Novel SCA19/22-associated KCND3 mutations disrupt human KV 4.3 protein biosynthesis and channel gating.

Mutations in the human voltage-gated K+ channel subunit KV 4.3-encoding KCND3 gene have been associated with the autosomal dominant neurodegenerative disorder spinocerebellar ataxia types 19 and 22 (SCA19/22). The precise pathophysiology underlying the dominant inheritance pattern of SCA19/22 remains elusive. Using cerebellar ataxia-specific targeted next-generation sequencing technology, we identified two novel KCND3 mutations, c.950 G>A (p.C317Y) and c.1123 C>T (p.P375S) from a cohort with inherited cerebellar ataxias in Taiwan. The patients manifested notable phenotypic heterogeneity that includes cognitive impairment. We employed in vitro heterologous expression systems to inspect the biophysical and biochemical properties of human KV 4.3 harboring the two novel mutations, as well as two previously reported but uncharacterized disease-related mutations, c.1013 T>A (p.V338E) and c.1130 C>T (p.T377M). Electrophysiological analyses revealed that all of these SCA19/22-associated KV 4.3 mutant channels manifested loss-of-function phenotypes. Protein chemistry and immunofluorescence analyses further demonstrated that these mutants displayed enhanced protein degradation and defective membrane trafficking. By coexpressing KV 4.3 wild-type with the disease-related mutants, we provided direct evidence showing that the mutants instigated anomalous protein biosynthesis and channel gating of KV 4.3. We propose that the dominant inheritance pattern of SCA19/22 may be explained by the dominant-negative effects of the mutants on protein biosynthesis and voltage-dependent gating of KV 4.3 wild-type channel.

Reenvisioning Traditional to Regenerative Therapeutic Advances in Managing Nonalcoholic Fatty Liver Disease in Diabetes Mellitus.

Reports indicate the increasing prevalence of liver disorders in diabetes mellitus (DM) patients. Clinically, it has also been revealed that the existence of nonalcoholic fatty liver disease (NAFLD) enhances the incidence of type 2 diabetes mellitus (T2DM), while T2DM exacerbates NAFLD to extremely severe forms of steatohepatitis, cirrhosis, and hepatocellular carcinoma. This implies the coexistence and bidirectional nature of NAFLD and T2DM, which function synergistically to drive adverse consequences in clinical practice. For treatment of such comorbid state, though the existing practices such as lifestyle management, traditional Chinese medicines (TCM), and pharmaceuticals have offered somewhat relief, the debate continues about the optimal therapeutic impacts. Recent developments in the field of tissue engineering have led to a renewed interest in novel biomaterial alternatives such as stem cells. This might be attributable to their differentiation potential towards hepatic and pancreatic lineage. These cellular therapies could be further complemented by platelet-derived biomaterials, TCM formulations, or any specific drug. Based on these abovementioned approaches, we aimed to comprehensively analyze various preclinical and clinical studies from traditional to regenerative therapeutic approaches in managing concomitant NAFLD and T2DM.

Osteoporosis Prevention by Adlay ( Yì Yǐ: The Seeds of Coix Lachryma-Jobi L. var. ma-yuen Stapf) in a Mouse Model.

Osteoporosis is characterized by reduced bone mass and quality due to an imbalanced bone remodeling. A grass crop, adlay (Coix lachryma-jobi), is a kind of nourishing food, which has also been used in traditional Chinese medicine. In this study, we investigated the effect of adlay (C. lachryma-jobi L. var. ma-yuen Stapf) on osteoporosis using an ovariectomized mouse model. The adlay diet (10% and 30% adlay in mouse diet) or water extract of adlay (0.3 g/kg/day) was given to ovariectomized mice for 4 weeks. In some experiments, the primary rat osteoblast cells were used to test the possible mechanism of adlay on osteoporosis. The body weight was slightly increased and uterus weight was markedly decreased in ovariectomized mice, which were not affected by adlay treatment. Adlay diet (30%) and adlay extract feedings significantly reversed the decreased bone alkaline phosphatase activity and calcium contents and bone mineral density in ovariectomized mice. Moreover, adlay extracts increased the osteoblast cell proliferation in a dose-dependent manner. Adlay extracts also increased the protein expressions of proliferating cell nuclear antigen and phosphorylated extracellular signal-regulated kinase (ERK) 1/2 in osteoblast cells. ERK inhibitor PD98059 significantly reversed the increased osteoblast cell proliferation by adlay extracts. Taken together, these findings indicate that adlay effectively alleviates the osteoporotic status in ovariectomized mice. Adlay is capable of increasing the proliferation of osteoblast cells via an ERK-regulated signaling pathway. Adlay may be a helpful healthy food for osteoporosis prevention.

Evaluation of osteoporosis prevention by adlay using a tissue culture model.

Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf ) is a grass crop, which has been used in traditional Chinese medicine and also as a nourishing food. Recently, some studies have indicated that adlay possesses some pharmacological effects including anti-allergic, anti-mutagenic, hypolipemic, and anti-diabetic effects. However, the effect of adlay on osteoporosis is still unknown. In this study, we investigated and evaluated the effect of adlay seed on the osteoporosis prevention. The methods of in vitro cultures of neonatal rat calvaria tissues or adult rat femoral metaphyseal tissues of bones isolated from normal or ovariectomized female rats were used for further investigation. Treatment with water extract of adlay seed could reverse the decreased alkaline phosphatase activities and calcium levels and increased tartrate-resistant acidic phosphatase activities induced by parathyroid hormone in cultured metaphyseal tissues. In ovariectomized rats, the alkaline phosphatase activities and calcium levels were significantly decreased and tartrate-resistant acidic phosphatase activities were increased in femoral metaphyseal tissues as compared with sham-control. Treatment with water extract of adlay seed could counteract these effects in ovariectomized rats. Taken together, these findings imply that adlay is capable of reversing the osteoporotic status in rats, and may be a helpful healthy food for osteoporosis prevention.