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Mojumdar, Enamul Haque
Publications (3 of 3) Show all publications
Labecka, N., Szczepanczyk, M., Mojumdar, E. H., Sparr, E. & Björklund, S. (2024). Unraveling UVB effects: Catalase activity and molecular alterations in the stratum corneum.. Journal of Colloid and Interface Science, 666, 176-188, Article ID S0021-9797(24)00709-4.
Open this publication in new window or tab >>Unraveling UVB effects: Catalase activity and molecular alterations in the stratum corneum.
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2024 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 666, p. 176-188, article id S0021-9797(24)00709-4Article in journal (Refereed) Published
Abstract [en]

AIM: Ultraviolet B (UVB) radiation can compromise the functionality of the skin barrier through various mechanisms. We hypothesize that UVB induce photochemical alterations in the components of the outermost layer of the skin, known as the stratum corneum (SC), and modulate its antioxidative defense mechanisms. Catalase is a well-known antioxidative enzyme found in the SC where it acts to scavenge reactive oxygen species. However, a detailed characterization of acute UVB exposure on the activity of native catalase in the SC is lacking. Moreover, the effects of UVB irradiation on the molecular dynamics and organization of the SC keratin and lipid components remain unclear. Thus, the aim of this work is to characterize consequences of UVB exposure on the structural and antioxidative properties of catalase, as well as on the molecular and global properties of the SC matrix surrounding the enzyme.

EXPERIMENTS: The effect of UVB irradiation on the catalase function is investigated by chronoamperometry with a skin covered oxygen electrode, which probes the activity of native catalase in the SC matrix. Circular dichroism is used to explore changes of the catalase secondary structure, and gel electrophoresis is used to detect fragmentation of the enzyme following the UVB exposure. UVB induced alterations of the SC molecular dynamics and structural features of the SC barrier, as well as its water sorption behavior, are investigated by a complementary set of techniques, including natural abundance 13C polarization transfer solid-state NMR, wide-angle X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and dynamic vapor sorption microbalance.

FINDINGS: The findings show that UVB exposure impairs the antioxidative function of catalase by deactivating both native catalase in the SC matrix and lyophilized catalase. However, UVB radiation does not alter the secondary structure of the catalase nor induce any observable enzyme fragmentation, which otherwise could explain deactivation of its function. NMR measurements on SC samples show a subtle increase in the molecular mobility of the terminal segments of the SC lipids, accompanied by a decrease in the mobility of lipid chain trans-gauche conformers after high doses of UVB exposure. At the same time, the NMR data suggest increased rigidity of the polypeptide backbone of the keratin filaments, while the molecular mobility of amino acid residues in random coil domains of keratin remain unaffected by UVB irradiation. The FTIR data show a consistent decrease in absorbance associated with lipid bond vibrations, relative to the main protein bands. Collectively, the NMR and FTIR data suggest a small modification in the composition of fluid and solid phases of the SC lipid and protein components after UVB exposure, unrelated to the hydration capacity of the SC tissue. To conclude, UVB deactivation of catalase is anticipated to elevate oxidative stress of the SC, which, when coupled with subtle changes in the molecular characteristics of the SC, may compromise the overall skin health and elevate the likelihood of developing skin disorders.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Catalase, Keratin filaments, Lipid multilamellar matrix, Oxidative stress, Stratum corneum, UVB, Ultraviolet radiation
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-66988 (URN)10.1016/j.jcis.2024.03.200 (DOI)38593652 (PubMedID)2-s2.0-85189861942 (Scopus ID)
Available from: 2024-04-26 Created: 2024-04-26 Last updated: 2024-04-26Bibliographically approved
Gunnarsson, M., Mojumdar, E. H., Topgaard, D. & Sparr, E. (2021). Extraction of natural moisturizing factor from the stratum corneum and its implication on skin molecular mobility. Journal of Colloid and Interface Science, 604, 480-491, Article ID S0021-9797(21)01070-5.
Open this publication in new window or tab >>Extraction of natural moisturizing factor from the stratum corneum and its implication on skin molecular mobility
2021 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 604, p. 480-491, article id S0021-9797(21)01070-5Article in journal (Refereed) Published
Abstract [en]

The natural moisturizing factor (NMF) is a mixture of small water-soluble compounds present in the upper layer of the skin, stratum corneum (SC). Soaking of SC in water leads to extraction of the NMF molecules, which may influence the SC molecular properties and lead to brittle and dry skin. In this study, we investigate how the molecular dynamics in SC lipid and protein components are affected by the removal of the NMF compounds. We then explore whether the changes in SC components caused by NMF removal can be reversed by a subsequent addition of one single NMF component: urea, pyrrolidone carboxylic acid (PCA) or potassium lactate. Samples of intact SC were investigated using NMR, X-ray diffraction, infrared spectroscopy and sorption microbalance. It is shown that the removal of NMF leads to reduced molecular mobility in keratin filaments and SC lipids compared to untreated SC. When the complex NMF mixture is replaced by one single NMF component, the molecular mobility in both keratin filaments and lipids is regained. From this we propose a general relation between the molecular mobility in SC and the amount of polar solutes which does not appear specific to the precise chemical identify of the NMF compounds.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
ATR-FTIR, NMF, Natural moisturizing factor, SAXD, Solid-state NMR, Stratum corneum, WAXD
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-45028 (URN)10.1016/j.jcis.2021.07.012 (DOI)000705824400007 ()34273783 (PubMedID)2-s2.0-85110022240 (Scopus ID)
Available from: 2021-08-20 Created: 2021-08-20 Last updated: 2024-02-05Bibliographically approved
Mojumdar, E. H., Madsen, L. B., Hansson, H., Taavoniku, I., Kristensen, K., Persson, C., . . . Engblom, J. (2021). Probing Skin Barrier Recovery on Molecular Level Following Acute Wounds: An In Vivo/Ex Vivo Study on Pigs.. Biomedicines, 9(4), Article ID 360.
Open this publication in new window or tab >>Probing Skin Barrier Recovery on Molecular Level Following Acute Wounds: An In Vivo/Ex Vivo Study on Pigs.
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2021 (English)In: Biomedicines, E-ISSN 2227-9059, Vol. 9, no 4, article id 360Article in journal (Refereed) Published
Abstract [en]

Proper skin barrier function is paramount for our survival, and, suffering injury, there is an acute need to restore the lost barrier and prevent development of a chronic wound. We hypothesize that rapid wound closure is more important than immediate perfection of the barrier, whereas specific treatment may facilitate perfection. The aim of the current project was therefore to evaluate the quality of restored tissue down to the molecular level. We used Göttingen minipigs with a multi-technique approach correlating wound healing progression in vivo over three weeks, monitored by classical methods (e.g., histology, trans-epidermal water loss (TEWL), pH) and subsequent physicochemical characterization of barrier recovery (i.e., small and wide-angle X-ray diffraction (SWAXD), polarization transfer solid-state NMR (PTssNMR), dynamic vapor sorption (DVS), Fourier transform infrared (FTIR)), providing a unique insight into molecular aspects of healing. We conclude that although acute wounds sealed within two weeks as expected, molecular investigation of stratum corneum (SC) revealed a poorly developed keratin organization and deviations in lipid lamellae formation. A higher lipid fluidity was also observed in regenerated tissue. This may have been due to incomplete lipid conversion during barrier recovery as glycosphingolipids, normally not present in SC, were indicated by infrared FTIR spectroscopy. Evidently, a molecular approach to skin barrier recovery could be a valuable tool in future development of products targeting wound healing.

Place, publisher, year, edition, pages
MDPI, 2021
Keywords
acute wound, histology, in vivo/ex vivo, lipid, pH, polarization transfer solid state NMR (PTssNMR), skin barrier, small and wide-angle X-ray diffraction (SWAXD), stratum corneum, trans-epidermal water loss (TEWL)
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-41657 (URN)10.3390/biomedicines9040360 (DOI)000642806400001 ()33807251 (PubMedID)2-s2.0-85104499829 (Scopus ID)
Available from: 2021-04-08 Created: 2021-04-08 Last updated: 2024-02-05Bibliographically approved
Projects
Pickering emulsions on skin: Effects of ethanol prior to, during and after application at different ambient conditions; Malmö UniversityWound healing: Importance of endogenous LMW compounds for skin recovery and their use as biomarkers for diagnostic purpose; Malmö University
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