Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dermis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed2000

Decrease in epidermal CD44 expression as a potential mechanism for abnormal hyaluronate accumulation in superficial dermis in lichen sclerosus et atrophicus.

CD44 is a polymorphic integral membrane glycoprotein that serves as the principal cell surface receptor for hyaluronate, the major component of the extracellular matrix. CD44 is abundantly found in the skin and functions as a cell adhesion molecule. In a recent study we have observed a massive dermal accumulation of hyaluronate as a result of the in vivo selective suppression of CD44 in keratinocytes in mice expressing a keratin 5 promoter-driven CD44 anti-sense transgene. As the histologic features of the dorsal skin of these transgenic mice display some similarities to those of the skin lesions of lichen sclerosus et atrophicus, we explored the nature of the material accumulated in the dermis of genital and extragenital lesions of 14 patients with lichen sclerosus et atrophicus by Alcian Blue and human CD44 receptor globulin stainings, as well as the epidermal expression of CD44 protein and mRNA by immunohistochemistry and in situ hybridization. In this study we provide evidence that hyaluronate is accumulated in the superficial dermis of lichen sclerosus et atrophicus lesions, in particular by the use of human CD44 receptor globulin staining, which binds specifically to hyaluronate. In addition we show that the protein and mRNA expression of CD44 in the epidermis of the involved lichen sclerosus et atrophicus skin from genital and extragenital areas is significantly decreased, and in some cases completely lost. In contrast, keratinocyte CD44 expression was un-altered in the skin lesions of lupus erythematosus, scleroderma and reticular erythematous mucinosis, despite the presence of a mucinous material in the dermis. These results suggest that a decrease in CD44 in the keratinocytes may be correlated with an abnormal dermal accumulation of hyaluronate in the lesions of lichen sclerosus et atrophicus, and may play a pathogenetic role in this disease. J Invest Dermatol 115:1054-1058 2000

Adolescent↗
PubMed1999

A new technique of reduction mammaplasty: dermis suspension and elimination of medial scars.

In the last decades new techniques of reduction mammaplasty significantly improved the results obtained and led to a reduced incidence of complications. However, some important problems like the loss of a natural submammary fold and alteration in the shape of the breast with time still remained mostly unsolved and the medial scars in the inverted T techniques are aesthetically unsatisfying. A new strategy for reduction mammaplasty has been developed based on a combination of advantages of other techniques. The principle of using de-epithelialized infra-areolar skin for dermis suspension prevents sagging of the remaining breast tissue behind the inframammary fold to create a long-lasting, natural shape of the reduced breast with an accentuated submammary fold. The central pedicle is favoured because of good modelling even in big reductions. Better vascular and nerve supply of the nipple-areola complex and the continuity of the lactiferous ducts are further advantages of the central pedicle. Secondary operations after reduction mammaplasty or augmentation usually dictate the use of a superior pedicle together with the dermis suspension technique. B-shaped skin incisions prevent medial submammary scars and can be used up to a 10 cm transposition distance of the nipple without disadvantage. The operative technique is described in detail. Examples are given for the primary procedure and the technique as a secondary correction. The principle of dermis suspension in combination with the prevention of a medial scar is applicable to reduction mammaplasty as well as mastopexy.

Adult↗
PubMed1996

The use of artificial dermis on the donor defect of the free forearm flap.

Microsurgical grafting of a free flap is an established technique of surgical reconstruction. The forearm free flap is frequently used following removal of oral and/or pharyngeal tumors. However, simple split-thickness skin grafting on full-thickness defects of the skin on the flexor side of the forearm results in deformations, pigmentation, and the adhesion of the graft to the tendons. The authors attempted to minimize such problems by repairing the flap donor site with a collagen sponge used as an artificial dermis. This artificial dermis was used to reconstruct postoperative defects in the skin of 5 patients. Split-thickness skin measuring 0.25 to 0.30 mm was grafted onto the defect. The donor site skin was successfully repaired in 2 to 3 weeks without adverse effects, without the development of depressed deformations, and with only slight pigmentation. The artificial dermis formed a matrix on the donor wound bed, with good cosmetic results.

Adolescent↗
PubMed2005

High throughput quantitative glycomics and glycoform-focused proteomics of murine dermis and epidermis.

Despite recent advances in our understanding of the significance of the protein glycosylation, the throughput of protein glycosylation analysis is still too low to be applied to the exhaustive glycoproteomic analysis. Aiming to elucidate the N-glycosylation of murine epidermis and dermis glycoproteins, here we used a novel approach for focused proteomics. A gross N-glycan profiling (glycomics) of epidermis and dermis was first elucidated both qualitatively and quantitatively upon N-glycan derivatization with novel, stable isotope-coded derivatization reagents followed by MALDI-TOF(/TOF) analysis. This analysis revealed distinct features of the N-glycosylation profile of epidermis and dermis for the first time. A high abundance of high mannose type oligosaccharides was found to be characteristic of murine epidermis glycoproteins. Based on this observation, we performed high mannose type glycoform-focused proteomics by direct tryptic digestion of protein mixtures and affinity enrichment. We identified 15 glycoproteins with 19 N-glycosylation sites that carry high mannose type glycans by off-line LC-MALDI-TOF/TOF mass spectrometry. Moreover the relative quantity of microheterogeneity of different glycoforms present at each N-glycan binding site was determined. Glycoproteins identified were often contained in lysosomes (e.g. cathepsin L and gamma-glutamyl hydrolase), lamellar granules (e.g. glucosylceramidase and cathepsin D), and desmosomes (e.g. desmocollin 1, desmocollin 3, and desmoglein). Lamellar granules are organelles found in the terminally differentiating cells of keratinizing epithelia, and desmosomes are intercellular junctions in vertebrate epithelial cells, thus indicating that N-glycosylation of tissue-specific glycoproteins may contribute to increase the relative proportion of high mannose glycans. The striking roles of lysosomal enzymes in epidermis during lipid remodeling and desquamation may also reflect the observed high abundance of high mannose glycans.

Amino Acid Sequence↗
PubMed1984

Effects of 12-O-tetradecanoylphorbol-13-acetate on the incorporation of labelled precursors into RNA, DNA and protein in epidermis, dermis and subcutis from precancerous mouse skin with reference to enhanced tumorigenesis.

The effects of a single application of 1.8 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) on precursor incorporation into RNA, DNA and protein in the epidermis, dermis and subcutis from 3-methylcholanthrene (MCA) injected precancerous mouse skin were studied at various time points between 3 and 96 h. In the precancerous tissues, the rates of incorporation of [3H]uridine into RNA did not alter appreciably from those in the control tissues; while the rates of [3H]methylthymidine incorporation into DNA were elevated with peaks appearing between 6 and 12 h, at 24 h and at 72 h in epidermis, dermis and subcutis. The rate of incorporation of [14C]leucine into protein was markedly elevated in all the three tissues which showed 3-4 sharp peaks. The maximum stimulation ranged between 14 and 20 times that of the control. A single application of TPA to the precancerous mouse skin induced early stimulation of precursor incorporation into all the three macromolecules in epidermis, dermis and subcutis. The increased stimulation was maintained for 36-72 h. The patterns of incorporation of [3H]methylthymidine into DNA gave rise to 2-3 peaks of elevated uptake in each tissue up to 36-48 h. A lowered rate of DNA synthesis between 48 and 60 h was followed by a peak at 72 h. In each group, epidermal mitotic activity correlated well with spurts of precursor incorporation into cellular DNA. The observations indicate that TPA recruits more cells into the DNA synthetic phase and accelerates selective growth of preneoplastic cells during tumor progression.

Animals↗
PubMed1985

32P-postlabeling analysis of DNA adducts persisting for up to 42 weeks in the skin, epidermis and dermis of mice treated topically with 7,12-dimethylbenz[a]anthracene.

The initial and persistent levels of 7,12-dimethylbenz[a]-anthracene (DMBA)-DNA adducts in mouse skin, epidermis and dermis after topical carcinogen application were studied by 32P-postlabeling assay. In the major experiment, a single dose of 1.2 mumol of the carcinogen was applied to the shaved backs of adult female BALB/cANN mice, and DNA was isolated from epidermis and dermis, respectively, 24 h and 1, 2, 3, 4, 8, 16, 24, 36 and 42 weeks later. Total binding at 24 h was approximately 34 and approximately 28 adducts in 10(7) normal nucleotides for epidermal and dermal DNA, respectively. (One adduct in 10(7) nucleotides equals 0.3 fmol adduct/microgram DNA.) While initial binding was higher in epidermal DNA, the adducts were approximately 10 times more persistent in dermal DNA: at 42 weeks, total binding levels were approximately 0.17 and approximately 1.7 adducts in 10(7) nucleotides for epidermis and dermis, respectively. To quantitate low levels of DMBA-DNA adducts, 32P-postlabeling assays were run in the presence of a limiting amount of carrier-free [gamma-32P]ATP; this was found to favor labeling of the adducts, thereby leading to a 20- to 100-fold enhancement of the method's sensitivity for individual adducts. One of the three major DMBA-DNA adducts was more persistent than were the others; the level of this adduct remained constant at approximately 60% of the total in epidermal and dermal DNA during the last 18 weeks of the 42-week observation period. Since a [3H]thymidine-labeling experiment showed a normal epidermal DNA turnover 40 weeks after DMBA treatment, it was concluded that the bulk of the persistent adducts was present in subpopulations of dormant cells. We have hypothesized that such cells, in the absence of a promoting stimulus, are incapable of division because of the adduction and/or mutation of genes critical for growth (proto-oncogenes), and may thus correspond to the 'latent tumor cells', as defined by Berenblum and Shubik in their classical analysis of the attributes of tumor initiation and promotion.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1986

Enhancement of collagen-degrading enzymes in the dermis after one topical application of tumor-promoting phorbol esters.

The effect of tumor-promoting and non-promoting skin mitogens on the induction of matrix degradation in the dermis of mouse skin has been examined. A stimulation of active collagenolytic and proteolytic enzyme levels was observed after application of the tumor promoters 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and 12-O-retinoylphorbol-13-acetate (RPA) as well as the non-promoting skin irritant Ca-ionophore A 23187, but not with the non-irritant mitogen 4-O-methyl-TPA. It therefore appears that the enhancement of collagenolytic and proteolytic enzymes after tumor promoter treatment is mainly due to the inflammation that is always caused by the promoter. However, a subfraction of collagenolytic enzymes that is not extracted from the dermis with 0.5 M NaCl but only with 5 M urea is specifically increased after treatment with TPA and RPA. This fraction is absent in A 23187- or 4-O-methyl-TPA-treated dermis. This indicates that apart from inflammation-induced matrix degradation there is also stimulation of enzymes which are directly related to tumor promotion.

Administration, Topical↗
PubMed1987

Skin tumor promotion is associated with increased type V collagen content in the dermis.

Tumor promotion in mouse skin depends upon establishment of hyperproliferation as well as inflammation and involves disturbance of normal communication between dermis and epidermis. As the collagenous matrix of the dermis is known to play an important role in the maintenance of normal dermal-epidermal interactions, alterations of the dermal collagen types during tumor promotion with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were investigated. In TPA-treated samples no difference between the relative content of type I and III collagen was observed, whereas the content of type V was significantly increased. When TPA treatment was discontinued before tumor development no increase of type V collagen was observed. Furthermore, treatment with the non-promoting mitogens 4-O-methyl-TPA and Ca-ionophore A 23187 did not result in any alterations of the matrix composition. These data indicate that the increase of type V collagen content is part of the disturbed tissue interactions between dermis and epidermis that facilitate tumor development.

Animals↗
PubMed1996

Immunohistochemical study of CD34-positive dendritic cells of human dermis.

The human dermis contains a heterogeneous network of cells with a dendritic morphology, including factor XIIIa+ dermal dendrocytes and CD34+ dendritic cells located around epidermal adnexae. Whereas dermal dendrocytes have been immunohistochemically studied, CD34+ dermal cells have not yet been well characterized. We studied by simple and double immunolabeling techniques on tissue sections of normal human skin the phenotype of these cells and found them to express vimentin and Te7 but none of the remaining markers sought (factor XIIIa, von Willebrand factor, CD1a, CD3, CD4, CD8, CD14, CD25, CD36, CD45, CD54, CD56, LFA-1, EGF-R, S-100 protein, Mac 387, and muscle-specific actin). Rare CD34+ cells of the interstitial dermis expressed human leukocyte antigen (HLA)-DR antigens, but this was not the case for periadnexal CD34+ cells. These results show that CD34+ dendritic cells of human dermis are mesenchymal cells bearing a unique immunophenotype different from that of (myo)fibroblasts, monocytes-macrophages, Langerhans cells, and factor XIIIa+ dermal dendrocytes. Whereas the involvement of CD34+ cells in some cutaneous tumors is well known, their physiologic role in normal skin remains to be established. On the basis of our results, we speculate that these cells could represent uncommitted mesenchymal cells, unique by virtue of CD34 antigen expression.

Actins↗
PubMed1999

The efficacy of collagen dermis membrane and fibrin on cultured epidermal graft using an athymic mouse model.

A human skin substitute consisting of human cultured keratinocytes, collagen dermis, and fibrin was evaluated in athymic mice. Eighty athymic mice were divided randomly into four groups. A 1.5x1.5-cm full-thickness wound defect was created on the back of each athymic mouse under anesthesia. These wounds were covered by sheets of cultured epidermal graft (group A), cultured epidermal graft with collagen dermis and fibrin (group B), cultured epidermal graft with collagen dermis (group C), or cultured epidermal graft with fibrin (group D). The grafts were secured and kept moist by specially designed saline gauze chambers. The take rates of the cultured graft with more than 50% of the wound covered were 65%, 15%, 50%, and 45% respectively. Group B had a significantly lower graft take rate, however the difference was not significant among groups A, C, and D. Light microscopy of biopsies of the grafted sites at 12 days showed complete epithelialization. The incidence of discharge from wound beds in groups A, B, C, and D was 0%, 15%, 15%, and 10% respectively. The results suggest that cultured cells are best grafted directly onto the wound bed or in combination with either a thin layer of collagen or fibrin but not both because the collagen dermal membrane and the fibrin together may impose too great a diffusion barrier for the cultured cell graft to become vascularized.

Animals↗
PubMed1986

Dermis grafts in socket reconstruction.

The feasibility of using dermis in socket reconstruction is explored in the rabbit. The results indicate that dermis may be a suitable source of graft material where mucous membrane replacement is needed. Histological sections of the grafts are provided and are contrasted with scleral grafts, a substance whose behavior is socket surgery has been studied previously. A clinical case is presented also of a patient with a severely contracted anophthalmic socket who was reconstructed successfully with a dermis graft.

Adult↗
PubMedDate not supplied

Acceleration of skin regeneration from cultured epithelial autografts by transplantation to homograft dermis.

Cultured epithelial autografts transplanted to homograft dermis were analyzed histopathologically from 9 days to 2.25 years after grafting and compared with cultured epithelial autografts transplanted to wound beds devoid of homograft dermis in the same patient. The results suggested that grafting to a dermal substrate accelerates biologic events in skin regeneration from cultured epithelial autografts. Both rete ridge development and normalization of the epidermal keratin program from a "hyperproliferative" to a normal pattern occurred months sooner in the cultured epithelial autografts placed on a dermal matrix. Regeneration of anchoring fibrils was also accelerated. Neither repopulation by Langerhans cells nor repigmentation appeared to be altered significantly by grafting to dermal tissue. By special stain, the elastin network of the allograft dermis could still be visualized at 2.25 years, indicating long-term persistence of the homograft matrix. By clinical assessment the rate of successful engraftment ("take rate") of cultured epithelial autografts grafted to allodermis was estimated to be about 95%, and long-term durability was excellent.

Adult↗
PubMed1998

Nerve and blood vessel growth in response to grafted dermis and cultured keratinocytes.

The aim of this study was to study innervation and angiogenesis in response to grafts of dermis and cultured keratinocytes using immunohistochemical techniques. In a porcine model, fresh autologous de-epidermalized dermis and cultured autologous keratinocytes were combined using a two-stage technique, to produce keratodermal grafts. Wounds were encased within skin graft chambers that prevented the influence of the surrounding skin. As grafts contracted, a peripheral rim of granulation tissue became exposed, allowing us to compare the wound bed beneath grafts with that beneath the raw granulating surface. Grafts were studied for 6 weeks. Angiogenesis was studied using antisera to von Willebrand factor to detect endothelial cells. Nerve growth was studied using antisera to S-100, a Schwann cell marker, and to four axonal markers: protein gene product 9.5, C-flanking peptide of neuropeptide Y, calcitonin gene-related peptide, and vasoactive intestinal peptide. In kerato-dermal grafts (n = 28), organization of blood vessels and nerve growth occurred only beneath areas with epidermal cover as compared with the surrounding granulation tissue. Initially, the immunoreactivity to von Willebrand factor was high, but in areas with epidermal cover it assumed a more orderly pattern with fewer blood vessels. Innervation was first detected by S-100 immunoreactivity seen at 1 to 2 weeks, closely followed by that to protein gene product 9.5 and much later to calcitonin gene-related peptide. C-flanking peptide of neuropeptide Y and vasoactive intestinal peptide immunoreactivity were detected in the wound depth surrounding large blood vessels at 4 to 6 weeks. In control wounds that had been either grafted with de-epidermalized dermis alone (n = 10) or allowed to granulate (n = 10), persistently there was high immunoreactivity to von Willebrand factor but minimal immunoreactivity to the neural markers. In conclusion, kerato-dermal grafts become innervated, and beneath their surface there is also vascular organization to resemble normal skin. Keratinocytes themselves may influence angiogenesis and innervation, as both processes failed to occur beneath granulating areas.

Animals↗
PubMed2001

Experimental assessment of the revascularization of acellular human dermis for soft-tissue augmentation.

The purpose of this experimental study was to determine whether acellular human dermis was capable of complete revascularization in a subcutaneous implantation site with various placement geometries. In young adult rabbit ears, four different sheet and rolled configurations were placed and harvested after 3, 7, 14, and 28 days with silicone rubber microangiographic injections followed by histologic analysis. Revascularization of single-layer acellular human dermis occurred rapidly and was essentially complete by 14 days after surgery. No differences were observed in the ingrowth of vessels regardless of how the basement membrane was oriented. In rolled configurations, vascular ingrowth throughout the implant was slower and had not completely penetrated the grafts by 28 days after surgery at study completion. Vessel ingrowth occurred through the implant surfaces contacting the surrounding soft tissue and along the open seam of the roll. No differences were seen whether the basement membrane was oriented on either the inside or the outside of the roll. Acellular human dermis is capable of significant revascularization of its compact collagen composition in the early postoperative period. In thicker geometries, the rate and completeness of vessel ingrowth are predictably slower. Whether complete revascularization of multilayered or rolled grafts is achieved cannot be determined from this study.

Animals↗
PubMed2003

Corporoplasty for advanced Peyronie's disease using venous and/or dermis patch grafting: new surgical technique and long-term patient satisfaction.

PURPOSE: We evaluated long-term results and patient satisfaction after corporoplasty using saphenous vein and/or dermis patch grafting in patients with advanced Peyronie's disease. MATERIALS AND METHODS: A total of 20 patients who underwent venous and/or dermis patch corporoplasty were followed a mean of 19 months. Postoperatively patients satisfaction was assessed using the International Index of Erectile Function questionnaire. The mean preoperative grade of deviation in this collective was 86 degrees, frequently associated with additional malrotation. RESULTS: Intraoperatively the deviation was straightened in all cases. Postoperatively 20% of patients complained of 1 or 2 cm. penile shortening and in 25% there was a slight deviation relapse of 5 to 15 degrees. Only 2 patients had recurrence (30 and 70 degrees, respectively. In 3 cases (15%) postoperative erectile dysfunction was treated successfully with sildenafil or prostaglandin E. Overall postoperative sexual satisfaction score on the International Index of Erectile Function was 2.76 of a possible 5, although erection and cohabitation status were rated higher with at 3 and 2.94, respectively. CONCLUSIONS: Saphenous vein interposition is safe and effective for high grade Peyronie's disease. In cases of insufficient vein anatomy additional dermis patch interposition is a good alternative. The limited median postoperative patient satisfaction score even for minor procedures with good objective results indicates only moderate overall satisfaction at a mean of 19 months postoperatively, which was likely due to high preoperative patient expectation of surgical correction.

Aged↗
PubMed2004

Porcine dermis interposition graft for repair of high grade anterior compartment defects with or without concomitant pelvic organ prolapse procedures.

PURPOSE: Recent literature suggests that graft interposition may decrease the incidence of cystocele recurrence. We describe our experience with porcine dermis interposition grafts for the repair of high grade cystoceles. MATERIALS AND METHODS: We retrospectively reviewed the charts of all women who underwent surgical repair of high grade cystocele. Prolapse was graded with the Baden-Walker and Pelvic Organ Prolapse Quantitation systems, and all patients were evaluated with multichannel videourodynamics. Concomitant stress urinary incontinence was corrected with a pubovaginal sling and vault prolapse was corrected with iliococcygeus vault suspension. Postoperatively patients were evaluated at 2 weeks, 2 months, 6 months and annually thereafter. RESULTS: A total of 70 patients underwent cystocele repair with a porcine dermis interposition graft. Concomitant procedures included a pubovaginal sling in 65 patients and vaginal vault suspension in 50. Mean followup was 24 months. There were no intraoperative complications. Of the patient 59 (91%) are currently dry. One patient had recurrent vault prolapse without cystocele (C -2), which was successfully repaired with abdominal sacral colpopexy. Six patients (8.6%) experienced recurrent grade II (Ba 0) cystocele but continued to be asymptomatic. Three others (4.3%) had recurrence of grade III (Ba +2) cystocele and elected not to undergo reoperation. Two of 6 de novo rectoceles (grade II, Ap and -1 and Bp 0) were repaired with site specific repairs. Superficial vaginal wound separation in 1 case was successfully treated conservatively. CONCLUSIONS: In cases of high grade cystocele interposition of porcine dermis represents a successful and safe treatment option. Cystocele recurrence is typically low grade and it frequently may not require additional surgery.

Animals↗
PubMed1984

Dermatitis herpetiformis: preparation of papillary dermis and the effect of proteolytic enzymes on the IgA deposits.

A technique has been devised to isolate the thin papillary part of the dermis from punch biopsies. Papillary dermis has been treated with various proteolytic enzymes in order to release or solubilize the granular IgA deposits from the papillary dermis of patients with dermatitis herpetiformis. Incubation of the thin skin preparations with pepsin caused a disappearance of the specific fluorescence with antibodies to human IgA. After peptic digestion small amounts of IgA could be detected in the supernatants. There was some evidence that this amount was larger for preparations from patients with dermatitis herpetiformis than from controls. Corresponding procedures with trypsin, collagenase, or elastase had no detectable effect on the IgA deposits. The experiments with elastase seemed to give support for previous reports on association between the granular IgA deposits and the microfibrils of elastic fibers.

Biopsy, Needle↗
PubMed1995

In human dermis, ultraviolet radiation induces expansion of a CD36+ CD11b+ CD1- macrophage subset by infiltration and proliferation; CD1+ Langerhans-like dendritic antigen-presenting cells are concomitantly depleted.

Antigen-presenting (APC), suppressor T-cell-inducing macrophages infiltrate both human and murine epidermis after ultraviolet radiation (UVR) exposure. To determine their derivation, we prepared epidermal cell and dermal cell suspensions from human keratome biopsy specimens obtained from nonexposed skin and from UVB-irradiated sites (3 d after four times the minimal erythema dose). Simultaneous triple-marker flow cytometric analysis established the extended phenotype of macrophages infiltrating sunburned human epidermis (CD1a- CD1c- CD11b+ CD11c+ CD36+ Fc gamma RII+ DR+). This then enabled us to track dermal cells of this phenotype after UVR in relation to the heterogeneous DR+ populations in normal dermis. By both in situ immunohistology and cell suspension flow cytometry, UVR induced an expansion of bone marrow-derived DR+ cells in the perivasculature and sub-basement membrane zone of the papillary dermis. Despite an overall expansion of DR+ cells, the CD1a+ CD1c+ CD36- DR+ Langerhans-cell-like dendritic APC subset of dermal DR+ cells was depleted (p < 0.05), indicating that UVR-induced epidermal Langerhans cell loss (from 95% to 7% of DR+ epidermal cells) is not accounted for by Langerhans cell accumulation in the dermis. By contrast, UVR exposure induced a selective expansion of the dermal macrophage subset, which is phenotypically identical to the monocytic/macrophagic APCs that appear in the epidermis after UV injury (p < 0.01). Cell cycle analysis (to determine whether this expansion was accounted for entirely by infiltration) revealed no increase in the percentage of DR+ CD36+ UVR-exposed dermal cells in S/G2/M phase; however, the expanded DR+ CD36+ subset continued its already substantial level of proliferation unabated. Therefore, epidermal macrophages derive not only from transcapillary migration, but also from in situ proliferation of a dermal precursor. Taken together, these findings show that UVR creates an epidermal and dermal APC milieu which is dominated by monocytic/macrophagic cells, through depletion of cells of dentritic APC phenotype, and concomitant selective dermal expansion of a CD1a- CD1c- CD11b+ CD36+ Fc gamma RII+ DR+ (monocyte/macrophage) population.

Adult↗