Sialylation of vasorin by ST3Gal1 facilitates TGF-β1-mediated tumor angiogenesis and progression.

ST3Gal1 is a key sialyltransferase which adds α2,3-linked sialic acid to substrates and generates core 1 O-glycan structure. Upregulation of ST3Gal1 has been associated with worse prognosis of breast cancer patients. However, the protein substrates of ST3Gal1 implicated in tumor progression remain elusive. In our study, we demonstrated that ST3GAL1-silencing significantly reduced tumor growth along with a notable decrease in vascularity of MCF7 xenograft tumors. We identified vasorin (VASN) which was shown to bind TGF-β1, as a potential candidate that links ST3Gal1 to angiogenesis. LC-MS/MS analysis of VASN secreted from MCF7, revealed that more than 80% of its O-glycans are sialyl-3T and disialyl-T. ST3GAL1-silencing or desialylation of VASN by neuraminidase enhanced its binding to TGF-β1 by 2- to 3-fold and thereby dampening TGF-β1 signaling and angiogenesis, as indicated by impaired tube formation of HUVECs, suppressed angiogenesis gene expression and reduced activation of Smad2 and Smad3 in HUVEC cells. Examination of 114 fresh primary breast cancer and their adjacent normal tissues showed that the expression levels of ST3Gal1 and TGFB1 were high in tumor part and the expression of two genes was positively correlated. Kaplan Meier survival analysis showed a significantly shorter relapse-free survival for those with lower expression VASN, notably, the combination of low VASN with high ST3GAL1 yielded even higher risk of recurrence (p = 0.025, HR = 2.967, 95% CI = 1.14-7.67). Since TGF-β1 is known to transcriptionally activate ST3Gal1, our findings illustrated a feedback regulatory loop in which TGF-β1 upregulates ST3Gal1 to circumvent the negative impact of VASN

A diverse range of bacterial and eukaryotic chitinases hydrolyzes the LacNAc (Gal<i>β</i>1-4GlcNAc) and LacdiNAc (GalNAc<i>β</i>1-4GlcNAc) motifs found on vertebrate and insect cells

There is emerging evidence that chitinases have additional functions beyond degrading environmental chitin, such as involvement in innate and acquired immune responses, tissue remodeling, fibrosis, and serving as virulence factors of bacterial pathogens. We have recently shown that both the human chitotriosidase and a chitinase from Salmonella enterica serovar Typhimurium hydrolyze LacNAc from Galβ1–4GlcNAcβ-tetramethylrhodamine (LacNAc-TMR (Galβ1–4GlcNAcβ(CH(2))(8)CONH(CH(2))(2)NHCO-TMR)), a fluorescently labeled model substrate for glycans found in mammals. In this study we have examined the binding affinities of the Salmonella chitinase by carbohydrate microarray screening and found that it binds to a range of compounds, including five that contain LacNAc structures. We have further examined the hydrolytic specificity of this enzyme and chitinases from Sodalis glossinidius and Polysphondylium pallidum, which are phylogenetically related to the Salmonella chitinase, as well as unrelated chitinases from Listeria monocytogenes using the fluorescently labeled substrate analogs LacdiNAc-TMR (GalNAcβ1–4GlcNAcβ-TMR), LacNAc-TMR, and LacNAcβ1–6LacNAcβ-TMR. We found that all chitinases examined hydrolyzed LacdiNAc from the TMR aglycone to various degrees, whereas they were less active toward LacNAc-TMR conjugates. LacdiNAc is found in the mammalian glycome and is a common motif in invertebrate glycans. This substrate specificity was evident for chitinases of different phylogenetic origins. Three of the chitinases also hydrolyzed the β1–6 bond in LacNAcβ1–6LacNAcβ-TMR, an activity that is of potential importance in relation to mammalian glycans. The enzymatic affinities for these mammalian-like structures suggest additional functional roles of chitinases beyond chitin hydrolysis

Expression analysis of a mouse orthologue of HSFY, a candidate for the azoospermic factor on the human Y chromosome

Heat shock transcription factor on Y (HSFY) is located in one of three candidate regions for azoospermic factor (AZF), AZFb on the Y chromosome. We and others have already revealed that some azoospermic males are missing the regions of the Y chromosome including HSFY. Previously, we showed that murine HSFY-like sequence〔mHSFYL(RikencDNA4933413G11Rik)〕, which is the mouse orthologue of HSFY, is exclusively expressed in testis. The sequences encoding the presumed DNA-binding domain in HSFY and mHSFYL were found in other mammals such as dogs, cows and chickens. To elucidate mHSFYL expression in the testes in detail, we carried out in situ hybridization. mHSFYL was predominantly expressed in round spermatids. Furthermore, we clarified the intracellular distribution of mHSFYL inCOS1 cells with HA- or GFP-tagged proteins. Both HA-mHSFYL and GFP-mHSFYL were located in the nucleus. Our results suggest that HSFY/mHSFYL may have evolutionarily conserved functions for spermatogenesis

COL25A1 triggers and promotes Alzheimer’s disease-like pathology in vivo

Collagen XXV alpha 1 (COL25A1) is a collagenous type II transmembrane protein purified from senile plaques of Alzheimer’s disease (AD) brains. COL25A1 alleles have been associated with increased risk for AD in a Swedish population. COL25A1 is specifically expressed in neurons and binds to aggregated Aβ in vitro. However, its contribution to the pathogenesis of AD and in vivo function are unknown. Here, we report that over-expression of COL25A1 in transgenic mice increases p35/p25 and β-site APP-cleaving enzyme 1 (BACE1) levels, facilitates intracellular aggregation and extracellular matrix deposits of Aβ, and causes synaptophysin loss and astrocyte activation. COL25A1 mice displayed reduced anxiety-like behavior in elevated plus maze and open field tests and significantly slower swimming speed in Morris water maze. In stable cell lines, motifs in noncollagenous domains of COL25A1 were important for the induction of BACE1 expression. These findings demonstrate that COL25A1 leads to AD-like pathology in vivo. Modulation of COL25A1 function may represent an alternative therapeutic intervention for AD

The primary headaches: genetics, epigenetics and a behavioural genetic model

The primary headaches, migraine with (MA) and without aura (MO) and cluster headache, all carry a substantial genetic liability. Familial hemiplegic migraine (FHM), an autosomal dominant mendelian disorder classified as a subtype of MA, is due to mutations in genes encoding neural channel subunits. MA/MO are considered multifactorial genetic disorders, and FHM has been proposed as a model for migraine aetiology. However, a review of the genetic studies suggests that the FHM genes are not involved in the typical migraines and that FHM should be considered as a syndromic migraine rather than a subtype of MA. Adopting the concept of syndromic migraine could be useful in understanding migraine pathogenesis. We hypothesise that epigenetic mechanisms play an important role in headache pathogenesis. A behavioural model is proposed, whereby the primary headaches are construed as behaviours, not symptoms, evolutionarily conserved for their adaptive value and engendered out of a genetic repertoire by a network of pattern generators present in the brain and signalling homeostatic imbalance. This behavioural model could be incorporated into migraine genetic research

Studies of spin-crossover complexes via solvo-thermal syntheses and their thermal relaxation of light excited kinetic phenomena

藉由溶劑熱法我們成功了合成了cis-[Fe(tzpy)2(NCS)2] (1)分子，由室溫單經繞射的結果，我們可以得知其與自旋轉換起始物同時也是異構物trans-[Fe(tzpy)2(NCS)2](2)在空間上分子堆疊，與晶體中單一分子的鍵長鍵角的比較， cis-[Fe(tzpy)2(NCS)2]與trans-[Fe(tzpy)2(NCS)2]分子在室溫下具有相似的鐵氮鍵長，也都跟一般Fe(Ⅱ)高自旋態下的鐵氮鍵長相似。兩者也具有相仿的假想八面體[FeN6]中心，只是在配位NCS基有著鄰位與順位的空間上排列不同，在單位晶格空間上cis-[Fe(tzpy)2(NCS)2]是trans-[Fe(tzpy)2(NCS)2]分子的兩倍。 這是首次對自旋轉換於cis-trans異構分子間的物理化學性質的研究。只有些微不同的順反異構分子。順反異構的cis-分子中鐵具有相似的配位環境，對於自旋轉換性質影響極大的配位場強度也應該極為類似。由變溫磁性所得的測量結果我們可以知道cis-[Fe(tzpy)2(NCS)2]在可所量測的溫度範圍中(5-300 K)一直都維持在高自旋態，這跟我們原先所預期的結果完全不同，有趣的是如何從唯一的變因，也就是晶體堆疊上的不同來解釋這兩Fe(Ⅱ) 錯合物異構物分子，在磁性性質上的巨大差異。由實驗結果可以發現雖然只有些微不同的順反異構分子，即可造成分子堆疊的極大差異，進而影響了自旋轉換的發生與否，及迥然不同的 變化。此外這也是首次以液熱（solvothermal）合成方法轉換cis-trans異構金屬錯合物分子。也證明了以液熱方法是除了以氧化還原方法之外，提供了另一條途徑，合成一般化學方法難以合成的幾何異構物。The novel complex Cis-[Fe(tzpy)2(NCS)2](1) has been synthesized successfully from spin crossover trans-[Fe(tzpy)2(NCS)2](2) isomer by solvothermal induced isomerization method. Single-crystal diffraction data was collected at 293 K by CAD-4 diffractometer. Complex (1) crystallizes in the monoclinic space group C 2/c with Z=4, a=14.828(4), b=11.485(5) &Aring; ,c=15.071(2) &Aring;, beta = 110.081(15) deg. The bond lengths of Fe-N are 2.249(4) &Aring;, 2.197(4) &Aring;, and 2.056(5) &Aring; for complex 1 and 2.217(2) &Aring;, 2.181(2) &Aring;, and 2.097(3) &Aring; for complex 2 at HS state. Solvothermal methods have provided rotes to otherwise inaccessible geometry isomers. Both complexes have a similar pseudo-octahedral [FeN6] core with the NCS- groups in the cis arrangement in 1 but trans in 2. Another Dinuclear (N`, N1, N2 ,N``)2 Double bridging complex [Fe2(bpt)2(NCS)2(CH3OH)2] (3) and unique spin crossover 1D ladder complex [Fe2(bpt)2(NCS)2(bpy)2]•MeOH (4) have been synthesized successfully also by solvo- thermal syntheses from spin crossover trans-[Fe(abpt)2(NCS)2] complex. Variable-temperature magnetic susceptibility measurement reveals that 1 and 3 staying in a high-spin state in the observed temperature range of 5-300 K. The 1D Spin-crossover complex 4 has a abrupt spin transition at 130 K and possesses unusual magnetic behavior. It is interesting to note that the steric possible conformation can be realized by hydro-(solvo-)thermal syntheses and the differences of the crystal packing and [FeⅡN6] octahedron geometry between these iron (Ⅱ) complexes result in a dramatic change in their magnetic properties. Further studies on the origin of the discrepancy in the crystal field responsible for this result are currently in progress.論文目錄 第一

Genotypes of the MTHFR C677T and MTRR A66G genes act independently to reduce migraine disability in response to vitamin supplementation

BACKGROUND: Migraine is a chronic disabling neurovascular condition that may in part be caused by endothelial and cerebrovascular disruption induced by hyperhomocysteinaemia. We have previously provided evidence indicating that reduction of homocysteine by vitamin supplementation can reduce the occurrence of migraine in women. The current study examined the genotypic effects of methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) gene variants on the occurrence of migraine in response to vitamin supplementation. METHODS: This was a 6-month randomized, double-blinded placebo-controlled trial of daily vitamin B supplementation (B(6), B(9) and B(12)) on reduction of homocysteine and of the occurrence of migraine in 206 female patients diagnosed with migraine with aura. RESULTS: Vitamin supplementation significantly reduced homocysteine levels (P0.1). When the vitamin-treated group was stratified by genotype, the C allele carriers of the MTHFR C677T variant showed a higher reduction in homocysteine levels (P<0.001), severity of pain in migraine (P=0.01) and percentage of high migraine disability (P=0.009) compared with those with the TT genotypes. Similarly, the A allele carriers of the MTRR A66G variants showed a higher level of reduction in homocysteine levels (P<0.001), severity of pain in migraine (P=0.002) and percentage of high migraine disability (P=0.006) compared with those with the GG genotypes. Genotypic analysis for both genes combined indicated that the treatment effect modification of the MTRR variant was independent of the MTHFR variant. CONCLUSION: This provided further evidence that vitamin supplementation is effective in reducing migraine and also that both MTHFR and MTRR gene variants are acting independently to influence treatment response in female migraineurs