Current Research Status of Tetraspanins CD81

Tetraspanins with special four-times acrossing membrane structure can contact outer, intrinsic membrane and transmembrane proteins, which forms a channel to connect the internal and external membrane signal.CD81, as one member of Tetraspanins, has a variety of biological activities and is widely dispersed and participates in the organism physiological responses.CD81 plays an important role in many cell process, and is closely related to the pathogenesis of many human diseases, and so widely watched.But the molecular structure, space conformation and physiological mechanisms of CD81 are still not entirely clear.We still need to do further research and discussion, especially, the comprehensively understanding of precise role of CD81 in the process of HCV into a host cell, it is vital for clinical application.This article would focus on the research progresses of molecular structure and biochemical characteristics, cell fusion effect, the virus-identified mechanism, the role in the immune system and clinical application on CD81.In summary, clarifing the function and role of CD81 is important to study the clinical pathogenesis and treatment of various diseases.     

Candidate serum metabolite biomarkers of residual feed intake and carcass merit in sheep

Mutton and lamb sales continue to grow globally at a rate of 5% per year. However, sheep farming struggles with low profit margins due to high feed costs and modest carcass yields. Selecting those sheep expected to convert feed efficiently and have high carcass merit, as early as possible in their life cycle, could significantly improve the profitability of sheep farming. Unfortunately, direct measurement of feed conversion efficiency (via residual feed intake [RFI]) and carcass merit is a labor-intensive and expensive procedure. Thus, indirect, marker-assisted evaluation of these traits has been explored as a means of reducing the cost of its direct measurement. One promising and potentially inexpensive route to discover biomarkers of RFI and/or carcass merit is metabolomics. Using quantitative metabolomics, we profiled the blood serum metabolome (i.e., the sum of all measurable metabolites) associated with sheep RFI and carcass merit and identified candidate biomarkers of these traits. The study included 165 crossbred ram-lambs that underwent direct measurement of feed consumption to determine their RFI classification (i.e., low vs. high) using the GrowSafe System over a period 40 d. Carcass merit was evaluated after slaughter using standardized methods. Prior to being sent to slaughter, one blood sample was drawn from each animal, and serum prepared and frozen at −80 °C to limit metabolite degradation. A subset of the serum samples was selected based on divergent RFI and carcass quality for further metabolomic analyses. The analyses were conducted using three analytical methods (nuclear magnetic resonance spectroscopy, liquid chromatography mass spectrometry, and inductively coupled mass spectrometry), which permitted the identification and quantification of 161 unique metabolites. Biomarker analyses identified three significant (P < 0.05) candidate biomarkers of sheep RFI (AUC = 0.80), seven candidate biomarkers of carcass yield grade (AUC = 0.77), and one candidate biomarker of carcass muscle-to-bone ratio (AUC = 0.74). The identified biomarkers appear to have roles in regulating energy metabolism and protein synthesis. These results suggest that serum metabolites could be used to categorize and predict sheep for their RFI and carcass merit. Further validation using a larger (3×) and more diverse cohort of sheep is required to confirm these findings.     

Proteomic analysis of urine from male dogs during early stages of tubulointerstitial injury in a canine model of progressive glomerular disease

Background: Sensitive and specific noninvasive biomarkers for tubulointerstitial injury are lacking, and proteomic techniques provide a powerful tool for biomarker discovery. Objective: The aim of this study was to identify novel urinary biomarkers of early tubulointerstitial injury in canine progressive renal disease using both 2‐dimensional differential in‐gel electrophoresis (2‐D DIGE), which identifies individual proteins, and surface‐enhanced laser desorption ionization time‐of‐flight mass spectrometry (SELDI‐TOF), which generates protein peak profiles. Methods: Urine was collected from 6 male dogs with X‐linked hereditary nephropathy (XLHN) at 2 time points (TP): 1) the onset of overt proteinuria (urine protein:creatinine ratio>2) and 2) the onset of azotemia (creatinine ≥1.2 mg/dL); corresponding renal biopsies were analyzed from 3 of the dogs. Urine samples from the 6 dogs were subjected to analysis by 2‐D DIGE and SELDI‐TOF. Urinary retinol‐binding protein (RBP) was evaluated in 25 male dogs with XLHN and normal control dogs by Western blot analysis. Results: Clinical data and histologic evaluation revealed reduced renal function and increased tubulointerstitial fibrosis at TP 2. A number of urine proteins and protein peaks were differentially present at the 2 time points, with several known biomarkers of renal disease identified in addition to several promising new biomarkers. RBP was first detected in urine approximately 2 months before onset of azotemia (TP 2), but after onset of overt proteinuria, and amounts increased with progression of disease. Conclusions: Proteomic techniques were successfully used to identify urinary biomarkers of renal disease in dogs with XLHN. Urinary RBP is a promising biomarker for early detection of tubulointerstitial damage and progression to end‐stage renal disease.     

Proteomic identification and profiling of canine lymphoma patients*

This study employed proteomic and bioinformatic approaches to identify serum biomarkers in canine lymphoma patients. Chilled serum samples derived from non‐lymphoma (n = 92) and lymphoma (n = 87) patients were shipped from first opinion veterinary practices, subjected to ion exchange chromatography and analysed by surface‐enhanced laser desorption ionization mass spectrometry. Nineteen serum protein peaks were identified between the two groups as being significantly different (P < 0.05) based upon their normalized ion intensities. Two biomarkers were identified that were capable of differentiating lymphoma and non‐lymphoma patients. Analysis of the test data provided a positive predictive value (PPV) of 82%. A clinical follow‐up study was carried out on 96 canine patients suspected of having lymphoma. Evaluation of this data gave a specificity value of 91%, sensitivity of 75%, PPV of 80% and negative predictive value of 88%. In conclusion, the expression pattern of two serum biomarkers has enabled serum samples to be classified into either lymphoma or non‐lymphoma categories.     

Bone biomarkers and risk of fracture in two‐ and three‐year‐old Thoroughbreds

The aim of this study was to determine whether bone biomarkers (osteocalcin, PICP, ICTP and CTX‐I) could be used to identify 2‐ and 3‐year‐olds at increased risk of fracture in the subsequent flat racing season. It was concluded that these bone biomarkers cannot be used to identify 2‐ and 3‐year‐olds that sustain a fracture. Whether bone biomarkers have better predictive value in older horses or when measured serially in the same animal remains to be determined.     

Atrial Natriuretic Peptide as an Indicator of the Severity of Valvular Regurgitation and Heart Failure in Horses

Natriuretic peptides are cardiac biomarkers, routinely used for diagnosis, prognosis, and guidance for treatment in human and small animal cardiology. However, their diagnostic and prognostic value in horses has received little study. The aim of this study was to investigate the plasma atrial natriuretic concentration (ANP_Pl) in a large group of horses with various degrees of valvular regurgitation (VR) and congestive heart failure (CHF). Clinical examination and two-dimensional time-motion mode and Doppler echocardiography were performed on 91 horses admitted to the Equine Teaching Hospital of Liege University, with either no, mild, moderate, or severe VR and presenting various stages of CHF. Plasma atrial natriuretic concentration was measured using a commercially available human radioimmunoassay test. Mean values of body weight, age, ANP_Pl, and echocardiographic parameters were compared among horses with no, mild, moderate, and severe VR and among horses in different CHF stages. Correlation and linear regression of ANP_Pl with each echocardiographic parameter and with the percentage of dilation of each of cardiac chambers were assessed. Horses with severe or moderate VR had significantly higher ANP_Pl than those with mild or no VR. Plasma atrial natriuretic concentration was significantly higher in horses presenting CHF than those without CHF. Plasma atrial natriuretic concentration was significantly correlated with the left atrial diameter and its percentage of dilation. These results suggest a diagnostic value of ANP_Pl in horses with VR, especially with tricuspid or mitral insufficiency with dilation of the atria.     

Trafficking of molecules between parasitic plants and their hosts

Parasitic plants have evolved various methods of invading host plants. Some invade aerial parts, whereas others invade the roots to obtain necessary nutrients for their development. Phelipanche and Orobanche spp. (broomrapes) and Cuscuta spp. (dodders) are holoparasitic plants that subsist on roots and shoots, respectively, of a variety of agricultural crops. These weeds are able to connect directly with the vascular system of the host, thereby acquiring the water, minerals and carbohydrates necessary for their own growth and reproduction. This exploitation by parasitic plants often causes severe losses in yield quality and quantity of host crops. The key to an effective means for controlling parasitic plants lies in the development of resistant crops, supported by an improved understanding of broomrape and dodder biology. The haustoria formed at the junctions of parasite and host open the way for translocation of a variety of molecules and macromolecules from the host to the parasite. At the same time, however, the haustoria also open opportunities for the development of methods to control parasitic plants. This review will summarise the current knowledge on translocation of siRNAs, mRNAs, viruses, sugars, proteins and herbicides from host to parasitic plants and the potential significance of such molecules to the parasite. Improved understanding of the molecular exchange between host plants and their parasites is expected to lead to the development of state‐of‐the‐art, effective approaches to parasitic weed management.     

Effects of one-time and two-time intra-articular injection of hyaluronic acid sodium salt after joint surgery in dogs

Thirty-one dogs with patellar luxation (grades 2 and 3) were categorized into three groups. Group 1 (G.1; n = 12) had sodium hyaluronate (SHA) intra-articularly injected into the stifle joint that received surgery. Group 2 (G.2; n = 10) received SHA twice: first after surgery and then 1 week later. Group 3 (G.3; n = 9) served as a control, without injection. Blood was collected before injection and then once a week for 4 weeks after injection for evaluation of chondroitin sulfate (CS-WF6) and hyaluronan (HA). The results revealed significantly (p < 0.05) improved clinical scores by the end of week 4 in G.1 and G.2 relative to G.3; however, there was no significant difference between G.1 and G.2. There was a significant decrease (p < 0.05) in serum CS-WF6 levels beginning at week 2 in G.1 and G.2. At weeks 3 and 4, serum HA in G.1 and G.2 differed from that in G.3 (p < 0.05). No significant difference (p > 0.05) was observed in serum biomarkers between G.1 and G.2. In conclusion, intra-articular injection with SHA after joint surgery may improve homeostasis of the joint, retarding the process of OA.     

高分子聚合物对土壤物理及坡面产流产沙特征的影响

 为研究高分子聚合物对土壤改良和防治水土流失的作用,选择聚丙烯酸、聚乙烯醇、脲醛树脂3种高分子聚合物,通过室内试验和人工模拟降雨试验,以不同浓度施入土壤,观察其对土壤物理及坡面产流产沙特性的影响。结果表明:1)3种高分子聚合物均是较好的土壤结构改良剂,经聚合物处理后的土壤水稳性团粒含量平均增加17.27%,渗透性能提高41.81%,密度减小11.18%,土壤持水能力较对照提高2.8倍。2)坡地喷施上述高分子聚合物能显著推迟产流时间,降低产流速度,与对照相比,施加聚合物的坡地减少径流量42.05%、土壤侵蚀量58%以上。3)根据其对土壤改良、减流减沙、防治土壤侵蚀效果的影响,确定3种高分子聚合物最佳施用浓度范围分别为116～145mL/m2,36～40 g/m2,180.0～240.0mL/m2,其中聚丙烯酸为作用效果最显著的高分子聚合物。上述3种高分子聚合物在改良土壤,防治水土流失方面有广泛的应用前景,今后还需对其效果持续性、最佳施用量等进一步研究。