Dingwei Zhang

Isolation and antitumor activities of acidic polysaccharide from Gynostemma pentaphyllum Makino

Two acidic polysaccharides (GP-B1 and GP-C1) were obtained from Gynostemma pentaphyllum. The molecular weights (Mw) of the two fractions were 79 kDa for GP-B1 and 126 kDa for GP-C1. GP-B1 was composed of Gal, Ara, Man, Rha, Xyl, Glc, GalA and GlcA in a molar ration of 3.5:3.2:0.6:0.9:0.3:0.5:0.6:0.4. GP-C1 consisted of Gal, Ara, Man, Rha, Glc, and GlcA in the proportions of 2.1:1.0:0.3:0.5:0.4:0.9. Among them, GP-B1 treatment had a significant inhibitory effect on the growth of melanoma B16 in vivo and in vitro. Meanwhile GP-B1 could increase the relative spleen weight and stimulate the splenocyte proliferation alone or combined with ConA. Moreover, GP-B1 treatment induced an evident increase in the level of serum TNF-α, IFN-γ, and IL-12 and a reduction for IL-10 production. These results indicate that the antitumor effects of GP-B1 are associated with immunostimulation.

Wnt/β-Catenin and Wnt5a/Ca Pathways Regulate Proliferation and Apoptosis of Keratinocytes in Psoriasis Lesions.

Background/Aims: Wnt5a is overexpressed in psoriasis lesions, however the mechanism by which Wnt5a is involved in the pathogenesis of psoriasis is not clear. To address this, the expression of Wnt5a in psoriatic lesions and its effect on keratinocyte cell proliferation and apoptosis was examined in vitro. Methods: The expression levels of WNT5A, and genes encoding its receptors frizzled2 (FZD2) and frizzled5 (FZD5) were examined in samples obtained from individuals with psoriasis and healthy controls. Knockdown of Wnt5a with short interfering (si)RNAs was performed in cultured HaCaT keratinocytes and normal human keratinocytes (NHK), and the expression of Wnt5a, protein kinase C (PKC), and β-catenin were determined, and cell cycle activity, proliferation and apoptosis were assessed. Results: The expression of WNT5A, FZD2 and FZD5 mRNA and protein were increased in psoriatic lesions. Wnt5a knockdown suppressed proliferation and induced apoptosis in HaCaT and NHK cells. Additionally, expression of PCNA, MKI67, CCND1, BCL2, CTNNB1, and genes encoding PKC and survivin were downregulated, whereas CASP3 was upregulated. The mRNA levels of the Wnt pathway inhibitors DKK1 and SFRP1 were upregulated, Western blotting analyses demonstrated reduction in β-catenin and PKC protein levels. Conclusion: Knockdown of Wnt5a suppresses the proliferation of keratinocytes and induces apoptosis by inhibiting the Wnt/β-catenin or Wnt5a/Ca2+ pathways.

Detection and comparison of two types of ATP2C1 gene mutations in Chinese patients with Hailey–Hailey disease

The gene ATP2C1 is identified as the defective gene in Hailey–Hailey disease (HHD). The nonsense and missense are two common types of mutations and have ,respectively, been detected in many HHD patients. The aims of our study were to identify the pathogenic ATP2C1 abnormality in Chinese HHD patients, and to compare nonsense and missense mutations in vivo to provide further understanding of the molecular and the physiological basis of HHD. The nucleotide sequencing of the ATP2C1 gene was performed in HHD patients, unaffected family members and 100 unrelated individuals. Meanwhile, we detected and analyzed the clinical manifestations, the expression of ATP2C1 mRNA and hSPCA1 protein in the two types of mutations. Three heterozygous mutations were identified, including a previously reported nonsense mutation (R799X), two novel missense mutations (D644G) and (R417K). The results of comparisons between two types of mutations showed that the common clinical features, the similarly low-level expressions of ATP2C1 mRNA and hSPCA1 protein, but the ATP2C1 mRNA expression of nonsense mutation was lower than missense mutation and even less than half the level of normal people. Our findings expand the known spectrum of ATP2C1 mutations in HHD. We supported the haploinsufficiency theory as prevalent mechanism in both types of mutations, and believed that the differences of ATP2C1 mRNA expressions in peripheral blood may relate with the type of mutation and reflect the state of illness of patients.

Wnt5a is involved in the pathogenesis of cutaneous lichen planus.

Cutaneous lichen planus (CLP) is a chronic inflammatory and immune‐mediated disease. Wnt5a is one of the most extensively studied Wnt proteins, and has important functions in stimulating inflammation, cell proliferation, cell fate determination and cell differentiation. Wnt5a expression in CLP has not been comprehensively studied to date.

Four novel mutations of the ATP2C1 gene in Chinese patients are associated with familial benign chronic pemphigus.

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Hailey–Hailey disease: investigation of a possible compensatory SERCA2 up-regulation and analysis of SPCA1, p63, and IRF6 expression

Hailey–Hailey disease (HHD) is caused by heterozygous mutations in the ATP2C1 gene, encoding the secretory pathway Ca2+ ATPase1 (SPCA1). SPCA1 and sarco/endoplasmic reticulum Ca2+ ATPase2 (SERCA2) encoded by ATP2A2 are two essential calcium pumps needed for Ca2+ homeostasis maintenance in keratinocytes. ATP2A2 mutations cause another hereditary skin disorder, Darier’s disease (DD). Previously, the compensatory expression of SPCA1 for SERCA2 insufficiency in DD was demonstrated, but it is not known whether a similar compensatory mechanism exists in HHD. Additionally, little is known about the role of p63 and interferon regulatory factor 6 (IRF6), two important regulatory factors involved in keratinocyte proliferation and differentiation, in HHD. Here, we used the skin biopsy samples from patients with HHD and human primary keratinocytes transfected with ATP2C1 siRNA to search for potential pathogenic mechanisms in HHD. We observed normal SERCA2 levels, but reduced p63, and increased IRF6 levels in HHD epidermal tissues and SPCA1-deficient keratinocytes. This suggests that there is no compensatory mechanism by SERCA2 for the SPCA1 deficiency in HHD. Moreover, the abnormal expression of p63 and IRF6 appears to be related to SPCA1 haploinsufficiency, with down-regulation of p63 probably resulting from IRF6 overexpression in HHD. We speculate that a novel pathogenic mechanism involving SPCA1, p63, and IRF6 may play a role in the skin lesions occurring in HHD.

Delayed-onset pachyonychia congenita caused by a novel mutation in the V2 domain of keratin 6b

explanation for the discrepancy relates to the degree of effect on various tissues to the target-specificity of imatinib because different tissues may have diverse c-kit isotypes. Our patient showed graying of more than 50% of the scalp and pubic hair with generalized skin hypopigmentation, but the rest of the hairs were not involved. This may suggest that imatinib has target-specificity or a varying degree of ckit inhibition not only between skin and hair but also between each hair. Besides hair graying, our patient also showed diffuse hair loss of the scalp, which is also a possible side-effect of imatinib. It is associated with plateletderived growth factor receptor (PDGFR)-regulated maintenance of the anagen phase of the hair cycle. The hair loss is thought to be related to inhibition of PDGFR by imatinib with resulting telonization of the hair follicles that eventually led to telogen effluvium. Both hair graying and hair loss are stressful for young female patients on antitumor therapy. Therefore, physicians should be aware of hair graying as an additional possible sideeffect of imatinib and notify patients.

Atrichia with Papular Lesions in a Chinese Family Caused by Novel Compound Heterozygous Mutations and Literature Review

Background: Congenital atrichia with papular lesions (APL) is characterized by complete absence of body hair shortly after birth, along with papules, and caused by mutations in the hairless gene (HR). Objective: To investigate whether APL with HR mutations might also be found among patients in non-consanguineous Chinese families and to discuss the phenotypic variations with the same mutations. Methods: DNA sequencing of the HR was performed in the Chinese pedigree and in 100 controls. Results: A nonsense mutation c.T2265A in the patient and his father as well as a 2bp deletion (3482delCT) in the patient and his mother were detected. Conclusion: Our study identified the first mutation in exon 10 in HR as well as the second novel compound heterozygous mutations in a Chinese family, also adding new variants to the knowledge of HR mutations in APL. Phenotypic heterogeneity in congenital atrichia might be subject to the founder genes or modifier genes.