Marta J. Petersen

Metalloproteinases and tissue inhibitor of metalloproteinases in mesothelial cells. Cellular differentiation influences expression.

Mesothelial cells play a critical role in the remodeling process that follows serosal injury. Although mesothelial cells are known to synthesize a variety of extracellular matrix components including types I, III, and IV collagens, their potential to participate in matrix degradation has not been explored. We now report that human pleural and peritoneal mesothelial cells express interstitial collagenase, 72- and 92-kD gelatinases (type IV collagenases), and the counterregulatory tissue inhibitor of metalloproteinases (TIMP). Our initial characterization of the mesothelial cell metalloenzymes and TIMP has revealed: (a) they are likely identical to corresponding molecules secreted by other human cells; (b) they are secreted rather than stored in an intracellular pool; (c) a primary site of regulation occurs at a pretranslational level; (d) phorbol myristate acetate, via activation of protein kinase C, upregulates expression of collagenase, 92-kD gelatinase, and TIMP, but has no effect on expression of 72-kD gelatinase; and (e) lipopolysaccharide fails to upregulate the biosynthesis of either metalloproteinases or TIMP. Of particular interest is the observation that the state of cellular differentiation has a striking influence on the expression of metalloenzymes and TIMP, such that epitheloid cells display a more matrix-degradative phenotype (increased 92-kD gelatinase and decreased TIMP) than their fibroblastoid counterparts. We speculate that mesothelial cells directly participate in the extracellular matrix turnover that follows serosal injury via elaboration of metalloproteinases and TIMP. Additionally, the reactive cuboidal mesothelium which is characteristic of the early response to serosal injury may manifest a matrix-degenerative phenotype favoring normal repair rather than fibrosis.

Usefulness (or Lack Thereof) of Immunophenotyping in Atypical Cutaneous T-Cell Infiltrates

Our purpose was to evaluate the interobserver concordance for the diagnoses of mycosis fungoides (MF), atypical dermatoses (AD), and benign dermatoses (BD) and the impact of T-cell immunophenotyping on the diagnoses MF, AD, and BD. Specimens of MF (n = 57), AD (n = 27), BD and normal skin (n = 54) were reviewed by 2 hematopathologists and 1 dermatopathologist to establish diagnostic interobserver concordance by routine morphologic examination. Immunophenotyping was performed to evaluate expression of CD2, CD3, CD4, CD5, CD7, CD8, CD20, CD30, and MIB-1. The interobserver concordance was fair to moderate compared with the original diagnosis. Partial deletion of CD2 alone was associated significantly with MF. Epidermal deletions of 2 or 3 T-cell antigens or 2 T-cell antigens not including CD7 were associated significantly with MF. An elevated CD4/CD8 ratio correlated with MF. Morphologic features were most diagnostic of MF. Immunophenotyping generally resulted in downgrading of the reaction pattern but was helpful in distinguishing MF from benign dermatoses.

A case of linear IgA disease presenting initially with IgG immune deposits

We describe a case of linear IgA bullous disease initially presenting with histopathologic and immunofluorescent findings consistent with bullous pemphigoid. Initial immunofluorescent studies demonstrated a predominance of linear IgG at the basement membrane zone (BMZ) of perilesional skin and a low titer circulating IgG anti-BMZ antibody. Repeat studies 3 years later revealed a predominance of linear IgA immune deposits at the BMZ and no circulating anti-BMZ antibody. Dapsone therapy was initiated at this time with a good therapeutic response noted. Suction blister studies, immunoelectron microscopy, split skin immunofluorescent studies and Western immune blot were performed and provided indirect evidence that the BMZ antigen in this case is distinct from the bullous pemphigoid antigen component of the BMZ.

REGULATION and INHIBITION OF COLLAGENASE EXPRESSION BY LONG‐WAVELENGTH ULTRAVIOLET RADIATION IN CULTURED HUMAN SKIN FIBROBLASTS*

The cellular mechanisms responsible for the connective tissue changes produced by chronic exposure to UV light are poorly understood. Collagenase, a metalloproteinase, initiates degradation of types I and III collagen and thus plays a key role in the remodeling of dermal collagen. Collagenase synthesis by fibroblasts and keratinocytes involves the protein kinase C (PKC) second messenger system, and corticosteroids have been shown to suppress its synthesis at the level of gene transcription. Long‐wavelength UV light (UVA,320–400 nm) stimulates the synthesis of interstitial collagenase, as well as increasing PKC activity, in human skin fibroblasts in vitro. This study explores the regulation of collagenase expression by UVA in cultured human skin fibroblasts. Specifically, the time course, the effect of actinomycin D, an inhibitor of RNA synthesis, as well as the effect of PKC inhibitors and dexa‐methasone on expression of collagenase following UVA irradiation were examined. After UVA irradiation, collagenase mRNA rose rapidly between 4 and 12 h postirradiation, peaking 18 h post‐UVA. Actinomycin D completely suppressed the UVA‐induced increase in collagenase mRNA. Thus, new RNA synthesis is required for the UVA‐induced increase in collagenase mRNA. The PKC inhibitor, H‐7, blocked the increase in collagenase mRNA in response to UVA in a dose‐dependent manner. Similarly, dexamethasone also inhibited collagenase gene expression induced by UVA in a dose‐dependent fashion; the majority of the inhibitory effect was seen within the first 4 h after irradiation. These studies demonstrate that the effect of UVA on collagenase gene expression is regulated at the pretranscriptional level and may involve the PKC pathway.

Characterization of Cellular Elements in Healed Cultured Keratinocyte Autografts Used to Cover Burn Wounds

Biopsy specimens from unburned skin were obtained from three severely burned patients and placed into tissue culture. After 2 to 3 weeks, the cultured keratinocytes were released from the Petri dishes and transplanted onto the patients burn wound, which had been completely excised down to muscle fascia, thereby removing all cutaneous elements. Healing cultured autografts were found to become repopulated with Langerhans cells within 3 to 6 weeks. A neodermis rich in fibronectin rapidly formed between the autografts and muscle fascia. However, using monoclonal antibodies to cytokeratins as markers of differentiation, we found that the autograft keratinocytes expressed an abnormal pattern of differentiation that was similar to the differentiation seen in hyperproliferative states such as psoriasis. In contrast, healed split-thickness graft donor sites and reepithelialized interstices of mesh grafts maintained the basal keratinocyte staining pattern of normal skin with the AE-1 monoclonal antibody.

IgA1 is the major IgA subclass in cutaneous blood vessels in Henoch–Schönlein purpura

Henoch–Schönlein purpura (HSP) is characterized by palpable purpura predominantly involving the lower extremities. On direct immunofluorescence IgA can be seen deposited in the blood vessel walls of the superficial dermis. The subclass distribution of antibodies to this IgA was studied in the biopsies of 28 patients with HSP by direct immunofluorescence using anti‐IgA1 and anti‐IgA2 specific monoclonal antibodies. All 28 patients’ biopsies demonstrated deposition of IgA1 while only one patient had IgA2 deposition. Positive and negative controls stained appropriately. This demonstrates that IgA1 is the dominant IgA subclass found in the skin in Henoch–Schönlein purpura.

Development of a nude mouse model to study human sebaceous gland physiology and pathophysiology.

Study of human sebaceous gland physiology and pathophysiology is limited by lack of an adequate animal model. This study was designed to develop an animal model using human face skin grafted onto the nude mouse to study human sebaceous glands. Full-thickness human face skin was grafted onto 60 adult male nude mice. 4 wk after grafting, androgens, which are known to stimulate sebaceous glands, were administered to test the system. Androgens were administered to 21 animals by implanted catheters that were filled with testosterone (T) or dihydrotestosterone (DHT). Empty catheters were implanted in 15 control animals. Graft biopsies and blood for androgen levels were obtained at time 1 (pre-catheter) and time 2 (26 d after catheter implantation). Three assessments were made on each biopsy: sebaceous gland volume, using an image analyzing computer; sebaceous cell size; and sebaceous gland labeling index. 29 mice completed the study through time 2. In the androgen-treated group, T levels (nanogram per milliliter) five times increased to 4.92 +/- 0.35, and DHT levels (nanogram per milliliter) increased 50 times to 16.70. In the androgen-treated group, sebaceous gland volume (micron 3 X 10(-3) increased from 896 +/- 194 to 3,233 +/- 754 (P less than 0.001), sebaceous cell area (micron 2) increased from 167 +/- 12 to 243 +/- 19 (P less than 0.001), and labeling index (percentage) increased from 2.7 +/- 0.7 to 6.4 +/- 0.9 (P less than 0.01). In the control group, sebaceous gland volume fell from 1,070 +/- 393 to 417 +/- 99 (NS), sebaceous cell size remained the same, and the labeling index fell from 5.1 +/- 1.9 to 3.2 +/- 1.1. After androgen administration, Halowax N-34, a known comedogen, or its vehicle, was applied to 15 grafts for 2-6 wk. Twice as many microcomedones were seen in the Halowax-treated grafts, compared with vehicle-treated grafts at the end of this time period. No visible comedones were produced. This study demonstrated that: (a) human sebaceous glands can be successfully transplanted and studied on the nude mouse; (b) after androgen stimulation, sebaceous gland volume, cell size, and labeling index increase; (c) microcomedones can be produced in the human skin grafts by the application of a comedogenic substance. Thus, this model demonstrates significant potential for the future study of human sebaceous gland physiology and pathology.

The Immunoglobulin A Antibody Response in Clinical Subsets of Mucous Membrane Pemphigoid

Background: Mucous membrane pemphigoid (MMP) is an immunobullous disease. In MMP there is frequently a mixed antibody response with the presence of IgA and/or IgG antibodies directed toward basement membrane zone antigens. The IgG antibody response in MMP has been studied, but the antigens to which the IgA antibodies react have not been studied. Objective: To determine the IgA autoantibody reactivity profiles in patients with MMP. Methods: Patients who had both ocular and oral MMP were compared with patients who had ocular or oral MMP and with patients who had cutaneous linear IgA disease (LABD) by Western immunoblot studies. Results: Five of 15 MMP patients and 1 of 5 LABD patients had IgA antibodies reactive with the 180-kD bullous pemphigoid antigen. Seven of 15 MMP patients had IgA antibodies reactive with the 97-kD LABD antigen. Conclusion: Major antigens in IgA MMP are the 180-kD bullous pemphigoid antigen and the 97-kD LABD antigen.

Characterization of the antibody response in oesophageal cicatricial pemphigoid

Cicatricial pemphigoid (CP) is a subepidermal, autoimmune bullous dermatosis. It is classified as a clinical subset of bullous pemphigoid (BP). However, it differs from BP in some significant ways: (i) in CP mucosal involvement with clinical scarring is prominent; (ii) there is a prominent IgA class antibody response alone or in addition to the IgG class antibody response; and (iii) there is a heterogeneous antibody response in CP, whereas in BP the majority of the antibodies are directed against a 180‐kDa hemidesmosomal protein, bullous pemphigoid antigen 2 (BPAg2). Oesophageal involvement in CP is a rare, but often devastating manifestation. In this study we examined the humoral autoimmune response in oesophageal CP, in an attempt to characterize the autoantibody reactivity profile. We used direct and indirect immunofluorescence and Western immunoblotting using normal human skin and oesophagus substrates. We studied patient sera over time in order to search for evidence of epitope spreading in these patients. All patients had positive direct immunofluorescence of perilesional oesophageal epithelium. All patients had positive circulating antibasement membrane zone autoantibody titres. There was a significant IgA class in addition to an IgG class autoantibody response. IgA and IgG antibodies demonstrated significant reactivity with BPAg2 and the 97 kDa linear IgA disease antigen on Western immunoblot suggesting intraprotein epitope spreading. There was no evidence of interprotein epitope spreading over time. Our findings suggest that there is a heterogeneous antibody response in oesophageal CP with the predominant antigen being BPAg2.

The Utah Remote Monitoring Project: Improving Health Care One Patient at a Time

BACKGROUND The expanding role of technology to augment diabetes care and management highlights the need for clinicians to learn about these new tools. As these tools continue to evolve and enhance improved outcomes, it is imperative that clinicians consider the role of telemonitoring, or remote monitoring, in patient care. This article describes a successful telemonitoring project in Utah. SUBJECTS AND METHODS This was a nonrandomized prospective observational preintervention-postintervention study, using a convenience sample. Patients with uncontrolled diabetes and/or hypertension from four rural and two urban primary care clinics and one urban stroke center participated in a telemonitoring program. The primary clinical outcome measures were changes in hemoglobin A1C (A1C) and blood pressure. Other outcomes included fasting lipids, weight, patient engagement, diabetes knowledge, hypertension knowledge, medication adherence, and patient perceptions of the usefulness of the telemonitoring program. RESULTS Mean A1C decreased from 9.73% at baseline to 7.81% at the end of the program (P<0.0001). Systolic blood pressure also declined significantly, from 130.7 mm Hg at baseline to 122.9 mm Hg at the end (P=0.0001). Low-density lipoprotein content decreased significantly, from 103.9 mg/dL at baseline to 93.7 mg/dL at the end (P=0.0263). Other clinical parameters improved nonsignificantly. Knowledge of diabetes and hypertension increased significantly (P<0.001 for both). Patient engagement and medication adherence also improved, but not significantly. Per questionnaires at study end, patients felt the telemonitoring program was useful. CONCLUSIONS Telemonitoring improved clinical outcomes and may be a useful tool to help enhance disease management and care of patients with diabetes and/or hypertension.