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Hereditary distal renal tubular acidosis (dRTA) is a rare genetic disease that is caused by mutations in SLC4A1, ATP6V1B1, or ATP6V0A4. However, there are many families with hereditary dRTA in whom the disease-causing genes are unknown. Accordingly, we performed whole exome sequencing and genetic studies of the members of a family with autosomal recessive dRTA of an unknown genetic etiology. Here, we report compound heterozygous pathogenic variations in tryptophan-aspartate repeat domain 72 (WDR72) (c.1777A>G [p.R593G] and c.2522T>A [p.L841Q]) in three affected siblings of a family with dRTA. Both variants segregated with dRTA in the family and were not observed in normal control subjects. Homologous modeling and in silico mutagenesis indicated that R593G and L841Q alter the H-bond formations in the nearby residues, affecting the WDR72 protein structure. All these evidences indicate that the identified WDR72 variations were probably to have caused hereditary dRTA in the reported family. In addition, homozygous nonsense mutation (c.2686C>T [p.R896X]) was identified in another family, strongly supporting the causal role of WDR72 in dRTA. Based on our literature review, WDR72 mutations associated with dRTA have not been previously described. This is the first identification of pathogenic variations in WDR72 as a cause of hereditary dRTA.

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Cholangiocarcinoma (CCA) is a cancer of the bile ducts that is associated with poor prognosis and poor treatment outcome. Approximately one-third of CCA patients can undergo surgery, but the recurrence rate is high and chemotherapy often cannot satisfactorily prolong survival. Cellular immunotherapy based on adoptive T-cell transfer is a potential treatment for CCA; however, the development of this technology and the search for an appropriate tumor-associated antigen are still ongoing. To enhance the cytotoxic activity of effector T cells against CCA, we developed self-differentiated monocyte-derived dendritic cells (SD-DC) presenting cAMP-dependent protein kinase type I-alpha regulatory subunit (PRKAR1A), which is an overexpressed protein that plays a role in the regulation of tumor growth to activate T cells for CCA cell killing. Dendritic cells (DCs) transduced with lentivirus harboring tri-cistronic cDNA sequences (SD-DC-PR) could produce granulocyte-macrophage colony-stimulating factor, interleukin-4, and PRKAR1A. SD-DC showed similar phenotypes to those of DCs derived by conventional method. Autologous effector T cells (CD3+, CD8+) activated by SD-DC-PR exhibited greater cytotoxic activity against CCA than those activated by conventionally-derived DCs. Effector T cells activated by SD-DC-PR killed 60% of CCA cells at an effector-to-target ratio of 15:1, which is approximately twofold greater than the cell killing performance of those stimulated with control DC. The cytotoxic activities of effector T cells activated by SD-DC-PR against CCA cells were significantly associated with the expression levels of PRKR1A in CCA cells. This finding that SD-DC-PR effectively stimulated autologous effector T cells to kill CCA cells may help to accelerate the development of novel therapies for treating CCA.

We have previously demonstrated that compound heterozygous (SAO/G701D) and homozygous (G701D/G701D) mutations of the anion exchanger 1 (AE1) gene, encoding erythroid and kidney AE1 proteins, cause autosomal recessive distal renal tubular acidosis (AR dRTA) in Thai patients. It is thus of interest to examine the prevalence of these mutations in the Thai population. The SAO and G701D mutations were examined in 844 individuals from north, northeast, central, and south Thailand. Other reported mutations including R602H, DV850, and A858D were also examined in some groups of subjects. The SAO mutation was common in the southern Thai population; its heterozygote frequency was 7/206 and estimated allele frequency 1.70%. However, this mutation was not observed in populations of three other regions of Thailand. In contrast, the G701D mutation was not found in the southern population but was observed in the northern, northeastern, and central populations, with heterozygote frequencies of 1/216, 3/205, and 1/217, and estimated allele frequencies of 0.23%, 0.73%, and 0.23%, respectively. The higher allele frequency of the G701D mutation in the northeastern Thai population corresponds to our previous finding that all Thai patients with AR dRTA attributable to homozygous G701D mutation originate from this population. This suggests that the G701D allele that is observed in this region might arise in northeastern Thailand. The presence of patients with compound heterozygous SAO/G701D in southern Thailand and Malaysia and their apparently absence in northeastern Thailand indicate that the G701D allele may have migrated to the southern peninsular region where SAO is common, resulting in pathogenic allelic interaction.

The therapeutic activities of food-derived bioactive proteins and peptides are attracting increased attention within the research community. Medicinal plants used in traditional medicines are an excellent source of bioactive proteins and peptides, especially those traditionally prepared by water extraction for use as tea or food supplement. In this study, novel bioactive peptides were isolated from enzymatic digests of 33 Thai medicinal plants. The inhibitory activity of each against dengue virus (DENV) infection was investigated. Of 33 plants, peptides from Acacia catechu extract demonstrated the most pronounced anti-DENV activity. Half maximal inhibitory concentration of 0.18 μg/ml effectively inhibited DENV foci formation. Treatment with 1.25 μg/ml crude peptide extract could reduce virus production less than 100-fold with no observable cell toxicity. Peptide sequences were determined by high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry. Two bioactive peptides isolated from Acacia catechu inhibited DENV foci formation >90% at the concentration of 50 μM; therefore, they are recommended for further investigation as antiviral peptides against DENV infection.

dRTA (distal renal tubular acidosis) and HS (hereditary spherocytosis) are two diseases that can be caused by mutations in the gene encoding the AE1 (anion exchanger 1; Band 3). dRTA is characterized by defective urinary acidification, leading to metabolic acidosis, renal stones and failure to thrive. HS results in anaemia, which may require regular blood transfusions and splenectomy. Mutations in the gene encoding AE1 rarely cause both HS and dRTA. In the present paper, we describe a novel AE1 mutation, Band 3 Edmonton I, which causes dominant HS and recessive dRTA. The patient is a compound heterozygote with the new mutation C479W and the previously described mutation G701D. Red blood cells from the patient presented a reduced amount of AE1. Expression in a kidney cell line showed that kAE1 (kidney AE1) C479W is retained intracellularly. As kAE1 is a dimer, we performed co-expression studies and found that, in kidney cells, kAE1 C479W and G701D proteins traffic independently from each other despite their ability to form heterodimers. Therefore the patient carries one kAE1 mutant that is retained in the Golgi (G701D) and another kAE1 mutant (C479W) located in the endoplasmic reticulum of kidney cells, and is thus probably unable to reabsorb bicarbonate into the blood. We conclude that the C479W mutant is a novel trafficking mutant of AE1, which causes HS due to a decreased cell-surface AE1 protein and results in dRTA due to its intracellular retention in kidney.

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