Dihydrolipoyl dehydrogenase as a potential UVB target in skin epidermis; using an integrated approach of label-free quantitative proteomics and targeted metabolite analysis

Ursolic Acid as a Protective Agent against UVB-Induced Metabolic and Epigenetic Alterations in Human Skin Keratinocytes: An Omics-Based Study

This study aimed to assess how ursolic acid (UA) can protect human skin keratinocytes from damage caused by UVB radiation. Utilizing an omics-based approach, we characterized the features of photodamage and investigated the potential of UA to reverse HaCaT cell subpopulation injury caused by UVB radiation. The most significant changes in metabolite levels after UA treatment were in pathways associated with phosphatidylcholine biosynthesis and arginine and proline metabolism. Treatment with UA can reverse the levels of certain metabolites, including creatinine, creatine phosphate, and succinic acid. Pathways activated by UA treatment in UVB-irradiated HaCaT cells were associated with several biological processes, including the positive regulation of protein modification process, cell division, and enzyme-linked receptor protein signaling pathway. Treatment with UA demonstrates the capability to mitigate the effects of UVB radiation on specific genes, including S100 calcium-binding protein A9 and IL6 receptor. DNA/CpG methylation indicates that UA can partially reverse some of the alterations in the UVB-induced CpG methylome. Utilizing integrated RNA sequencing and methylation sequencing data, starburst plots illustrate the correlation between mRNA expression and CpG methylation status. UA potentially influences the metabolic pathway of glycerophospholipid metabolism by modulating the expression of several key enzymes, including phospholipase A2 group IIA and lipin 2. Altogether, these results indicate that UVB radiation induces metabolic reprogramming, epigenetic changes, and transcriptomic shifts. Meanwhile, UA demonstrates the capacity to inhibit or reduce the severity of these alterations, which may underlie its potential protective role against skin damage caused by UVB exposure. Prevention Relevance: Our research indicates that UA has the potential to mitigate or lessen the impact of UVB radiation, which is known to cause metabolic reprogramming, epigenetic alterations, and transcriptomic changes. These effects could be responsible for UA's possible protective function against skin damage induced by UVB exposure.

Roles of Dihydrolipoamide Dehydrogenase in Health and Disease

Significance: Dihydrolipoamide dehydrogenase (DLDH) is a flavin-dependent disulfide oxidoreductase. The active form of DLDH is a stable homodimer, and its deficiencies have been linked to numerous metabolic disorders. A better understanding of redox and nonredox features of DLDH may reveal druggable targets for disease interventions or preventions. Recent Advances: In this article, the authors review the different roles of DLDH in selected pathological conditions, including its deficiency in humans, its role in stroke and neuroprotection, skin photoaging, Alzheimer's disease, and DLDH as a nondehydrogenating protein, and construction of genetically modified DLDH animal models for further studying the role of DLDH in specific pathological conditions. DLDH is also vulnerable to oxidative modifications in pathological conditions. Critical Issues: Novel animal models need to be constructed using gene knockdown techniques to investigate the redox- and nonredox roles of DLDH in related metabolic diseases. Specific small-molecule DLDH inhibitors need to be discovered. The relationship between modifications of specific amino acid residues in DLDH and given pathological conditions is an interesting area that remains to be comprehensively evaluated. Future Directions: Cell-specific or tissue-specific knockdown of DLDH creating specific pathological conditions will provide more insights into the mechanisms, whereby DLDH may have therapeutic values under a variety of pathological conditions. Antioxid. Redox Signal. 39, 794-806.

Serum Metabolomics Analysis of Skin-Involved Systemic Lupus Erythematosus: Association of Anti-SSA Antibodies with Photosensitivity

Purpose

Systemic lupus erythematosus is a heterogeneous autoimmune disease in which skin involvement is a common manifestation. It is currently thought that the photosensitivity of SLE skin involvement is associated with anti-SSA antibodies. This study aimed to expand the current state of knowledge surrounding the molecular pathophysiology of SLE skin photosensitivity through Serum metabolomics analysis.

Patients and Methods

The serum metabolites of 23 cases of skin-involved SLE (SI) group, 14 cases of no SI (NSI) group, and 30 cases of healthy controls (HC) were analyzed by using UPLC-MS/MS technology, and subgroup analysis was performed according to the expression of anti-SSA antibodies in SI. MetaboAnalyst 5.0 was used for enrichment analysis and ROC curve construction, identifying serum metabolic markers of skin-involved SLE associated with anti-SSA antibodies.

Results

We identified several metabolites and metabolic pathways associated with SLE photosensitivity. Two metabolites, SM (d18:1/24:0) and gamma-CEHC can distinguish between anti-SSA antibody-positive and negative SI, with AUC of 0.829 and 0.806. These two photosensitization-related substances may be potential markers of skin involvement in SLE associated with anti-SSA antibody.

Conclusion

This study provides new insights into the pathogenesis of SI patients, and provides a new molecular biological basis for the association between anti-SSA antibodies and skin photoallergic manifestations of SLE.

Ameliorative effect of dandelion (Taraxacum officinale) peptides on benzo(a)pyrene-induced oxidative stress and inflammation in human umbilical vein endothelial cells

Dandelion (Taraxacum officinale) is widely consumed as a health food and a traditional medicine. However, the protective effect of dandelion bio-active peptides (DPs) against polycyclic aromatic hydrocarbon-induced blood vessel inflammation and oxidative damage is not well documented. In the current study, four novel DPs were isolated using an activity tracking method. The protective activity of the DPs against benzo(a)pyrene (Bap)-induced human umbilical vein endothelial cell (HUVEC) damage was explored. The results indicated that DP-2 [cycle-(Thr-His-Ala-Trp)] effectively inhibited Bap-induced reactive oxygen species (ROS) and malondialdehyde (MDA) overproduction and reinforced antioxidant enzyme activity while inhibiting the production of inflammatory factors in HUVECs. Moreover, DP-2 increased NAD(P)H:quinone oxidoreductase 1, heme oxygenase-1, and nuclear factor E2-releated factor 2 expression levels by activating the PI3K/Akt signaling pathway. In addition, DP-2 attenuated Bap-induced HUVEC apoptosis via the Bcl-2/Bax/cytochrome c apoptotic pathway. These results suggest that DP-2 is a promising compound for protecting HUVECs from Bap-induced inflammatory and oxidative damage.

Ameliorative effect of the probiotic peptide against benzo(α)pyrene-induced inflammatory damages in enterocytes

Probiotics are living bacteria that provide health benefits to the host when consumed in sufficient quantities. However, the protective effect of the bioactive peptides isolated from the probiotics against benzo(α)pyrene (BaP) induced gastrointestinal injury has never been investigated. The current work used a bio-assay guided technique to identify-four new cyclic peptides in BaP-induced Caco-2 cell culture and mouse colitis model. Lactobacillus rhamnosus cycle (Thr-His-Ala-Trp) peptide-1 (LRCP-1) effectively inhibited BaP-induced epithelial cytokine over-release and intracellular ROS over-production. Simultaneously, LRCP-1 attenuated BaP-induced NAD (P)H: oxidases (NOXs), Matrix metalloproteinases (MMPs) over-expression, respectively. Furthermore, increased NAD (P)H: quinone oxidoreductase 1 (NQO1)/heme oxygenase-1 (HO-1)/nuclear factor E2-related factor 2 (Nrf2) expression and aryl hydrocarbon receptor (AhR) pathway activation induced by the BaP-exposure were also inhibited after the LRCP-1 treatment. Notably, LRCP-1 is a promising agent protecting gastrointestinal epithelial cells from BaP-induced inflammatory and oxidative damages.

Anemopsis californica Attenuates Photoaging by Regulating MAPK, NRF2, and NFATc1 Signaling Pathways

Long-term exposure of the skin to solar radiation causes chronic inflammation and oxidative stress, which accelerates collagen degradation. This contributes to the formation of wrinkles and dark spots, skin fragility, and even skin cancer. In this study, Anemopsis californica (AC), a herb from North America that is well known for treating microorganism infection and promoting wound healing, was investigated for its photoprotective effects. The biological effects of AC were studied on two in vitro models, namely, lipopolysaccharide (LPS)-induced macrophages and ultraviolet B (UVB)-irradiated dermal fibroblasts, to characterize its underlying molecular mechanisms. The results showed that AC decreased the mRNA levels of inflammatory mediators in sensitized macrophages, including cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX-2). Moreover, AC alleviated UVB-induced photoaging in dermal fibroblasts by restoring procollagen synthesis. This resulted from the regulation of excessive reactive oxygen species (ROS) by AC, which was mediated by the activation of the antioxidative system nuclear factor erythroid 2-related factor 2 (NRF2). AC also alleviated oxidative stress and inflammatory responses by inhibiting the phosphorylation of mitogen-activated protein kinase (MAPK) and interfering with the nuclear translocation of the immune regulator nuclear factor of activated T-cells 1 (NFATc1). In conclusion, the protective effects of AC on skin cellular components suggested that it has the potential for use in the development of drugs and cosmetics that protect the skin from UVB-induced chronic inflammation and aging.

Long-term transcriptomic and proteomic effects in Sprague Dawley rat thyroid and plasma after internal low dose 131I exposure

Background

Radioiodide (¹³¹I) is commonly used to treat thyroid cancer and hyperthyroidis.¹³¹I released during nuclear accidents, have resulted in increased incidence of thyroid cancer in children. Therefore, a better understanding of underlying cellular mechanisms behind ¹³¹I exposure is of great clinical and radiation protection interest. The aim of this work was to study the long-term dose-related effects of ¹³¹I exposure in thyroid tissue and plasma in young rats and identify potential biomarkers.

Materials and methods

Male Sprague Dawley rats (5-week-old) were i.v. injected with 0.5, 5.0, 50 or 500 kBq ¹³¹I (D_thyroid ca 1–1000 mGy), and killed after nine months at which time the thyroid and blood samples were collected. Gene expression microarray analysis (thyroid samples) and LC-MS/MS analysis (thyroid and plasma samples) were performed to assess differential gene and protein expression profiles in treated and corresponding untreated control samples. Bioinformatics analyses were performed using the DAVID functional annotation tool and Ingenuity Pathway Analysis (IPA). The gene expression microarray data and LC-MS/MS data were validated using qRT-PCR and ELISA, respectively.

Results

Nine ¹³¹I exposure-related candidate biomarkers (transcripts: Afp and RT1-Bb, and proteins: ARF3, DLD, IKBKB, NONO, RAB6A, RPN2, and SLC25A5) were identified in thyroid tissue. Two dose-related protein candidate biomarkers were identified in thyroid (APRT and LDHA) and two in plasma (DSG4 and TGM3). Candidate biomarkers for thyroid function included the ACADL and SORBS2 (all activities), TPO and TG proteins (low activities). ¹³¹I exposure was shown to have a profound effect on metabolism, immune system, apoptosis and cell death. Furthermore, several signalling pathways essential for normal cellular function (actin cytoskeleton signalling, HGF signalling, NRF2-mediated oxidative stress, integrin signalling, calcium signalling) were also significantly regulated.

Conclusion

Exposure-related and dose-related effects on gene and protein expression generated few expression patterns useful as biomarkers for thyroid function and cancer.

Downregulation of dihydrolipoyl dehydrogenase by UVA suppresses melanoma progression via triggering oxidative stress and altering energy metabolism

Melanoma, the most severe form of skin cancer, has poor prognosis and is resistant to chemotherapy. Targeting cancer metabolism is a promising approach in cancer therapeutics. Dihydrolipoyl dehydrogenase (DLD) is a mitochondrial enzyme with diaphorase activity. Here we report a pivotal role of DLD in melanoma cell progression and proliferation. Suppression DLD expression by low intensity UVA (125 mJ/cm²) increased intracellular ROS production and decreased mitochondrial membrane potential thereby inducing autophagy cell death which were confirmed by increased LC3BII and decreased p62 expression in melanoma cells. Knockdown of DLD in melanoma cells also showed similar results. More so, suppression of DLD significantly inhibits in vivo melanoma growth and tumor proliferation. In addition, suppression of DLD increased the NAD+/NADH ratio in melanoma cells and also inhibits TCA cycle related metabolites. DLD downregulation markedly increased α-ketoglutarate and decreased succinic acid suggesting that DLD suppression may have decreased TCA cycle downstream metabolites, resulting in the alteration of mitochondrial energy metabolism Thus the downregulation of DLD induced autophagic cell death in melanoma cells and inhibits in vivo tumor growth and proliferation by increasing ROS production and altering energy metabolism. Our findings suggest that DLD plays a pivotal role in melanoma progression and proliferation.

Isolation and identification of three water-soluble selenoproteins in Se-enriched Agaricus blazei Murrill

Selenoproteins in selenium (Se)-enriched vegetables play an important role in human health. In this study, three water-soluble selenoproteins PR-Se-1, PR-Se-2 and PR-Se-3 in Agaricus blazei Murrill (ABM) were isolated by anion exchange chromatography, gel filtration chromatography and SDS-PAGE. Sequence analyses performed by HPLC-MS/MS showed that PR-Se-1, a 114024 Da selenoprotein with 1019 amino acids (AAs), is an isoenzyme of isocitrate dehydrogenase. PR-Se-2, a 53983 Da selenoprotein with 508 AAs, is a kind of dihydrolipoyl dehydrogenase. PR-Se-3, a 47179 Da selenoprotein with 415 AAs, is a kind d-proline reductase. Se content is high at 26.1 μg/g, and selenocystine is the predominant Se unit in the three selenoproteins. Se content of ABM is 9.15 μg/g, and the organic form of Se accounts for ~81% of total Se content. ABM could be a promising source of Se in Se-poor regions.

Plasma metabonomics and proteomics studies on the anti-thrombosis mechanism of aspirin eugenol ester in rat tail thrombosis model

Aspirin eugenol eater (AEE), a new drug compound, was synthesized through the combination of aspirin and eugenol. Antithrombotic effects of AEE have been confirmed in carrageenan-induced rat tail thrombosis model. However, its mechanism is unclear. With the application of integrated approach combining proteomics and metabolomics, the profilings of protein and metabolite in plasma were examined in thrombosis rat pretreated with AEE, aspirin and eugenol, respectively. A clear separation of the plasma metabolic profiles from different groups was found in score plots. 15 metabolites related with the metabolism of fatty acid, energy and amino acid were found. A total of 144, 38, 41 and 54 differentially abundant proteins (DAPs) were identified in control, AEE, aspirin and eugenol group, respectively. Proteomic results showed that aspirin modulated 7 proteins in amino acid metabolism and 4 proteins in complement system; eugenol regulated the 8 proteins related with coagulation cascades and fibrinogen; AEE improved 3 proteins in TCA cycle and 3 in lipid metabolism. Integrated analysis suggested that AEE improved fatty acid, energy and lipid metabolism to against thrombosis. Results of this study indicated AEE had different action mechanism on thrombosis from aspirin and eugenol, and contribute to understanding the mechanisms of AEE on thrombosis. SIGNIFICANCE: Thrombosis is a threat to human health, and there is an urgent need for new drug. In this study, compared with the model group, plasma metabolic profiles in AEE-treated rats were clearly separated; 15 metabolites and 38 proteins were picked out. These metabolites and proteins may assist in understanding the action mechanism of AEE on thrombosis. The results of plasma metabonomics and proteomics also revealed the different action mechanism among AEE, aspirin and eugenol on thrombosis. This study established the foundation to further evaluate the druggability of AEE on thrombosis treatment.

Mass spectrometry-based proteomics reveals the distinct nature of the skin proteomes of photoaged compared to intrinsically aged skin

OBJECTIVE

With increasing age, skin is subject to alterations in its organization, which impact on its function as well as having clinical consequences. Proteomics is a useful tool for non-targeted, semi-quantitative simultaneous investigation of high numbers of proteins. In the current study, we utilize proteomics to characterize and contrast age-associated differences in photoexposed and photoprotected skin, with a focus on the epidermis, dermal-epidermal junction and papillary dermis.

METHODS

Skin biopsies from buttock (photoprotected) and forearm (photoexposed) of healthy volunteers (aged 18-30 or ≥65 years) were transversely sectioned from the stratum corneum to a depth of 250 μm. Following SDS-PAGE, each sample lane was segmented prior to analysis by liquid chromatography-mass spectrometry/mass spectrometry. Pathway analysis was carried out using Ingenuity IPA.

RESULTS

Comparison of skin proteomes at buttock and forearm sites revealed differences in relative protein abundance. Ageing in skin on the photoexposed forearm resulted in 80% of the altered proteins being increased with age, in contrast to the photoprotected buttock where 74% of altered proteins with age were reduced. Functionally, age-altered proteins in the photoexposed forearm were associated with conferring structure, energy and metabolism. In the photoprotected buttock, proteins associated with gene expression, free-radical scavenging, protein synthesis and protein degradation were most frequently altered.

CONCLUSION

This study highlights the necessity of not considering photoageing as an accelerated intrinsic ageing, but as a distinct physiological process.

Prediction of skin anti-aging clinical benefits of an association of ingredients from marine and maritime origins: Ex vivo evaluation using a label-free quantitative proteomic and customized data processing approach

BACKGROUND

The application of ingredients from marine and maritime origins is increasingly common in skin care products, driven by consumer expectations for natural ingredients. However, these ingredients are typically studied for a few isolated in vitro activities.

OBJECTIVES

The purpose of this study was to carry out a comprehensive evaluation of the activity on the skin of an association of ingredients from marine and maritime origins using label-free quantitative proteomic analysis, in order to predict the clinical benefits if used in a skin care product.

METHODS

An aqueous gel containing 6.1% of ingredients from marine and maritime origins (amino acid-enriched giant kelp extract, trace element-enriched seawater, dedifferentiated sea fennel cells) was topically applied on human skin explants. The skin explants' proteome was analyzed in a label-free manner by high-performance liquid nano-chromatography coupled with tandem mass spectrometry. A specific data processing pipeline (CORAVALID) providing an objective and comprehensive interpretation of the statistically relevant biological activities processed the results.

RESULTS

Compared to untreated skin explants, 64 proteins were significantly regulated by the gel treatment (q-value ≤ 0.05). Computer data processing revealed an activity of the ingredients on the epidermis and the dermis. These significantly regulated proteins are involved in gene expression, cell survival and metabolism, inflammatory processes, dermal extracellular matrix synthesis, melanogenesis and keratinocyte proliferation, migration, and differentiation.

CONCLUSIONS

These results suggest that the tested ingredients could help to preserve a healthy epidermis and dermis, and possibly to prevent the visible signs of skin aging.

Sample Treatment for Tissue Proteomics in Cancer, Toxicology, and Forensics

Since the birth of proteomics science in the 1990, the number of applications and of sample preparation methods has grown exponentially, making a huge contribution to the knowledge in life science disciplines. Continuous improvements in the sample treatment strategies unlock and reveal the fine details of disease mechanisms, drug potency, and toxicity as well as enable new disciplines to be investigated such as forensic science.This chapter will cover the most recent developments in sample preparation strategies for tissue proteomics in three areas, namely, cancer, toxicology, and forensics, thus also demonstrating breath of application within the domain of health and well-being, pharmaceuticals, and secure societies.In particular, in the area of cancer (human tumor biomarkers), the most efficient and multi-informative proteomic strategies will be covered in relation to the subsequent application of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and liquid extraction surface analysis (LESA), due to their ability to provide molecular localization of tumor biomarkers albeit with different spatial resolution.With respect to toxicology, methodologies applied in toxicoproteomics will be illustrated with examples from its use in two important areas: the study of drug-induced liver injury (DILI) and studies of effects of chemical and environmental insults on skin, i.e., the effects of irritants, sensitizers, and ionizing radiation. Within this chapter, mainly tissue proteomics sample preparation methods for LC-MS/MS analysis will be discussed as (i) the use of LC-MS/MS is majorly represented in the research efforts of the bioanalytical community in this area and (ii) LC-MS/MS still is the gold standard for quantification studies.Finally, the use of proteomics will also be discussed in forensic science with respect to the information that can be recovered from blood and fingerprint evidence which are commonly encountered at the scene of the crime. The application of proteomic strategies for the analysis of blood and fingerprints is novel and proteomic preparation methods will be reported in relation to the subsequent use of mass spectrometry without any hyphenation. While generally yielding more information, hyphenated methods are often more laborious and time-consuming; since forensic investigations need quick turnaround, without compromising validity of the information, the prospect to develop methods for the application of quick forensic mass spectrometry techniques such as MALDI-MS (in imaging or profiling mode) is of great interest.

Secretomic analysis of Beauveria bassiana related to cattle tick, Rhipicephalus microplus, infection

Beauveria bassiana is widely studied as an alternative to chemical acaricides in controlling the cattle tick Rhipicephalus microplus. Although its biocontrol efficiency has been proved in laboratory and field scales, there is a need to a better understanding of host interaction process at molecular level related to biocontrol activity. In this work, applying a proteomic technique multidimensional protein identification technology (MudPIT), the differential secretome of B. bassiana induced by the host R. microplus cuticle was evaluated. The use of the host cuticle in a culture medium, mimicking an infection condition, is an established experimental model that triggers the secretion of inducible enzymes. From a total of 236 proteins, 50 proteins were identified exclusively in infection condition, assigned to different aspects of infection like host adhesion, cuticle penetration and fungal defense, and stress. Other 32 proteins were considered up- or down-regulated. In order to get a meaningful global view of the secretome, several bioinformatic analyses were performed. Regarding molecular function classification, the highest number of proteins in the differential secretome was assigned in to hydrolase activity, enzyme class of all cuticle-degrading enzymes like lipases and proteases. These activities were also further validated through enzymatic assays. The results presented here reveal dozens of specific proteins and different processes potentially implicated in cattle tick infection improving the understanding of molecular basis of biocontrol of B. bassiana against R. microplus.

Promoting new concepts of skincare via skinomics and systems biology-From traditional skincare and efficacy-based skincare to precision skincare

Traditional skincare involves the subjective classification of skin into 4 categories (oily, dry, mixed, and neutral) prior to skin treatment. Following the development of noninvasive methods in skin and skin imaging technology, scientists have developed efficacy-based skincare products based on the physiological characteristics of skin under different conditions. Currently, the emergence of skinomics and systems biology has facilitated the development of precision skincare. In this article, the evolution of skincare based on the physiological states of the skin (from traditional skincare and efficacy-based skincare to precision skincare) is described. In doing so, we highlight skinomics and systems biology, with particular emphasis on the importance of skin lipidomics and microbiomes in precision skincare. The emerging trends of precision skincare are anticipated.

Thymus vulgaris alleviates UVB irradiation induced skin damage via inhibition of MAPK/AP-1 and activation of Nrf2-ARE antioxidant system

Solar ultraviolet (UV) radiation-induced reactive oxidative species is mainly responsible for the development of photoageing. Rosmarinic acid was one of the main bioactive components detected in Thymus vulgaris (TV) we extracted. In this study, UVB-induced skin damages have been shown to be ameliorated by treatment with TV in hairless mice (HR-1) skin, demonstrated by decreased matrix metalloproteinases (MMPs) and increased collagen production. However, the underlying molecular mechanism on which TV acted was unclear. We examined the photoprotective effects of TV against UVB and elucidated the molecular mechanism in normal human dermal fibroblasts. Thymus vulgaris remarkably prevented the UVB-induced reactive oxygen species and lactate dehydrogenase. Dose-dependent increase in glutathione, NAD(P)H: quinone oxidoreductase1 and heme oxygenase-1, by TV was confirmed by increased nuclear accumulation of Nrf2. Furthermore, 5-Methoxyindole-2-carboxylic acid was introduced as a specific inhibitor of dihydrolipoyl dehydrogenase (DLD). We demonstrated that Nrf2 expression was regulated by DLD, which was a tricarboxylic acid cycle-associated protein that decreased after UVB exposure. Besides, TV significantly diminished UVB induced phosphorylation of mitogen activated protein kinases pathway, containing extracellular signal-regulated kinase, Jun N-terminal kinase and p38, which consequently reduced phosphorylated c-fos and c-jun. Our results suggest that TV is a potential botanical agent for use against UV radiation-induced oxidative stress mediated skin damages.

Skin aging caused by intrinsic or extrinsic processes characterized with functional proteomics

The skin provides protection against environmental stress. However, intrinsic and extrinsic aging causes significant alteration to skin structure and components, which subsequently impairs molecular characteristics and biochemical processes. Here, we have conducted an immunohistological investigation and established the proteome profiles on nude mice skin to verify the specific responses during aging caused by different factors. Our results showed that UVB-elicited aging results in upregulation of proliferating cell nuclear antigen and strong oxidative damage in DNA, whereas chronological aging abolished epidermal cell growth and increased the expression of caspase-14, as well as protein carbonylation. Network analysis indicated that the programmed skin aging activated the ubiquitin system and triggered obvious downregulation of 14-3-3 sigma, which might accelerate the loss of cell growth capacity. On the other hand, UVB stimulation enhanced inflammation and the risk of skin carcinogenesis. Collectively, functional proteomics could provide large-scale investigation of the potent proteins and molecules that play important roles in skin subjected to both intrinsic and extrinsic aging.

Towards finding the linkage between metabolic and age-related disorders using semantic gene data network analysis

A metabolic disorder (MD) occurs when the metabolic process is disturbed. This process is carried out by thousands of enzymes participating in numerous inter-dependent metabolic pathways. Critical biochemical reactions that involve the processing and transportation of carbohydrates, proteins and lipids are affected in metabolic diseases. Therefore, it is of interest to identify the common pathways of metabolic disorders by building protein-protein interactions (PPI) for network analysis. The molecular network linkages between MD and age related diseases (ARD) are intriguing. Hence, we created networks of protein-protein interactions that are related with MD and ARD using relevant known data in the public domain. The network analysis identified known MD associated proteins and predicted genes and or its products of ARD in common pathways. The genes in the common pathways were isolated from the network and further analyzed for their co-localization and shared domains. Thus, a model hypothesis is proposed using interaction networks that are linked between MD and ARD. This data even if less conclusive finds application in understanding the molecular mechanism of known diseases in relation to observed molecular events