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Biomedical subjects

D N Sauder

Publications and source records attributed to D N Sauder.

At least 19 recordsLinked to original sources
PubMed1992

Identification and characterization of a partial cDNA expressing interleukin-1-like activity in keratinocytes.

A partial cDNA has been isolated from the human keratinocyte cell line COLO-16 which is distinct from either IL-1 alpha or beta and encodes a protein which displays some of the biological properties associated with IL-1. The 720 bp partial cDNA hybridized on Northern blots of COLO-16 mRNA to a 1.6 kbp message of low abundance. Expression of the partial cDNA in COS-1 cells resulted in activity in three IL-1 assays: thymocyte co-stimulation, D10.G4.1 T-cell stimulation and fibroblast proliferation. Antisera generated against synthetic peptides based on inferred protein sequence from the cDNA reacted with a 20 kDa and 30 kDa species in both the COLO-16 cell line and PMA-stimulated normal human keratinocytes. These novel species were also present in PMA-stimulated and unstimulated human dermal fibroblasts and human T-cell lines.

Amino Acid Sequence↗
PubMed1992

Combined treatment with oral etretinate and electron beam therapy in patients with cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome).

BACKGROUND: Total skin irradiation for early-stage mycosis fungoides produces clinical remission in 90% of patients, but the median duration of remission is only 2 to 4 years. Etretinate has proven efficacy in advanced mycosis fungoides. Its potential as adjuvant therapy to radiation could be limited by toxicity from the combination. OBJECTIVE: Our purpose was to determine whether oral etretinate at 1 mg/kg can be combined with 35 Gy of radiation without intensifying or prolonging the radiation reaction and to determine the relapse-free survival rate. METHODS: Twenty-three patients began etretinate on day one of radiation and the dose was reduced for nose bleeds, dry skin, or hyperlipidemia. During the reaction skin toxicity questionnaires were completed weekly. Nine concurrent patients receiving only radiation completed identical forms. RESULTS: Etretinate did not intensify the skin reaction but did prolong it by 2 weeks. At a median follow-up of 2 years the relapse-free survival rate in complete responders was similar to stage-matched concurrent and historic control subjects. CONCLUSIONS: Both radiation and etretinate can be given together with acceptable toxicity and without compromising either therapy.

Administration, Oral↗
PubMed1992

Inhibition of interleukin-1 beta mRNA expression and interleukin-1 alpha and beta secretion by a specific human recombinant interleukin-1 receptor antagonist in human peripheral blood mononuclear cells.

The transcription and translation of interleukin-1 (IL-1) may have a pleiotropic effect on the immune system and inflammatory diseases. Recently it has been reported that human monocytes not only produce IL-1 but also induce, with adherent IgG, the secretion of an IL-1 receptor antagonist (IL-1Ra), which can play an essential in vivo and in vitro role in the regulation of IL-1 activity. Recombinant human (rh) IL-1Ra is structurally similar to IL-1 beta but with no IL-1-like activity, and specifically binds to the IL-1 receptor. To more fully evaluate and clarify the inhibitory effect of rhIL-1 receptor antagonist on IL-1 we have studied the influence of rhIL-1Ra on IL-1 transcription and translation. In this report we show that IL-1 beta mRNA from peripheral blood mononuclear cells (PBMC) is strongly inhibited (66%) when rhIL-1Ra (250 ng/ml) was added to cultured cells activated with lipopolysaccharide (LPS) (100 ng/ml) for 4 hr, determined with the slot blot analysis. The addition of exogenous rhIL-1 beta to the cell culture diminished the inhibitory effect (44%). Moreover, we report that the block of IL-1 mRNA transcription consequently leads to the inhibition of IL-1 alpha and IL-1 beta secretion in human PBMC, as measured by ELISA method. In fact, herein we show that LPS activates human PBMC to secrete IL-1 beta and IL-1 alpha, an effect inhibited, in a dose-dependent fashion by rhIL-1Ra (0.025-250 ng/ml) in an overnight incubation. Since IL-1 is a strong inducer of IL-1 synthesis in vivo and in vitro, in our study we used rh IL-1 alpha to stimulate the secretion of IL-1 beta in human PBMC. This activation, carried out overnight, also provoked the release of IL-1 beta in a dose-dependent manner, which was strongly inhibited by rhIL-1Ra used at different concentrations (0.025-250 ng/ml). The inhibitory effect exerted by IL-1Ra on human PBMC IL-1 mRNA transcription and the down-regulation of secretion of IL-1 beta stimulated by IL-1 alpha, may contribute to therapeutic effects in inflammatory diseases such as rheumatoid arthritis and other autoimmune diseases.(ABSTRACT TRUNCATED AT 400 WORDS)

Cells, Cultured↗
PubMed1992

Keratinocyte cytokines.

It is now clear that keratinocytes produce a wide range of cytokines that can be regarded as important mediators of intercellular communication. A major emphasis has been placed on IL-1 because of its relationships with other cytokines and other differentiated tissues. Dysregulation of IL-1, IL-1 receptor, and inhibitory factors for IL-1 may cause imbalance of skin biology, leading to perpetuation of immune and inflammatory events. Interaction of IL-1 with other cytokines in vivo is also important in the understanding of the pathophysiology of skin diseases. More fundamental questions regarding the homeostatic significance of IL-1 in keratinocytes still remain to be answered.

Colony-Stimulating Factors↗
PubMed1991

Langerhans cell histiocytosis in monozygotic twins.

Langerhans cells histiocytosis, one of a group of histiocytosis syndromes characterized by Langerhans cell infiltration, has many clinical manifestations. In the past 30 years, numerous cases of presumed Letterer-Siwe disease, the acute multiorgan variant, have been reported in twins and siblings. Only recently has the Histiocyte Society established a criterion for a "definitive diagnosis" of Langerhans cell histiocytosis--the presence of Birbeck granules within the cells of the histiocytic infiltrate. We report the fatal outcome of Langerhans cell histiocytosis in monozygotic twin infants. There is no satisfactory explanation why Langerhans cell histiocytosis occurs concurrently in twins. We suggest that cytokines may provide an endogenous signal that triggers the pathologic proliferation of Langerhans cells.

Diseases in Twins↗
PubMed1991

Polymyositis: a manifestation of chronic graft-versus-host disease.

Polymyositis developed in a patient who had had bone marrow transplants for the treatment of acute myeloid leukemia. There was no previous evidence of graft-versus-host disease. Polymyositis has previously been reported to be associated with graft-versus-host disease; this article suggests that polymyositis may represent its sole manifestation.

Adult↗
PubMed1991

Augmentation of granulocyte/macrophage colony-stimulating factor expression by ultraviolet irradiation is mediated by interleukin 1 in Pam 212 keratinocytes.

Keratinocytes are a potent source of a variety of cytokines including granulocyte-macrophage colony-stimulating factor (GM-CSF). In this study, we have shown that ultraviolet B (UVB) irradiation augments GM-CSF mRNA expression by murine keratinocytes. This is reflected in the increased production of GM-CSF protein by these cells. In the same cell population, exposure to UVB irradiation increases interleukin 1 alpha (IL-1 alpha) mRNA and IL-1 protein as detected by bioactivity. This increase in IL-1 alpha precedes the increase of GM-CSF mRNA. Addition of recombinant IL-1 alpha to the medium increases GM-CSF mRNA expression. Anti-IL-1 alpha antibodies can completely inhibit UV-augmented GM-CSF mRNA expression. These results demonstrate that UVB irradiation-induced augmentation of GM-CSF is mediated by UV-induced IL-1 alpha.

Animals↗
PubMed1991

Regulation of GM-CSF and IL-3 production from the murine keratinocyte cell line PAM 212 following exposure to ultraviolet radiation.

Ultraviolet radiation (UVR) exposure induces profound changes in the synthesis and secretion of various cytokines both in vivo and in vitro. Little is known regarding the mechanism of these responses. This investigation evaluated the effects of UVR on the ability of a murine keratinocyte line (PAM 212) to produce interleukin 3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF). Subconfluent rapidly dividing PAM 212 cells were shown by RNA slot-blot hybridization studies to have increased levels of mRNA for both IL-3 and GM-CSF within 1 h of UVR exposure. However, only GM-CSF-specific bioactivity, as determined by antibody neutralization studies, was shown to increase above baseline in cell supernatants. Cells grown to confluence responded differently to UVR. Under these culture conditions an apparent decrease in bioactivity was detected after UVR exposure for both growth factors, and no change in mRNA levels was detected. In addition to culture density, removal of extracellular calcium or sodium during irradiation, treatment with amiloride, or inhibition of new mRNA synthesis with cordycepin was shown to influence the UVR-induced alteration in release of IL-3 or GM-CSF bioactivity from both confluent and subconfluent PAM 212 cells. These results demonstrate that UVR influences the release of the colony stimulating factors GM-CSF and IL-3 from keratinocyte, and suggests that the state of cell growth and conditions of membrane ion transport influence the mechanisms regulating secretion of those factors.

Animals↗
PubMed1990

Fetal bovine serum contains an inhibitor of interleukin-1.

The keratinocyte cell line COLO-16 constitutively produces factors with interleukin-1 (IL-1) activity including IL-1 alpha and IL-1 beta. IL-1 activity assayed by thymocyte proliferation from cell supernatants was 20-50% less if cells were maintained in media containing 10% fetal bovine serum (FBS) compared to media without serum 24 h prior to harvest. The increased IL-1 activity in supernatants from cells in serum free media was not due to increased cellular levels of IL-1 alpha or IL-1 beta mRNA. Similarly, IL-1 activity recovered from conditioned supernatants of COS cells transfected with expression vectors containing IL-1 beta cDNA was approximately 22-45% less in cells grown in 20% FBS medium compared to similar cultures grown for 3 days post transfection in 1% FBS. When serial dilutions of recombinant IL-1 were made in buffer containing 10% FBS and assayed by a thymocyte proliferation method, a 30-50% decrease in activity was observed. IL-1 activity was also measured by its ability to induce prostaglandin E2 synthesis by fibroblasts. When COS conditioned supernatants were applied to fibroblast cultures there was 30% less prostaglandin E2 activity from fibroblasts treated with COS supernatants containing 20% FBS, compared to supernatants containing 1% FBS. The inhibitor molecule was partially purified by gel filtration and found to have a molecular weight of approximately 85,000. The presence of FBS in cell-conditioned media significantly reduces the sensitivity of IL-1 detection by bioassay techniques.

Animals↗
PubMed1990

IL-1 activity is reduced in psoriatic skin. Decreased IL-1 alpha and increased nonfunctional IL-1 beta.

IL-1 may influence or be influenced by a number of abnormalities present in psoriasis; including keratinocyte proliferation, eicosanoid production, fibroblast activation, endothelial cell adhesiveness, T cell infiltration and activation, cyclic nucleotide metabolism, and transmembrane signal transduction mechanisms. We assessed IL-1 regulation in normal, uninvolved, and involved skin of psoriatic patients using immunofluorescence microscopy, a sensitive ELISA method to quantitate immunoreactive IL-1 beta and IL-1 alpha protein levels, the thymocyte proliferation costimulation assay, costimulation of the LBRM.33 IL-1-sensitive cell line, and Northern blotting of cellular RNA to quantitate IL-1 alpha and beta mRNA. IL-1 beta was easily detectable by immunofluorescence microscopy and found to be localized predominantly in epidermal keratinocytes, whereas IL-1 alpha was not detectable with this method. Immunoreactive IL-1 beta was found to be elevated in cytosolic extracts derived from involved psoriatic keratomes relative to keratomes of normal skin. The elevated IL-1 beta protein was accompanied by elevated levels of IL-1 beta mRNA in psoriatic skin relative to normal skin. In contrast, immunoreactive IL-1 alpha levels were markedly reduced in lesional psoriatic skin. In functional assays using both the thymocyte proliferation assay and the LBRM.33 cell line, IL-1 activity from psoriatic involved skin keratomes was markedly reduced relative to that of uninvolved psoriatic keratomes and normal skin. All activity of both normal and psoriatic skin was attributable to IL-1 alpha. The elevated IL-1 beta immunoreactive protein present in psoriatic skin was found to be functionally inactive in these assays. The inactivity of the IL-1 beta was not due to an artifact of the cytosolic method of preparation because IL-1 beta released by psoriatic skin into the media was also nonfunctional. This was in keeping with the demonstration that the IL-1 beta was nonfunctional despite existing as a processed molecule. Taken together, these data demonstrate uncoordinated regulation of IL-1 alpha and Il-1 beta in psoriasis. The profound and complex changes in this system suggest IL-1 dysregulation may be integrally involved in the inflammatory, biochemical, and proliferative processes involved in the pathophysiology of psoriasis.

Biological Assay↗
PubMed1990

Pretibial epidermolysis bullosa: report of a case.

Pretibial epidermolysis bullosa is a rare variant of hereditary epidermolysis bullosa that is characterized by the delayed onset of a blistering eruption limited to the pretibial area. We present a case in a 48-year-old woman. Immunofluorescence mapping demonstrated blister formation below the basement membrane. This was confirmed by ultrastructural investigations that also revealed rudimentary anchoring fibrils similar to those described in the dominant dystrophic forms of epidermolysis bullosa.

Basement Membrane↗
PubMed1990

Expression and modulation of nerve growth factor in murine keratinocytes (PAM 212).

Nerve growth factor (NGF) is a polypeptide that is required for normal development and maintenance of the sympathetic and sensory nervous systems. Skin has been shown to contain relatively high amounts of NGF, which is in keeping with the finding that the quantity of NGF in a tissue is proportional to the extent of sympathetic innervation of that organ. Since the keratinocyte, a major cellular constituent of the skin, is known to produce other growth factors and cytokines, our experiments were designed to determine whether keratinocytes are a source of NGF. Keratinocyte-conditioned media from the keratinocyte cell line PAM 212 contained NGF-like activity, approximately 2-3 ng/ml, as detected by the neurite outgrowth assay. Freshly isolated BALB/c keratinocytes contained approximately 0.1 ng/ml. Using a cDNA probe directed against NGF, we demonstrated the presence of a 1.3-kb NGF mRNA in both PAM 212 and BALB/c keratinocytes. Since ultraviolet radiation (UV) is a potentially important modulating factor for cytokines in skin, we examined the effect of UV on NGF mRNA expression. Although UV initially inhibited the expression of keratinocyte NGF mRNA (4 h), by 24 h an induction of NGF mRNA was seen. The NGF signal could also be induced by phorbol esters. Thus, keratinocytes synthesize and express NGF, and its expression is modulated by UVB and phorbol esters.

Animals↗
PubMed1990

Interleukin-1 enhances epidermal wound healing.

Previous in vitro studies suggest that the interleukin-1 (IL-1) proteins may be important for skin function. Keratinocytes are known to synthesize IL-1 in response to injury and IL-1 has been shown to stimulate fibroblast and keratinocyte growth, collagen synthesis by fibroblasts, and chemotaxis of keratinocytes. In order to evaluate the ability of IL-1 to enhance wound healing, recombinant human IL-1 alpha was applied topically in a water-miscible cream to partial thickness wounds made on the backs of pathogen-free adult pigs. The wounded site was excised at various times for assessment of epidermal regeneration. This study shows a statistically significant enhancement of healing of the IL-1-treated wounds compared with either air-exposed or vehicle-treated wounds. Histologic examination of biopsies from IL-1-treated wounds indicated complete and architecturally normal epidermal regeneration. Porcine keratinocytes and membranes prepared from porcine skin were found to possess high affinity receptors for human IL-1 alpha. This study suggests that topical administration of IL-1 may be useful for the promotion of wound healing.

Administration, Cutaneous↗
PubMed1990

Keratinocyte cytokines and growth factors. Functions in skin immunity and homeostasis.

Evidence has been presented to support the theory that the KC, by virtue of its production of cytokines and growth factors, is an integral component of the immune system. The production of cytokines by the KC is normally carefully regulated in order to maintain normal body homeostasis. Malfunction of the regulatory processes controlling cytokine release may result in the development of skin disease.

Cell Division↗
PubMed1990

Expression of interleukin-1 beta in a human keratinocyte cell line.

The human keratinocyte cell line COLO-16 expresses mRNA homologous to human IL-1 alpha and IL-beta (transcript sizes 2.3 and 1.6 kb, respectively). A 1.2 kbp cDNA was selected with a human IL-1 beta probe from a lambda gt11 library constructed using poly A+ RNA from COLO-16 cells. Sequence analysis revealed that this cDNA was nearly identical to the 3' 1.2 kb of human monocyte IL-1 beta. When this cDNA was expressed in COS cells using a mammalian expression vector, IL-1 activity was detected in the cell conditioned supernatants using assays for D10-T-cell, thymocyte and fibroblast proliferation. Western analysis of lysates from COS cells transfected with this clone revealed the presence of a -17 kDa protein which reacted with antisera to human IL-1 beta. This protein was the same size as the processed form of IL-1 beta present in COLO-16 cells suggesting that this cDNA encodes the mature form of IL-1 beta. COLO-16 cells contain proteins of -30 kDa and 17 kDa which are immunoreactive with specific antisera for human IL-1 alpha and human IL-1 beta. Despite the presence of four-fold greater amounts of immunoreactive IL-1 beta protein than IL-1 alpha in cell lysates, all the IL-1 activity in the lysate could be neutralized by antisera to IL-1 alpha. IL-1 beta comprised only 25% of the IL-1 activity in the cell-conditioned media, all remaining activity was neutralized by antisera to IL-1 alpha. Whereas IL-1 alpha protein in both cell lysates and conditioned supernatants was predominantly in the processed -17 kDa form, IL-1 beta proteins were primarily of the processed and inactive 30kDa species. This apparent inability of keratinocytes to process IL-1 beta may explain our observations that the IL-1 activity secreted by COLO-16 cells is principally due to IL-1 alpha.

Amino Acid Sequence↗