Pattern-recognition receptors in duck (Anas platyrhynchos): identification, expression and function analysis of toll-like receptor 3

1. Innate immunity provides the first line of defence against pathogenic organisms through a myriad of germline encoded receptors called pattern-recognition receptors (PRRs). Toll-like receptor (TLR) 3, as an important member of PRRs, is indispensable for host defence against viral infection by recognising virus-derived RNAs. However, little is known about the structure and function of TLR3 in ducks (Anas platyrhynchos), a natural host for the avian influenza virus.2. This study cloned the full-length cDNA of duck TLR3 using reverse transcription polymerase chain reaction (RT-PCR) with rapid amplification of cDNA ends (RACE). The cDNA sequence of duck TLR3 was 4046 bp in length and encoded 895 amino acids. Multiple sequence alignment showed that duck TLR3 shared high similarity with that from other vertebrates.3. Quantitative real-time PCR (qRT-PCR) analysis suggested that TLR3 mRNA was constitutively expressed in all tissues tested, having higher levels in the kidney, liver, breast muscle, ovary and heart. After stimulation with viral- or bacterial-mimics, including LPS, poly(I:C), pam3CSK4, FLS-1, FLA-ST and R848, the TLR3 transcript was significantly upregulated. Meanwhile, overexpression of duck TLR3 significantly promoted the transcription of IFN-β, IRF7, TRIF, Mx, STAT1 and STAT2 mRNA after stimulation with poly(I:C).4. These results suggested that TLR3 play an important role in resistance against viral and bacterial infections in ducks.

Cardioprotection by remote ischemic conditioning is transferable by plasma and mediated by exosomes

Background

Remote ischemic conditioning (RIC) by brief periods of limb ischemia and reperfusion protects against ischemia-reperfusion injury. However, the mechanism is unknown.

Purpose

We studied the role of exosomes for mediating the cardioprotective signal and whether they accumulate in injured myocardium.

Methods

Blood samples from 12 healthy male volunteers were obtained prior to and one hour after RIC. Plasma obtained before and after RIC (n=4) (P-Pre and P-Post) was used to evaluate the transferability of RIC. Pre- and Post-RIC plasma (n=8) was separated into an exosome rich fraction (Exo-Pre and Exo-Post) and an exosome depleted fraction (Prot-Pre and Prot-Post) by size exclusion chromatography. All studies were carried out in duplicate samples from each volunteer. Infarct size was compared in Sprague-Dawley rat hearts perfused with plasma, exosomes and exosome depleted fractions in a Langendorff model. We investigated changes in the miRNA content of the exosomes after RIC by a human miRNA panel. Additionally, fluorescently labeled exosomes isolated from C2C12 cells were used to assess accumulation in injured myocardium in an in vivo rat model. Rats were divided into an infarct group (n=6) (left anterior descending artery ligation) and a sham group (n=6) (without ligation). Labelled exosomes were injected in the femoral vein prior to reperfusion. Exosome-accumulation in infarcted or sham myocardium was evaluated.

Results

P-Post reduced infarct size by 15% points compared with P-Pre (55±4% vs 70±6%, p=0.03) (Fig. 1a). Exo-Post reduced infarct size by 16% points compared with Exo-Pre (53±15% vs 68±12%, p=0.03) (Fig. 1b). Prot-Post did not affect infarct size compared to Prot-Pre (64±3% and 68±10%, p>0.99). We found miRNA-16, miRNA-144 and miRNA-451 to be upregulated in exosomes after RIC and the mTOR-pathway as a potential target for these miRNAs. In the in vivo model, labelled exosomes accumulated more intensively in the infarct area than in remote areas and sham hearts (Fig. 1c).

Conclusion

Cardioprotection by RIC is mediated by exosomes with a changed miRNA profile and exosomes accumulate in injured myocardium.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Novo synergy

Effect of TFAM on ATP content in tachypacing primary cultured cardiomyocytes and atrial fibrillation patients

Atrial fibrillation (AF) is one of the most common types of arrhythmia worldwide; although a number of theories have been proposed to explain the mechanisms of AF, the treatment of AF is far from satisfactory. Energy metabolism is associated with the development of AF. Mitochondrial transcription factor A (TFAM) serves a role in the maintenance and transcription of mitochondrial DNA. The present study aimed to investigate the association between TFAM and AF and the effect of TFAM on ATP content in cardiomyocytes. Left atrial appendage tissues were collected from 20 patients with normal sinus rhythm (SR) and 20 patients with AF, and the expression levels of TFAM in SR and AF tissues were evaluated. In addition, a tachypacing model of primary cultured cardiomyocytes was constructed to assess ATP content, cell viability and expression levels of TFAM, mitochondrially encoded (MT)-NADH dehydrogenase 1 (ND1), MT-cytochrome c oxidase 1 (CO1), NADH ubiquinone oxidoreductase core subunit 1 (NDUFS1) and cytochrome c oxidase subunit 6C (COX6C). Finally, the effects of overexpression and inhibition of TFAM on ATP content, cell viability and the expression levels of MT-ND1 and MT-CO1 were investigated. The expression levels of TFAM were decreased in AF tissues compared with SR tissues (P<0.05). The ATP content, cell viability and expression levels of TFAM, MT-ND1 and MT-CO1 were decreased in tachypacing cardiomyocytes compared with non-pacing cardiomyocytes (P<0.05), whereas the expression levels of NDUFS1 and COX6C were not changed (P>0.05). Overexpression of TFAM increased ATP content, cell viability and expression levels of MT-ND1 and MT-CO1 (P<0.05). The inhibition of TFAM decreased ATP content, cell viability and expression levels of MT-ND1 and MT-CO1 (P<0.05). In summary, the results of the present study demonstrated that the expression levels of TFAM were decreased in AF tissues and tachypacing cardiomyocytes and that the restoration of TFAM increased the ATP content by upregulating the expression levels of MT-ND1 and MT-CO1 in tachypacing cardiomyocytes. Thus, TFAM may be a novel beneficial target for treatment of patients with AF.

Ultrasound-assisted leaching of spent lithium ion batteries by natural organic acids and H2O2

Ultrasound-assisted bioacid leaching was examined for the extraction of valuable metals from spent lithium ion batteries (LIBs). In this work, organic acids in lemon juice were used as the leaching agent together with H₂O₂. Three effective factors, namely solid/liquid (S/L) ratio, lemon juice percentage, and H₂O₂ volume percentage, were optimized using Response Surface Methodology (RSM). The optimal conditions were found to be 0.98% (w/v) S/L ratio, 57.8% (v/v) lemon juice and 8.07% (v/v) H₂O₂ in the leaching liquor, achieving recovery of 100% Li, 96% Co and 96% Ni. Furthermore, the individual effects of ultrasound, H₂O₂ and lemon juice on metal recovery were studied and the results showed that without H₂O₂ or lemon juice, the metal recovery rates decreased greatly while the absence of ultrasound reduced recovery rates to a much smaller extent, indicating that both H₂O₂ and lemon juice were essential in the leaching process. The effect of time on the metals recoveries was examined and results showed that Li and Co recovery reached 100% with the leaching time of 35 min. The modified shrinking core modeling results suggested that chemical reaction was the rate controlling step.

Identification of key genes in atrial fibrillation using bioinformatics analysis

Background

Atrial fibrillation (AF) is one of the most common arrhythmia, which brings huge burden to the individual and the society. However, the mechanism of AF is not clear. This paper aims at screening the key differentially expressed genes (DEGs) of atrial fibrillation and to construct enrichment analysis and protein-protein interaction (PPI) network analysis for these DEGs.

Methods

The datasets were collected from the Gene Expression Omnibus database to extract data of left atrial appendage (LAA) RNA of patients with or without AF in GSE79768, GSE31821, GSE115574, GSE14975 and GSE41177. Batch normalization, screening of the differential genes and gene ontology analysis were finished by R software. Reactome analysis was used for pathway analysis. STRING platform was utilized for PPI network analysis. At last, we performed reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to validate the expression of key genes in 20 sinus rhythm (SR) LAA tissues and 20 AF LAA tissues.

Results

A total of 106 DEGs were screened in the merged dataset. Among these DEGs, 74 genes were up-regulated and 32 genes down-regulated. DEGs were mostly enriched in extracellular matrix organization, protein activation cascade and extracellular structure organization. In PPI network, we identified SPP1, COL5A1 and VCAN as key genes which were associated with extracellular matrix. RT-qPCR showed the same expression trend of the three key genes as in our bioinformatics analysis. The expression levels of SPP1, COL5A1 and VCAN were increased in AF tissues compared to SR tissues (P < 0.05).

Conclusion

According to the analyses which were conducted by bioinformatics tools, genes related to extracellular matrix were involved in pathology of AF and may become the possible targets for the diagnosis and treatment of AF.

A NOVEL INTRAGENIC DELETION RELATED TO THE ARGININE VASOPRESSIN V2 RECEPTOR CAUSES NEPHROGENIC DIABETES INSIPIDUS

BACKGROUND

Nephrogenic diabetes insipidus (NDI) is a disease characterized by a defective response to the antidiuretic hormone (ADH) of the renal collecting duct leading to a decline in the ability of the pro-urine concentration.

CASE PRESENTATION

A 23-year-old man presented with an over 20-year history of polyuria concomitant with hydronephrosis. The diagnosis of NDI was established by gene analysis as well as a water-deprivation and vasopressin test. All exons of arginine vasopressin V2 receptor (AVPR2) gene were amplified and sequenced. A novel hemizygous intragenic inframe deletion, cDNA 255^th bp to 263^th bp in exon 2 of AVPR2, was identified. These relevant translations from the 85^th amino acid Asp to 88^th amino acid Val were missed and replaced by amino acid Glu. After treating the patient with hydrochlorothiazide, his symptoms improved significantly.

CONCLUSION

The genetic analysis revealed a novel X-linked intragenic inframe deletion, AVPR2 gene cDNA 255^th bp to 263^th bp, causing NDI.

One-year outcome with a bovine pericardial valve

Objectives

To evaluate the safety and effectiveness of a novel surgical bovine pericardial valve for aortic and mitral valve replacements.

Methods

Between March 2016 and October 2017, 197 patients (mean age, 66.9 ± 4.9 years; 40.6% were women) underwent aortic valve replacement and mitral valve replacement and were implanted with the Cingular bovine pericardial valve (Shanghai Cingular Biotech Corporation, Shanghai, China) in a prospective, multicenter, single-arm trial in China. A total of 161 aortic and 49 mitral prostheses were implanted. Patients were followed up to 1 year. The primary end point was the 1-year overall rate of valve-related complications, including thromboembolic event, valve thrombosis, major hemorrhage event, major perivalvular leak, and prosthetic valve endocarditis.

Results

The 1-year overall rate of valve-related complications was 0.5% (95% confidence interval, 0.1%-3.7%). The 1-year survival was 96.4%. The mean gradient and effective orifice area for aortic prostheses at 1 year postoperatively were 12.8 ± 4.4 mm Hg and 1.9 ± 0.3 cm², respectively. Particularly, the mean gradients and effective orifice area for 19 mm and 21 mm sizes of aortic prostheses at 1 year were 17.0 ± 3.8 mm Hg and 1.6 ± 0.2 cm², 13.1 ± 4.0 mm Hg and 1.8 ± 0.1 cm², respectively. Patient–prosthesis mismatch occurred in only 1.3% patients for aortic valve implantation at 1 month. No structural valve deterioration and no endocarditis occurred.

Conclusions

The Cingular bovine pericardial valve was safe and effective for surgical aortic and mitral valve replacement. The 1-year rate of valve-related complications was very low. Early hemodynamic performance was excellent even for the small aortic root.

Aortic and mitral valve surgery for infective endocarditis with reconstruction of the intervalvular fibrous body: an analysis of clinical outcomes

Background

Reconstruction of the aorto-mitral curtain (AMC) for invasive double-valve infective endocarditis (IE) is a rare and challenging procedure. This study presents the short- and mid-term results of reconstruction of AMC in a single center.

Methods

From 2016 to 2019, 14 patients with invasive double-valve underwent surgical reconstruction of the AMC, along with either double valve replacement or aortic valve replacement with mitral valve repair. Two patients were diagnosed as Behcet’s disease. Bicuspid aortic valve was detected in six patients. Mean follow up was 18.9±12.2 months.

Results

Positive blood culture was found in 10 (71.4%) patients: 3 of Abiotrophia defective (21.4%). The mean cardiopulmonary bypass (CPB) time was 154.5±25.9 minutes and the mean cross-clamp time was 116.8±18.2 minutes. One patient died of multiple organ failure (7.1%) 60 days after surgery. There was 1 (7.1%) case of stroke, 1 (7.1%) of atrioventricular block with pacemaker implantation, 1 (7.1%) of reoperation for bleeding. There was no late death during follow-up. The survival at 3 years was 92.9%. Freedom from reoperation at 1, 2, and 3 years was 100%, 100%, and 100% during follow-up, respectively.

Conclusions

The double-valve replacement and AMC reconstruction (the Commando procedure) is an effective technique in complex heart valve disease. The short- and mid-term results with this technique are optimal, with a very low in-hospital mortality and nearly 100% of long-term survival during follow-up.

Correction: Ultrasound-assisted leaching of vanadium from fly ash using lemon juice organic acids

Correction for ‘Ultrasound-assisted leaching of vanadium from fly ash using lemon juice organic acids’ by G. Rahimi et al., RSC Adv., 2020, 10, 1685–1696, DOI: 10.1039/C9RA09352G.

Ultrasound-assisted leaching of vanadium from fly ash using lemon juice organic acids

In this work, vanadium (V) was selectively extracted from fuel-oil fly ash using a leaching process utilizing organic acids extracted from lemon juice with assistance from ultrasound and H₂O₂. Response Surface Methodology (RSM) was used to optimize the main operating factors. The V recovery was 88.7% at the optimal conditions: 27.9% (v/v) lemon juice, 10% (v/v) hydrogen peroxide (H₂O₂), solid/liquid (S/L) ratio 0.01% (w/v), ultrasound power 159 W at 20 kHz in 2 h, and initial temperature of 35 °C. The effect of time on the V recovery was examined. The maximum recovery was 100% after 3 h. Furthermore, the individual effects of ultrasound and H₂O₂ on V recovery were studied, and the results showed that without H₂O₂ and ultrasound, the V recovery decreased greatly, indicating that both factors were essential in the leaching process. According to the modified shrinking core model, test results indicated that mass diffusion was the controlling step of the overall reaction kinetics. The activation energy of the leaching reaction in the temperature range 25 to 65 °C was found to be 17.1 kJ mol⁻¹.

In this work, vanadium (V) was selectively extracted from fuel-oil fly ash using a leaching process utilizing organic acids extracted from lemon juice with assistance from ultrasound and H₂O₂.

Inhibition of long noncoding RNA growth arrest–specific 5 attenuates cerebral injury induced by deep hypothermic circulatory arrest in rats

OBJECTIVE

We sought to investigate cerebroprotection by targeting long noncoding RNA growth arrest-specific 5 in a rat model of prolonged deep hypothermic circulatory arrest.

METHODS

Deep hypothermic circulatory arrest was conducted for 60 minutes when the pericranial temperature was cooled to 18°C in rats. Dual luciferase assay was used to detect the binding relationship between growth arrest-specific 5 and putative target microRNAs. Adeno-associated viral vectors containing growth arrest-specific 5 small interfering RNA or negative control small interfering RNA were administered by intracerebroventricular injection 14 days before deep hypothermic circulatory arrest. Expressions of growth arrest-specific 5, microRNA-23a, phosphate and tension homology, Bcl-2-associated X protein, Bcl-2, phospho-protein kinase B, protein kinase B, and cleaved caspase-3 in the hippocampus were measured by quantitative reverse transcription polymerase chain reaction and Western blot. Spatial learning and memory functions were evaluated by the Morris water maze test. The hippocampus was harvested for histologic examinations and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling staining.

RESULTS

Luciferase assay showed that growth arrest-specific 5 targeted and inhibited microRNA-23a expression. After deep hypothermic circulatory arrest, hippocampal growth arrest-specific 5 expression was significantly enhanced with a robust decrease of hippocampal microRNA-23a expression. Small interfering RNA growth arrest-specific 5 significantly inhibited growth arrest-specific 5 expression and enhanced microRNA-23a expression in the hippocampus, accompanied with decreases of phosphate and tension homology and Bcl-2-associated X protein expression, and increases of Bcl-2 expression and phospho-protein kinase B/protein kinase B ratio. Growth arrest-specific 5 knockdown inhibited neuronal apoptosis, attenuated histologic damages, and increased the number of surviving neurons in the hippocampus. Spatial learning and memory functions after deep hypothermic circulatory arrest were also markedly improved by growth arrest-specific 5 inhibition.

CONCLUSIONS

Inhibition of large noncoding RNA growth arrest-specific 5 can provide a powerful cerebroprotection against deep hypothermic circulatory arrest, which may be mediated through microRNA-23a/phosphate and tension homology pathway.

Three-dimensional echocardiography of mitral Barlow's disease with infective endocarditis: Perforations or cleft-like indentations?

Barlow's disease is a complicated form of degenerative mitral valve (MV) disease. Infective endocarditis (IE) often occurs on the basis of primary heart diseases and may be combined with valve perforations. Cleft-like indentations (CLIs) were suggested by Ring et al. in 2013. They are located at the inter-scallop position and involve at least one-half of the valve. Herein, we report a case of Barlow's disease combined with IE and CLIs, which was confirmed intra-operatively and by histopathological examination. The CLIs were misdiagnosed by two-dimensional transthoracic echocardiography as perforations, but rightly interpreted by preoperative three-dimensional echocardiography. The possibility of CLIs should be considered in the evaluation of mitral regurgitation caused by myxomatous MV diseases.

Evaluation of a hybrid small caliber vascular graft in a rabbit model

OBJECTIVE

A hybrid small-caliber artificial vascular graft based on bilayer porcine small intestinal submucosa (SIS) with curdlan and dipyridamole mixture film serving as the so-called sandwich filler was developed for biological performance evaluation. We evaluated the performance of the graft and filler.

METHODS

SIS was coated with heparin by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. Curdlan acted as the carrier of dipyridamole. Three types of graft tubes (2 mm internal diameter and 20 mm in length) were manufactured: bilayer SIS with 10% curdlan + 10% dipyridamole mixture film (SCD), bilayer SIS with 10% curdlan film (SC), and monolayer SIS (S). The remodeling characteristics of the grafts were evaluated by implanting them as bypass in rabbit carotid arteries for 2 and 3 months. Each group contained 16 rabbits, and 16 nonsurgical rabbits served as the control group.

RESULTS

Eight rabbits of each group, including the graft occluded group, were killed at 2 months and the others were killed at 3 months. Follow-up showed that all 8 grafts in SCD group were patent at 2 months. Six of 16 grafts in the SC group and 5 of 16 grafts in the S group were occluded at 2 months. One of 8 SCD grafts were occluded at 3 months and the patent showed a confluent endothelium without intimal hyperplasia. The neointima layer was composed of circumferentially aligned vascular smooth muscle cells. At 3 months, SC and S group grafts showed incomplete endothelialization and varying degrees of mural thrombus, accompanied by occlusion in the SC group (3 of 8) and S group (2 of 8).

CONCLUSIONS

The novel hybrid small caliber artificial vascular graft exhibited an improvement in revascularization resulting in high patency rate.

Cold-inducible ribonucleic acid-binding protein attenuates acute kidney injuries after deep hypothermic circulatory arrest in rats

OBJECTIVES

Cold-inducible ribonucleic acid-binding protein (CIRP) has been identified to play a role in the antiapoptotic effect of hypothermia. We sought to investigate the renoprotection of CIRP in a rat model of deep hypothermic circulatory arrest.

METHODS

Overexpression and knockdown of CIRP were achieved in vivo by directly injecting lentivirus vectors containing packaging lentivirus (pL)/internal ribosome entry site (IRES)/green fluorescent protein (GFP)-CIRP or pL/short hairpin RNA (shRNA)/F-cold inducible RNA binding protein (F-CIRP)-A into the renal parenchyma of rats 7 days before deep hypothermic circulatory arrest under the ultrasound guidance. The vehicles or control lentivirus vectors were given to the control group or the control vector group, respectively. Renal function and apoptosis activity were evaluated by serum cystatin C, serum/tissue neutrophil gelatinase-associated lipocalin and terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick-end labelling assay at 24 h after surgery. The expression of CIRP messenger RNA (mRNA) was assessed by quantitative real-time polymerase chain reaction. Protein expression of CIRP and caspase 3 was tested by Western blot.

RESULTS

Compared with the sham group, rats in the control group showed increased expression of CIRP mRNA, CIRP protein, caspase 3 and the apoptotic rate (P < 0.01). However, when compared with the control group, rats in the pL/IRES/GFP-CIRP group showed significantly decreased caspase 3 and apoptosis activities while further increased expression of CIRP mRNA and protein. Rats in the pL/shRNA/F-CIRP-A group showed increased caspase 3 and apoptosis activities and further decreased expression of CIRP mRNA and protein (P < 0.01), when compared with the control group. Renal function was markedly protected in the pL/IRES/GFP-CIRP group and impaired in the pL/shRNA/F-CIRP-A group.

CONCLUSIONS

Our findings suggest that the CIRP exerts a robust renoprotective effect by inhibiting apoptosis in the rat model of deep hypothermic circulatory arrest.