CIB2 Is a Novel Endogenous Repressor of Atrial Remodeling.

BACKGROUND: Atrial fibrillation (AF) is a highly prevalent condition that can cause or exacerbate heart failure, is an important risk factor for stroke, and is associated with pronounced morbidity and death. Genes uniquely expressed in the atria are known to be essential for maintaining atrial structure and function. Atrial tissue remodeling contributes to arrhythmia recurrence and maintenance. However, the mechanism underlying atrial remodeling remains poorly understood. This study was designed to investigate whether other uncharacterized atrial specific genes play important roles in atrial physiology and arrhythmogenesis. METHODS: RNA-sequencing analysis was used to identify atrial myocyte specific and angiotensin II-responsive genes. Genetically modified, cardiomyocyte-specific mouse models (knockout and overexpression) were generated. In vivo and in vitro electrophysiological, histology, and biochemical analyses were performed to determine the consequences of CIB2 (calcium and integrin binding family member 2 protein) gain and loss of function in the atrium. RESULTS: Using RNA-sequencing analysis, we identified CIB2 as an atrial-enriched protein that is significantly downregulated in the left atria of patients with AF and mouse models of AF from angiotensin II infusion or pressure overload. Using cardiomyocyte-specific Cib2 knockout (Cib2-/-) and atrial myocyte-specific Cib2-overexpressing mouse models, we found that loss of Cib2 enhances AF occurrence, prolongs AF duration, and correlates with a significant increase in atrial fibrosis under stress. Conversely, Cib2 overexpression mitigates AF occurrence and atrial fibrosis triggered by angiotensin II stress. Mechanistically, we revealed that CIB2 competes with and inhibits CIB1-mediated calcineurin activation, thereby negating stress-induced structural remodeling and AF. CONCLUSIONS: Our data suggest that CIB2 represents a novel endogenous and atrial-enriched regulator that protects against atrial remodeling and AF under stress conditions. Therefore, CIB2 may represent a new potential target for treating AF.

Specialized cis-Acting RNA Elements Balance Genome Cyclization to Ensure Efficient Replication of Yellow Fever Virus.

Genome cyclization is essential for viral RNA (vRNA) replication of the vertebrate-infecting flaviviruses, and yet its regulatory mechanisms are not fully understood. Yellow fever virus (YFV) is a notorious pathogenic flavivirus. Here, we demonstrated that a group of cis-acting RNA elements in YFV balance genome cyclization to govern efficient vRNA replication. It was shown that the downstream of the 5'-cyclization sequence hairpin (DCS-HP) is conserved in the YFV clade and is important for efficient YFV propagation. By using two different replicon systems, we found that the function of the DCS-HP is determined primarily by its secondary structure and, to a lesser extent, by its base-pair composition. By combining in vitro RNA binding and chemical probing assays, we found that the DCS-HP orchestrates the balance of genome cyclization through two different mechanisms, as follows: the DCS-HP assists the correct folding of the 5' end in a linear vRNA to promote genome cyclization, and it also limits the overstabilization of the circular form through a potential crowding effect, which is influenced by the size and shape of the DCS-HP structure. We also provided evidence that an A-rich sequence downstream of the DCS-HP enhances vRNA replication and contributes to the regulation of genome cyclization. Interestingly, diversified regulatory mechanisms of genome cyclization, involving both the downstream of the 5'-cyclization sequence (CS) and the upstream of the 3'-CS elements, were identified among different subgroups of the mosquito-borne flaviviruses. In summary, our work highlighted how YFV precisely controls the balance of genome cyclization to ensure viral replication. IMPORTANCE Yellow fever virus (YFV), the prototype of the Flavivirus genus, can cause devastating yellow fever disease. Although it is preventable by vaccination, there are still tens of thousands of yellow fever cases per year, and no approved antiviral medicine is available. However, the understandings about the regulatory mechanisms of YFV replication are obscure. In this study, by a combination of bioinformatics, reverse genetics, and biochemical approaches, it was shown that the downstream of the 5'-cyclization sequence hairpin (DCS-HP) promotes efficient YFV replication by modulating the conformational balance of viral RNA. Interestingly, we found specialized combinations for the downstream of the 5'-cyclization sequence (CS) and upstream of the 3'-CS elements in different groups of the mosquito-borne flaviviruses. Moreover, possible evolutionary relationships among the various downstream of the 5'-CS elements were implied. This work highlighted the complexity of RNA-based regulatory mechanisms in the flaviviruses and will facilitate the design of RNA structure-targeted antiviral therapies.

Key Residue in the Precursor Region of M Protein Contributes to the Neurovirulence and Neuroinvasiveness of the African Lineage of Zika Virus.

The Zika virus (ZIKV) represents an important global health threat due to its unusual association with congenital Zika syndrome. ZIKV strains are phylogenetically grouped into the African and Asian lineages. However, the viral determinants underlying the phenotypic differences between the lineages remain unknown. Here, multiple sequence alignment revealed a highly conserved residue at position 21 of the premembrane (prM) protein, which is glutamic acid and lysine in the Asian and African lineages, respectively. Using reverse genetics, we generated a recombinant virus carrying an E21K mutation based on the genomic backbone of the Asian lineage strain FSS13025 (termed E21K). The E21K mutation significantly increased viral replication in multiple neural cell lines with a higher ratio of M to prM production. Animal studies showed E21K exhibited increased neurovirulence in suckling mice, leading to more severe defects in mouse brains by causing more neural cell death and destruction of hippocampus integrity. Moreover, the E21K substitution enhanced neuroinvasiveness in interferon alpha/beta (IFN-α/ß) receptor knockout mice, as indicated by the increased mortality, and enhanced replication in mouse brains. The global transcriptional analysis showed E21K infection profoundly altered neuron development networks and induced stronger antiviral immune response than wild type (WT) in both neural cells and mouse brains. More importantly, the reverse K21E mutation based on the genomic backbone of the African strain MR766 caused less mouse neurovirulence. Overall, our findings support the 21st residue of prM functions as a determinant for neurovirulence and neuroinvasiveness of the African lineage of ZIKV. IMPORTANCE The suspected link of Zika virus (ZIKV) to birth defects led the World Health Organization to declare ZIKV a Public Health Emergency of International Concern. ZIKV has been identified to have two dominant phylogenetic lineages, African and Asian. Significant differences exist between the two lineages in terms of neurovirulence and neuroinvasiveness in mice. However, the viral determinants underlying the phenotypic differences are still unknown. Here, combining reverse genetics, animal studies, and global transcriptional analysis, we provide evidence that a single E21K mutation of prM confers to the Asian lineage strain FSS130125 significantly enhanced replication in neural cell lines and more neurovirulent and neuroinvasiveness phenotypes in mice. Our findings support that the highly conserved residue at position 21 of prM functions as a determinant of neurovirulence and neuroinvasiveness of the African lineage of ZIKV in mice.

Porcine germline genome engineering.

Germline editing, the process by which the genome of an individual is edited in such a way that the change is heritable, has been applied to a wide variety of animals [D. A. Sorrell, A. F. Kolb, Biotechnol. Adv. 23, 431-469 (2005); D. Baltimore et al., Science 348, 36-38 (2015)]. Because of its relevancy in agricultural and biomedical research, the pig genome has been extensively modified using a multitude of technologies [K. Lee, K. Farrell, K. Uh, Reprod. Fertil. Dev. 32, 40-49 (2019); C. Proudfoot, S. Lillico, C. Tait-Burkard, Anim. Front. 9, 6-12 (2019)]. In this perspective, we will focus on using pigs as the model system to review the current methodologies, applications, and challenges of mammalian germline genome editing. We will also discuss the broad implications of animal germline editing and its clinical potential.

Single-nucleus transcriptome sequencing reveals hepatic cell atlas in pigs.

BACKGROUND: As the largest substantive organ of animals, the liver plays an essential role in the physiological processes of digestive metabolism and immune defense. However, the cellular composition of the pig liver remains poorly understood. This investigation used single-nucleus RNA sequencing technology to identify cell types from liver tissues of pigs, providing a theoretical basis for further investigating liver cell types in pigs. RESULTS: The analysis revealed 13 cells clusters which were further identified 7 cell types including endothelial cells, T cells, hepatocytes, Kupffer cells, stellate cells, B cells, and cholangiocytes. The dominant cell types were endothelial cells, T cells and hepatocytes in the liver tissue of Dahe pigs and Dahe black pigs, which accounts for about 85.76% and 82.74%, respectively. The number of endothelial cells was higher in the liver tissue of Dahe pigs compared to Dahe black pigs, while the opposite tendency was observed for T cells. Moreover, functional enrichment analysis demonstrated that the differentially expressed genes in pig hepatic endothelial cells were significantly enriched in the protein processing in endoplasmic reticulum, MAPK signaling pathway, and FoxO signaling pathway. Functional enrichment analysis demonstrated that the differentially expressed genes in pig hepatic T cells were significantly enriched in the thyroid hormone signaling pathway, B cell receptor signaling pathway, and focal adhesion. Functional enrichment analysis demonstrated that the differentially expressed genes in pig hepatic hepatocytes were significantly enriched in the metabolic pathways. CONCLUSIONS: In summary, this study provides a comprehensive cell atlas of porcine hepatic tissue. The number, gene expression level and functional characteristics of each cell type in pig liver tissue varied between breeds.

Elevated high-sensitivity C-reactive protein levels increase the risk of new-onset cardiac conduction disorders.

BACKGROUND: Previous studies have reported that inflammatory responses can promote the onset of cardiovascular diseases; however, its association with cardiac conduction disorders remains unclear. The present community-based cohort study aimed to elucidate the effects of inflammatory responses on the risk of developing cardiac conduction disorders. METHODS: After the exclusion of participants failing to meet the inclusion criteria, 86,234 eligible participants (mean age: 50.57 ± 11.88 years) were included. The participants were divided into high-sensitivity C-reactive protein (hsCRP) ≤ 3 mg/L, and hsCRP > 3 mg/L groups based on hsCRP values. Multivariate Cox proportional hazard model was used to analyze the relationship between inflammatory responses and various cardiac conduction disorders. RESULTS: After adjusting for confounding factors, we observed that compared with the hsCRP ≤ 3 mg/L group, the hsCRP > 3 mg/L group exhibited increased risks of atrioventricular block (hazard ratio [HR]:1.64, 95%confidence interval [CI] 1.44-1.87) and left (HR:1.25, 95% CI 1.07-1.45) and right bundle branch block (HR:1.31, 95% CI 1.17-1.47). Moreover, the risk of various cardiac conduction disorders increased for every 1 standard deviation increase in log (hsCRP). The restricted cubic spline function confirmed a linear relationship between log (hsCRP) and the risk of developing cardiac conduction disorders (All nonlinearity P > 0.05). CONCLUSIONS: High hsCRP levels are an independent risk factor for cardiac conduction disorders, and hsCRP levels are dose-dependently associated with the risk of conduction disorders. Our study results may provide new strategies for preventing cardiac conduction disorders.

Propofol Inhibits Ferroptotic Cell Death Through the Nrf2/Gpx4 Signaling Pathway in the Mouse Model of Cerebral Ischemia-Reperfusion Injury.

Ferroptosis is characterized by excessive accumulation of iron and lipid peroxides, which are involved in ischemia, reperfusion-induced organ injury, and stroke. Propofol, an anesthetic agent, has neuroprotective effects due to its potent antioxidant, anti-ischemic, and anti-inflammatory properties. However, the relationship between propofol and ferroptosis is still unclear. In the current study, we elucidated the role of ferroptosis in the neuroprotective effect of propofol in mouse brains subjected to cerebral ischemia reperfusion injury (CIRI). Ferroptosis was confirmed by Western blotting assays, transmission electron microscopy, and glutathione assays. Propofol regulated Nrf2/Gpx4 signaling, enhanced antioxidant potential, inhibited the accumulation of lipid peroxides in CIRI-affected neurons, and significantly reversed CIRI-induced ferroptosis. Additionally, Gpx4 inhibitor RSL3 and Nrf2 inhibitor ML385 attenuated the effects of propofol on antioxidant capacity, lipid peroxidation, and ferroptosis in CIRI-affected neurons. Our data support a protective role of propofol against ferroptosis as a cause of cell death in mice with CIRI. Propofol protected against CIRI-induced ferroptosis partly by regulating the Nrf2/Gpx4 signaling pathway. These findings may contribute to the development of future therapies targeting ferroptosis induced by CIRI.

Enhancer-driven transcription of MCM8 by E2F4 promotes ATR pathway activation and glioma stem cell characteristics.

BACKGROUND: Glioma stem cells (GSCs) are responsible for glioma recurrence and drug resistance, yet the mechanisms underlying their maintenance remains unclear. This study aimed to identify enhancer-controlled genes involved in GSCs maintenance and elucidate the mechanisms underlying their regulation. METHODS: We analyzed RNA-seq data and H3K27ac ChIP-seq data from GSE119776 to identify differentially expressed genes and enhancers, respectively. Gene Ontology analysis was performed for functional enrichment. Transcription factors were predicted using the Toolkit for Cistrome Data Browser. Prognostic analysis and gene expression correlation was conducted using the Chinese Glioma Genome Atlas (CGGA) data. Two GSC cell lines, GSC-A172 and GSC-U138MG, were isolated from A172 and U138MG cell lines. qRT-PCR was used to detect gene transcription levels. ChIP-qPCR was used to detect H3K27ac of enhancers, and binding of E2F4 to target gene enhancers. Western blot was used to analyze protein levels of p-ATR and γH2AX. Sphere formation, limiting dilution and cell growth assays were used to analyze GSCs growth and self-renewal. RESULTS: We found that upregulated genes in GSCs were associated with ataxia-telangiectasia-mutated-and-Rad3-related kinase (ATR) pathway activation, and that seven enhancer-controlled genes related to ATR pathway activation (LIN9, MCM8, CEP72, POLA1, DBF4, NDE1, and CDKN2C) were identified. Expression of these genes corresponded to poor prognosis in glioma patients. E2F4 was identified as a transcription factor that regulates enhancer-controlled genes related to the ATR pathway activation, with MCM8 having the highest hazard ratio among genes positively correlated with E2F4 expression. E2F4 bound to MCM8 enhancers to promote its transcription. Overexpression of MCM8 partially restored the inhibition of GSCs self-renewal, cell growth, and the ATR pathway activation caused by E2F4 knockdown. CONCLUSION: Our study demonstrated that E2F4-mediated enhancer activation of MCM8 promotes the ATR pathway activation and GSCs characteristics. These findings offer promising targets for the development of new therapies for gliomas.

In vitro and in vivo development of interspecies Asian elephant embryos reconstructed with pig enucleated oocytes.

Interspecies somatic cell nuclear transfer (iSCNT) has an immense potential to rescue endangered animals and extinct species like mammoths. In this study, we successfully established an Asian elephant's fibroblast cell lines from ear tissues, performed iSCNT with porcine oocytes and evaluated the in vitro and in vivo development of reconstructed embryos. A total of 7780 elephant-pig iSCNT embryos were successfully reconstructed and showed in vitro development with cleavage rate, 4-cell, 8-cell and blastocyst rate of 73.01, 30.48, 5.64, and 4.73%, respectively. The total number of elephant-pig blastocyte cells and diameter of hatched blastocyte was 38.67 and 252.75 µm, respectively. Next, we designed species-specific markers targeting EDNRB, AGRP and TYR genes to verify the genome of reconstructed embryos with donor nucleus/species. The results indicated that 53.2, 60.8, and 60.8% of reconstructed embryos (n = 235) contained elephant genome at 1-cell, 2-cell and 4-cell stages, respectively. However, the percentages decreased to 32.3 and 32.7% at 8-cell and blastocyst stages, respectively. Furthermore, we also evaluated the in vivo development of elephant-pig iSCNT cloned embryos and transferred 2260 reconstructed embryos into two surrogate gilts that successfully became pregnant and a total of 11 (1 and 10) fetuses were surgically recovered after 17 and 19 days of gestation, respectively. The crown-rump length and width of elephant-pig cloned fetuses were smaller than the control group. Unfortunately, none of these fetuses contained elephant genomes, which suggested that elephant embryos failed to develop in vivo. In conclusion, we successfully obtained elephant-pig reconstructed embryos for the first time and these embryos are able to develop to blastocyst, but the in vivo developmental failure needs further investigated.

Correlation study on the relationship between dyslipidemia and carotid intima-media thickness in patients with diabetes mellitus.

Objective: To investigate the correlation between dyslipidemia and carotid intima-media thickness (IMT) in patients with diabetes mellitus. Methods: A descriptive research design was adopted in this study. One hundred and twenty patients with Type-2 diabetes mellitus who were admitted to the physical examination center of The Fourth Hospital of Hebei Medical University from June 2020 to June 2021 for physical examination were recruited to the experimental group. The 120 patients were divided into three groups according to carotid IMT: normal group, thickened group, and plaque group. Forty healthy people who underwent a physical examination during the same period were recruited as the control group. The differences in IMT in various parts of the experimental group and the control group and the differences in blood lipid indexes were compared and analyzed. In addition, the correlation between mean IMT of bilateral common carotid arteries and blood lipid levels in normal, thickened and plaque groups was compared and analyzed. Results: The intima-media thicknesses of the internal carotid artery and bilateral common carotid arteries of the patients in the experimental group were significantly thicker than those in the healthy control group, the levels of TC, TG and LDL were higher than those in the control group, while the level of HDL was lower than that in the control group, with a statistically significant difference (p=0.00). The levels of fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), TG, TC and LDL were positively correlated with the mean IMT of bilateral common carotid arteries (p<0.05), while the level of HDL was negatively correlated with the mean IMT of bilateral common carotid arteries (p<0.05). Conclusion: Dyslipidemia and glucose metabolism in patients with Type-2 diabetes mellitus have a close bearing on carotid IMT. Clinically, patients with Type-2 diabetes mellitus can be judged by monitoring carotid IMT for dyslipidemia, atherosclerosis and other related complications.

Delayed body development with reduced triglycerides levels in leptin transgenic pigs.

Leptin is a well-known adipokine that plays critical role in adiposity. To further investigate the role of leptin in adiposity, we utilized leptin overexpressing transgenic pigs and evaluated the effect of leptin on growth and development, fat deposition, and lipid metabolism at tissue and cell level. Leptin transgenic pigs were produced and divided into two groups: elevated leptin expression (leptin ( +)) and normal leptin expression group (control). Results indicated that leptin ( +) pigs had elevated leptin protein and mRNA expression levels and exhibited sluggish growth and development followed by decreased subcutaneous fat thickness, low serum triglycerides, saturated, unsaturated fatty acids and high cholesterol esters (p < 0.05). There were differences in the lipid metabolism related genes at different fat depots, including upregulation of PPARγ, AGPAT6, PLIN2, HSL and ATGL in subcutaneous, PPARγ in perirenal, and FAT/CD36 and PLIN2 in mesenteric adipose tissues and downregulation of AGPAT6 and ATGL in perirenal and AGPAT6 in mesenteric adipose tissues (p < 0.05). Additionally, in-vitro cultured leptin ( +) preadipocytes exhibited upregulation of PPARγ, FAT/CD36, ACACA, AGPAT, PLIN2, ATGL and HSL as compared to control (p < 0.05). These findings suggested that homeostasis imbalance in lipolysis and lipogenesis at adipose tissue and adipocytes levels led to low subcutaneous fat depots in leptin overexpression pigs. These pigs can act as model for obesity and related metabolic disorder.

RCAN1 deficiency aggravates sepsis-induced cardiac remodeling and dysfunction by accelerating mitochondrial pathological fission.

OBJECTIVE: Cardiac dysfunction and remodeling are serious complications of sepsis and are the main causes of death in sepsis. RCAN1 is a feedback regulator of cardiac hypertrophy. Here, we aim to investigate the role of RCAN1 in septic cardiomyopathy. METHODS: Mice were randomly divided into control-WT, control-RCAN1-/-, LPS-induced WT and LPS-induced RCAN1-/- groups, some with Midiv-1 or KN93 treatment. The protein levels of RCAN1, p-ERK1/2, NFAT3, Drp1, p-Drp1, p-CaMKII in mouse hearts or cultured cardiomyocytes were determined by Western blotting. Myocardial function was assessed by echocardiography. Cardiac hypertrophy and fibrosis were detected by H&E and Masson's trichrome staining. Mitochondrial morphology was examined by transmission electron microscope. Serum level of LDH was detected by ELISA. RESULTS: Our data show that RCAN1 was downregulated in septic mouse heart and LPS-induced cardiomyocytes. RCAN1-/- mice showed a severe impairment of cardiac function, and increased myocardial hypertrophy and fibrosis. The protein levels of NFAT3 and p-ERK1/2 were significantly increased in the heart tissues of RCAN1-/- mice. Further, RCAN1 deficiency aggravated sepsis-induced cardiac mitochondrial injury as indicated by increased ROS production, pathological fission and the loss of mitochondrial membrane potential. Inhibition of fission with Mdivi-1 reversed LPS-induced cardiac hypertrophy, fibrosis and dysfunction in RCAN1-/- mice. Moreover, RCAN1 depletion promoted mitochondrial translocation of CaMKII, which enhanced fission and septic hypertrophy, while inhibition of CaMKII with KN93 reduced excessive fission, improved LPS-mediated cardiac remodeling and dysfunction in RCAN1-/- mice. CONCLUSIONS: Our finding demonstrated that RCAN1 deficiency aggravated mitochondrial injury and septic cardiomyopathy through activating CaMKII. RCAN1 serves as a novel therapeutic target for treatment of sepsis-related cardiac remodeling and dysfunction.

Water-driven Successive Structural Transformation in a Two-Dimensional (2D) Lead-Free Hybrid Double Perovskite.

Hybrid organic-inorganic halide perovskites (HOIPs) have received continued interest for their structure diversity and potential application in optoelectronic, solar cells, nonlinear optics (NLO), and ferroelectrics. Structural symmetry breaking induced by water molecules in single-crystal-to-single-crystal (SCSC) transformations is beneficial to develop ferroelectrics or second-harmonic generation (SHG) materials. Along this line, a water-containing two-dimensional (2D) double perovskite, (C6H16N2)2AgBiBr8·H2O (1), was prepared. Acentric 1 suffered a twice SCSC transformation when subjected to dehydration and rehydration, where the new centric (C6H16N2)2AgBiBr8 (2) and acentric (C6H16N2)2AgBiBr8·0.5H2O (3) were generated. In contrast to the irreversible transformation from 1 to 2 (symmetry: P21 → Pmna), it is prominent that the reversible conversion of centric 2 to acentric 3 (symmetry: Pmna ↔ P21212). The result validated the effect of guest water on inducing structural transformation and symmetry breaking of 2D perovskites, inspiring further explorations on water-involved 2D materials.

Bilateral triceps tendon approach is flexible and efficient in the treatment of type C distal humerus fractures.

PURPOSE: The purpose of this study was to assess and compare elbow range of motion, triceps extension strength and functional results of type C (AO/OTA) distal humerus fractures treated with bilateral triceps tendon (BTT) approach and olecranon osteotomy (OO). At the same time, we are also trying to know whether BTT approach can provide sufficient vision for comminuted intra-articular fractures of the distal humerus, and whether it is convenient to convert to the treatment to total elbow arthroplasty (TEA) or OO. METHODS: Patients treated with OO and BTT approaches for type C distal humerus fractures between July 2014 and December 2017 were retrospectively reviewed. Inclusion criteria include: (1) patients' age were more than 18 years old, (2) follow-up was no less than 6 months, and (3) patients were diagnosed with type C fractures (based on the AO/OTA classification). Exclusion criteria include: (1) open fractures (Gustillo type 2 or type 3), (2) treated by other approaches, and (3) presented with combined injuries of ipsilateral upper extremities, such as ulnar nerve. Elbow range of motion and triceps extension strength testing were completely valuated, when the fractures had healed. Assessment of functional results using the Mayo elbow performance score and complications were conducted in final follow-up. The data were compared using the two tailed Student's t-test. All data were presented as mean ± standard deviation. RESULTS: Eighty-six patients of type C distal humerus fractures, treated by OO and BTT approach were retrospectively reviewed between July 2014 and December 2017. Fifty-five distal humerus fractures (23 males and 32 females, mean age 52.7 years) treated by BTT approach or OO were included in this study. There were 10 fractures of type C1, 16 type C2 and 29 type C3 according to the AO/OTA classification. Patients were divided into two surgical approach groups chosen by the operators: BTT group (28 patients) and OO group (27 patients). And the mean follow-up time of all patients was 15.6 months (range, 6-36 months). Three cases in BTT group were converted to TEA, and one converted to OO. Only one case in BTT group presented poor articular reduction with a step more than 2 mm. There were not significantly different in functional outcomes according to the Mayo elbow performance score, operation time and extension flexion motion are values between BTT group and OO group (p > 0.05). Complications and reoperation rate were also similar in the two groups. Triceps manual muscle testing were no significant difference in the two groups, even subdivided in elder patients (aged >60 years old). CONCLUSION: BTT is a safe approach to achieve similar functional result comparing with OO. BTT were not suitable for every case with severe comminuted pattern, but it avoids the potential complications related to OO, and has no complications concerning with triceps tendon. It is convenient for open reduction internal fixation and flexible to be converted to OO, as well as available to be converted to TEA in elder patients.

Integrin ß1D Deficiency-Mediated RyR2 Dysfunction Contributes to Catecholamine-Sensitive Ventricular Tachycardia in Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a hereditary heart disease characterized by fatty infiltration, life-threatening arrhythmias, and increased risk of sudden cardiac death. The guideline for management of ARVC in patients is to improve quality of life by reducing arrhythmic symptoms and to prevent sudden cardiac death. However, the mechanism underlying ARVC-associated cardiac arrhythmias remains poorly understood. METHODS: Using protein mass spectrometry analyses, we identified that integrin ß1 is downregulated in ARVC hearts without changes to Ca2+-handling proteins. As adult cardiomyocytes express only the ß1D isoform, we generated a cardiac specific ß1D knockout mouse model and performed functional imaging and biochemical analyses to determine the consequences of integrin ß1D loss on function in the heart in vivo and in vitro. RESULTS: Integrin ß1D deficiency and RyR2 Ser-2030 hyperphosphorylation were detected by Western blotting in left ventricular tissues from patients with ARVC but not in patients with ischemic or hypertrophic cardiomyopathy. Using lipid bilayer patch clamp single channel recordings, we found that purified integrin ß1D protein could stabilize RyR2 function by decreasing RyR2 open probability, mean open time, and increasing mean close time. Also, ß1D knockout mice exhibited normal cardiac function and morphology but presented with catecholamine-sensitive polymorphic ventricular tachycardia, consistent with increased RyR2 Ser-2030 phosphorylation and aberrant Ca2+ handling in ß1D knockout cardiomyocytes. Mechanistically, we revealed that loss of DSP (desmoplakin) induces integrin ß1D deficiency in ARVC mediated through an ERK1/2 (extracellular signal-regulated kinase 1 and 2)-fibronectin-ubiquitin/lysosome pathway. CONCLUSIONS: Our data suggest that integrin ß1D deficiency represents a novel mechanism underlying the increased risk of ventricular arrhythmias in patients with ARVC.

Short Direct Repeats in the 3' Untranslated Region Are Involved in Subgenomic Flaviviral RNA Production.

Mosquito-borne flaviviruses consist of a positive-sense genome RNA flanked by the untranslated regions (UTRs). There is a panel of highly complex RNA structures in the UTRs with critical functions. For instance, Xrn1-resistant RNAs (xrRNAs) halt Xrn1 digestion, leading to the production of subgenomic flaviviral RNA (sfRNA). Conserved short direct repeats (DRs), also known as conserved sequences (CS) and repeated conserved sequences (RCS), have been identified as being among the RNA elements locating downstream of xrRNAs, but their biological function remains unknown. In this study, we revealed that the specific DRs are involved in the production of specific sfRNAs in both mammalian and mosquito cells. Biochemical assays and structural remodeling demonstrate that the base pairings in the stem of these DRs control sfRNA formation by maintaining the binding affinity of the corresponding xrRNAs to Xrn1. On the basis of these findings, we propose that DRs functions like a bracket holding the Xrn1-xrRNA complex for sfRNA formation.IMPORTANCE Flaviviruses include many important human pathogens. The production of subgenomic flaviviral RNAs (sfRNAs) is important for viral pathogenicity as a common feature of flaviviruses. sfRNAs are formed through the incomplete degradation of viral genomic RNA by the cytoplasmic 5'-3' exoribonuclease Xrn1 halted at the Xrn1-resistant RNA (xrRNA) structures within the 3'-UTR. The 3'-UTRs of the flavivirus genome also contain distinct short direct repeats (DRs), such as RCS3, CS3, RCS2, and CS2. However, the biological functions of these ancient primary DR sequences remain largely unknown. Here, we found that DR sequences are involved in sfRNA formation and viral virulence and provide novel targets for the rational design of live attenuated flavivirus vaccine.

Regional Brain and Spinal Cord Volume Loss in Spinocerebellar Ataxia Type 3.

BACKGROUND: Given that new therapeutic options for spinocerebellar ataxias are on the horizon, there is a need for markers that reflect disease-related alterations, in particular, in the preataxic stage, in which clinical scales are lacking sensitivity. OBJECTIVE: The objective of this study was to quantify regional brain volumes and upper cervical spinal cord areas in spinocerebellar ataxia type 3 in vivo across the entire time course of the disease. METHODS: We applied a brain segmentation approach that included a lobular subsegmentation of the cerebellum to magnetic resonance images of 210 ataxic and 48 preataxic spinocerebellar ataxia type 3 mutation carriers and 63 healthy controls. In addition, cervical cord cross-sectional areas were determined at 2 levels. RESULTS: The metrics of cervical spinal cord segments C3 and C2, medulla oblongata, pons, and pallidum, and the cerebellar anterior lobe were reduced in preataxic mutation carriers compared with controls. Those of cervical spinal cord segments C2 and C3, medulla oblongata, pons, midbrain, cerebellar lobules crus II and X, cerebellar white matter, and pallidum were reduced in ataxic compared with nonataxic carriers. Of all metrics studied, pontine volume showed the steepest decline across the disease course. It covaried with ataxia severity, CAG repeat length, and age. The multivariate model derived from this analysis explained 46.33% of the variance of pontine volume. CONCLUSION: Regional brain and spinal cord tissue loss in spinocerebellar ataxia type 3 starts before ataxia onset. Pontine volume appears to be the most promising imaging biomarker candidate for interventional trials that aim at slowing the progression of spinocerebellar ataxia type 3. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Symptoms of systemic lupus erythematosus are diagnosed in leptin transgenic pigs.

Leptin is a well-known adipokine that plays a critical role in immune responses. To further explore the immunological roles of leptin, we developed a transgenic leptin pig controlled by the pig leptin (pleptin) promoter to overexpress leptin. Symptoms typically associated with systemic lupus erythematosus (SLE) were evident in this transgenic pig strain, including anemia, leukopenia, and thrombocytopenia as well as kidney and liver impairment. Histologically, there were increased immunoglobulin G (IgG) levels, elevated antiplatelet antibody (APA) levels, and deposition of immune complexes in the kidney and liver. In addition, anti-double-stranded DNA antibodies (dsDNAs), antinuclear antibodies (ANAs), and antinucleosome antibodies (ANuAs) were all significantly increased in serum immunological examinations. These findings were also accompanied by repression of the regulatory T cell (Treg) ratio. Significantly, glucocorticoid experimental therapies partially relieved the autoimmune responses and bleeding symptoms observed in these transgenic leptin pigs. Together, these results indicate that leptin plays a critical role in the development of autoimmune disorders and demonstrate that our transgenic leptin pigs can act as a valuable model of SLE.

The influence of pre-existing hypertension on coronavirus disease 2019 patients.

Hypertension represents one of the most common pre-existing conditions and comorbidities in Coronavirus disease 2019 (COVID-19) patients. To explore whether hypertension serves as a risk factor for disease severity, a multi-centre, retrospective study was conducted in COVID-19 patients. A total of 498 consecutively hospitalised patients with lab-confirmed COVID-19 in China were enrolled in this cohort. Using logistic regression, we assessed the association between hypertension and the likelihood of severe illness with adjustment for confounders. We observed that more than 16% of the enrolled patients exhibited pre-existing hypertension on admission. More severe COVID-19 cases occurred in individuals with hypertension than those without hypertension (21% vs. 10%, P = 0.007). Hypertension associated with the increased risk of severe illness, which was not modified by other demographic factors, such as age, sex, hospital geological location and blood pressure levels on admission. More attention and treatment should be offered to patients with underlying hypertension, who usually are older, have more comorbidities and more susceptible to cardiac complications.

The long-term impact of a chronic total occlusion in a non-infarct-related artery on acute ST-segment elevation myocardial infarction after primary coronary intervention.

OBJECTIVES: To investigate the long-term outcome of patients with acute ST-segment elevation myocardial infarction (STEMI) and a chronic total occlusion (CTO) in a non-infarct-related artery (IRA) and the risk factors for mortality. METHODS: The enrolled cohort comprised 323 patients with STEMI and multivessel diseases (MVD) that received a primary percutaneous coronary intervention between January 2008 and November 2013. The patients were divided into two groups: the CTO group (n = 97) and the non-CTO group (n = 236). The long-term major adverse cardiovascular and cerebrovascular events (MACCE) experienced by each group were compared. RESULTS: The rates of all-cause mortality and MACCE were significantly higher in the CTO group than they were in the non-CTO group. Cox regression analysis showed that an age ≥ 65 years (OR = 3.94, 95% CI: 1.47-10.56, P = 0.01), a CTO in a non-IRA(OR = 5.09, 95% CI: 1.79 ~ 14.54, P < 0.01), an in-hospital Killip class ≥ 3 (OR = 4.32, 95% CI: 1.71 ~ 10.95, P < 0.01), and the presence of renal insufficiency (OR = 5.32, 95% CI: 1.49 ~ 19.01, P = 0.01), stress ulcer with gastraintestinal bleeding (SUB) (OR = 6.36, 95% CI: (1.45 ~ 28.01, P = 0.01) were significantly related the 10-year mortality of patients with STEMI and MVD; an in-hospital Killip class ≥ 3 (OR = 2.97,95% CI:1.46 ~ 6.03, P < 0.01) and the presence of renal insufficiency (OR = 5.61, 95% CI: 1.19 ~ 26.39, P = 0.03) were significantly related to the 10-year mortality of patients with STEMI and a CTO. CONCLUSIONS: The presence of a CTO in a non-IRA, an age ≥ 65 years, an in-hospital Killip class ≥ 3, and the presence of renal insufficiency, and SUB were independent risk predictors for the long-term mortality of patients with STEMI and MVD; an in-hospital Killip class ≥ 3 and renal insufficiency were independent risk predictors for the long-term mortality of patients with STEMI and a CTO.