[Identification and preliminary validation of potential biomarkers in the peripheral blood mononuclear cells of atopic dermatitis].

Objective: To explore the difference of peripheral blood mononuclear cells (PBMC) transcripts between atopic dermatitis (AD) and healthy controls, and to screen and preliminarily validate potential biomarkers of AD. Methods: From January 2021 to May 2022, blood samples from 9 AD patients and 10 healthy controls were collected from the Dermatology and Cosmetic Center of the Third Affiliated Hospital of Chongqing Medical University, ribonucleic acid-sequencing (RNA-seq) was used to determine the transcriptome and relative expression of PBMC, the differentially expressed genes (DEGs) were analyzed by gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction networks (PPI) analysis, and the potential biomarkers were identified by quantitative real-time PCR (qRT-PCR). Results: The age of patients in the AD group [M (Q1, Q3)] was 26.50 (22.75, 30.50) years old, and the course of disease [M (Q1, Q3)] was 15 (10, 20) years,and the age of the healthy control group [M (Q1, Q3)] was 37.00 (27.75, 40.25) years old. Compared with healthy controls, 1 044 DEGs were detected in PBMC samples in AD group, including 668 up-regulated genes and 376 down-regulated genes. Differential variable splicing (AS) showed that mutually exclusive exons (46.74%) and skipped exon (31.01%) accounted for a large proportion. GO and KEGG enrichment analysis revealed that AD is closely linked to DEGs implicated in the inflammatory response and cytokine interaction and signal pathway. Comprehensive enrichment analysis and PPI analysis selected the expression of 8 candidate genes (CCL4, CCR3, CXCR5, NFKBIA, CXCL1, IL-1B, CCL20, LY96), which was confirmed by qRT-PCR and were consistent with that of RNA-seq. Conclusions: CCL4, CCR3, CXCR5, NFKBIA, CXCL1, IL-1B, CCL20 and LY96 might be potential biomarkers of AD, participating in the occurrence and development of AD.

[Multicenter clinical epidemiological analysis of elderly atopic dermatitis in China].

Objective: To investigate and analyze the clinical features of elderly atopic dermatitis (AD) in China. Methods: Based on the National Clinical Research and Homogeneous Diagnosis and Treatment Project for Type 2 Inflammation Dermatosis, a total of 2 281 patients aged 65 years or older were enrolled from 172 grade A tertiary hospitals who were diagnosed as atopic dermatitis from June 2021 to February 2023, and their demographics, clinical feature, and disease severity, etc. were collected. Elderly AD patients were divided into groups based on gender, history of allergic diseases (with or without a personal or family history of allergic diseases), and clinical features (site of onset, AD signs) and scales were compared within the groups. Median (Q1, Q3) was used for quantitative data. Results: The age of 2 281 elderly AD patients was 73.02 (68.83, 79.62) years old, among whom there were 1 649 males (72.29%) and 632 females (27.71%). A total of 2 244 cases were recorded with the information of the onset stage, of whom 1 713 cases (76.34%) occurred in the elderly stage. A total of 2 136 cases were recorded with the information of personal or family history of allergic diseases, of which 1 076 cases (50.37%) had a personal or family history of allergic diseases, and 1 060 (49.63%) had no history of allergic diseases. Skin lesions were predominantly involved in the waist, back, buttocks, and AD signs were mainly eczema-like skin lesions on the cheek and/or scalp and/or limb extension. Patients with moderate to severe AD accounted for 60.58% (1 327 cases), moderate to severe itching accounted for 81.32% (1 781 cases). Patients with anxiety and depression accounted for 46.14% (1 011 cases) and 39.27% (860 cases), respectively. Men had a higher EASI score than women [9.67 (4.77, 19.28) vs 8.45 (3.98, 17.11), P=0.040]. EASI, HADS-anxiety and WI-NRS scores were higher in patients with history of allergic diseases than those without allergy history [ (9.79 (4.84, 19.96) vs 8.96 (4.05, 18.31), P=0.015; 7.22 (3.49, 10.00) vs 6.81 (3.12, 9.33), P=0.012; 7.64 (5.62, 9.07) vs 7.38 (5.35, 8.91), P=0.036]. Conclusion: Elderly AD patients have their own exclusive clinical manifestations, and the understanding of these characteristics is beneficial for guiding clinical development of targeted management plans. Elderly AD patients are mostly senile onset, and male patients are more than female patients, skin lesions are mainly distributed on the extended side, and the disease burden is heavy.

Mini review: surveillance of Lyme borreliosis in Southeast Asia and method of diagnosis.

Lyme borreliosis is caused by the Gram-negative spirochetes Borrelia spp., particularly Borrelia burgdorferi sensu lato complex. The disease is transmitted through the bite of the infected black-legged Ixodes tick. Lyme borreliosis extensively occurs in the Northern Hemisphere, mainly in the United States. Lyme borreliosis cases are also detected in Asian countries including Korea, Nepal, China, Taiwan, and Japan. However, there is an inadequate understanding of Lyme borreliosis in the Southeast Asian region. Hence, this review aims to provide a brief update on the prevalence of Lyme borreliosis infection in Southeast Asia based on the latest literature on this issue. Lyme borreliosis has been discovered in human serum in Indonesia, Malaysia, and Singapore. The human serum samples were mainly examined with ELISA test using Borrelia spp. IgG and IgM antigens. Borrelia spp. also has been detected in ticks found on host animals such as Sundamys muelleri and Python in Malaysia, Thailand, and Laos. Polymerase chain reaction (PCR) is used to detect the presence of Borrelia DNAs in the samples. The published studies have demonstrated that Borrelia spp. exists in Southeast Asia and although the incidence is relatively low, it is believed that Lyme disease cases are under-reported.

Prospective, multicentre study of screening, investigation and management of hyponatraemia after subarachnoid haemorrhage in the UK and Ireland.

BACKGROUND: Hyponatraemia often occurs after subarachnoid haemorrhage (SAH). However, its clinical significance and optimal management are uncertain. We audited the screening, investigation and management of hyponatraemia after SAH. METHODS: We prospectively identified consecutive patients with spontaneous SAH admitted to neurosurgical units in the United Kingdom or Ireland. We reviewed medical records daily from admission to discharge, 21 days or death and extracted all measurements of serum sodium to identify hyponatraemia (<135 mmol/L). Main outcomes were death/dependency at discharge or 21 days and admission duration >10 days. Associations of hyponatraemia with outcome were assessed using logistic regression with adjustment for predictors of outcome after SAH and admission duration. We assessed hyponatraemia-free survival using multivariable Cox regression. RESULTS: 175/407 (43%) patients admitted to 24 neurosurgical units developed hyponatraemia. 5976 serum sodium measurements were made. Serum osmolality, urine osmolality and urine sodium were measured in 30/166 (18%) hyponatraemic patients with complete data. The most frequently target daily fluid intake was >3 L and this did not differ during hyponatraemic or non-hyponatraemic episodes. 26% (n/N=42/164) patients with hyponatraemia received sodium supplementation. 133 (35%) patients were dead or dependent within the study period and 240 (68%) patients had hospital admission for over 10 days. In the multivariable analyses, hyponatraemia was associated with less dependency (adjusted OR (aOR)=0.35 (95% CI 0.17 to 0.69)) but longer admissions (aOR=3.2 (1.8 to 5.7)). World Federation of Neurosurgical Societies grade I-III, modified Fisher 2-4 and posterior circulation aneurysms were associated with greater hazards of hyponatraemia. CONCLUSIONS: In this comprehensive multicentre prospective-adjusted analysis of patients with SAH, hyponatraemia was investigated inconsistently and, for most patients, was not associated with changes in management or clinical outcome. This work establishes a basis for the development of evidence-based SAH-specific guidance for targeted screening, investigation and management of high-risk patients to minimise the impact of hyponatraemia on admission duration and to improve consistency of patient care.

[Analysis of current status and influencing factors of inflammatory factors among electrical workers in Hainan province].

Objective: To analyze the level and influence factors of inflammatory factors among electrical workers in Hainan Province. Methods: A total of 509 electrical workers were selected as the research subjects with random cluster sampling in September 2020. Basic information was collected by questionnaire, the serum IL-6, IL-8 and TNF-α levels of the subjects were detected by Luminex.Mann-Whitney U test and Kruskal-wallis H test were used for univariate analysis. Ordinal logistic regression analysis was used for potential influencing factors of the level of inflammatory factors. Results: The median concentrations of IL-6, IL-8 and TNF-α in serum were 2.78, 9.77 and 8.18 pg/ml. Compared with women, male was a risk factor for the increase of IL-6 levels (OR=1.80, 95%CI: 1.08~3.00, P=0.024) . Compared with 51-60 years old, 21-31 years old (OR=0.27, 95%CI: 0.18~0.42, P<0.001) , 31-41 years old (OR=0.27, 95%CI: 0.17~0.43, P<0.001) and 41-51 years old (OR=0.64, 95%CI: 0.41~0.99, P=0.043) were protective factors for the increase of IL-8 level. Compared with day shift workers, shift work was a risk factor for the increase of IL-8 level (OR=1.73, 95%CI: 1.21~2.48, P=0.003) . Compared with women, male was a risk factor for the increase of TNF-α levels (OR=2.87, 95%CI: 1.70~4.86, P<0.001) . Compared with workers who exposed to 7 or more occupational hazard factors, exposed to 1~3 (OR=0.53, 95%CI: 0.30~0.92, P=0.024) occupational hazard factors were protective factors for the increase of TNF-α levels. Conclusion: The level of inflammatory factors was related to sex, age, work system and occupational environment, which can provide basic data for follow-up research on occupational population.

[Peripheral T and B lymphocytes in patients with occupational medicamentosa-like dermatitis due to trichloroethylene].

Objective: To investigate the changes in liver function and peripheral regulatory lymphocytes before and after treatment in patients with occupational medicamentosa-like dermatitis due to trichloroethylene (OMDT) . Methods: In December 2019, 16 patients with OMDT (8 patients with erythema multiforme and 8 with erythema multiforme major) who were admitted from February 2017 to February 2019 were enrolled as subjects. Liver function parameters and percentages of peripheral regulatory lymphocytes were measured before and after treatment, and the changes in liver function and peripheral regulatory T and B lymphocytes and their correlation were analyzed. Results: Before treatment, compared with the healthy control group, the experimental group had significantly higher levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , total bilirubin (TBIL) , direct bilirubin (DBIL) and gamma-glutamyl transpeptidase (GGT) and significantly lower levels of total protein (TP) , albumin (ALB) and cholinesterase (CHE) (P<0.05) . Compared with the healthy control group, the experimental group had significantly lower percentages of lymphocytes, CD4(+) T cells, CD4(+)CD25(+) Tregs, CD19(+)CD24(+)CD27(+) Bregs and CD4(+)/CD8(+) ratio, as well as a significantly higher percentage of CD8(+) T cells (P<0.05) . Before treatment, the levels of ALT, AST, GGT and DBIL were negatively correlated with the percentages of CD4(+)CD25(+) Tregs, CD19(+)CD24(+)CD27(+) Bregs, CD4(+) T cells and CD4(+)/CD8(+) ratio (r=-0.386 to -0.809, P<0.05) and was positively correlated with the percentage of CD8(+) T cells (except DBIL) (r=0.503-0.568, P<0.05) . The levels of TP and ALB were positively correlated with the percentages of CD4(+)CD25(+) Tregs, CD19(+)CD24(+)CD27(+)Bregs and CD4(+) T cells (r= 0.351-0.784, P<0.05) , ALB was negatively correlated with the percentage of CD8(+) T cells (r=-0.315, P<0.05) . CHE was positively correlated with the percentages of CD4(+)CD25(+) Tregs, CD19(+)CD24(+)CD27(+)Bregs and CD4(+)/CD8(+) ratio (r=0.390-0.527, P<0.05) . Conclusion: Immune dysfunction is observed in patients with OMDT, which may be caused by the imbalance of regulatory lymphocytes. And liver injury may be associated with the increase of CD8(+) T cells and the reductions of percentages of CD4(+) T cells, CD4(+)CD25(+) Tregs, CD19(+)CD24(+)CD27(+)Bregs and CD4(+)/CD8(+) ratio.

[Correlation analysis of eosinophils in peripheral blood and polyp tissues of patients with chronicrhinosinusitis with nasal polyps].

Objective:To explore the correlation between peripheral blood eosinophils and tissue eosinophils in patients with chronic rhinosinusitis with nasal polyps(CRSwNP) in different periods.Method:This trial was a prospective study involved 342 patients with CRSwNP who were treated by endoscopic sinus surgery in the Huai'an First People's Hospital, Nanjing Medical University in 2008, 2012 and 2016. Nasal polyp resection specimens were stained by HE.Tissue eosinophils were counted per high-power field, and peripheral blood eosinophils were collected from blood routine examination before operation.The relationship between peripheral blood eosinophils and tissue eosinophils were evaluated.Result:The correlation between peripheral blood eosinophils and tissue eosinophils was positive in nasal polyps in 2008,2012 and 2016(r= 0.275,0.435,0.505, respectively). AUC values were all greater than 0.7. Conclusion:There is a positive correlation between peripheral blood eosinophils and tissue eosinophils infiltration in patients with CRSwNP. Although the cutoff value is changing, peripheral blood eosinophils can be used as an indicator for predicting eosinophilic CRSwNP.

Germanene on single-layer ZnSe substrate: novel electronic and optical properties.

In this work, the structural, electronic and optical properties of germanene and ZnSe substrate nanocomposites have been investigated using first-principles calculations. We found that the large direct-gap ZnSe semiconductors and zero-gap germanene form a typical orbital hybridization heterostructure with a strong binding energy, which shows a moderate direct band gap of 0.503 eV in the most stable pattern. Furthermore, the heterostructure undergoes semiconductor-to-metal band gap transition when subjected to external out-of-plane electric field. We also found that applying external strain and compressing the interlayer distance are two simple ways of tuning the electronic structure. An unexpected indirect-direct band gap transition is also observed in the AAII pattern via adjusting the interlayer distance. Quite interestingly, the calculated results exhibit that the germanene/ZnSe heterobilayer structure has perfect optical absorption in the solar spectrum as well as the infrared and UV light zones, which is superior to that of the individual ZnSe substrate and germanene. The staggered interfacial gap and tunability of the energy band structure via interlayer distance and external electric field and strain thus make the germanene/ZnSe heterostructure a promising candidate for field effect transistors (FETs) and nanoelectronic applications.

Endothelial progenitor cell miR-126 promotes homing of endothelial progenitor cells within arterial thrombus in patients with cerebral infarction and its molecular mechanism.

OBJECTIVE: The present study was designed to investigate the effect of microRNA-126 (miR-126) on the migration and homing of endothelial progenitor cells (EPCs) within arterial thrombus of cerebral infarction patients. MATERIALS AND METHODS: EPCs from rat bone marrow were isolated, and miR-126 overexpressed EPCs were constructed by lentiviral transfection. Then, the middle cerebral artery occlusion (MCAO) model was established by the method of thread ligation. Successfully established model rats were randomly divided into miR-126 overexpression EPC group, miR-126 wild type EPC group, and normal saline group. One day after the infarction, the miR-126 overexpression EPCs, miR-126 wild type EPCs, and normal saline, were injected into the lateral ventricle of the corresponding groups. Also, the transplanted cells were tracked by cell dye SPDiIC18. The expression of tight junction proteins ZO-1 and Claudin-5 in brain tissue was detected by Western blotting. RESULTS: Transplanted cells were detected in the cerebral infarction area 3 days after transplantation by cell dye SP-DiIC18. The number of homing EPCs in miR-126 overexpression group was significantly higher than that of miR-126 wild type EPC group (p < 0.05). Also, the protein expression of ZO-1 and Claudin-5 in the miR- 126 overexpression EPC group was significantly higher compared with that of the miR-126 wild type EPC group and the normal saline group. CONCLUSIONS: miR-126 overexpression EPCs, which were transplanted in the lateral ventricle, can home to the cerebral infarction areas via increasing increase.

Multiple variants in 5q31.1 are associated with systemic lupus erythematosus susceptibility and subphenotypes in the Han Chinese population.

BACKGROUND: A previous study provided evidence for a genetic association between PPP2CA on 5q31.1 and systemic lupus erythematosus (SLE) across multi-ancestral cohorts, but failed to find significant evidence for an association in the Han Chinese population. OBJECTIVES: To explore the association between this locus and SLE using data from our previously published genome-wide association study (GWAS). METHODS: Single-nucleotide polymorphisms (SNPs) rs7726414 and rs244689 (near TCF7 and PPP2CA in 5q31.1) were selected as candidate independent associations from a large-scale study in a Han Chinese population consisting of 1047 cases and 1205 controls. Subsequently, 3509 cases and 8246 controls were genotyped in two further replication studies. We then investigated the SNPs' associations with SLE subphenotypes and gene expression in peripheral blood mononuclear cells. RESULTS: Highly significant associations with SLE in the Han Chinese population were detected for SNPs rs7726414 and rs244689 by combining the genotype data from our previous GWAS and two independent replication cohorts. Further conditional analyses indicated that these two SNPs contribute to disease susceptibility independently. A significant association with SLE, age at diagnosis < 20 years, was found for rs7726414 (P = 0·001). The expression levels of TCF7 and PPP2CA messenger RNA in patients with SLE were significantly decreased compared with those in healthy controls. CONCLUSIONS: This study found evidence for multiple associations with SLE in 5q31.1 at genome-wide levels of significance for the first time in a Han Chinese population, in a combined genotype dataset. These findings suggest that variants in the 5q31.1 locus not only provide novel insights into the genetic architecture of SLE, but also contribute to the complex subphenotypes of SLE.

Proteomic Profiling Analysis Reveals a Link between Experimental Autoimmune Uveitis and Complement Activation in Rats.

Uveitis is an autoimmune disease that usually damages the vision function, leading to poor visual quality in patients. As an autoimmune ocular inflammatory disease, the pathogenesis of uveitis is associated with abnormal expression of some proteins and aberrant regulation of multiple signalling pathways. Nevertheless, the detailed mechanism remains unclear. In this study, we induced an experimental autoimmune uveitis (EAU) model in rats. We determined the levels of C3a and membrane attack complex C5b-9 (soluble C5b-9, sC5b-9) in both plasma and aqueous humour, identified the differentially expressed proteins in plasma by liquid chromatography-tandem mass spectrometry and employed bioinformatics algorithms to analyse differentially expressed proteins in EAU rat plasma. The results demonstrate that there were 168 differentially expressed plasma proteins in EAU rats versus control subjects. The levels of sC5b-9 and C3a were elevated in the plasmas and aqueous humours of EAU rats. Gene ontology enrichment analysis showed that the differentially expressed proteins in EAU rat plasma were mainly involved in metabolic and immune processes. Kyoto encyclopedia of genes and genomes (KEGG) pathway annotation, database for annotation, visualization and integrated discovery (DAVID) and protein-protein interaction analyses revealed that the differentially expressed proteins in EAU rat plasmas were closely associated with complement and coagulation cascades, metabolic pathways, NF-kappa B, PI3K-Akt, Toll-like receptors and autophagy. Overall, the differentially expressed proteins in EAU rat plasmas are mainly involved in the complement and coagulation cascades. The pathogenesis of uveitis closely correlates with complement activation.

DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENT AT THE OUTER SURFACE OF A CRYOVIAL BEING PLUNGED INTO LIQUID NITROGEN.

BACKGROUND: Cell survival upon cryopreservation is affected by the cooling rate. However, it is difficult to model the heat transfer process or to predict the cooling curve of a cryoprotective agent (CPA) solution due to the uncertainty of its convective heat transfer coefficient (h). OBJECTIVE: To measure the h and to better understand the heat transfer process of cryovials filled with CPA solution being plunged in liquid nitrogen. MATERIALS AND METHODS: The temperatures at three locations of the CPA solution in a cryovial were measured. Different h values were selected after the cooling process was modeled as natural convection heat transfer, the film boiling and the nucleate boiling, respectively. And the temperatures of the selected points are simulated based on the selected h values. h was determined when the simulated temperature best fitted the experimental temperature. RESULTS: When the experimental results were best fitted, according to natural convection heat transfer model, h(1) = 120 W/(m(2)·K) while due to film boiling and nucleate boiling regimes h(f) = 5 W/(m(2)·K) followed by h(n) = 245 W/(m(2)·K). These values were verified by the differential cooling rates at the three locations of a cryovial. CONCLUSION: The heat transfer process during cooling in liquid nitrogen is better modeled as film boiling followed by nucleate boiling.

Correlations of abnormal ultrasound audio-visual images of ovarian cortex surface and pelvic adhesion in infertile patients.

OBJECTIVE: The aim of this study was to evaluate the related factors between abnormal ultrasonic appearance of ovarian and pelvic adhesion in infertile women. MATERIALS AND METHODS: Forty-eight cases were examined with transvaginal ultrasonography (TVUS) if there was pelvic adhesion before surgery (experiment group), and the surgical group was used as control. The specificity of pelvic adhesion was evaluated. RESULTS: Thirty-nine cases were abnormal in experiment group and 38 cases were confirmed with surgery, while one case was normal. Nine cases were normal in study group and six cases were confirmed with surgery, while three cases were abnormal. There were 91.7% (44/48) in coincidence rate and 97.4% (38/39) in positive predictive value. CONCLUSION: Infertility in women with pelvic adhesion with abnormal ovarian appearance, may be examined specifically with TVUS.

A single-nucleotide polymorphism rs4639966 in 11q23.3 is associated with clinical features of systemic lupus erythematosus in the Chinese population.

In our previous genome-wide association study (GWAS), we identified an association signal of the single-nucleotide polymorphism (SNP) rs4639966 (p = 1.25 × 10(-16), odds ratio [OR] = 1.29) within 11q23.3. The aim of this study was to investigate its relationship with disease subphenotypes, including renal nephritis, photosensitivity, antinuclear antibody (ANA), age at diagnosis, malar rash, discoid rash, immunological disorder, oral ulcer, hematological disorder, neurological disorder, serositis, arthritis and vasculitis. In this study, we used 4199 cases and 8255 controls from our previous GWAS to explore the association between 11q23.3 with subphenotypes of systemic lupus erythematosus (SLE). Data were analyzed with PLINK 1.07 software. Significant associations were found for the SNP rs4639966 of 11q23.3 with SLE of age at diagnosis <20 years (OR = 1.18, p = 0.0049), malar rash (OR = 1.13, p = 0.01) and vasculitis (OR = 1.17, p = 0.02). The study suggested that 11q23.3 might not only play important roles in the development of SLE, but also contribute to the complex phenotypes of SLE.

Genetic variant rs4982958 at 14q11.2 is associated with allergic rhinitis in a Chinese Han population running title: 14q11.2 is a susceptibility locus for allergic rhinitis.

BACKGROUND: Allergic rhinitis (AR) is one of the most common diseases caused by the combined effects of intrinsic factors (susceptibility genes and immunological status) and the external environment. Analyses of ascendant family history of atopic disease suggest that AR and atopic dermatitis might share a similar genetic background. OBJECTIVE: To conduct a case-control study in a Chinese Han population to evaluate the potential influence of single nucleotide polymorphisms (SNPs) at FLG, 5q22.1, 11q13.5, 14q11.2 and 20q13.33 on AR. METHODS: Ten SNPs--rs11204971 and rs3126085 at FLG, rs10067777, rs7701890, rs13360927, and rs13361382 at 5q22.1, rs6010620 at 20q13.33, rs7936562 and rs7124842 at 11q13.5, and rs4982958 at 14q11.2 were genotyped in 363 cases and 668 controls using the Sequenom MassArray system. Data were analyzed with PLINK 1.07 software. RESULTS: The T allele of rs4982958 at 14q11.2 was observed to be significantly associated with AR (P = .002, OR = 0.73, P(Bonferront) = .02). Genotype-based association testing revealed that the recessive model might provide the best fit for rs4982958 (P(Bonferroni) = .01). In subphenotype analyses, the rs4982958 T allele was also significantly associated with persistent AR (P = .01) and more than 2 positive skin prick tests (P = .038). CONCLUSION: We identified a novel susceptibility locus 14q11.2 for AR that might bear candidate genes conferring susceptibility to AR and affecting disease phenotypes.

Aggregatibacter actinomycetemcomitans leukotoxin is post-translationally modified by addition of either saturated or hydroxylated fatty acyl chains.

Aggregatibacter actinomycetemcomitans, a common inhabitant of the human upper aerodigestive tract, produces a repeat in toxin (RTX), leukotoxin (LtxA). The LtxA is transcribed as a 114-kDa inactive protoxin with activation being achieved by attachment of short chain fatty acyl groups to internal lysine residues. Methyl esters of LtxA that were isolated from A. actinomycetemcomitans strains JP2 and HK1651 and subjected to gas chromatography/mass spectrometry contained palmitoyl (C16:0, 27-29%) and palmitolyl (C16:1 cis Δ9, 43-44%) fatty acyl groups with smaller quantities of myristic (C14:0, 14%) and stearic (C18:0, 12-14%) fatty acids. Liquid chromatography/mass spectrometry of tryptic peptides from acylated and unacylated recombinant LtxA confirmed that Lys(562) and Lys(687) are the sites of acyl group attachment. During analysis of recombinant LtxA peptides, we observed peptide spectra that were not observed as part of the RTX acylation schemes of either Escherichia coliα-hemolysin or Bordetella pertussis cyclolysin. Mass calculations of these spectra suggested that LtxA was also modified by the addition of monohydroxylated forms of C14 and C16 acyl groups. Multiple reaction monitoring mass spectrometry identified hydroxymyristic and hydroxypalmitic acids in wild-type LtxA methyl esters. Single or tandem replacement of Lys(562) and Lys(687) with Arg blocks acylation, resulting in a >75% decrease in cytotoxicity when compared with wild-type toxin, suggesting that these post-translational modifications are playing a critical role in LtxA-mediated target cell cytotoxicity.

ClC-2 contributes to tonic inhibition mediated by α5 subunit-containing GABA(A) receptor in experimental temporal lobe epilepsy.

Temporal lobe epilepsy (TLE), characterized by spontaneous recurrent seizures, learning and memory impairments is associated with neurodegeneration, abnormal reorganization of the circuitry and loss of functional inhibition in hippocampus. In adult hippocampus, the GABAergic cells mediate the major inhibitory function of the principal neurons, promoting the Cl(-) entry through the GABA(A) receptor, whether through phasic (synaptic) or tonic (extrasynaptic) conductance. Aside from classical synaptic component, tonic GABAergic inhibition mediated by extrasynaptic GABA(A) receptor received increasing attention over the past years. There is growing evidence that tonic inhibition plays an important role in epilepsy, memory and cognition. Since GABA(A) receptor-mediated inhibition depends on the maintenance of intracellular Cl(-) concentration at low levels in mature neurons, a shift in E(cl) is likely to participate in the generation and not merely a consequence of TLE. As we know, chloride channel-2 (ClC-2) is a member of the supergene family of voltage-gated chloride channels, it constitutes part of the background conductance and is involved in chloride extrusion. Here we show that ClC-2 were upregulated functionally in CA1 pyramidal cells in pilocarpine-treated rats, and that an observed increase in ClC-2 currents in CA1 pyramidal cells was reversed by L655,708, a specific antagonist of α5 subunit-containing GABA(A) receptor.

One novel and two recurrent mutations in the keratin 5 gene identified in Chinese patients with epidermolysis bullosa simplex.

Epidermolysis bullosa simplex (EBS) is a group of inherited skin diseases, characterized by the formation of intraepidermal blisters. We performed genetic analysis of the keratin 5 (KRT5) gene in two Chinese pedigrees. One novel missense mutation was identified in a patient with sporadic EBS (general, non-Dowling-Meara). Sequence analysis showed a heterozygous T > A transition at nucleotide 1730 of KRT5, changing phenylalanine (Phe) to tyrosine (Tyr) at position 577 of the keratin 5 (K5). In addition, two recurrent mutations c.1649delG (p.Gly550AlafsX77) and c.508G > (p.Glu170Lys) in KRT5 were identified in Chinese patients with mottled pigmentation EBS and localized EBS, respectively. None of the mutations were found in any unaffected family members or in an additional 100 unrelated control samples. These results suggest that these mutations are pathogenic and might be one of the potential causes of EBS in these Chinese patients.