCAM and BACE2 might play functional roles in the occurrence of HSCR. These novel findings might shed new light on the pathogenesis of HSCR.

Endoscopic repeat isolated tricuspid valve surgery after left-sided valve replacement: valvuloplasty or replacement.

BACKGROUND: The strategy of isolated tricuspid valve surgery has undergone innovations in recent years. This study aimed to summarize our experience using an endoscopic approach to repeat isolated tricuspid valve surgery (RITS) after left-sided valve replacement (LSVR). METHODS: From June 2013 to May 2019, 79 patients underwent endoscopic RITS after LSVR at our institution. Patients were divided into the tricuspid valvuloplasty (TVP) group (N.=49) and the tricuspid valve replacement (TVR) group (N.=30); perioperative outcomes and follow-up results were compared. RESULTS: There were seven postoperative deaths (8.9%). In-hospital mortality was higher in the TVR group than in the TVP group, although this difference was not statistically significant (13.3% vs. 6.1%, P=0.417). More patients experienced residual moderate-to-severe tricuspid regurgitation (TR) at discharge in the TVP group than in the TVR group (26.7% vs. 0%, P=0.003). Five patients died from heart, and multiorgan failure during follow-up; the overall 3- and 5-year survival rates were 93.8% [95% confidence interval (CI): (87.1-99.9%)] and 85.3% (95% CI: 73.3-99.2%), respectively, and no significant differences were found between the two groups (P=0.103). The overall rates of the 3- and 5-year freedom from severe recurrent TR were 93.2% (95% CI: 85.9-99.9%) and 89.0% (78.7-99.9%), respectively, and no significant difference was found between groups (P=0.176). CONCLUSIONS: Repeat isolated tricuspid valve surgery after left-sided valve replacement is associated with adverse perioperative outcomes. Endoscopic access offers an alternative approach for RITS after LSVR with acceptable results. TVP results in lower surgical mortality than TVR while carrying a higher risk of residual moderate-to-severe TR.

Total thoracoscopic repair of ventricular septal defect: A single-center experience.

OBJECTIVES: To explore the safety and efficacy of total thoracoscopic repair of ventricular septal defects (VSD). We compared clinical outcomes of VSD via a total thoracoscopic approach with those of mini-sternotomy. METHODS: We retrospectively reviewed clinical data from patients with VSD from 2012 to January 2019. According to the surgical pattern, they were divided into two groups: the total thoracoscopic surgery group (36 patients, 27 females, aged 29 ± 9.52 years), and a mini-sternotomy group (31 patients, 12 females, aged 28 ± 8.67 years). RESULTS: There were no deaths in either group. In the thoracoscopic group, cardiopulmonary bypass (CPB) time and aortic cross-clamping (ACC) time were significantly longer than those of the mini-sternotomy group (CPB time: 112 ± 23.16 min vs. 78 ± 37.90 min, respectively, p < .001; ACC time: 65 ± 19.94 min vs. 50 ± 24.90 min, respectively, p < .001). postoperative hospital stay time (5.11 ± 2.48 days vs. 5.90 ± 6.27 days, p = .488) and chest drainage (139.86 ± 111.71 ml vs. 196.13 ± 147.34 ml, p = .081) tended to be lower in the thoracoscopy group, although there was no significant difference. No residual shunt or tricuspid regurgitation was found at follow-up. CONCLUSIONS: Total thoracoscopic repair is safe and effective in patients with VSD, with or without tricuspid regurgitation.

Common variation of the NSD1 gene is associated with susceptibility to Hirschsprung's disease in Chinese Han population.

BACKGROUND: Hirschsprung's disease (HSCR) is the most common congenital cause of intestinal obstruction in children. Sotos syndrome (SoS) is an overgrowth disorder with constipation and sometimes accompanied by HSCR. NSD1 gene mutation is the main cause of SoS. We aimed to investigate association of NSD1 common single nucleotide polymorphisms (SNPs) with HSCR susceptibility in Chinese Han population. METHOD: We genotyped 15 SNPs encompassing NSD1 gene region in 420 HSCR patients and 1665 controls on Fludigm EP1 platform. Association analysis was performed between cases and controls. RESULT: Rs244709 was the most associated SNP with HSCR susceptibility of the sample set (PAllelic = 9.69 × 10-5, OR = 1.37, 95% CI: 1.17-1.61). Gender stratification analysis revealed that NSD1 SNPs were associated with HSCR in males, but not in females. The nonsynonymous coding SNP rs28932178 in NSD1 exon 5 represented the most significant signal in males (PAllelic = 6.43 × 10-5, OR = 1.42, 95% CI: 1.20-1.69). The associated SNPs were expression quantitative trait loci (eQTLs) of nearby genes in multiple tissues. NSD1 expression levels were higher in aganglionic colon tissues than ganglionic tissues (P = 3.00 × 10-6). CONCLUSION: NSD1 variation conferred risk to HSCR in males, indicating SoS and HSCR may share common genetic factors. IMPACT: This is the first study to reveal that NSD1 variation conferred risk to Hirschsprung's disease susceptibility in males of Chinese Han population, indicating Sotos syndrome and Hirschsprung's disease may share some common genetic background. This study indicates more attention should be paid to the symptom of constipation in patients with Sotos syndrome. Our results raise questions about the role of NSD1 in the development of enteric nervous system and the pathogenesis of Hirschsprung's disease.

Cystic fibrosis in 2 children with Pseudomonas aeruginosa infection / 中华实用儿科临床杂志

Clinical data of 2 children with cystic fibrosis (CF) and Pseudomonas aeruginosa infection in the Department of Pediatrics of Sichuan Provincial People′s Hospital from April 2018 to June 2019 were retrospectively analyzed.Patient 1 was an 11-year-old girl with no history of recurrent respiratory infections. Pseudomonas aeruginosa was found in the first sputum culture.A large number of yellow and white secretions were visible under repeated fiberoptic bronchoscopy.Chest CT showed multiple spots and tree-in-bud signs around the bronchi of both lungs. CFTR gene test results revealed 3 heterozygous mutations: c.2909G>A (chr7: 117246728), c.*133T>A (chr7: 117307295) and c. *125delT (chr7: 117307285). The other patient was a 7-year-old boy with a history of recurrent respiratory infections.His parents were close relatives.Multiple cultures of sputum and bronchoalveolar lavage fluid of the boy were Pseudomonas aeruginosa, and chest CT suggested dilation and inflammation in bronchi of both lungs.Gene detection showed that the c. 380T>G homozygous mutation at chromosome chr7-117171059 resulted in an amino acid change p. leu127stop (nonsense mutation). This article suggests that CF should be considered for Pseudomonas aeruginosa infected children having signs of bronchiectasis on chest CT and a large number of secretions under bronchoscopy.Besides, it is necessary for such kind of children to perform genetic testing in time to confirm the diagnosis as soon as possible.

Association of Variants in PLD1, 3p24.1, and 10q11.21 Regions With Hirschsprung's Disease in Han Chinese Population.

Background and Aims: Hirschsprung's disease (HSCR) is a rare genetically heterogeneous congenital disorder. A recent study based on whole genome sequencing demonstrated that common variants at four novel loci, which contained two intronic variants on CASQ2 and PLD1, and intergenic variants located between SLC4A7 and EOMES at 3p24.1, and between LINC01518 and LOC283028 at 10q11.21, were associated with HSCR susceptibility. To validate these associations with HSCR susceptibility, we performed a case-control study in a Han Chinese sample set. Methods: We selected four previously identified single nucleotide polymorphisms (SNPs) for replication, along with tag SNPs to cover the four associated regions. In total, 61 SNPs were genotyped in 420 HSCR patients and 1,665 healthy controls from the Han Chinese population. Results: None of the 14 tag SNPs in the CASQ2 gene region, including the previously associated rs9428225, showed an association with HSCR. Among the 24 tag SNPs from the SLC4A7-EOMES region at 3p24.1, rs2642925 [odds ratio (OR) = 1.41, 95% confidence interval (95% CI) = 1.10-1.79; P Additive = 0.007] and the previously associated SNP rs9851320 showed a suggestive association (OR = 1.22, 95% CI = 1.01-1.47; P Additive = 0.042). A non-synonymous SNP, rs2287579, in PLD1 showed a suggestive association with HSCR susceptibility (OR = 1.71, 95% CI = 1.18-2.46; P Additive = 0.004). Additionally, the previously associated PLD1 SNP rs12632766 showed a suggestive significance (OR = 1.20, 95% CI = 1.01-1.42, P Additive = 0.038). In the LINC01518-LOC283028 region at 10q11.21, three SNPs meet the study-wide significance threshold. Rs17153309 was the most associated SNP (OR = 1.60, 95% CI = 1.34-1.90; P Additive = 1.13 × 10-7). The previously associated SNP rs1414027 also showed significant association (OR = 1.43, 95% CI = 1.20-1.70, P Additive = 3.92 × 10-5). Two associated SNPs at 10q11.21 (rs1414027 and rs624804) were expression quantitative trait loci in digestive tract tissues from GTEx databases. Conclusions: Our results confirmed that variants of the LINC01518-LOC283028 region were associated with HSCR in the Han Chinese population. Additionally, the susceptibility of SNPs in the LINC01518-LOC283028 region were associated with the expression levels of nearby genes. These results provide new insight into the pathogenesis of HSCR.

Modified unicaval drainage in reoperative isolated tricuspid valve repair via totally thoracoscopic approach.

AIM: The aim of this study was to investigate the feasibility, safety, and clinical effect of modified unicaval drainage for thoracoscopic reoperative isolated tricuspid valve repair, compared with conventional bicaval drainage. METHODS: A total of 45 consecutive cases of patients who underwent thoracoscopic reoperative isolated tricuspid valve repair on beating-heart were enrolled and divided into two groups according to the different venous drainage (Group A: modified unicaval drainage, Group B: conventional bicaval drainage). A retrospective analysis of perioperative data and clinical outcomes were performed and all the surviving cases were followed up. Re-evaluation of echocardiography and electrocardiogram was performed prior to discharge, and at first month, sixth month, and every year follow-up. RESULTS: The overall postoperative 30-day mortality was 4.5% in Group A and 8.7% in Group B. The postoperative tricuspid valve regurgitation grade of both groups decreased significantly from preoperative regurgitation grade, p < 0.001, without intergroup significant difference, p = 0.815. Follow-up duration ranged from 6 to 38 months, there was one death at 24 months in Group A, and another at 9 months in Group B, respectively. Nobody from both groups experienced reintervention for residual tricuspid regurgitation. No significant difference could be identified about the incidence of postoperative morbidities and follow-up adverse events. CONCLUSION: Both strategies of caval venous drainage can provide satisfactory exposure for thoracoscopic reoperative isolated tricuspid valve repair and equivalent favorable postoperative outcome. And the modified unicaval drainage group may even preserve the anesthetic time and decrease the risk of iatrogenic jugular injury, achieving a more simplified procedure with better cosmetic outcome.

Association of common variation in ADD3 and GPC1 with biliary atresia susceptibility.

Biliary atresia (BA) is an idiopathic neonatal cholestatic disease. Recent genome-wide association study (GWAS) revealed that common variation of ADD3, GPC1, ARF6, and EFEMP1 gene was associated with BA susceptibility. We aimed to evaluate the association of these genes with BA in Chinese population. Twenty single nucleotide polymorphisms (SNPs) in these four genes were genotyped in 340 BA patients and 1,665 controls. Three SNPs in ADD3 were significantly associated with BA, and rs17095355 was the top SNP (PAllele = 3.23×10-6). Meta-analysis of published data and current data indicated that rs17095355 was associated with BA susceptibility in Asians and Caucasians. Three associated SNPs were expression quantitative trait loci (eQTL) for ADD3. Two GPC1 SNPs in high linkage disequilibrium (LD) showed nominal association with BA susceptibility (PAllele = 0.03 for rs6707262 and PAllele = 0.04 for rs6750380), and were eQTL of GPC1. Haplotype harboring these two SNPs almost reached the study-wide significance (P = 0.0035). No association for ARF6 and EFEMP1 was found with BA risk in the current population. Our study validated associations of ADD3 and GPC1 SNPs with BA risk in Chinese population and provided evidence of epistatic contributions of genetic factors to BA susceptibility.

Effect of miR-195-5p on cardiomyocyte apoptosis in rats with heart failure by regulating TGF-ß1/Smad3 signaling pathway.

PURPOSE: The present study set out to investigate the effect of miR-195-5p on cardiomyocyte apoptosis in rats with heart failure (HF) and its mechanism. METHODS: HF rat model and hypoxia/reoxygenation (H/R) cardiomyocyte model were established. miR-195-5p expression and transforming growth factor-ß1 (TGF-ß1)/signal transduction protein (Smad)3 signaling pathway in HF rats and H/R cardiomyocytes were interfered. miR-195-5p expression was tested by Rt-PCR, TGF-ß1/Smad3 signaling pathway related proteins were detected by Western Blot, apoptosis of HF rat cardiomyocytes was tested by TUNEL, and apoptosis of cardiomyocytes induced by H/R was checked by flow cytometry. RESULTS: miR-195-5p was lowly expressed in myocardium of HF rats, while TGF-ß1 and Smad3 proteins were high-expressed. Up-regulating miR-195-5p expression could obviously inhibit cardiomyocyte apoptosis of HF rats, improve their cardiac function, and inhibit activation of TGF-ß1/Smad3 signaling pathway. Up-regulation of miR-195-5p expression or inhibition of TGF-ß1/Smad3 signaling pathway could obviously inhibit H/R-induced cardiomyocyte apoptosis. Dual-luciferase reporter enzyme verified the targeted relationship between miR-195-5p and Smad3. CONCLUSION: miR-195-5p can inhibit cardiomyocyte apoptosis and improve cardiac function in HF rats by regulating TGF-ß1/Smad3 signaling pathway, which may be a potential target for HF therapy.

Early outcomes of mitral valvuloplasty by minimally invasive surgery or sternotomy.

BACKGROUND: Disagreement exists regarding methods for repair of the mitral valve. We compared early outcomes of mitral valvuloplasty by a minimally invasive technique and by a median sternotomy. METHODS: The data of 507 patients (mean age 47.9 ± 15.2 years) undergoing mitral valvuloplasty from January 2015 to June 2018 were analyzed retrospectively. In the study group (n = 225), mitral valvuloplasty via a totally thoracoscopic approach was performed by a single surgeon. In the control group (n = 282), mitral valvuloplasty via the traditional median sternotomy was carried out by other cardiac surgeons in our hospital. Clinical data, surgical results, and follow-up findings in the two groups were comparatively analyzed. RESULTS: In the study group, the blood transfusion rate (5.3% vs. 20.9%, p < 0.05) and incidences of poor wound healing (0 vs. 5.3%, p < 0.05) and respiratory tract infection (4.4% vs. 16.3%, p < 0.05) were lower, and postoperative hospitalization was shorter (5.9 ± 4.0 vs. 10.7 ± 8.4 days, p < 0.05). Within 30 days after surgery, no patient died in the study group while one died in the control group. The duration of follow-up was 12-36 months (mean 22.9 ± 8.8 months). During follow-up, there were 1 and 0 cases of redo surgery and 1 and 3 deaths in the study group and control group, respectively. CONCLUSION: Mitral valvuloplasty via a minimally invasive approach is superior to the traditional median sternotomy in terms of early outcomes, especially when performed by experienced surgeons.