[Thioredoxin-reductase in fibroblasts of human dermis in the process of aging.]

The aim of this work was to examine the content of thioredoxin-reductase in fibroblasts of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of thioredoxin-reductase in age-dependent changes in the number of fibroblasts in the dermis. Thioredoxin-reductase, proliferating cells nuclear antigen (PCNA), marker of fibroblasts vimentin were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for thioredoxin reductase in the dermis is increased from 20 weeks of pregnancy until 20 years old, is not changed from 21 to 60 years old, and is increased again from 61 to 85 years old. Most expressed age related increase in portion of thioredoxin-reductase positive dermal fibroblasts is present form birth until 20 years as compared to antenatal period. General number and percent of PCNA positive fibroblasts in dermis are decreased with age with more expressed changes until 40 years old. Correlation analysis showed that age dependent decrease in the number of fibroblasts and their proliferative activity is significantly associated with increase in thioredoxin-reductase positive fibroblasts in dermis. Results obtained allow to suggest that thioredoxin-reductase plays a role in age dependent decrease in the number of fibroblasts and their proliferation in human dermis.

[Thioredoxin interacting protein in fibroblasts of human dermis in the process of aging.]

The aim of this work was to examine the content of thioredoxin interacting protein in fibroblasts of human dermis from the development until 85 years old, and defining of a role of thioredoxin interacting protein in age-dependent changes in the number of fibroblasts in the dermis. Thioredoxin interacting protein, proliferating cells nuclear antigen (PCNA), marker of fibroblasts vimentin were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for thioredoxin interacting protein in the dermis is increased from 20 weeks of pregnancy until 60 years old followed by a little decrease in age interval 61-85 years old. General number and percent of PCNA positive fibroblasts in dermis are decreased with age with more expressed changes until 40 years old. Correlation analysis showed that age dependent decrease in the number of fibroblasts and their proliferative activity is significantly associated with increase in thioredoxin interacting protein positive fibroblasts in dermis. Results obtained allow to suggest that thioredoxin interacting protein plays a role in age dependent decrease in the number of fibroblasts and their proliferation in human dermis.

[Thioredoxin in fibroblasts of human dermis in the process of aging.]

The aim of this work was to examine the content of thioredoxin in fibroblasts of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of thioredoxin in age-dependent changes in the number of fibroblasts in the dermis. Thioredoxin, proliferating cells nuclear antigen (PCNA), marker of fibroblasts vimentin were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for thioredoxin in the dermis is increased from 20 weeks of pregnancy until 85 years old. Most expressed age related increase in portion of thioredoxin positive dermal fibroblasts (more than 9 times) is present form birth until 20 years as compared to antenatal period. General number and percent of PCNA positive fibroblasts in dermis are decreased with age with more expressed changes until 40 years old. Correlation analysis showed that age dependent decrease in the number of fibroblasts and their proliferative activity is significantly associated with increase in thioredoxin positive fibroblasts in dermis. Results allow to suggest that thioredoxin play a role in age dependent decrease in the number of fibroblasts and their proliferation in human dermis.

[Changes in the number of p23-positive fibroblasts in human dermis with aging.]

The aim of this work was to examine the content of p23 in fibroblasts of human dermis from 20 weeks of pregnancy until 85 years old, and defining of a role of p23 in age-dependent changes in the number and proliferation of fibroblasts in the dermis. p23, proliferating cells nuclear antigen (PCNA), fibroblasts marker vimentin were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for p23 in the dermis is gradually increased from 20 weeks of pregnancy until 85 years old. Age-related increase in a portion of fibroblasts with positive staining for p23 is significantly correlated with an age-related decrease in total number and percent of PCNA positive fibroblasts in human dermis. Age-related increase in the content of p23 in fibroblasts is involved in an age-dependent decrease in their total number and proliferation in the dermis.

[Aryl hydrocarbon receptor interacting protein (AIP) in human dermis during aging.]

The aim of this work was to examine the content of aryl hydrocarbon receptor interacting protein (AIP) in fibroblasts of human dermis from 20 weeks of pregnancy until 85 years old, and defining of a role of AIP in age-dependent changes in the number of fibroblasts in the dermis. AIP, proliferating cells nuclear antigen (PCNA) were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for AIP in the dermis is gradually increased from 20 weeks of pregnancy until 85 years old. A total number and percent of PCNA positive fibroblasts in dermis decreased with progression of age. Most sufficient age-dependent reduction in a total and PCNA positive number of dermal fibroblast was observed from antenatal until 40 years of life. Correlation analysis showed that both age-dependent decrease in the number of fibroblasts and retardation of their proliferation are significantly associated with age-related increase in the number of AIP positive fibroblasts in dermis. Results allow to suggest that AIP is involved in age-dependent decrease in the number and proliferation of fibroblasts in human dermis.

[Heat shock protein 90 (HSP90) in age-dependent changes in the number of fibroblasts in human skin.]

The aim of this work was to examine the content of heat shock protein 90 (HSP90) in fibroblasts of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of HSP90 in age-dependent changes in the number of fibroblasts in the dermis. HSP90, proliferating cells nuclear antigen (PCNA) were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for HSP90 in the dermis is not changed from 20 weeks of development to 20 years old. Percent of HSP90 positive fibroblasts in dermis is decreased from 21 to 60 years old. From 61 year, the number of HSP90 positive fibroblasts in dermis is increased. Age-related changes in the number of HSP90 positive fibroblasts is not statistically associated with an age-related decrease in a total number and percent of PCNA positive fibroblasts the dermis.

[Arylhydrocarbon receptor nuclear translocator (ARNT) in human skin during aging.]

The aim of this work was to examine the content of arylhydrocarbon receptor nuclear translocator (ARNT) in fibroblasts of human dermis from 20 weeks of pregnancy until 85 years old, and defining of a role of ARNT in age-dependent changes in the number of fibroblasts in the dermis. ARNT, proliferating cells nuclear antigen (PCNA) were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for ARNT in the dermis is decreased from 20 weeks of pregnancy to 40 years old. Percent of ARNT positive fibroblasts in dermis is increased sufficiently since 41 year old until 60-85 years old group. A total number and percent of PCNA positive fibroblasts in dermis decreased with progression of age. Most sufficient age-dependent reduction in a total and PCNA positive number of dermal fibroblast was observed from antenatal until 40 years of life. Age-related changes in the content of ARNT in fibroblasts is not associated with an age-related decrease in total number and percent of PCNA positive fibroblasts the dermis.

[Role of mechanosensitive protein Piezo1 in human age-dependent changes in the number of fibroblasts and blood vessels in human skin.]

The aim of this work was to examine the content of Piezo1 in fibroblasts and blood vessels of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of Piezo1 in age-dependent changes in the number of fibroblasts and blood vessels in the dermis. Piezo1, proliferating cells nuclear antigen (PCNA), endothelial cells marker CD31 were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for Piezo1 in the dermis is decreased from 20 weeks of pregnancy to 40 years old. Percent of Piezo1 positive fibroblasts in dermis is increased sufficiently since 41 years old until 60-85 years old group. The content of Piezo1 in blood vessels in the human dermis is decreased sufficiently from 20 weeks of pregnancy until 40 years old. Age-related changes in the content of Piezo1 in fibroblasts and blood vessels is not associated with an age-related decrease in total number and percent of PCNA positive fibroblasts, the number of blood vessels in the dermis.

[Transforming growth factor-ß (TGF-ß) in human skin in the process of aging.]

The aim of this work was to examine the content of transforming growth factor-ß (TGF-ß) in fibroblasts and blood microvessels of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of TGF-ß in age-dependent changes in the number of fibroblasts and blood microvessels in the dermis. TGF-ß, proliferating cells nuclear antigen (PCNA), endothelial cells marker CD 31 were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for TGF-ß in the dermis is increased from 20 weeks of pregnancy until 85 years old. More expressed growth in percent of TGF-ß positive fibroblasts in the human dermis is observed after birth and after 40 years old. The content of TGF-ß in blood microvessels in the human dermis is decreased sufficiently from 41 years old. Age-related increase in a portion of fibroblasts with positive staining on TGF-ß is associated with an age-related decrease in total number and percent of PCNA positive fibroblasts in human dermis. Age-related decrease in the content of TGF-ß in blood microvessels is accompanied with an age-related decrease in their number in the dermis. Age-related increase in the content of TGF-ß in fibroblasts is involved in an age-dependent decrease in their total number and proliferation in the dermis. Age-related decrease in the content of TGF-ß in blood microvessels in dermis takes part in the age-related diminishing of blood microvessels number in the dermis.

[Mechanosensitive Yes-associated protein in human skin during aging.]

The aim of this work was to examine the content of Yes-associated protein (YAP) in fibroblasts and blood microvessels of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of YAP in age-dependent changes in the number of fibroblasts and blood microvessels in the dermis. YAP, proliferating cells nuclear antigen (PCNA), endothelial cells marker CD31 were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for YAP in the dermis is decreased from 20 weeks of pregnancy to 40 years old. Percent of YAP positive fibroblasts in dermis is increased sufficiently since 41 years old until 60-85 years old group. The content of YAP in blood microvessels in the human dermis is decreased sufficiently from 20 weeks of pregnancy until 40 years old. Age-related changes in the content of YAP in fibroblasts and blood microvessels is not statistically associated with an age-related decrease in total number and percent of PCNA positive fibroblasts, the number of blood vessels in the dermis.

[Mechanosensitive protein of Hippo regulatory pathway - transcription coactivator with PZD-binding motif (TAZ) in human skin during aging.]

The aim of this work was to examine the content of transcription coactivator with PZD-binding motif (TAZ) in fibroblasts and blood vessels of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of TAZ in age-dependent changes in the number of fibroblasts and blood vessels in the dermis. TAZ, proliferating cells nuclear antigen (PCNA), endothelial cells marker CD31 were detected with indirect immunohistochemical technique. Results showed that portion of fibroblasts with positive staining for TAZ in the dermis is decreased from 20 weeks of pregnancy to 40 years old. Percent of TAZ positive fibroblasts in dermis is increased since 41 years old until 60-85 years old group. The content of TAZ in blood vessels in the human dermis is decreased sufficiently from 20 weeks of pregnancy until 40 years old followed by an increase from 41 years old. From 61 to 85 years of life, content of TAZ in dermal vessels was not differ from those in 41-60 age group. Age-related changes in the content of TAZ in fibroblasts and blood vessels is not associated with an age-related decrease in total number and percent of PCNA positive fibroblasts, the number of blood vessels in the dermis.

Number, Proliferative Activity, and Expression of Thyroid Hormone Receptors in Dermal Fibroblasts in Mice with Changed Thyroid Status.

We studied the intensity of age-specific changes in the dermis (number and proliferative activity of fibroblasts) in mice with normal and experimentally changed level of thyroid hormones. Receptors of thyroid hormones, TR-α and TR-ß, in mouse dermal fibroblasts were identified by immunohistochemical methods. The relative expression of Thra, Thrb, and Dio2 genes was assessed by real-time PCR analysis. From the second to fifth month of life, the number of fibroblasts in the connective tissue layer of mouse skin decreased by 42.3%. The number of fibroblasts in the dermis of 5-month-old mice treated with Thyrozol significantly decreases by 25.9% (p<0.05), and vice versa, in mice receiving thyroxin this parameter increased by 4.7% in comparison with the control (p>0.05). TR-α and TR-ß were identified in dermal fibroblasts in all groups of mice. No differences in the content TR-α and Thra gene expression in 2- and 5-month-old mice of the control and experimental were revealed. TR-ß content in dermal fibroblasts of 2-month-old animals was maximum and exceeded this value in 5-month-old control mice by 25%. The number of these receptors decreased by 33.3% in mice treated with Thyrozol and increased by 25% in animals receiving thyroxin injection in comparison with the control. Relative expression of Thrb gene significantly increased only in mice treated with thyroxin. Comparative analysis of the relative expression of Dio2 gene revealed no differences between the experimental and control groups. Changes in the level of thyroid hormones, content of TR-ß, and relative Thrb gene expression contribute to agerelated shifts in the number and proliferative activity of mouse dermal fibroblasts.

[Thyroid hormone receptors in human skin during aging.]

This work was aimed to study levels of thyroid hormone receptors in human dermal fibroblasts from the development to deep aging. Skin specimens from human fetuses died antenatally from 20 to 40 weeks of pregnancy, humans died from different causes from birth to 85 years of life were used for the study. Total number of fibroblasts, percent of proliferating cells nuclear antigen (PCNA) positive dermal fibroblasts, expression of thyroid hormone receptors-α and -ß in dermal fibroblasts were examined. PCNA and thyroid hormone receptors were viewed immunohistochemically. A total number of fibroblasts in dermis were counting in sections stained with haematoxylin and eosin. Results showed that maximal levels of thyroid hormone receptors-α and -ß were observed from 20 to 40 weeks of pregnancy. The levels of thyroid hormone receptors-α and -ß were decreased from birth to 40 years of life. From 41 to 85 years, the levels of thyroid hormone receptors were approximately the same. A total number and percent of PCNA positive fibroblasts in dermis decreased with progression of age. Most sufficient age-dependent reduction in a total and PCNA positive number of dermal fibroblast was observed from antenatal until 40 years of life. Correlation analysis and one-way ANOVA showed that age-dependent decrease in the number of fibroblasts and retardation of their proliferation in human dermis is significantly associated with age-related decrease in the level of thyroid hormone receptors-α and -ß in dermal fibroblasts. Results allow to suggest that thyroid hormone receptors are involved in age-dependent decrease in the number and proliferation of fibroblasts in human dermis.

[The influence of metformin on age-related changes in the number and proliferation of dermal fibroblasts in mice.]

The goal of our work was to examine the effects of metformin on age-related changes in the number and proliferation of dermal fibroblasts in mice. The study of the dermis was carried out at five months' mice that received drinking water with metformin at concentrations 500 mg/l from two months (within 90 days). Five months' mice received drinking water without metformin and they were as a control. Material of two months' mice was also used in the work. We counted the total number of dermal fibroblasts and lobe of fibroblasts with positive coloration on Ki-67. The results showed that there has been a decrease in the total number of dermal fibroblasts by 42,3% from two months of mouse's life up to five months and lobe of fibroblasts with positive coloration on Ki-67 by 12%. The total number of dermal fibroblasts in five months' mice was lower for 13,4%by using metformin. The lobe of fibroblasts with positive coloration on Ki-67 was reduced by 27,3% in comparison with information of animals that have not received metformin. Thus, age-related reduction of dermal fibroblasts in mice is due to decline in their proliferative activity. Metformin has an inhibited impact on proliferation of dermal fibroblasts in mice.

[Age-related changes in the expression of lamin B receptors in fibroblasts of human dermis].

The aim of this work was to study lamin B receptors in human skin at different ages. Lamin B receptors, proliferating cells nuclear antigen (PCNA) were detected in sections of the skin by indirect immunohistochemistry. Our results showed that both portion of dermal fibroblasts with positive staining for lamin B receptors and intensity of staining of fibroblasts for lamin B receptors were maximal from birth to 20 years as compared to all other examined age-periods (from 20 weeks of pregnancy to 85 years old). General number of fibroblasts and number of fibroblasts with positive staining for PCNA in dermis were diminished with age. The most significant decrease in the number of fibroblasts and PCNA positive fibroblasts were observed from 20 years old. An increase in the level of lamin B receptors in dermal fibroblasts observed from birth to 20 years old may be regarded as one of start events leading to age-dependent decrease in the number of fibroblasts in human dermis.

[Age-related changes in the content of sirtuin 1 in fibroblasts of human dermis].

The goal of our work was to examine content of sirtuin 1 in human skin at different ages to uncover a role of sirtuin 1 in aging of human skin. Sirtuin 1, proliferating cells nuclear antigen (PCNA) were detected by indirect immunohistochemistry in sections of the skin of human fetuses died antenatally from 22 to 40 weeks of pregnancy and humans from birth to 85 years old, died from various causes. Our results showed that the level of sirtuin 1 in dermal fibroblasts was decreased from prenatal period to 85 years old. Both the number of fibroblasts and their proliferative activity were also decreased through life. Age-related decrease in sirtuin 1 content in dermal fibroblasts is statistically significant correlated with age-dependent decrease in proliferation. Therefore, lowering of sirtuin 1 content in dermal fibroblasts occurring with age can be regarded as a mechanism which leads to inhibition of proliferation of dermal fibroblasts.

[Age-related changes in the content of serine-arginine protein kinase 1 (SRPK1) in human dermis.]

The aim of our work was to examine content of serine-arginine protein kinase 1 (SRPK1) in human dermis at different ages (from 20 weeks of pregnancy to 85 years old). SRPK1, proliferating cells nuclear antigen (PCNA ), endothelial marker CD31 were detected in sections of the skin by indirect immunohistochemistry. Results showed, that content of SRPK1 in dermal fibroblasts was increased form antenatal period to 20 years of life followed by a decrease until 61-85 years period. SRPK1 content in dermal blood vessels is slowly gradually increased from antenatal period to 61-85 age interval. The number of fibroblasts and their proliferative activity, the number of CD31 positive blood vessels in dermis were decreased from antenatal period to 61-85 years period of life. Age-dependent decrease in SRPK1 in dermal fibroblasts from 20 years is associated with a reduction in the number and proliferative activity of fibroblasts. Age-related increase in SRPK1 content in dermal blood vessels is associated with a diminishing of the number of blood vessels. Hence, it can be supposed that SRPK1 has different actions on proliferation of differ components of dermis during aging.

[Lamin B1 and lamin B2 in human skin in the process of aging].

The aim of this work was to study B type lamins in human skin at different ages. Lamins B1 and B2 were detected in sections of the skin by indirect immunohistochemistry. There were 62,3 % of dermal fibroblasts with positive staining for lamin B1 at the period from 20 to 40 weeks of gestation. From birth to 40 years, 41-42 % of fibroblasts containing lamin B1 were found in the dermis. In age interval from 41 to 85 years, 57-60 % of dermal fibroblasts had a positive staining for lamin B1. The number of fibroblasts containing lamin B2 was gradually decreased from 80,6 to 68,6 % from 20 weeks of gestation to 85 years old. Expression of lamin B1 in the nuclei of fibroblasts was reduced from birth to 40 years old. Content of lamin B2 in the nuclei of fibroblasts was almost constant from 20 weeks of gestation to 85 years old. Number of fibroblasts in dermis was diminished with age. The most significant decrease in the number of fibroblasts was observed from 20 weeks of gestation to 20 years old. Results allow to suggest the participation of lamin B1 in triggering age-dependent decrease in the number of fibroblasts in the dermis in humans.

Lamin A and lamin-associated polypeptide 2 (LAP-2) in human skin in the process of aging.

At present time, relationships between lamins and processes leading to aging are established. Mutations of genes of lamins lead to diseases, one of them is progeria. This disease is caused by violation of splaysing of lamin A gene and accumulation the farnezylated prelamin A (progerin) in the nucleus. LAP-2 is an important factor which regulates and stabilizes the lamin A. However, roles of lamin A and LAP-2 in behavior of population of dermal fibroblasts in relation to age were not examined. The aim of this research was to study A type lamin and LAP-2 in human skin at different ages. Lamin A and LAP-2 were detected in sections of the skin by indirect immunohistochemistry. The number of fibroblasts containing lamin A was gradually decreased from 90,4 to 76,9 % from 20 weeks of gestation to 85 years old. There were 32 % of dermal fibroblasts with positive staining for LAP-2 at the period from 20 weeks of gestation to 20 years old. From 21 to 40 years, 37,8 % of fibroblasts containing lamin A were found in the dermis. In age interval 41-85 years, 49-51 % of dermal fibroblasts had a positive staining for LAP-2. Content of lamin A in the nuclei of fibroblasts was almost constant from 20 weeks of gestation to 85 years old. Expression of LAP-2 in the nuclei of fibroblasts was reduced from birth to 20 years old but increased from 21 years old. Number of fibroblasts and PCNA+ fibroblasts in dermis was diminished with age. The most significant decrease in the number of fibroblasts was observed from 20 weeks of gestation to 20 years old. Results allow to assume the participation of lamin A and LAP-2 in triggering age-dependent decrease in the number of fibroblasts in the dermis in humans.

[CHANGES OF THE CONTENT OF DLL4 AND Jag-1 ANGIOGENESIS REGULATORS IN HUMAN DERMIS IN ONTOGENESIS].

The goal of this study was to examine the contents of D114 and Jag-1 angiogenesis regulators in human dermis at different age periods. D114 and Jag-1 were demonstrated by indirect immunohistochemistry in skin sections of fetuses of 20-40 gestational weeks and in persons aged from birth to 85 years. D114 was studied in 150 skin samples of 72 females and 78 males, while Jag-1 was examined in 120 samples of 58 females and 62 males. It is found that the immunoreactivity was mainly expressed by the endothelial cells. Vessels, which gave a positive reaction to D114 and Jag-1, were found throughout the entire thickness of the dermis, both in fetuses, and people of all age groups. Expression of D114 in the vessels of dermal microvasculature was shown to increase from 20 weeks of gestation to 20 years. With the further age increase, the intensity of the reaction of blood vessels for D114 was decreased. Expression of Jag-1 in dermal microvessels was enhanced from 20 weeks of gestation to 85 years. The results are discussed in connection with the role of D114 and Jag-1 in angiogenesis in human dermis during ontogeny.