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Basic Thermal Physiology: What Processes Lead to the Temperature Distribution on the Skin Surface
Published in Kurt Ammer, Francis Ring, The Thermal Human Body, 2019
Sweat from eccrine and apocrine glands differ in composition. Water accounts to 99% of eccrine sweat. Further components are sodium, chloride, potassium, calcium, magnesium, lactate, ammonia, amino acids, urea and bicarbonate. In addition, several proteins and peptides have been identified including the antimicrobial peptide dermcidin [79].
Angiogenesis and Roles of Adhesion Molecules in Psoriatic Disease
Published in Siba P. Raychaudhuri, Smriti K. Raychaudhuri, Debasis Bagchi, Psoriasis and Psoriatic Arthritis, 2017
Asmita Hazra, Saptarshi Mandal
In contrast to the cationic antimicrobials above, dermicidin (DCD) is an anionic antimicrobial protein secreted by eccrine sweat glands, and it is also a skeletal muscle myokine. It is secreted as a 110-amino-acid precursor whose first 30 amino acids may be cleaved into Y-P30. Although DCD expression is constitutive in eccrine sweat glands and is not supposedly increased in inflammatory conditions like psoriasis, DCD is known to be upregulated in chronic wounds. Y-P30 multimerizes with pleiotrophin and binds to syndecan 2 and 3. The survival-promoting peptide Y-P30 has neurite outgrowth-promoting effects in vitro and is known to also be expressed in placenta—a highly angiogenic organ. DCD and its 526 bp splice variant DCD-SV, coding for a 12.1 kDa protein with a different C-terminus without the hydrophobic coiled-coil structure (amino acids 80–103), are thought to be essential for the antibacterial function, and are involved in the aggressiveness of breast carcinoma through ERB-B signaling. Downregulation of DCD resulted in decreased levels of several genes involved in oxidative stress, hypoxia, and angiogenesis, including disulfide isomerase–associated 3, 4, and 6 (PDIA); the stress 70 kDa protein chaperone (STCH); the heat shock 70 kDa protein 5 (GRP78); hypoxia-inducible gene 2 protein (HIG2), and VEGFA and B.
Pathophysiology of Atopic Dermatitis and Atopiform Dermatitis
Published in Donald Rudikoff, Steven R. Cohen, Noah Scheinfeld, Atopic Dermatitis and Eczematous Disorders, 2014
Antimicrobial peptides (AMPs) are low-molecular-weight, primarily cationic proteins produced by keratinocytes that function as endogenous antibiotics active against bacteria, viruses, and fungi, and which directly modulate certain immune functions (Howell 2007). The two main classes of AMPs in skin are the β-defensins and canthelicidins. In human skin there are four known defensins, human β-defensins (HBDs) 1, 2, 3, and 4, and one canthelicidin LL-37. Dermicidin is an AMP present in sweat. Under normal circumstances, keratinocytes produce AMPs that inhibit the growth of pathogenic bacteria, fungi, and viruses on the skin surface.
Bio-chemical markers of chronic, non-infectious disease in the human tear film
Published in Clinical and Experimental Optometry, 2022
Sultan Alotaibi, Maria Markoulli, Jerome Ozkan, Eric Papas
Using microcapillary tubes to collect (presumably) basal secretions, the total protein content in the tears of patients with Alzheimer’s disease has been found to increase and several proteins were differentially expressed relative to normals.102 Thus, lipocalin-1, lactotransferrin, extracellular glycoprotein lacritin, lysozyme-C and prolactin inducible protein all decreased, while there was a marked increase in dermcidin. All the upregulated proteins are produced in the lacrimal gland, while dermcidin is an antimicrobial peptide, secreted by sweat glands, with a role in the immune system.103 Based on ROC analysis, combining the responses of lipocalin-1, dermcidin, lysozyme-C and extracellular glycoprotein lacritin would have 81% sensitivity and 77% specificity for diagnosing Alzheimer’s disease.102
The clinical implications of the microbiome in the development of allergy diseases
Published in Expert Review of Clinical Immunology, 2021
Atopic dermatitis (AD) is a chronic inflammatory skin disease of complex origin. Genetics, a disrupted skin barrier, a type 2 biased immune response, and skin dysbiosis contribute to the development and severity of the disease. The prevalence in Western countries is increasing and especially infants and children are affected [87,88]. The skin of patients with atopic dermatitis differs from those of healthy persons with altered physical, chemical, and defense properties. Antimicrobial peptides such as the cathelicidin LL-37, β-defensins, and dermicidin are released in lower amounts in AD skin reducing the defense against microbes and altering the microbial colonization. In patients with AD, loss of microbial diversity correlates with the severity of symptoms. Atopic dermatitis patients typically show high colonization with Staphylococcus aureus, especially in lesional skin areas compared to nonlesional skin or skin from healthy controls. S. aureus numbers are significantly increased in atopic dermatitis patients compared to healthy controls. S. aureus of atopic dermatitis patients displays better adhesion properties, mechanisms to disrupt the skin barrier, and induces a proinflammatory environment [46,47,89]. S. aureus produces numerous toxins and superantigens, which are associated with T cell stimulations and expansion as well as cytokine production. The role of Staphylococcus epidermidis in AD is not fully clear and was found to be associated with less severe disease course [90]. S. epidermidis and S. hominis are coagulase-negative Staphylococcus (CoNS) species that can produce antimicrobial peptides specifically targeting and eliminating S. aureus. CoNS strains with antimicrobial activity against S. aureus were found to be decreased in AD patients compared to healthy controls [91]. Thus, local modification of microbial composition by topical probiotics might have an enormous potential for mitigating the skin disease. While S. hominis with antimicrobial activity reduced the number of previously applied S. aureus on pig skin or on the back of mice, S. hominis without antimicrobial activity showed no effect. In a small study with human atopic dermatitis patients, a single application of S. hominis significantly reduced S. aureus numbers [91]. Nevertheless, also other probiotic strains such as S. thermophiles, V. filiformis, S. epidermidis and L. johnsonii exert beneficial effects on AD disease course [90,92].
Molecular docking study on europium nanoparticles and mussel adhesive protein for effective detection of latent fingerprints
Published in Biomarkers, 2023
T. R. Poorani, C. Ramya, Ramya Manohar
The next interaction was done with dermcidin and metal conjugate. The active binding site of the metal nanoparticle protein conjugate with dermcidin was found to be at (Leu) 274, (Asn) 277, (Phe) 278, (Asp) 281, (Phe) 422, (Asp) 423, (Leu) 425, (Ser) 426, (Gly) 17, (Lys) 20, (Leu) 21 by CASTp server. From the output of the docking analysis, the binding energy of the dermcidin with the metal conjugate and europium nanoparticle conjugates were found to be − 6.49 kcal/mol and −16.76 kcal/mol respectively, which was a very high affinity when compared to previous interaction with calmodulin residue. With this binding affinity, the pKi value was calculated and found to be 4.777 kcal/mol/non-H atom for europium oxide and 11.771 kcal/mol/non-H atom for europium nanoparticle. Further, the bond strength was identified by the van dar Waals interaction between the conjugate and the dermcidin protein, which was determined to be −16.51 kcal/mol for europium oxide conjugate and − 23.17 kcal/mol for europium nanoparticle conjugate. Then this dermcidin protein has three chains A, B and C as depicted in Figure 12. Among these chains, the interaction with metal conjugate was formed by chains A and B, whereas the eunp conjugate formed interactions with all the three chains as demonstrated in Figure 13. Further chain A of dermcidin forms 2 salt bridges and chain B forms 1 salt bridge for metal conjugate and chain A forms 4 salt bridges with the europium nanoparticle conjugate. This interaction includes 5 hydrogen bonds formed with metal conjugate, where 4 hydrogen bonds were formed by chain A residues that include, His 38, Gly 33, Asp 28, Gly 22 and 1 hydrogen bond was formed at Asp 45 of the chain B in dermcidin protein. In addition to that the europium nanoparticle formed 39 hydrogen bonds with chain A which includes Asp 50, Phe 87, Thr 88, Thr 89, Val 90, Ala 53, Gln 52, Asp 54, Asp 85, Ile 55, Ile 56, Lys 81, Gln 74, Val 57, Leu 58, Ser 86, Lys 77, Phe 59, Asp 60, Asp 61, Ser 63, Tyr 73. The interactions between the conjugate and the protein molecule were found to be higher in the hydrophobic pockets. Those hydrophobic interactions were formed by the following amino acids of dermcidin protein. Those amino acids are Val 37, Leu 44, Ala 36, Val 43, Leu 29, Val 26, Ala 25, Leu 21, Leu 18, Val 32 of chain A and Val 37, Leu 48, Leu 44 of chain B. The interactions were schematically represented in Figure 14 representing their bonding nature. Then the conjugate formed certain non-bonded contacts with 510 and 410 amino acids of Dermcidin with Eu2O3 conjugate and eunp conjugate. The interface statistics of Eu2O3-MAP and Eunp: MAP conjugates with dermcidin are listed in Table 4.