Jiakui Li

Seroprevalence of Toxoplasma gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China

Toxoplasma gondii (T. gondii), a zoonotic parasite infects almost all warm-blooded animals and causes significant economic losses. To date, however, it is still unclear whether yaks from the Qinghai-Tibetan plateau of China are exposed to T. gondii. On the present study, a survey was conducted for the first time, to investigate the seroprevalence of T. gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau (Qinghai, Tibet, Hongyuan area of Sichuan province). A total of 905 and 736 serum samples were collected from yaks in these areas in 2012 and 2013, respectively and assayed for T. gondii antibodies by an indirect hemagglutination test (IHA). The results showed that seroprevalence on plateau was 21.7% and 29.1% in 2012 and 2013, respectively with the prevalence of 22.4%, 19.4% and 25.5% in 2012 for Qinghai, Tibet and Hongyuan of Sichuan, respectively and of 26.4%, 27.0% and 33.7% for these three regions in 2013, respectively. The present survey indicated that the infection with T. gondii in yaks was widely spread in recent years on the plateau causing a high risk factor for animals and humans.

A review on epidemiology, global prevalence and economical losses of fasciolosis in ruminants

Fasciolosis is an important plant borne trematode zoonosis in ruminants caused by the Fasciola hepatica and Fasciola gigentica, It is classified as a neglected tropical disease and found in more than 50 countries especially where sheep and cattle are reared. Fasciolosis is a serious animal health problems in many rural and urban areas of world, causing significant financial losses due to decrease in production and viscera condemnation in animals. Accurate diagnosis of fasciolosis is always remained a challenging task for the field practitioners. There is no comprehensive summary on the occurrence and distribution of the infection at international level. Therefore, we intended to provide a complete overview on the prevalence and epidemiology of fasciolosis in farm animals from a global prospective. It includes to map the global distribution of fasciolosis in different areas of the world to identify the endemic regions which may be a source of potential disease outbreak. The financial liability related to fasciolosis on the livestock production has also been addressed. For this purpose, the published data during 2000-2015 (15 years) on fasciolosis was reviewed and collected by electronic literature search of four databases including Google, PubMed, Science Direct, and Web of Science. Data presented are contemplated to enhance our current understanding of the parasites geographical distribution, host range, and economic losses. Information provided would be useful for the application of more effective control strategies against fasciolosis in different geo-economics regions of the world.

Hsp90 inhibitor celastrol reinstates growth plate angiogenesis in thiram-induced tibial dyschondroplasia

ABSTRACT Tibial dyschondroplasia (TD) is an important long bone defect of broiler chickens that disturbs the proximal growth plate and is characterized by non-vascularized cartilage, a distended growth plate and lameness. Celastrol, a medicinal root extract from the plant Tripterygium wilfordii, is reported widely as a well-known heat-shock protein 90 (Hsp90) inhibitor. Recently, Hsp90 inhibition in chondrocyte differentiation and growth-plate vascularization were effective in restoring the morphology of the growth plate. The present study was aimed at investigating Hsp90 inhibition in TD using celastrol. The broiler chicks were divided into three groups; Control; TD induced (40 mg/kg thiram) and celastrol treatment. Hsp90, vascular endothelial growth factor and Flk-1 expressions were evaluated by quantitative real-time polymerase chain reaction and the protein levels of Hsp90 were measured by Western blot analysis. Antioxidant enzymes were determined to assess the liver damage caused by thiram and the protective effects of the medicine were evaluated by levels of serum biomarkers. The expression levels of Hsp90 and vascular endothelial growth factor mRNA transcripts were increased while Flk-1 receptor was decreased in TD-affected chicks. Celastrol therapy inhibited Hsp90 mRNA and protein levels and up-regulated the expressions of receptor Flk-1 in TD-affected tibial growth plates significantly (P < 0.05) in addition to rectifying the damaging effects of thiram on the liver by decreasing the levels of aspartate aminotransferase, alanine aminotransferase and malondialdehyde and correcting the oxidative imbalance. In conclusion, administering celastrol to dyschondroplastic chicks prevented un-vascularized growth plate, lameness and reinstated angiogenesis. Celastrol may be efficacious for the treatment of TD through the inhibition of Hsp90 expression and limiting the liver damage caused by thiram in broiler chickens.

Zinc Supplementation Protects against Cadmium Accumulation and Cytotoxicity in Madin-Darby Bovine Kidney Cells

Cadmium ions (Cd2+) have been reported to accumulate in bovine tissues, although Cd2+ cytotoxicity has not been investigated thoroughly in this species. Zinc ions (Zn2+) have been shown to antagonize the toxic effects of heavy metals such as Cd2+ in some systems. The present study investigated Cd2+ cytotoxicity in Madin-Darby bovine kidney (MDBK) epithelial cells, and explored whether this was modified by Zn2+. Exposure to Cd2+ led to a dose- and time-dependent increase in apoptotic cell death, with increased intracellular levels of reactive oxygen species and mitochondrial damage. Zn2+ supplementation alleviated Cd2+-induced cytotoxicity and this protective effect was more obvious when cells were exposed to a lower concentration of Cd2+ (10 μM), as compared to 50 μM Cd2+. This indicated that high levels of Cd2+ accumulation might induce irreversible damage in bovine kidney cells. Metallothioneins (MTs) are metal-binding proteins that play an essential role in heavy metal ion detoxification. We found that co-exposure to Zn2+ and Cd2+ synergistically enhanced RNA and protein expression of MT-1, MT-2, and the metal-regulatory transcription factor 1 in MDBK cells. Notably, addition of Zn2+ reduced the amounts of cytosolic Cd2+ detected following MDBK exposure to 10 μM Cd2+. These findings revealed a protective role of Zn2+ in counteracting Cd2+ uptake and toxicity in MDBK cells, indicating that this approach may provide a means to protect livestock from excessive Cd2+ accumulation.

Differential expression of extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in avian tibial dyschondroplasia

Tibial dyschondroplasia (TD) is an avian bone disorder of different aetiologies that may be associated with lameness. The disorder is characterized by focal disruption of endochondral bone formation, with a lack of matrix proteolysis and an accumulation of non-mineralized avascular cartilage. The aim of this study was to determine the expression of extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in normal, thiram-induced TD lesions and in the process of recovery from TD in broiler chickens. An extracellular matrix (ECM) degrading enzyme, matrix metalloproteinase-9 (MMP-9), was selected to investigate the effects of CD147 in the degradation of ECM. Gene expression was analysed by quantitative real-time polymerase chain reaction and protein levels by immunohistochemistry and western blotting. The birds were divided into three groups: thiram fed; recovery; and controls. Genes encoding CD147 and MMP-9 were down-regulated during the development of the disease, and were up-regulated during recovery. Western blotting also showed lower protein levels of CD147 in TD, which increased during the recovery phase associated with ECM degradation and growth plate repair. The findings of this study suggest that ECM has a crucial role in the occurrence of TD and that CD147 appears to play a pivotal role in matrix proteolysis in the chicken, similar to that in other species.

Expression of Genes Encoding Matrilin-3 and Cyclin-I During the Impairment and Recovery of Chicken Growth Plate in Tibial Dyschondroplasia

SUMMARY Tibial dyschondroplasia (TD) is a skeletal disease characterized by the disruption of endochondral bone formation in avian species. The aim of this study was to determine the expression of Matrilin-3 and Cyclin-I genes in chicken growth plate during impairment and recovery from TD. Gene expressions were analyzed by polymerase chain reaction, and proteins by immunohistochemistry and in situ hybridizations. Expression of genes encoding Matrilin-3 and Cyclin-I were diminished with parallel decrease in proteins during TD, with fewer signs of cartilage cell differentiation. In contrast, there was an increase in mRNA expressions and protein levels of both genes during the recovery phase. These findings suggest that the Matrilin-3 and Cyclin-I genes also play a role in chondrocyte differentiation during the impairment and recovery of growth plate in TD. RESUMEN Nota de Investigación—Expresión de genes que codifican para matrilin-3 y ciclina-I durante el deterioro y recuperación de la placa de crecimiento de pollos con discondroplasia de en la tibia. La discondroplasia tibial (TD) es una enfermedad del esqueleto que se caracteriza por la interrupción de la formación de hueso endocondral en especies aviares. El objetivo de este estudio fue determinar la expresión de los genes para matrilin-3 y de ciclina-I en la placa de crecimiento de pollos durante el deterioro y la recuperación por discondroplasia tibial. Se analizó la expresión de los genes mediante la reacción en cadena de la polimerasa, y las proteínas se analizaron mediante técnicas de inmunohistoquímica e hibridación in situ. La expresión de los genes que codifican para matrilin-3 y ciclina-I disminuyeron de manera paralela con las proteínas durante la discondroplasia tibial con algunos signos de diferenciación de las células del cartílago. En contraste, hubo un aumento en la expresión de ARN mensajero y de los niveles de proteína de ambos genes durante la fase de recuperación. Estos hallazgos sugieren que los genes matrilin-3 y ciclina-I también juegan un papel en la diferenciación de condrocitos en el deterioro y recuperación de la placa de crecimiento en la discondroplasia tibial.

Tibial dyschondroplasia is highly associated with suppression of tibial angiogenesis through regulating the HIF-1α/VEGF/VEGFR signaling pathway in chickens

Tibial dyschondroplasia (TD) is an intractable poultry problem that is characterized by the appearance of non-vascularized and non-mineralized cartilage masses in tibial growth plates (TGPs). However, the role of angiogenesis inhibition in the occurrence of TD remains unknown. In this study, we found that, compared to low-altitude Arbor Acres chickens (AACs), high-altitude Tibetan chickens showed higher tibial vascular distributions that were accompanied by up-regulation of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor A (VEGFA) and VEGF receptors. These observations provide insights into hypoxia-induced angiogenesis, which may be related to the absence of TD in high-altitude native Tibetan chickens. Importantly, hypoxia experiments also showed that during hypoxia, tibial angiogenesis was enhanced, which was due to pro-angiogenic factor up-regulation (including VEGFA, VEGFR1, VEGFR2, and IL-8), in AACs. Moreover, we observed that thiram-induced TD could strongly inhibit tibial angiogenesis in the hypertrophic zone through coordinated down-regulation of HIF-1α and pro-angiogenic factors, leading to a disruption in the blood supply to the TGP. Taken together, these findings reveal that the occurrence of TD is highly associated with inhibition of tibial angiogenesis through down-regulated expression of HIF-1α, VEGFA and VEGF receptors, which results in suppression of TGP development.

High altitude hypoxia as a factor that promotes tibial growth plate development in broiler chickens

Tibial dyschondroplasia (TD) is one of the most common problems in the poultry industry and leads to lameness by affecting the proximal growth plate of the tibia. However, due to the unique environmental and geographical conditions of Tibet, no case of TD has been reported in Tibetan chickens (TBCs). The present study was designed to investigate the effect of high altitude hypoxia on blood parameters and tibial growth plate development in chickens using the complete blood count, morphology, and histological examination. The results of this study showed an undesirable impact on the overall performance, body weight, and mortality of Arbor Acres chickens (AACs) exposed to a high altitude hypoxic environment. However, AACs raised under hypoxic conditions showed an elevated number of red blood cells (RBCs) and an increase in hemoglobin and hematocrit values on day 14 compared to the hypobaric normoxia group. Notably, the morphology and histology analyses showed that the size of tibial growth plates in AACs was enlarged and that the blood vessel density was also higher after exposure to the hypoxic environment for 14 days, while no such change was observed in TBCs. Altogether, our results revealed that the hypoxic environment has a potentially new role in increasing the blood vessel density of proximal tibial growth plates to strengthen and enhance the size of the growth plates, which may provide new insights for the therapeutic manipulation of hypoxia in poultry TD.

In Vitro Effect of Apigenin and Danshen in Tibial Dyschondroplasia Through Inhibition of Heat-Shock Protein 90 and Vascular Endothelial Growth Factor Expressions in Avian Growth Plate Cells

SUMMARY Tibial dyschondroplasia (TD) is one of the common skeletal abnormalities in fast-growing birds, and it is characterized by nonvascularized, unmineralized, and nonviable cartilage in the tibial growth plate that fails to form bone. The aim of this study was to check the in vitro effect of apigenin and danshen on heat-shock protein 90 (Hsp90) and vascular endothelial growth factor (VEGF) expressions in avian growth plate cells treated with sublethal concentration of thiram. Initially, chondrocytes from chicken growth plates were isolated on culturx ed medium with and without various concentration of thiram to determine the sublethal dose. Then, to check the effect of apigenin and danshen, the chondrocytes were treated first with a sublethal (2.5 μM) concentration of thiram and then with different doses (10, 20, 40, and 80 μM) of apigenin and danshen. The mRNA expression levels of Hsp90 and VEGF genes were evaluated by quantitative reverse transcription polymerase chain reaction (RT-qPCR). The results showed that the expression levels of Hsp90 and VEGF mRNA transcripts were increased significantly (P < 0.05) in thiram-treated chondrocytes culture medium up to 1.5-fold, whereas apigenin and danshen therapy to chondrocytes in culture medium significantly (P < 0.05) reduced the Hsp90 and VEGF expression levels. In conclusion, up-regulation of both (Hsp90 and VEGF) genes and damage to chondrocytes in culture medium caused by thiram can be restored by using apigenin and danshen. Therefore, apigenin and danshen therapies are suggested and encouraged as a promising approach to control TD in broiler chickens.

Recovery of Chicken Growth Plate by Heat-Shock Protein 90 Inhibitors Epigallocatechin-3-Gallate and Apigenin in Thiram-Induced Tibial Dyschondroplasia

SUMMARY Tibial dyschondroplasia (TD) is an important tibiotarsal bone disorder characterized by an avascular and nonmineralized growth plate; it is attributed to abnormal differentiation of chondrocytes and causes lameness. Heat-shock protein 90 (Hsp90) is a proangiogenic factor in animal tissues; however, its gene expression increases in cases of chicken TD. The objective of this study was to evaluate the efficacy of epigallocatechin-3-gallate (EGCG) and apigenin in thiram-induced TD birds; these substances were used because of their Hsp90 inhibitory activities. The histologic study of growth plates was carried out with hematoxylin and eosin staining, and the Hsp90 gene expression was examined by reverse transcription quantitative real-time PCR. Results showed that as compared to a control group, TD-affected birds displayed changes in chondrocyte differentiation, with lack of blood vessels, and an increased expression of Hsp90 was observed significantly (P < 0.05). However, on administering the EGCG and apigenin to TD-affected birds, the normal chondrocyte columnar organization was restored with vascularization and decreased Hsp90 expression activity (P < 0.05), which ultimately abrogated the lameness. Our results suggested that Hsp90 is the key factor in the development of TD, and EGCG and apigenin have a novel effect on Hsp90 inhibition properties, thus reducing the lameness and leg deformity in chicken broilers.