Phosphorylated vimentin-triggered fibronectin matrix disaggregation enhances the dissemination of Treponema pallidum subsp. pallidum across the microvascular endothelial barrier.

Fibronectin (FN) is an essential component of the extracellular matrix (ECM) that protects the integrity of the microvascular endothelial barrier (MEB). However, Treponema pallidum subsp. pallidum (Tp) breaches this barrier through elusive mechanisms and rapidly disseminates throughout the host. We aimed to understand the impact of Tp on the surrounding FN matrix of MEB and the underlying mechanisms of this effect. In this study, immunofluorescence assays (IF) were conducted to assess the integrity of the FN matrix surrounding human microvascular endothelial cell-1 (HMEC-1) with/without Tp co-culture, revealing that only live Tp exhibited the capability to mediate FN matrix disaggregation in HMEC-1. Western blotting and IF were employed to determine the protein levels associated with the FN matrix during Tp infection, which showed the unaltered protein levels of total FN and its receptor integrin α5ß1, along with reduced insoluble FN and increased soluble FN. Simultaneously, the integrin α5ß1-binding protein-intracellular vimentin maintained a stable total protein level while exhibiting an increase in the soluble form, specifically mediated by the phosphorylation of its 39th residue (pSer39-vimentin). Besides, this process of vimentin phosphorylation, which could be hindered by a serine-to-alanine mutation or inhibition of phosphorylated-AKT1 (pAKT1), promoted intracellular vimentin rearrangement and FN matrix disaggregation. Moreover, within the introduction of additional cellular FN rather than other Tp-adhered ECM protein, in vitro endothelial barrier traversal experiment and in vivo syphilitic infectivity test demonstrated that viable Tp was effectively prevented from penetrating the in vitro MEB or disseminating in Tp-challenged rabbits. This investigation revealed the active pAKT1/pSer39-vimentin signal triggered by live Tp to expedite the disaggregation of the FN matrix and highlighted the importance of FN matrix stability in syphilis, thereby providing a novel perspective on ECM disruption mechanisms that facilitate Tp dissemination across the MEB.

Uncovering the mechanisms of host mitochondrial cardiolipin release in syphilis: Insights from human microvascular endothelial cells.

The release of host mitochondrial cardiolipin is believed to be the main factor that contributes to the production of anti-cardiolipin antibodies in syphilis. However, the precise mechanism by which mitochondria release cardiolipin in this context remains elusive. This study aimed to elucidate the mechanisms underlying mitochondrial cardiolipin release in syphilis. We conducted a cardiolipin quantitative assay and immunofluorescence analysis to detect mitochondrial cardiolipin release in human microvascular endothelial cells (HMEC-1), with and without Treponema pallidum (Tp) infection. Furthermore, we explored apoptosis, a key mechanism for mitochondrial cardiolipin release. The potential mediator molecules were then analyzed through RNA-sequence and subsequently validated using in vitro knockout techniques mediated by CRISPR-Cas9 and pathway-specific inhibitors. Our findings confirm that live-Tp is capable of initiating the release of mitochondrial cardiolipin, whereas inactivated-Tp does not exhibit this capability. Additionally, apoptosis detection further supports the notion that the release of mitochondrial cardiolipin occurs independently of apoptosis. The RNA-sequencing results indicated that microtubule-associated protein2 (MAP2), an axonogenesis and dendrite development gene, was up-regulated in HMEC-1 treated with Tp, which was further confirmed in syphilitic lesions by immunofluorescence. Notably, genetic knockout of MAP2 inhibited Tp-induced mitochondrial cardiolipin release in HMEC-1. Mechanically, Tp-infection regulated MAP2 expression via the MEK-ERK-HES1 pathway, and MEK/ERK phosphorylation inhibitors effectively block Tp-induced mitochondrial cardiolipin release. This study demonstrated that the infection of live-Tp enhanced the expression of MAP2 via the MEK-ERK-HES1 pathway, thereby contributing to our understanding of the role of anti-cardiolipin antibodies in the diagnosis of syphilis.

Recurrent neural network for predicting absence of heterozygosity from low pass WGS with ultra-low depth.

BACKGROUND: The absence of heterozygosity (AOH) is a kind of genomic change characterized by a long contiguous region of homozygous alleles in a chromosome, which may cause human genetic disorders. However, no method of low-pass whole genome sequencing (LP-WGS) has been reported for the detection of AOH in a low-pass setting of less than onefold. We developed a method, termed CNVseq-AOH, for predicting the absence of heterozygosity using LP-WGS with ultra-low sequencing data, which overcomes the sparse nature of typical LP-WGS data by combing population-based haplotype information, adjustable sliding windows, and recurrent neural network (RNN). We tested the feasibility of CNVseq-AOH for the detection of AOH in 409 cases (11 AOH regions for model training and 863 AOH regions for validation) from the 1000 Genomes Project (1KGP). AOH detection using CNVseq-AOH was also performed on 6 clinical cases with previously ascertained AOHs by whole exome sequencing (WES). RESULTS: Using SNP-based microarray results as reference (AOHs detected by CNVseq-AOH with at least a 50% overlap with the AOHs detected by chromosomal microarray analysis), 409 samples (863 AOH regions) in the 1KGP were used for concordant analysis. For 784 AOHs on autosomes and 79 AOHs on the X chromosome, CNVseq-AOH can predict AOHs with a concordant rate of 96.23% and 59.49% respectively based on the analysis of 0.1-fold LP-WGS data, which is far lower than the current standard in the field. Using 0.1-fold LP-WGS data, CNVseq-AOH revealed 5 additional AOHs (larger than 10 Mb in size) in the 409 samples. We further analyzed AOHs larger than 10 Mb, which is recommended for reporting the possibility of UPD. For the 291 AOH regions larger than 10 Mb, CNVseq-AOH can predict AOHs with a concordant rate of 99.66% with only 0.1-fold LP-WGS data. In the 6 clinical cases, CNVseq-AOH revealed all 15 known AOH regions. CONCLUSIONS: Here we reported a method for analyzing LP-WGS data to accurately identify regions of AOH, which possesses great potential to improve genetic testing of AOH.

The dose response of erythemal area and intensity on the unprotected skin fits well to a logistic 3P model in SPF tests of a Chinese population, which has the potential to improve the precision and consistency of minimal erythema dose determination.

BACKGROUND: The current ISO guidelines for minimal erythema dose (MED) determination require assessment of erythema area of UV-irradiated skin sites. However, this parameter has not been adequately quantified in daily practice. The aims of this study were to investigate the dose response on the unprotected skin sites by quantifying the erythema area and intensity and to show the potential for improving the precision and consistency of MEDu determination by developing predictive models. METHODS: Standard radiation tests were conducted on the back of 31 healthy Chinese volunteers and the MEDu site of each subject was clinically determined by dermatologists. Images of test sites were captured 24 h after radiation, and the erythema area (%EA) and intensity (∆a*) were measured by image analysis. The data were fitted to a logistic 3P function to obtain dose-response curves, and a set of logit (inverse-logistic) models were then derived. An erythema area threshold of %EA = 52% was established to predict MEDu based on the clinical endpoints defined by ISO 24444:2019. RESULTS: Analysis of the clinically determined MEDu sites revealed wide ranges of %EA (62.3 ± 15% SD) and ∆a* (2.96 ± 0.92 SD). The dose response fitted well to a logistic 3P model (mean R2 = 0.965 and 0.975 for %EA and ∆a*, respectively). Applying the area threshold, values of MEDu were determined by the logit model for the test population, which significantly improved the consistency of MEDu determination (52 ± 0% SD and 2.73 ± 0.61 SD for %EA and ∆a*, respectively). CONCLUSION: This study demonstrated that the dose response of UV-induced erythema can be quantified and modeled once the erythema area and intensity are measured. The results of this study show the potential to improve the precision and consistency of MEDu determination in an SPF test. The similar potential in photodermatological, therapeutic, and diagnostic applications was also implied.

A Non-Immunized and BSA-Template Aggregation-Induced Emission Sensor for Noninvasive Detection of Cystatin C in the Clinical Diagnosis of Diabetes Nephropathy.

Diabetes nephropathy (DN) is one of the main causes of death in patients with diabetes. Cystatin C (Cys C) is a reliable indicator of glomerular filtration function. Therefore, it is urgent and meaningful to obtain early warning of DN by noninvasive measurement of Cys C. In this investigation, a novel fluorescence sensor (BSA-AIEgen sensor) was synthesized by cross-linking the aggregation-induced emission (AIE) characteristics of 2-(4-bromophenyl)-3-(4-(4-(diphenylamino) styryl) phenyl) fumaronitrile (TPABDFN) and bovine serum albumin (BSA), which exhibited the "On" state owing to the restriction of the intramolecular motions (RIM) phenomenon of TPABDFN. Intriguingly, a decrease in fluorescence of BSA-AIEgen sensors could be found owing to BSA on the surface of BSA-AIEgen sensor hydrolyzed by papain, but a reverse phenomenon emerged with the increase of Cys C content as the inhibitor of papain. Hence, Cys C was successfully detected by employing the fluorescent differential display and the linear range was from 12.5 ng/mL to 800 ng/mL (R2 = 0.994) with the limit of detection (LOD) of 7.10 ng/mL (S/N = 3). Further, the developed BSA-AIEgen sensor successfully differentiates patients with diabetes nephropathy from volunteers with the advantages of high specificity, low cost, and simple operation. Accordingly, it is expected to become a non-immunized method to monitor Cys C for the early warning, noninvasive diagnosis, and drug efficacy evaluation of diabetes nephropathy.

Altered Gene Expression in Acne Vulgaris Patients Treated by Oral Isotretinoin: A Preliminary Study.

BACKGROUND/OBJECTIVE: The role of gene expression changes in acne patients treated by oral isotretinoin (ISO) and in influencing the ISO therapeutic effects is still unclear. In this study, we investigated the gene profiles of patients with severe acne who responded variously to ISO therapy. METHODS: The peripheral blood of 113 acne vulgaris patients (Pillsbury IV grade) was collected before treatment. After 8 weeks of oral ISO, nine acne patients were selected and divided into the following groups. A: effectively treated by ISO, group B: ineffectively treated by ISO, group C: ISO-induced acne flare-up, and 3 healthy subjects were included as control group D. The peripheral blood of patients pre- and post-treatment was subjected to high-throughput RNA sequencing technology and bioinformatics analysis of the separate groups (n = 3). The candidate genes were validated by qRT-PCR. RESULTS: Comparing pre- and post-oral ISO treatment, gene expression was changed as 39 genes in ISO-effective group, 345 genes in ISO-ineffective group, and 57 genes in ISO-induced acne flare-up group. Comparing the ISO-induced acne flare-up group with healthy control subjects revealed 34 upregulated genes and 23 downregulated genes, while comparing the ISO-induced acne flare-up group with ISO-ineffective patients identified 1835 changed genes. Expression of GATA2 (2.73 fold, P=0.024512), C4BPA (35.87 folds, P=0.038073), and CCR5 (2.48 folds, P=0.004681) increased in the ISO-induced acne flare-up patients. Meanwhile, the expression of DEFA3 (0.18 fold, P=0.041934), ELANE (0.14 fold, P=0.030767), MMP9 (0.41 fold, P=0.013383), and RPS4Y1 (0.00018 fold, P=0.000986) decreased when compared with ISO-ineffective patients. CONCLUSION: Oral ISO treatment could temporarily alter gene expression in acne patients. ISO therapeutic mechanisms were involved, not only in regulating the inflammatory reaction but also in the process of DNA repair. GATA2, C4BPA, CCR5, DEFA3, ELANE, MMP9, and RPS4Y1 might be susceptible to genes that could participate in the ISO-induced aggravation of acne.

The Overexpression of Epidermal Growth Factor (EGF) in HaCaT Cells Promotes the Proliferation, Migration, Invasion and Transdifferentiation to Epidermal Stem Cell Immunophenotyping of Adipose-Derived Stem Cells (ADSCs).

BACKGROUND AND OBJECTIVES: The application of adipose derived stem cells (ADSCs) in skin repair has attracted much attention nowadays. Epidermal growth factor (EGF) participates in the progress of skin proliferation, differentiation and so forth. We aimed to explore the role of EGF in the proliferation, invasion, migration and transdifferentiation into epidermal cell phenotypes of ADSCs. METHODS AND RESULTS: ADSCs were extracted from adipose tissues from patient. Immunophenotyping was determined by flow cytometry. Overexpressed EGF or siEGF was transfected by lentiviruses. EGF was determined by enzyme linked immunosorbent assay (ELISA) or western blot. ADSCs and HaCaT cells were co-cultured by Transwell chambers. Conditioned medium (CM) was obtained from cultured HaCaT cells and used for the culturing of ADSCs. Cell viability was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Invasion rate was measured by Transwell invasion assay and migration rate by wound healing test. mRNA and protein levels were measured by qPCR and western blot respectively. The extracted cells from adipose tissues were identified as ADSCs by morphology and immunophenotyping. The expression of EGF was up or down regulated constantly in HaCaT cell line after transfection. EGF overexpression upregulated the proliferation, migration and invasion rates of ADSCs, and EGF expression regulated the expression of cytokeratin-19 (CK19) and integrin-ß as well. CONCLUSIONS: EGF could be served as a stimulus to promote the proliferation, migration, and invasion as well as the transdifferentiation into epidermal stem cell immunophenotyping of ADSCs. The results showed that EGF had a promising effect on the repair of skin wound.

Overexpressed vascular endothelial growth factor in adipose derived stem cells attenuates fibroblasts and skin injuries by ultraviolet radiation.

Adipose-derived stem cells (ADSCs) and vascular endothelial growth factor (VEGF) contribute to the healing of wound. The purpose of the present study was to investigate the role of VEGF produced by ADSCs in the protection of fibroblasts and skin of mice from ultraviolet (UV) radiation. ADSCs and fibroblasts were extracted from adipose and skin on the abdomen of mice by enzyme digestion methods. ADSCs surface markers were detected using flow cytometry, and immunofluorescence was used to identify fibroblasts. The expression of VEGF in modified ADSCs with lentivirus was determined. Fibroblasts were injured by UV radiation and co-cultured with ADSCs carrying overexpressed VEGF or normal VEGF. Cell cycle was assessed by flow cytometry. Mice were treated with UV radiation dorsally and injected with ADSCs containing overexpressed VEGF or normal VEGF. mRNA and protein levels of cell senescence-related genes were measured by qPCR and western blot. It was found that ADSCs with overexpressed VEGF not only promoted the effect of ADSCs on down-regulating senescence-associated (SA)-ß-Gal, p21 and matrix metalloproteinase (MMP)-1, the healing of wound injured by UV radiation and up-regulating collagen I expression in fibroblasts and wound, but also on inhibiting cell cycle arrest in fibroblasts injured by UV radiation and preventing the skin from photoaging caused by UV radiation. VEGF expression in ADSCs played a key role in protecting skin fibroblasts from ageing, which further allowed the skin to resist photoaging, thereby promoting the recovery of wound injured by UV radiation.

Repair Effects of KGF on Ischemia-Reperfusion-Induced Flap Injury via Activating Nrf2 Signaling.

BACKGROUND: Ischemia-reperfusion (IR) injury is a main cause to and the mechanism of necrosis after flap transplantation. Researches were hardly conducted on the role and possible mechanism of keratinocyte growth factor (KGF) in association with IR flap injury. MATERIALS AND METHODS: A CoCl2-stimulated hypoxia cell model was established to investigate the effects of KGF on cell viability, apoptosis, cell cycle, and reactive oxygen species level. The experiments were performed by cell counting kit-8 and flow cytometry as required. Meanwhile, the expressions of cell cycle-related and nuclear factor E2-related factor 2 (Nrf2) signaling-related genes were determined using quantitative real-time PCR and Western blot. The right dorsolateral areas of Institute of Cancer Research mice were marked as flaps, the pedicle of which formed an IR process through clamping and loosening. Tissue morphologies were observed using hematoxylin and eosin staining 24 h after the surgery. The effects of KGF on cell apoptosis and associated genes expressions were studied by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, immunohistochemistry, and Western blot. RESULTS: HaCAT cells treated with 40 µM CoCl2 could not only reduce cell viability, promote cell apoptosis, arrest G1 phase of cell cycle and increase the activity of reactive oxygen species but also downregulate the expressions of c-myc, c-fos, transforming growth factor-α, Nrf2, heme oxygenase-1, and gamma-glutamyl cysteine synthetase. Additional recombinant human KGF, on one hand, could protect the cells from hypoxia injury. On the other hand, recombinant human KGF could significantly inhibit cell apoptosis, increase KGF activity, and increase the Nrf2, heme oxygenase-1, and gamma-glutamyl cysteine synthetase proteins levels in IR flap tissues. CONCLUSIONS: KGF played an important role in protecting mice flaps from IR injury, and the possible mechanism was involved in activating the Nrf2 signaling.

Pyridine nucleotide-disulphide oxidoreductase domain 2 (PYROXD2): Role in mitochondrial function.

Pyridine Nucleotide-Disulphide Oxidoreductase Domain 2 (PYROXD2), a Hepatitis B virus X protein (HBx)-interacting protein, is significantly down-regulated in hepatocellular carcinoma (HCC), however its exact biological function remains unclear. The aim of this study is to investigate the subcellular localization and biological function of PYROXD2 in hepatic cells. The results showed that PYROXD2 was imported to the mitochondrial inner membrane/matrix by Tom40 and Tim23, but not Mia40. PYROXD2 151-230aa might be the mitochondrial targeting sequence. PYROXD2 interacted with complex IV subunit COX5B. Knockout of PYROXD2 decreased MMP, intracellular ROS, complex IV activity, cell proliferation, ATP content and mtDNA copy number, but increased mtROS levels and the number of immature mitochondria. In summary, our data illustrated that PYROXD2 localizes to the mitochondrial inner membrane/matrix, and it plays important roles in regulating mitochondrial function.

Prevalence of low inflammatory tinea genitalis in southern China.

BACKGROUND: Emergence of highly inflammatory genital dermatophyte infections has been reported from Southeast Asia. In view of this, knowledge of the non-outbreak fungal flora of the genitals is required as a baseline study. OBJECTIVES: We present our 12-year experience in a tertiary clinic with the diagnosis of scrotal fungal infections. METHODS: A retrospective review was performed of patients with a diagnosis of scrotal fungal infections proven by direct microscopy and culture. Clinical, mycological and treatment data were collected. RESULTS: In total, 35 male patients were identified, of which 27 concerned dermatophyte infections and eight were yeasts. Nannizzia gypsea was the most common agent (48.6%), presenting as thick pseudomembraneous lesions limited to the scrotum. Trichophyton rubrum (22.9%) and Epidermophyton floccosum (5.7%) mainly presented erythematous, dry and scaly lesions and involving more sites besides the scrotum. Candida albicans (n = 3), C. glabrata (n = 2), C. guilliermondii (n = 1) and Trichosporon asteroides (n = 1), presented various lesions. Sports, sweating and concurrent tineas are hypothesised as predisposing factors. CONCLUSIONS: The prevalent causative agent of scrotum infections is N. gypsea, but wide species diversity is observed. All infections show mild skin inflammation. It is suggested that this genital fungal flora represents the current situation prior to clonal dermatophyte outbreaks.

Towards testing big data analytics software: the essential role of metamorphic testing.

In the rapidly growing field of big data analysis, scientists from numerous domains such as computer science and biology are constantly challenged by an unprecedented amount of data. While many software programs have been constructed to support processing and analyzing continuous information flow, one under-appreciated challenge in this field is software quality assurance of these big data software platforms. Metamorphic testing, which was proposed to alleviate the oracle problem in the software engineering community, has become an effective approach for software verification and validation. Recent years, we have witnessed successful applications of metamorphic testing in a variety of domains, ranging from bioinformatics to deep learning. In this letter, we review some main applications of metamorphic testing on big data and present visions for the challenges in future research.

Characteristic features of neck skin aging in Chinese women.

INTRODUCTION: Neck skin aging is of particular interest to skin scientists and dermatologists because of the increasing demand for neck wrinkle improvement. This study aimed to determine the neck aging features of Chinese women and to investigate the clinical alterations and mechanical, topographical, and biophysical properties of neck skin. METHODS: A total of 450 Chinese women (age range: 16-66 years) were clinically examined and graded by the same dermatologist using standardized photographs. The skin properties were assessed by noninvasive skin measuring devices. RESULTS: The results showed that different neck aging signs, including the horizontal neck fold, neck sagging, hollowing of emaciated neck, platysmal bands, and neck texture, appeared in different ages, and all of them worsened age-dependently since they manifested. The skin elasticity markedly changed before the onset of most of the aging signs and showed a negative correlation with both age and the severity of these signs. Transepidermal water loss (TEWL) was positively correlated with age, whereas hydration and pH were not significantly correlated with age. We also found that wrinkles (SEw) and average roughness (Ra) were significantly correlated with age. SEw, smoothness, the average depth of roughness (Rz), TEWL, and erythema index were significantly and positively correlated with the severity of the horizontal neck fold, neck sagging, hollowing of emaciated neck, and platysmal bands. CONCLUSION: This is the first study to emphasize that age causes diverse changes in Chinese women's neck skin. The changes in skin elasticity may effectively predict neck aging before the onset of most of the neck aging signs.

The Topological Properties of Stimuli Influence Fear Generalization and Extinction in Humans.

Fear generalization is an etiologically significant indicator of anxiety disorders, and understanding how to inhibit it is important in their treatment. Prior studies have found that reducing fear generalization using a generalization stimulus (GS) is ineffective in removing a conditioned fear that incorporates local features, and that topological properties appear to play a comparatively more significant role in the processes of perception and categorization. Our study utilized a conditioned-fear generalization design to examine whether the topological properties of stimuli influence the generalization and return of fear. Fear was indexed using online expectancy ratings and skin conductance responses (SCRs). The study's 52 participants were divided into three groups: Group 1, conditioned danger cue (CS+) extinction; Group 2, extinction of one GS; Group 3, extinction of three GSs. We found that the three groups acquired conditioned fear at the same level. In the generalization and extinction phase, fear was transferred to the GS with the same topological properties as CS+, and gradual decreases in both shock expectancy and SCRs over non-reinforced extinction trials were observed. In the test phase, participants' online expectancy ratings indicated that fear did not return in Group 1, but did return in Groups 2 and 3. All three groups demonstrated successful GS fear extinction, but only Group 1 did not show a return of fear for CS+. Regarding SCRs results, none of the groups demonstrated a return of fear, suggesting that utilization of topological properties successfully reduced the return of conditioned fear. Our results indicate that, in clinical settings, using GS with topological equivalence to CS+ might offer a potential method with which to extinct conditioned fear.

DDM1 guards against telomere truncation in Arabidopsis.

KEY MESSAGE: Prolonged hypomethylation of DNA leads to telomere truncation correlated with increased telomere recombination, transposon mobilization and stem cell death. Epigenetic pathways, including DNA methylation, are crucial for telomere maintenance. Deficient in DNA Methylation 1 (DDM1) encodes a nucleosome remodeling protein, required to maintain DNA methylation in Arabidopsis thaliana. Plants lacking DDM1 can be self-propagated, but in the sixth generation (G6) hypomethylation leads to rampant transposon activation and infertility. Here we examine the role of DDM1 in telomere length homeostasis through a longitudinal study of successive generations of ddm1-2 mutants. We report that bulk telomere length remains within the wild-type range for the first five generations (G1-G5), and then precipitously drops in G6. While telomerase activity becomes more variable in later generation ddm1-2 mutants, there is no correlation between enzyme activity and telomere length. Plants lacking DDM1 also exhibit no dysregulation of several known telomere-associated transcripts, including TERRA. Instead, telomere shortening coincides with increased G-overhangs and extra-chromosomal circles, consistent with deletional recombination. Telomere shortening also correlates with transcriptional activation of retrotransposons, and a hypersensitive DNA damage response in root apical meristems. Since abiotic stresses, including DNA damage, stimulate homologous recombination, we hypothesize that telomere deletion in G6 ddm1-2 mutants is a by-product of elevated genome-wide recombination in response to transposon mobilization. Further, we speculate that telomere truncation may be beneficial in adverse environmental conditions by accelerating the elimination of stem cells with aberrant genomes.

Myeloid zinc finger 1 protein is a key transcription stimulating factor of PYROXD2 promoter.

Previous studies revealed that PYROXD2 was more highly expressed in normal liver tissue and liver cell lines than in cancer tissue and cancer cell lines, which indicated that decreased PYROXD2 expression may be involved in hepatocarcinogenesis. To identify the mechanisms which regulate PYROXD2 gene transcription, we constructed a series of luciferase reporter plasmids and used them to perform luciferase­based reporter assays with HepG2, Sk-hep1, L02 and 293T cells with the purpose of characterizing the PYROXD2 reporter region. Our results revealed that the transcription factor myeloid zinc finger 1 (MZF1) is necessary for PYROXD2 gene transcription and that it functions as a trans-activator. DNA binding assays revealed that the MZF1 protein binds to the cis-element TGGGGA located in the -320/-312 region of the PYROXD2 promoter. This promoter had a significantly enhanced activity when the MZF1 protein was overexpressed and a significantly decreased activity when the MZF1 protein expression was silenced. However, MZF1 gene expression was not significantly correlated with PYROXD2 protein expression in the samples of resected tumor tissues, which revealed that the PYROXD2 promoter transcription activity was determined by the aggregated effect of numerous transcription factors. This finding may be helpful in understanding the underlying mechanism which regulates the PYROXD2 expression.

PM2.5 Exposure Elicits Oxidative Stress Responses and Mitochondrial Apoptosis Pathway Activation in HaCaT Keratinocytes.

BACKGROUND:: PM2.5 (aerodynamic diameter ≤ 2.5 µm) is a dominant and ubiquitous air pollutant that has become a global concern as PM2.5 exposure has been linked to many adverse health effects including cardiovascular and pulmonary diseases. Emerging evidence supports a correlation between increased air PM2.5 levels and skin disorders although reports on the underlying pathophysiological mechanisms are limited. Oxidative stress is the most common mechanism of PM2.5-induced adverse health effects. This study aimed to investigate PM2.5-induced oxidative damage and apoptosis in immortalized human keratinocyte (HaCaT) cells. METHODS:: HaCaT cells were exposed to 0, 25, 50, 100, or 200 µg/ml PM2.5 for 24 h. Reactive oxygen species (ROS) generation, lipid peroxidation products, antioxidant activity, DNA damage, apoptotic protein expression, and cell apoptosis were measured. RESULTS:: PM2.5 exposure (0-200 µg/ml) for 24 h resulted in increased ROS levels (arbitrary unit: 201.00 ± 19.28, 264.50 ± 17.91, 305.05 ± 19.57, 427.95 ± 18.32, and 436.70 ± 17.77) and malondialdehyde production (0.54 ± 0.05 nmol/mg prot, 0.61 ± 0.06 nmol/mg prot, 0.68 ± 0.05 nmol/mg prot, 0.70 ± 0.05 nmol/mg prot, and 0.76 ± 0.05 nmol/mg prot), diminished superoxide dismutase activity (6.47 ± 0.28 NU/mg prot, 5.97 ± 0.30 NU/mg prot, 5.15 ± 0.42 NU/mg prot, 4.08 ± 0.20 NU/mg prot, and 3.76 ± 0.37 NU/mg prot), and increased DNA damage and apoptosis in a dose-dependent manner in HaCaT cells. Moreover, cytochrome-c, caspase-3, and caspase-9 expression also increased proportionately with PM2.5 dosing. CONCLUSION:: PM2.5 might elicit oxidative stress and mitochondria-dependent apoptosis that likely manifests as skin irritation and damage.

Skin Erythema, Pigmentation and Hydration Kinetics after Ultraviolet Radiation-induced Photodamage in Southern Chinese Women.

Although there have been some studies about changes of skin erythema and pigmentation following ultraviolet radiation in other races, the relevant data in Chinese have never been achieved. Thus, we evaluated the long-time course of skin erythema, pigmentation and hydration changes after different doses of solar-simulated ultraviolet (SSUV) irradiation in 26 Chinese women for 168 days. The erythema index increased abruptly and peaked during 3 days of SSUV exposure, then slowly returned to the baseline level starting at day 7 and completely recovered during 168-day course of this study only in one minimal erythema doses (MED) SSUV irradiation. The melanin index started to slowly increase at day 3 of SSUV exposure, peaking at day 14 and gradually returned to the baseline level thereafter, but did not return to the baseline level during 168-day course in all doses. Skin hydration slowly declined at day 3 of exposure, hitting the lowest point at day 7, then slowly recovered starting at day 14 and completely returned to the baseline level at day 28 only in 1.5MED. These results will serve as baseline data on Chinese skin and provide useful references for the treatment of serious skin photodamage in Chinese.

Molecular signal networks and regulating mechanisms of the unfolded protein response.

Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum (ER). One of the primary mechanisms is the unfolded protein response (UPR). In this review, we primarily focus on the latest signal webs and regulation mechanisms of the UPR. The relationships among ER stress, apoptosis, and cancer are also discussed. Under the normal state, binding immunoglobulin protein (BiP) interacts with the three sensors (protein kinase RNA-like ER kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1α (IRE1α)). Under ER stress, misfolded proteins interact with BiP, resulting in the release of BiP from the sensors. Subsequently, the three sensors dimerize and autophosphorylate to promote the signal cascades of ER stress. ER stress includes a series of positive and negative feedback signals, such as those regulating the stabilization of the sensors/BiP complex, activating and inactivating the sensors by autophosphorylation and dephosphorylation, activating specific transcription factors to enable selective transcription, and augmenting the ability to refold and export. Apart from the three basic pathways, vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR)-phospholipase C-γ (PLCγ)-mammalian target of rapamycin complex 1 (mTORC1) pathway, induced only in solid tumors, can also activate ATF6 and PERK signal cascades, and IRE1α also can be activated by activated RAC-alpha serine/threonine-protein kinase (AKT). A moderate UPR functions as a pro-survival signal to return the cell to its state of homeostasis. However, persistent ER stress will induce cells to undergo apoptosis in response to increasing reactive oxygen species (ROS), Ca2+ in the cytoplasmic matrix, and other apoptosis signal cascades, such as c-Jun N-terminal kinase (JNK), signal transducer and activator of transcription 3 (STAT3), and P38, when cellular damage exceeds the capacity of this adaptive response.

Dynamic Interactions of Arabidopsis TEN1: Stabilizing Telomeres in Response to Heat Stress.

Telomeres are the essential nucleoprotein structures that provide a physical cap for the ends of linear chromosomes. The highly conserved CST (CTC1/STN1/TEN1) protein complex facilitates telomeric DNA replication and promotes telomere stability. Here we report three unexpected properties of Arabidopsis thaliana TEN1 that indicate it possesses functions distinct from other previously characterized telomere proteins. First, we show that telomeres in ten1 mutants are highly sensitive to thermal stress. Heat shock causes abrupt and dramatic loss of telomeric DNA in ten1 plants, likely via deletional recombination. Second, we show that AtTEN1 has the properties of a heat-shock induced molecular chaperone. At elevated temperature, AtTEN1 rapidly assembles into high molecular weight homo-oligomeric complexes that efficiently suppress heat-induced aggregation of model protein substrates in vitro. Finally, we report that AtTEN1 specifically protects CTC1 from heat-induced aggregation in vitro, and from heat-induced protein degradation and loss of telomere association in vivo. Collectively, these observations define Arabidopsis TEN1 as a highly dynamic protein that works in concert with CTC1 to preserve telomere integrity in response to environmental stress.