A decrease of mitochondrial ubiquitin ligase increases the secretion of matrix metalloproteinase-1 by dermal fibroblasts through the induction of ER stress

BACKGROUND

We previously reported that the level of mitochondrial ubiquitin ligase (MITOL) protein in fibroblasts was decreased by UVA and that the knock-down (KD) of MITOL increased the secretion of matrix metalloprotease-1 (MMP-1) by fibroblasts. A recent study reported that MITOL suppresses endoplasmic reticulum (ER) stress by stabilizing the interaction between ER and mitochondria (MT) through the ubiquitination of mitofusin 2. These facts suggest that a decrease of MITOL would increase the secretion of MMP-1 through ER stress, but the detailed mechanism of that process in dermal fibroblasts remains unclear. Thus, this study was conducted to clarify the involvement of ER stress in the oversecretion of MMP-1 induced by the decreased MT quality caused by MITOL-KD.

METHODS

MITOL-KD normal human dermal fibroblast (NHDFs) were prepared by treating them with MITOL-small interfering RNA, after which their MMP-1 protein levels were measured. ER stress in NHDFs was evaluated by measuring the mRNA levels of spliced X-box binding protein 1 (sXBP1) and the protein levels of inositol-requiring enzyme 1α (IRE1α).

RESULTS

MITOL-KD NHDFs enhanced the secretion of MMP-1 via interleukin-6 (IL-6) elicited by the activation of nuclear factor-kappa B (NF-κB). The secretion of MMP-1 could be abrogated by a neutralizing IL-6 antibody and by JSH23, which is an inhibitor of NF-κB activation. Furthermore, MITOL-KD NHDFs as well as UVA-irradiated NHDFs showed increased ER stress levels. In addition, tunicamycin, which is an inducer of ER stress, also increased MMP-1 secretion.

CONCLUSION

These results suggested that the decrease of MITOL caused the oversecretion of MMP-1 via NF-κB-IL-6 signaling through the activation of ER stress in fibroblasts.

Possible Involvement of Dermal Fibroblasts in Modulating Nrf2 Signaling in Epidermal Keratinocytes

Epidermal keratinocytes protect themselves by cooperating with neighboring cells against internal and external stresses, which leads not only to the maintenance of cell homeostasis but also to the prevention of skin aging. Although it is known that nuclear factor (NF)-E2-related factor 2 (Nrf2) signaling plays a pivotal role in ameliorating oxidative stress and inflammatory responses under stress situations, it is unclear whether Nrf2 signaling in keratinocytes cooperates with neighboring cells such as dermal fibroblasts. Thus, this study was conducted to examine the influence of dermal fibroblasts on Nrf2 signaling in epidermal keratinocytes using a co-culture system. The results show that expression levels of Nrf2-regulated antioxidant factors, such as glutathione and heme oxygenase-1, in HaCaT keratinocytes (HaCaT KCs) are up-regulated in the presence of normal human dermal fibroblasts (NHDFs). In addition, the secretion of pro-inflammatory molecules, including interleukin-1α (IL-1α) and prostaglandin E₂ (PGE₂), is suppressed in co-cultures of NHDFs and UVB-irradiated HaCaT KCs. Interestingly, the localization of Nrf2 protein in HaCaT KCs was immediately translocated from the cytoplasm to the nucleus after the co-culture with NHDFs. These results suggest the possibility that Nrf2 signaling in keratinocytes is regulated in cooperation with dermal fibroblasts.

Intracellular oxidative stress induced by calcium influx initiates the activation of phagocytosis in keratinocytes accumulating at S-phase of the cell cycle after UVB irradiation

BACKGROUND

Phagocytosis is an essential process that maintains cellular homeostasis. In the epidermis, the phagocytosis of melanosomes into keratinocytes is important to protect their DNA against damage from ultraviolet B (UVB) radiation. Furthermore, it is considered that UVB activates the phagocytosis by keratinocytes but the detailed mechanism involved is not fully understood.

OBJECTIVE

To clarify the mechanism of UVB-enhanced phagocytosis in keratinocytes, we investigated the relationship between the phagocytic ability of keratinocytes and the cell cycle stage of keratinocytes.

METHODS

The phagocytic ability of keratinocytes was evaluated using the incorporation of fluorescent beads after exposure to UVB or oxidative stress. S-phase was evaluated by BrdU incorporation and immunostaining of cyclin D1. Intracellular calcium levels of keratinocytes were measured using the probe Fluo-4AM.

RESULTS

The phagocytosis of fluorescent beads into keratinocytes was enhanced by UVB and also by oxidative stress. We found that keratinocytes exposed to UVB or oxidative stress were at S-phase of the cell cycle. Furthermore, keratinocytes synchronized to S-phase showed a higher phagocytic ability according to the increased intracellular ROS level. The UVB-enhanced phagocytosis and entrance into S-phase of keratinocytes was abolished by ascorbic acid, a typical antioxidant. Keratinocytes synchronized to S-phase and exposed to UVB or oxidative stress had increased levels of intracellular calcium and their enhanced phagocytic abilities were diminished by the calcium ion chelator BAPTA-AM.

CONCLUSION

Taken together, intracellular oxidative stress induced by intracellular calcium influx mediates the UVB-enhanced phagocytic ability of keratinocytes accumulating at S-phase of the cell cycle.

The role of chaperone complex HSP90-SGT1-RAR1 as the associated machinery for hybrid inviability between Nicotiana gossei Domin and N. tabacum L

Two cultured cell lines (GTH4 and GTH4S) of a Nicotiana interspecific F1 hybrid (N. gossei × N. tabacum) were comparatively analyzed to find genetic factors related to hybrid inviability. Both cell lines proliferated at 37 °C, but after shifting to 26 °C, GTH4 started to die similar to the F1 hybrid seedlings, whereas GTH4S survived. As cell death requires de novo expression of genes and proteins, we compared expressed protein profiles between the two cell lines, and found that NgSGT1, a cochaperone of the chaperone complex (HSP90-SGT1-RAR1), was expressed in GTH4 but not in GTH4S. Agrobacterium-mediated transient expression of NgSGT1, but not NtSGT1, induced cell death in leaves of N. tabacum, suggesting its possible role in hybrid inviability. Cell death in N. tabacum was also induced by transient expression of NgRAR1, but not NtRAR1. In contrast, transient expression of any parental combinations of three components revealed that NgRAR1 promoted cell death, whereas NtRAR1 suppressed it in N. tabacum. A specific inhibitor of HSP90, geldanamycin, inhibited the progression of hypersensitive response-like cell death in GTH4 and leaf tissue after agroinfiltration. The present study suggested that components of the chaperone complex are involved in the inviability of Nicotiana interspecific hybrid.

3-O-Laurylglyceryl ascorbate improves the development of sensitive skin through the reduction of oxidative stress

Skin sensitivity is a serious problem for many people, and it can be induced by various factors such as UV irradiation, physical and mental stresses, air pollution, dry air and so on. Skin dryness triggered by UV and dry air is one of the most important causes inducing the development of sensitive skin, and it has been reported that oxidative stress contributes to skin dryness. In this study, we investigated whether treatment with 3-O-laurylglyceryl ascorbate (VC-3LG), which is an amphipathic ascorbic acid derivative, can suppress the development of sensitive skin. The results demonstrate that VC-3LG restores the expression levels of interleukin-1α, nerve growth factor and matrix metalloprotease-9 in the dry skin models of reconstructed human epidermal equivalents (RHEEs) and in H₂ O₂ -treated keratinocytes. In addition, VC-3LG suppresses the dendrite elongation of nerve cells induced in RHEEs by dry skin conditions and by H₂ O₂ treatment of keratinocytes. Therefore, we consider that treatment of the skin with VC-3LG is an effective approach to improve the development of sensitive skin.

Impairment of the autophagy system in repetitively UVA-irradiated fibroblasts

BACKGROUND

Autophagy is known as an intracellular cleanup system necessary to maintain homeostasis of the skin. Many studies have pointed out the relationship between aging and the inactivation of autophagy function, which suggests that the inactivation of autophagy occurs in aged skin. However, the aging process of the skin is complicated compared with other organs, because the skin is localized at the border between the inside of the body and the environment. Thus, skin aging is strongly affected by environmental factors, and it is well recognized that ultraviolet (UV) radiation is an important environmental factor that promotes skin aging. Therefore, characterizing the autophagic phenotypes induced by environmental factors is important to understand the process of skin aging.

METHODS

In order to demonstrate the status of autophagy during environment-induced aging of the skin, we investigated the autophagy profiles of normal human dermal fibroblasts (NHDFs) treated with repetitive UVA irradiation as model fibroblasts in photoaged skin.

RESULTS

Repetitively UVA-irradiated NHDFs showed increased numbers of autophagosomes, which coincided with the accumulation of p62 and increased levels of LAMP-1 and lysosomes. The behavior of repetitively UVA-irradiated NHDFs on autophagy was similar to that of NHDFs treated with hydroxychloroquine (HCQ), which is an inhibitor of lysosomal proteinase.

CONCLUSION

In summary, these results demonstrate that repetitively UVA-irradiated fibroblasts have reduced autophagy function due to the dysfunction of lysosomes.

3-O-Glyceryl-2-O-hexyl Ascorbate Suppresses Melanogenesis through Activation of the Autophagy System

The formation of skin pigmentation requires multiple steps, namely the activation of melanocytes, the synthesis of melanin, the transport of melanosomes to the tips of melanocyte dendrites and the transfer of melanosomes from melanocytes to surrounding keratinocytes. Recently, we reported that melanosomes accumulate in melanocytes when melanosome transport is disrupted and that they are then degraded by the autophagy system. In this study, we examined whether 3-O-glyceryl-2-O-hexyl ascorbate (VC-HG) suppresses melanogenesis through the activation of autophagy since VC-HG interferes with melanosome transport through the down-regulated expression of MyosinVa and Kinesin. The results demonstrate that VC-HG-treated B16 cells show an activation of autophagy through an increased expression level of Microtubule-associated protein 1 light chain 3 (LC3)-II and a decreased expression level of p62. Furthermore, the decrease of melanin content elicited by VC-HG was partially abolished by hydroxychloroquine or pepstatin A which are inhibitors of autophagy. Taken together, we conclude that VC-HG suppresses melanogenesis by activating the autophagy system.

Structural Requirements of Alkylglyceryl-l-Ascorbic Acid Derivatives for Melanogenesis Inhibitory Activity

l-Ascorbic acid has multifunctional benefits on skin aesthetics, including inhibition of melanin production, and is widely used in cosmetics. It, however, has low stability and poor skin penetration. We hypothesize that alkylglyceryl-l-ascorbic acid derivatives, highly stable vitamin C–alkylglycerol conjugates, would have similar anti-melanogenic activity with better stability and penetration. We test 28 alkylglyceryl-l-ascorbic acid derivatives (1–28) on theophylline-stimulated B16 melanoma 4A5 cells to determine if they inhibit melanogenesis and establish any structure–function relationships. Although not the most potent inhibitors, 3-O-(2,3-dihydroxypropyl)-2-O-hexyl-l-ascorbic acid (6, IC₅₀ = 81.4 µM) and 2-O-(2,3-dihydroxypropyl)-3-O-hexyl-l-ascorbic acid (20, IC₅₀ = 117 µM) are deemed the best candidate derivatives based on their inhibitory activities and low toxicities. These derivatives are also found to be more stable than l-ascorbic acid and to have favorable characteristics for skin penetration. The following structural requirements for inhibitory activity of alkylglyceryl-l-ascorbic acid derivatives are also determined: (i) alkylation of glyceryl-l-ascorbic acid is essential for inhibitory activity; (ii) the 3-O-alkyl-derivatives (2–14) exhibit stronger inhibitory activity than the corresponding 2-O-alkyl-derivatives (16–28); and (iii) derivatives with longer alkyl chains have stronger inhibitory activities. Mechanistically, our studies suggest that l-ascorbic acid derivatives exert their effects by suppressing the mRNA expression of tyrosinase and tyrosine-related protein-1.

3-O-Glyceryl-2-O-hexyl ascorbate suppresses melanogenesis by interfering with intracellular melanosome transport and suppressing tyrosinase protein synthesis

BACKGROUND

Ascorbic acid (AsA) has multifunctional benefits on skin beauty, such as the reduction in oxidative stress and the induction of collagen production. Among them, the prevention and improvement of skin pigmentation by AsA is a most important benefit for people. However, it is well known that AsA not only is quite unstable in formulations but it also has a low capability of skin penetration due to its hydrophilic property. In addition, existing water-soluble AsA derivatives that were developed to improve its stability also have low skin penetration.

AIM

To investigate the potential of a newly synthesized amphiphilic derivative of AsA, 3-O-Glyceryl-2-O-hexyl ascorbate (VC-HG), which has an added glyceryl group and a hexyl group, on skin beauty focusing on its skin lightening/whitening effects.

METHODS

DNA microarray analysis and real-time PCR were used to clarify the effects of VC-HG on melanogenesis using B16 mouse melanoma cells. The effects of VC-HG on melanin synthesis, tyrosinase protein levels, and the inhibition of tyrosinase activity were evaluated.

RESULTS

DNA microarray analysis revealed that treatment with VC-HG downregulated the expression of genes encoding tyrosinase and MyosinVa. Further, real-time PCR analysis showed the downregulation of tyrosinase, MyosinVa, Rab27a, and Kinesin mRNAs following VC-HG treatment. In addition, VC-HG caused decreases in tyrosinase protein levels and melanin synthesis.

CONCLUSION

We conclude that VC-HG has an impact on skin lightening/whitening by inhibiting tyrosinase protein synthesis and interfering with intracellular melanosome transport.

Viral load and ganciclovir (GCV) concentration in cerebrospinal fluid of patients successfully treated with GCV or valGCV for human herpesvirus 6 encephalitis/myelitis following umbilical cord blood transplantation

We describe successful treatment of 3 cases of human herpesvirus 6 (HHV-6) encephalitis/myelitis following cord blood transplantation (CBT). Ganciclovir (GCV) (10 mg/kg/day) reduced HHV-6 load to undetectable levels in cerebrospinal fluid (CSF). Early dose reduction in the presence of HHV-6 detectable in CSF resulted in an increased HHV-6 load. GCV was capably shifted to valganciclovir (VGCV) with an almost equivalent concentration. GCV/VGCV may be effective for HHV-6 encephalitis/myelitis after CBT, although HHV-6 load in CSF should be monitored.

3-O-Laurylglyceryl ascorbate reinforces skin barrier function through not only the reduction of oxidative stress but also the activation of ceramide synthesis

OBJECTIVE

A higher trans-epidermal water loss (TEWL) occurs in rough skin, in elder skin and also in atopic dermatitis. An impaired skin barrier function is considered to be caused by an incomplete construction of the intercellular lamellar structure due to the quantitative reduction of ceramides. Since these symptoms coexist with oxidative stress, we hypothesized that impairment of the skin barrier function is accelerated by oxidative stress. Thus, the purpose of this study was to clarify the effect of oxidative stress on ceramide synthesis and to characterize whether antioxidants can improve skin barrier function. 3-O-Laurylglyceryl ascorbate (VC-3LG), which is a newly amphipathic derivative of ascorbic acid, was evaluated as a candidate antioxidant.

METHODS

We characterized the mRNA expression levels of serine palmitoyltransferase (SPT) in normal human epidermal keratinocytes (NHEKs) treated with H₂ O₂ using real-time PCR analysis. In order to evaluate the effect of VC-3LG on skin barrier function, we used several assays with reconstructed human epidermis equivalents (RHEEs).

RESULTS

Ceramide synthesis was down-regulated in NHEKs by oxidative stress. Treatment with VC-3LG abrogated the down-regulation of SPT mRNA in NHEKs caused by oxidative stress, and stimulated SPT mRNA expression levels. In experiments characterizing the antioxidative properties of VC-3LG, VC-3LG reduced oxidative stress in NHEKs by up-regulating catalase mRNA expression. In addition, VC-3LG stimulated the skin barrier function in RHEEs, which had lower TEWL values compared with untreated RHEEs. Furthermore, VC-3LG increased the quantity of ceramide in RHEEs.

CONCLUSION

Taken together, we conclude that VC-3LG reinforces the skin barrier function due to its reduction of oxidative stress and its promotion of ceramide synthesis.

3-O-Laurylglyceryl ascorbate activates the intracellular antioxidant system through the contribution of PPAR-γ and Nrf2

BACKGROUND

Ascorbic acid (AsA) has multifunctional effects on physiology and aging including the prevention and improvement of skin pigmentation and wrinkles. AsA has scavenging effects against various types of reactive oxygen species (ROS), which are initiators of aging and premature aging of the skin. However, AsA not only has a quite unstable characteristic, but also has low skin penetration. In addition, existing water-soluble AsA derivatives are not effective to improve its penetration of the skin.

OBJECTIVE

To investigate the antioxidant effect of a newly synthesized amphipathic derivative of AsA, 3-O-laurylglyceryl ascorbate (VC-3LG), in which a laurylglyceryl group was introduced into AsA.

METHODS

Intracellular ROS levels in keratinocytes were evaluated using the 2',7'-Dichlorofluorescein diacetate (DCFHDA) assay. Real-time PCR was used to investigate the mechanism of the antioxidant effect of VC-3LG.

RESULTS

Although VC-3LG had less ability to scavenge ROS compared to AsA, it elicited a superior reduction of intracellular ROS levels, with or without extracellular stimuli such as exposure to H2O2 or UVB. The results show that VC-3LG up-regulates the expression of mRNAs encoding peroxisome proliferator activated receptor-γ (PPAR-γ) and nuclear factor E2-related factor 2 (Nrf2), which in turn up-regulate the levels of mRNAs encoding γ-glutamyl cysteine synthase (γ-GCS), heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO1). Furthermore, the Nrf2 mRNA level is down-regulated in siPPAR-γ treated cells, and the effects of VC-3LG on PPAR-γ and Nrf2 mRNA levels are reduced by PPAR-γ knockdown.

CONCLUSION

Taken together, we conclude that VC-3LG has an antioxidant effect and scavenges ROS directly as well as stimulating intracellular antioxidants such as GSH through the PPAR-γ and Nrf2 signaling pathway.

Genetic polymorphism in IFNL4 and response to pegylated interferon-α and ribavirin in Japanese chronic hepatitis C patients

A genetic polymorphism of the newly discovered interferon-λ 4 (IFNL4) gene was associated with hepatitis C virus (HCV) clearance in individuals of African ancestry. To assess whether a dinucleotide variant of IFNL4 (ss469415590) also affected treatment outcome of antiviral therapy in Japan, we genotyped 213 patients with chronic genotype 1 HCV infection and 176 healthy subjects. The ΔG allele was associated with treatment failure [odds ratio (OR) 4.73, P = 0.019], as was the IFL3 rs8099917 single nucleotide polymorphism (SNP) (OR 5.06, P = 0.068). The correlation between ss469415590 and rs8099917 was high (r(2)  = 0.92, D' = 0.98). Multivariate analysis revealed that the rs8099917 SNP was independently associated with treatment failure (OR 5.28, P = 0.009). Therefore, ss469415590 may be another predictive marker of antiviral therapy outcome in the Japanese population.

Super high resolution for single molecule-sequence-based typing of classical HLA loci at the 8-digit level using next generation sequencers

Current human leukocyte antigen (HLA) DNA typing methods such as the sequence-based typing (SBT) and sequence-specific oligonucleotide (SSO) methods generally yield ambiguous typing results because of oligonucleotide probe design limitations or phase ambiguity for HLA allele assignment. Here we describe the development and application of the super high-resolution single-molecule sequence-based typing (SS-SBT) of HLA loci at the 8-digit level using next generation sequencing (NGS). NGS which can determine an HLA allele sequence derived from a single DNA molecule is expected to solve the phase ambiguity problem. Eight classical HLA loci-specific polymerase chain reaction (PCR) primers were designed to amplify the entire gene sequences from the enhancer-promoter region to the 3' untranslated region. Phase ambiguities of HLA-A, -B, -C, -DRB1 and -DQB1 were completely resolved and unequivocally assigned without ambiguity to single HLA alleles. Therefore, the SS-SBT method described here is a superior and effective HLA DNA typing method to efficiently detect new HLA alleles and null alleles without ambiguity.

Lack of association of Toll-like receptor 9 gene polymorphism with Beh�et?s disease in Japanese patients

Toll-like receptors (TLRs) play an important role in the induction of defense mechanisms of the innate and adaptive immune responses to microbial pathogens. Genetic polymorphisms within the TLR9 gene have been reported to be associated with a variety of inflammatory and infectious diseases. Behçet's disease (BD) is a chronic inflammatory disease, and the etiology of BD has yet to be fully elucidated. We investigated the potential association of the TLR9 gene with susceptibility to BD by analyzing the frequency of nine single nucleotide polymorphisms (SNPs) in a population of 200 Japanese BD patients and 102 randomized controls. Our results showed that SNPs in the TLR9 gene were not significantly associated with susceptibility to BD.

Association between human polymorphic DNA markers and hypoxia adaptation in Sherpa detected by a preliminary genome scan

Genetic determinants of resistance to hypobaric hypoxia in the Sherpa are still unknown. Since adaptive gene variants must still be subjected to positive selection, linkage disequilibrium between such variants and specific alleles of flanking DNA markers is expected. Following this line of reasoning, we performed a human genome scan using 998 polymorphic DNA markers in 7 unrelated Sherpa porters living in the Solu-Khumbu area. This minimalist approach succeeded in detecting 8 DNA markers showing homozygosity for the same shared allele. Analysis of additional DNA samples from 2 more Sherpa porters focused our attention on three polymorphic DNA markers (D6S1697, D14S274, D17S1795) showing homozygosity for the same shared allele in 8 out 9 tested individuals. Analysis of DNA samples from Sherpa and non-Sherpa populations of Nepal proved HW equilibrium in both populations for markers D14S274 and D17S1795, while an excess of heterozygotes was observed in the Sherpa population for marker D6S1697. A significant difference in allele frequencies for D14S274 and D17S1795 between the two populations was observed. These findings exclude the possibility that homozygosity for 3 specific loci in 8 unrelated individuals might be ascribed to inbreeding or recent genetic drift. We therefore conclude that the chromosomal segments detected by such DNA markers may include genes involved in adaptation to hypobaric hypoxia.

The haplotype block, NFKBIL1-ATP6V1G2-BAT1-MICB-MICA, within the class III-class I boundary region of the human major histocompatibility complex may control susceptibility to hepatitis C virus-associated dilated cardiomyopathy

Cardiomyopathy is a heart muscle disease with impaired stretch response that can result in severe heart failure and sudden death. A small proportion of hepatitis C virus (HCV)-infected patients may be predisposed to develop dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). The molecular mechanisms involved in the predisposition remain unknown due in part to the lack of information on their genetic background. Because the human leukocyte antigen (HLA) region has a pivotal role in controlling the susceptibility to HCV-induced liver disease, we hypothesized that particular HLA alleles and/or non-HLA gene alleles within the human major histocompatibility complex (MHC) genomic region might control the predisposition to HCV-associated DCM (HCV-DCM) and/or HCV-associated HCM (HCV-HCM). Here, we present mapping results of the MHC-related susceptibility gene locus for HCV-associated cardiomyopathy by analyzing microsatellite and single nucleotide polymorphism markers. To delineate the susceptibility locus, we genotyped 44 polymorphic markers scattered across the entire MHC region in a total of 59 patients (21 HCV-DCM and 38 HCV-HCM) and 120 controls. We mapped HCV-DCM susceptibility to a non-HLA gene locus spanning from NFKBIL1 to MICA gene loci within the MHC class III-class I boundary region. Our results showed that HCV-DCM was more strongly associated with alleles of the non-HLA genes rather than the HLA genes themselves. In addition, no significant association was found between the MHC markers and HCV-HCM. This marked difference in the MHC-related disease susceptibility for HCV- associated cardiomyopathy strongly suggests that the development of HCV- DCM and HCV-HCM is under the control of different pathogenic mechanisms.

Association of polymorphic MHC microsatellites with GVHD, survival, and leukemia relapse in unrelated hematopoietic stem cell transplant donor/recipient pairs matched at five HLA loci

In order to determine whether matching/mismatching for microsatellite polymorphism provides useful information on acute graft-vs-host disease (GVHD), survival, and leukemia relapse in hematopoietic stem cell (HSC) transplantation, we genotyped for polymorphisms at 13 microsatellite loci within the major histocompatibility complex (MHC) of 100 unrelated HSC transplant donor-recipient pairs who were matched at five classical human leukocyte antigen (HLA) loci. A high percentage of allele matching was obtained for five microsatellite loci, DQCARII (96%), MICA (93%), MIB (89%), C1-3-1 (93%), and D6S510 (97%), that are localized within 100 kb of the HLA-DR, HLA-DQ, HLA-B, HLA-C, or HLA-A locus. In contrast, the other eight microsatellites are located farther away from the HLA classical loci and have much lower percentages of allele matching [e.g. tumor necrosis factor a (TNFa) (73%), TNFd (74%), D6S273 (64%), C3-2-11 (46%), C5-3-1 (50%), C5-4-5 (63%), C5-2-7 (68%), and D6S265 (81%)]. Therefore, there were at least eight microsatellite markers with relatively high percentages of mismatches in the donor/recipient pairs with acute or chronic GVHD, poor graft survival, and leukemia relapse. However, there were no statistically significant associations between mismatched donor-recipient pairs at the 13 microsatellite loci and acute or chronic GVHD, graft survival, and leukemia relapse. Nevertheless, allele matching at the microsatellite TNFd locus near the TNFa gene was found by the Fisher's exact double-sided test to be significantly associated with decreased survival in the grade III/IV acute GVHD group. Overall, these results suggest that the matching of microsatellite polymorphisms within the HLA region, especially the ones farthest from the classical HLA loci, was not useful indicator for the outcome of HSC transplantation from unrelated donors. In this regard, the future determination of the genome-wide microsatellite genotypes in HLA-matched donor-recipient pairs, outside the MHC, may be a better possibility for identifying minor histocompatibility genes in linkage disequilibria with microsatellites as potential predictive markers for the occurrence of acute GVHD and survival rate in HSC transplantation.

Conversion from tacrolimus to cyclosporine microemulsion therapy in liver transplant recipients

The calcineurin inhibitors cyclosporine and tacrolimus have distinct advantages and drawbacks. Therefore it is important to tailor their use to the patient's tolerance. In some patients, the need to ameliorate the adverse effects of tacrolimus may necessitate a switch to cyclosporine-based therapy. Rescue therapy with a cyclosporine microemulsion (Neoral)-based regimen for transplant patients intolerant of tacrolimus has been evaluated to assess the best method of switching and determine the initial and maintenance doses of Neoral in children and adults. Our aims were to evaluate not only these facets, but also the pharmacokinetics of Neoral in stable patients, including target 2-hour postdose blood concentrations (C2) of cyclosporine in liver transplant recipients. Eighteen liver transplant patients switched from tacrolimus to Neoral underwent a program of cyclosporine blood level monitoring. The conversions were conducted safely; the incidence of acute rejection episodes was low (11.1%). Statistical analysis showed that the C2 correlated with the area under the time-blood concentration curve of cyclosporine for 0 to 4 hours after dosing (R=0.970). We determined the maintenance doses of Neoral for pediatric and adult patients as well as the feasibility of C2 quantitated monitoring in liver transplantation.

Analysis of microsatellite polymorphism around the HLA-B locus in Iranian patients with Behçet's disease

We have previously suggested that in a Japanese population the susceptible locus for Behçet's disease (BD) is HLA-B51 itself. To confirm this finding in another population, we performed HLA class I typing using the PCR-SSP method and analyzed eight polymorphic markers distributed within 1100 kb around the HLA-B gene using automated sequencer and subsequent automated fragment detection by fluorescent-based technology with the DNA samples of 84 Iranian patients with BD and 87 healthy ethnically matched controls. As a result, three microsatellite alleles (MICA-A6, MIB-348, C1-4-1-217) and HLA-B51 were found to be strongly associated with BD. Of these alleles HLA-B51 is the most strongly associated allele. There were no alleles that were increased in allele frequency at any microsatellite loci centromeric of MICA or telomeric of HLA-B51. Therefore, HLA-B51 was confirmed to be by far the most strongly associated gene with BD in an Iranian population.

Susceptibility locus for non-obstructive azoospermia is localized within the HLA-DR/DQ subregion: primary role of DQB1*0604

Non-obstructive azoospermia is a male infertility characterized by no or little sperm in semen as a result of a congenital dysfunction in spermatogenesis. Previous studies have reported a higher prevalence of particular human leukocyte antigen (HLA) antigens in non-obstructive azoospermia. As the expression of the RING3 gene located in the HLA class II region was predominant in the testis, mainly around spermatids and pachytene spermatocytes, it is tempting to speculate that RING3 is one of the strong candidate genes responsible for the pathogenesis of the disease. In this study, the genetic polymorphism in the RING3 gene was investigated by the direct sequencing technique. As a result, a total of 14 single nucleotide polymorphisms were identified. Among them, six were localized in the coding region but none of them was accompanied by an amino-acid substitution. No significant difference in the allelic distribution at these 14 polymorphic sites was observed between the patients and healthy controls, suggesting that the susceptible gene for non-obstructive azoospermia is not the RING3 gene. Then, in order to map the susceptibility locus for non-obstructive azoospermia precisely within the HLA region, 11 polymorphic microsatellite markers distributed from the SACM2L gene just outside the HLA class II region (187 kb telomeric of the DPB1 gene) to the OTF3 gene in the HLA class I region were subjected to association analysis in the patients. Statistical analysis of distribution in the allelic frequency at each microsatellite locus demonstrated that the pathogenic gene for non-obstructive azoospermia is located within the HLA-DR/DQ subregion. In fact, DRB1*1302 and DQB1*0604 were found to be strongly associated with non-obstructive azoospermia by polymerase chain reaction-based DNA typing. Further, haplotype analysis suggested that the DQB1*0604 allele may play a decisive role in the pathogenesis of non-obstructive azoospermia.

Primary structure, developmental expression and functional properties of an inward rectifier K+ channel of the tunicate

A cDNA encoding for a tunicate inward rectifier K+ channel (TuIRK) was isolated. TuIRK exhibited the highest similarity (approximately 50%) with mammalian Kir2 (IRK) subfamily. Maternal RNA of TuIRK was detected by RT-PCR in unfertilized eggs. By in situ hybridization, the transcript was observed at the 32-cell stage, restricted at the 64-cell stage in anterior epidermal cells of a4-2 blastomere lineage, and disappeared at the late gastrula stage. Therefore, TuIRK was identified to be the inward rectifier whose expression was previously reported to change dramatically upon the neural/epidermal cell fate selection. In Xenopus oocytes, TuIRK expressed a strongly inward rectifying K+ current. The basic electrophysiological properties of TuIRK were similar to those of the mouse IRK1 (mIRK1), except that the sensitivity to the block by extracellular Mg2+ was much lower than that of mIRK1. To identify the structural determinant, we made mutants of the pore region, and then of the extracellular loop (N226 of TuIRK, and E125 of mIRK1). In E125N mutant of mIRK1, the sensitivity to the Mg2+ block was decreased significantly, whereas N226E of TuIRK1 did not acquire the sensitivity. These results demonstrate the contribution of this site to the Mg2+ block and the presence of additional determinant(s).

Sequencing-based typing of HLA-B*51 alleles and the significant association of HLA-B*5101 and -B*5108 with Behçet's disease in Greek patients

Behçet's disease (BD) is widely known to be strongly associated with human leukocyte antigen (HLA) B51 in many different ethnic groups.Recently, HLA-B51 allele typing of Greek BD patients was performed to study the distribution of B*5101-B*5107 alleles in this Greek population, the B51 antigen strongly associated with BD was found to be predominantly encoded by allele B*5101. As it is now known that the B51 antigen can be encoded by 21 alleles, B*5101-B*5121, we performed HLA-B*51 allele genotyping among 58 Greek patients with BD. After serological HLA typing, typing of HLA-B*51 alleles was performed using the polymerase chain reaction-sequencing-based typing (PCR-SBT) method. The frequency of the B51 antigen was found to be significantly higher in the patient group as compared with the control group (75.9% of patients vs 22.0% of controls. In the genotyping of B51 alleles, 34 out of 44 B51-positive patients possessed B*5101, 13 out of the 44 carried B*5108. In contrast, all of the 9 B51-positive normal controls carried B*5101. This study revealed a strong association between Greeks with BD, both B*5101, B*5108, provided important insights into the molecular mechanism underlying the association between HLA status, this disease.

HLA-B*51 allele analysis by the PCR-SBT method and a strong association of HLA-B*5101 with Japanese patients with Behçet's disease

Behçet's disease (BD) is known to be associated with human leukocyte antigen (HLA) B51 in many different ethnic groups. An increased incidence of HLA-B51 in the patient group has also been reported in a Japanese population. Recently, the B51 antigen has been identified to comprise 21 alleles, B*5101-B*5121. Further, not only HLA-B*5101 but also HLA-B*5108 were found to be relatively increased in the patient groups among Italian and Saudi Arabian populations. Therefore, we performed HLA-B*51 allele genotyping by the polymerase chain reaction-sequencing based typing (PCR-SBT) method in order to investigate whether there is any correlation of one particular B51-associated allele with Japanese BD. Ninety-six Japanese patients with BD and 132 healthy Japanese volunteers were enrolled in this study. As a result, the phenotype frequency of the B51 antigen was confirmed to be remarkably increased in the patient group as compared to the ethnically matched control group (59.4% in patients vs. 13.6% in controls; Pc=0.0000000000098, R.R.=9.3). In the B*51 allele genotyping, 56 out of 57 B51-positive patients were defined as B*5101 and the remaining one was B*5102. In contrast, all of 18 B51-positive normal controls were B*5101. None of the Japanese patients and healthy controls carried the HLA-B*5108 allele. This study revealed that B*51 allelic distribution in Japanese was different from those in Italian and Saudi Arabian populations, and that the significantly high incidence of the HLA-B51 antigen in the Japanese BD patient group was mostly caused by the significant increase of the HLA-B*5101 allele.

Stratification analysis of MICA triplet repeat polymorphisms and HLA antigens associated with ulcerative colitis in Japanese

We previously reported a conserved haplotype of HLA B52-DR2 and a significantly high frequency of the major histocompatibility complex (MHC) class I chain-related gene A (MICA) transmembrane-short tandem repeat (TM-STR) 6 allele in Japanese patients with ulcerative colitis (UC). To examine the predominance of the MICA TM-STR 6 allele as a marker of the susceptibility to UC within the susceptible haplotype, the association of each allele with UC was estimated following stratification of the patients to control for any possible confounding effects of other alleles positively associated with UC. Sixty-four patients with UC and 236 unrelated healthy controls were included in this study. All subjects were Japanese. HLA-A, -B, -C, and -DR antigens were determined serologically. A triplet repeat polymorphism of the MICA was determined by direct sequencing. To control for the effect of linkage disequilibrium, Mantel-Haenszel weighed odds ratios were calculated. Significantly higher phenotype frequencies of B52, MICA TM-STR 6, and DR2 were observed in patients with UC. Linkage disequilibria among alleles associated with UC revealed that a B52 - MICA TM-STR 6 - DR2 haplotype was conserved in patients with UC, as in controls. When the association of HLA-B52 was estimated after patient stratification for the possible confounding effect of MICA TM-STR 6 or DR2, a strong significant association of B52 with UC was still observed. In contrast, no association with UC was observed for MICA TM-STR 6 or DR2, after stratification of the possible confounding effect of HLA-B52. These results imply that the significant increase in MICA TM-STR 6 in Japanese patients with UC is attributable to linkage disequilibrium with HLA-B52.

Allelic structure and distribution of two STR loci, D8S580 and D22S442, in the Japanese population

The allelic frequency and structural characteristics of two STR loci D8S580 and D22S442 were investigated using blood samples from 143 unrelated healthy Japanese individuals. Thirty-eight alleles in D8S580 locus and 13 alleles in D22S442 locus were identified. The discrimination power, heterozygosity, and the polymorphic information content of those loci displayed high values (0.98, 0.88, and 0.87 in D8S580 and 0.97, 0.86 and 0.85 in D22S442), and their frequency distributions met Hardy-Weinberg equilibrium expectations. The allelic pattern of D8S580 was complex and differentiated into three groups (group I: alleles 184-194bp; group II: alleles 203-223, 235, 239, 243, 252 and 255bp; group III: alleles 227-286bp). Most of their alleles contained five categories of repeat units (A: aaaag; B: aaag; C: aagg; D: caag; E: agaa). On the other hand, D22S442 contained only two types of repeat units (A: agga; B: aggg). The present study, hence, proves that both D8S580 and D22S442 are highly polymorphic and represent stable genetic markers applicable to forensic investigations.

Neuronal form in the central nervous system of the tadpole larva of the ascidian Ciona intestinalis

The dorsal tubular central nervous system (CNS) of the ascidian tadpole larva is a diagnostic feature by which the chordate affinities of this group, as a whole, are recognized. We have used two methods to identify larval neurons of Ciona intestinalis. The first is serial electron microscopy (EM), as part of a dedicated study of the visceral ganglion (1), and the second is the transient transfection of neural plate progeny with green fluorescent protein (GFP) (2), to visualize the soma and its neurites of individual neurons in whole-mounted larvae of C. intestinalis. Our observations reveal that ascidian larval neurons are simple inform, with a single axonal neurite arising from a soma that is either monopolar or has only very few, relatively simple neurites arising from it, as part of a presumed dendritic arbor. Somata in the visceral ganglion giving rise to axons descending in the caudal nerve cord are presumed to be those of motor neurons.

HLA class I genotyping including HLA-B*51 allele typing in the Iranian patients with Behçet's disease

It is well known that Behçet's disease (BD) is strongly associated with human leukocyte antigen (HLA) B51 in many ethnic groups. However, there has been no published report as yet with respect to this association among the Iranian people. Furthermore, since it is now known that the B51 antigen can be encoded by 21 alleles, B*5101-B*5121, we performed HLA-B*51 allele typing as well as HLA class I genotyping of 48 Iranian patients with this disease. As a result, the frequency of the B*51 allele was significantly higher (62.1%) in the patient group as compared with the ethnically matched control group (31.8%) (Pc=0.067, R.R.=3.51). In the genotyping of B*51 alleles, 33 out of the 36 B*51-positive patients possessed B*5101 and the remaining 3 carried B*5108. This study revealed that Iranian patients with BD also had a strong association with HLA-B51. In addition, this significantly high incidence of HLA-B*51 was found to be caused by an increase in both the HLA-B*5101 and HLA-B*5108 alleles. However, there was no significant difference in the HLA-B*51 allelic distribution between the patient and control groups.

Characterization of the amyR gene encoding a transcriptional activator for the amylase genes in Aspergillus nidulans

The Aspergillus nidulans amyR gene and its cDNA were cloned and sequenced. The genomic gene comprised 2,092 bp, interrupted by two short introns, and encoded a cys-6 zinc transcriptional activator (AMYR) of 662 amino acid residues with a calculated molecular mass of 72,862 Da. Disruption of the amyR gene caused defects in the utilization of maltose and starch and abolished expression of the taaG2 gene encoding A. oryzae Taka-amylase A, which is inducibly and abundantly expressed in the wild-type A. nidulans. Expression of the amyR gene was under the control of the carbon catabolite repressor, CREA. The growth defect of the malA1 mutant on maltose was complemented by the amyR gene; and the amyR gene derived from the mutant possessed a single mutation, from A to T, at position 1,483, resulting in a substitution of His478 to Leu. These results indicate that the amyR gene is identical to the genetically defined malA gene. AMYR possessed five domains (Zn and MH1-MH4) homologous to Mal63p, a transcriptional activator for the genes involved in maltose utilization in Saccharomyces cerevisiae. The His478 to Leu substitution lay within the MH3 domain, corresponding to the negative regulatory domain of Mal63p which relieves the inhibitory effect on the activation function in response to maltose.

A second susceptibility gene for developing rheumatoid arthritis in the human MHC is localized within a 70-kb interval telomeric of the TNF genes in the HLA class III region

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease with a multifactorial genetic basis. However, pathogenic genes for RA other than the human leukocyte antigen (HLA)-DRB1 gene have yet to be identified. Here, we investigated whether there is a second susceptibility locus for RA within the human major histocompatibility complex using 18 microsatellite markers distributed from the centromeric (HSET) to the telomeric end (P5-15) of the 3.6-Mb HLA region. Statistical studies of associated alleles on each microsatellite locus showed that one pathogenic gene for RA in the HLA region is localized in the DRB1 gene, as expected. Further, a second susceptibility gene of RA was suggested to be present in the HLA class III region, narrowed to 70 kb, that is just telomeric of the TNF gene cluster (TNFA and LTA) and that is located between the microsatellites TNFa and C1-2-A. In this critical segment, four expressed genes have been thus far identified, NFKBIL1 (IkappaBL), ATP6G, BAT1, and MICB, all of which are candidate genes for determining susceptibility to RA. These results exclude the possibility of involvement of the TNFA genes (TNF-alpha) in the development of RA, which was suggested previously to be a strong candidate for RA in the class III region.

Microsatellite mapping of a susceptible locus within the HLA region for Behçet's disease using Jordanian patients

Behçet's disease (BD) has been established to be associated with HLA-B51. However, it has not been revealed whether the HLA-B51 gene itself or another gene located near the HLA-B gene is directly involved in the pathogenesis of BD. Previously, using Japanese BD patients, our group has narrowed down a BD-causative gene to 46 kb between the MICA and HLA-B genes by means of fine mapping analysis with eight microsatellite markers distributed within a 1100 kb segment around the HLA-B gene. To know whether this mapping result is generally observed in BD of another population we have investigated repeat polymorphisms of the same microsatellite markers in Jordanian BD patients. Furthermore, we have evaluated these data by Mantel-Haenzel stratified analysis to find out a primarily associated locus for BD. As a result, HLA-B51 was found to be the most strongly and primarily associated marker. This result suggests that the pathogenic gene of BD is HLA-B51 itself, but unlikely to be other genes located in the vicinity of HLA-B.