Thrombopoietin and its receptor expression in pediatric patients with chronic immune thrombocytopenia

Plasma concentration of thrombopoietin in dogs with immune thrombocytopenia

BACKGROUND

Immune thrombocytopenia (ITP) is a common cause of severe thrombocytopenia in dogs. The pathogenesis of nonassociative, primary ITP (pITP) appears complex, with ill-defined thrombopoietic response.

OBJECTIVES

Develop an immunoassay to measure plasma canine thrombopoietin (TPO) concentration and characterize TPO concentrations in dogs with pITP.

ANIMALS

Forty-one healthy dogs, 8 dogs in an induced ITP model (3 control, 5 ITP), and 58 pITP dogs.

METHODS

Recombinant canine TPO (rcTPO) was purchased and its identity confirmed by mass spectrometry. Monoclonal antibodies were raised to rcTPO and used to configure a sandwich ELISA using streptavidin-biotin detection. Assay performance, coefficients of variability, and healthy dog plasma TPO reference interval (RI) were determined, followed by assay of ITP samples.

RESULTS

Assay dynamic range was 15 pg/mL (lower limit of detection) to 1000 pg/mL TPO, with limit of quantitation of 62 pg/mL. Plasma TPO RI was 0 to 158 pg/mL, with plasma TPO <62 pg/mL for 35/41 healthy dogs. All dogs with induced ITP developed marked increases in plasma TPO concentration. Peak values ranged from 515 to >6000 pg/mL. In contrast, only 2/58 pITP dogs had TPO values above RI.

CONCLUSIONS AND CLINICAL IMPORTANCE

Plasma TPO concentration is paradoxically low at diagnosis for most dogs with pITP. This finding suggests that ineffective thrombopoiesis contributes to thrombocytopenia in pITP dogs and supports evaluating TPO receptor agonist treatment as used for pITP in humans. The TPO assay provides a new tool to study thrombopoiesis in pITP and other thrombocytopenic syndromes in dogs.

Therapeutic Effects and Associated Mechanisms by which "Fuyang Jiedu Huayu" Granules Treat Chronic Liver Failure in the Rat

Aim

Fuyang Jiedu Huayu (FYJDHY) granules are a combination of five traditional Chinese medicines with known therapeutic effects against chronic liver failure (CLF). The aim of the present study was to investigate the efficacy of FYJDHY to ameliorate the effects of carbon tetrachloride- (CCl4-) induced CLF in rats and to explore the possible molecular mechanisms underlying its therapeutic efficacy.

Methods

A model of chronic liver failure was established by intraperitoneal injection of 50% carbon tetrachloride into SD rats for 8 weeks. After establishing the model, rats were treated with either low-dose (4.725 kg/d), medium-dose (9.45 kg/d), or high-dose (18.9 g/kg/d) FYJDHY for 2 weeks. After treatment, samples of liver tissue and blood were harvested from rats in each group. Serum ALT, AST, and TBIL levels and prothrombin time were measured using a biochemical analyzer. The expression of Gab1 (Grb2-associated binder 1), TPO (thrombopoietin), and its receptor c-Mpl were measured using quantitative real-time PCR (RT-PCR) and Western blot analysis, and assessment of histological improvement in liver tissue was by H&E-stained tissue sections.

Results

Compared with the model group, serum ALT, AST, and TBIL levels and PT of rats in the intervention group were significantly reduced (P < 0.05). In addition, FYJDHY alleviated pathological damage to liver tissue and increased the expression of Gab1, TPO, and its receptor c-Mpl in liver tissue, to levels statistically significant compared with the model group (P < 0.05).

Conclusions

The therapeutic effect of FYJDHY on CLF may be related to the promotion of angiogenesis and improvement in hemopoietic function in individuals suffering from CLF.

The Role of Ubiquitin E3 Ligase in Atherosclerosis

Atherosclerosis is a chronic inflammatory vascular disease. Atherosclerotic cardiovascular disease is the main cause of death in both developed and developing countries. Many pathophysiological factors, including abnormal cholesterol metabolism, vascular inflammatory response, endothelial dysfunction and vascular smooth muscle cell proliferation and apoptosis, contribute to the development of atherosclerosis and the molecular mechanisms underlying the development of atherosclerosis are not fully understood. Ubiquitination is a multistep post-translational protein modification that participates in many important cellular processes. Emerging evidence suggests that ubiquitination plays important roles in the pathogenesis of atherosclerosis in many ways, including regulation of vascular inflammation, endothelial cell and vascular smooth muscle cell function, lipid metabolism and atherosclerotic plaque stability. This review summarizes important contributions of various E3 ligases to the development of atherosclerosis. Targeting ubiquitin E3 ligases may provide a novel strategy for the prevention of the progression of atherosclerosis.