Biomedical subjects

L Staiano-Coico

Publications and source records attributed to L Staiano-Coico.

At least 19 recordsLinked to original sources

PubMed1992

Transforming growth factor-beta 1 acts cooperatively with sodium n-butyrate to induce differentiation of normal human keratinocytes.

Growth factors with established biological activity toward cultured normal human epidermal keratinocytes (NHEKs) (e.g., transforming growth factor-beta, TGF-beta; retinoic acid, RA) initiate programmed changes in cellular maturation which differ with regard to the specific differentiation pathway (normal or abnormal) analyzed. Sodium butyrate (NaB) initiates one form of epidermal differentiation leading to enhanced cornified envelope (CE) formation which involves abrogation of the normally inhibitory effect of RA on NHEK maturation. NaB also induces TGF-beta mRNA in the maturing suprabasal compartment, suggesting that TGF-beta may play a role in NaB-initiated NHEK differentiation. Treatment with TGF-beta 1 alone, however, only marginally increased (by twofold) the number of detergent-resistant CEs compared to control NHEKs and did not alter the prevalence of fully mature enucleated CEs. TGF-beta 1 was quite effective in inducing significant levels of CE expression when used simultaneously with suboptimal concentrations of NaB. The cooperative action of suboptimal NaB and TGF-beta 1 generated numbers of CEs which, in fact, exceeded the incidence of mature CEs formed in response to optimal levels of NaB alone. Neutralizing antibodies to TGF-beta, moreover, effectively reduced the incidence of CE formation in cultures treated with optimal NaB concentrations, further implicating endogenous TGF-beta activity in the NaB-initiated NHEK differentiation model. It is suggested, therefore, that within the NaB-induced pathway of NHEK differentiation, TGF-beta can positively modulate expression of the differentiated phenotype but alone is insufficient for generation of mature CEs.

Butyrates↗

PubMed1992

Cell shape changes during transition of basal keratinocytes to mature enucleate-cornified envelopes: modulation of terminal differentiation by fibronectin.

Normal human keratinocytes (NHK) in submerged culture were used to assess mechanisms associated with in vitro exposure to known stimulators (sodium butyrate; NaB) and inhibitors (fibronectin; FN) of NHK maturation. A multiparameter approach was used to define cell types generated under a range of growth conditions. Differentiation induced in response to NaB occurred through a series of morphologically distinct phenotypes and culminated in the formation of enucleate-cornified envelopes. Two-dimensional electrophoresis provided a limited database to evaluate global changes in cellular protein composition as a function of induced differentiation. Proteins were identified that characterized predominantly basal cell cultures, NaB-treated cells, and fully differentiated NHKs. Growth of NHKs on FN suppressed both spontaneous and NaB-directed maturation and inhibited maximal expression of protein changes associated with the differentiated state. Thus, the composition of the extracellular matrix can modulate (at both the morphologic and protein levels) the response of basal NHKs to a potent differentiation-inducing agent. Abrogation of NHK maturation by FN was not due to adverse effects on cellular metabolism, abortive differentiation, or altered timing of induced differentiation. FN appears to exert its suppressive effect by either maintaining an early stem cell phenotype which is poorly competent for terminal maturation or attenuating an as yet unknown aspect of the NaB-initiated differentiation cascade.

Actins↗

PubMed1992

Anthralin decreases keratinocyte TGF-alpha expression and EGF-receptor binding in vitro.

Anthralin is an effective topical treatment for active psoriasis; however, its mechanism of action is unknown. Both TGF-alpha and its receptor, the EGF receptor, are overexpressed in active psoriatic plaques and might, therefore, play a role in psoriatic epidermal hyperplasia. In order to assess whether anthralin might act via alteration of this growth factor pathway, we examined the in vitro effects of pharmacologic concentrations of anthralin on cultured normal human keratinocytes. Keratinocyte proliferation was inhibited by 98% at an anthralin concentration of 10 ng/ml. In contrast, lymphocyte proliferation was inhibited by only 50% at an anthralin concentration of 10 micrograms/ml. Anthralin treatment did not induce cell-cycle-specific growth arrest as assessed by flow-cytometric analysis of acridine-orange-stained keratinocytes. Northern analysis of anthralin-treated keratinocytes demonstrated a marked decrease in TGF-alpha mRNA expression. Anthralin-treated keratinocytes showed decreased binding of 125I-EGF and 125I-IGF-I to their respective receptors, but EGF receptor binding was inhibited to a greater extent. Anthralin decreased ligand-binding affinity and cell-surface numbers of EGF receptors as assessed by Scatchard analysis of 125I-EGF binding to anthralin-treated keratinocytes. These results indicate that anthralin alters components of the EGF receptor pathway in cultured keratinocytes and that these effects might contribute to the clinical efficacy of anthralin in the treatment of active psoriasis.

Anthralin↗

PubMed1991

Ploidy in invasive colorectal cancer. Implications for metastatic disease.

A retrospective study was performed to determine the ploidy of superficial (above muscularis propria) and deep (below muscularis propria) biopsy specimens from the primary colorectal cancer of 88 patients with Dukes Stage C2 and D colorectal tumors. The ploidy of lymph node and liver metastases was compared with that of the superficial and deep specimen from the corresponding primary tumor. Among the tumors studied, 78% exhibited nondiploid stemlines. In 19% of the tumors, the ploidy of the superficial biopsy differed from that of the deep biopsy. Among these discordant tumors, all of the deep biopsy specimens corresponded in ploidy to the liver metastases, whereas most of the superficial specimens were similar in ploidy to the lymph node metastases. Our observations suggest that measurement of a single site may not be sufficient to detect nondiploid stemlines within a tumor. They also suggest that measurement of deeper parts of invasive tumors may be more reflective of the phenotype of distant metastases than measurement of superficial specimens.

Colorectal Neoplasms↗

PubMed1991

A characteristic Mls-1a response precedes Mls-1a anergy in vivo.

T cells expressing V beta 6 variable gene segments of the T cell receptor undergo blast formation and divide in mice after injection of lymphoid cells bearing minor lymphocyte-stimulating (Mls)-1a gene products. This in vivo Mls-1a response resembles in vitro Mls-1a stimulation; it is dose dependent, not MHC-class II haplotype restricted, but requires expression of functional IE gene products. The in vivo Mls-1a response is followed by a complete and specific in vivo Mls-1a anergy and a partial in vitro Mls-1a anergy. The measurement of a Mls-1a response in vivo and of the establishment of in vivo anergy to it provides a convenient method to assay Mls-1a reactivity of T cells in vivo on a cell-by-cell basis in terms of cell surface phenotype, size, and mitotic activity.

Animals↗

PubMed1991

Cyclosporine in psoriasis treatment. Inhibition of keratinocyte cell-cycle progression in G1 independent of effects on transforming growth factor alpha/epidermal growth factor receptor pathways.

Cyclosporine, an immunosuppressive drug, is effective in the treatment of recalcitrant psoriasis. Previous work suggested that keratinocyte hyperproliferation and inflammation are linked in psoriasis and that immune mechanisms participate in the pathogenesis of psoriasis. Transforming growth factor (TGF) alpha may be an important regulatory factor of epidermal growth as overproduction of TGF-alpha is associated with epidermal hyperplasia in psoriatic plaques and epidermal growth factor receptors are overexpressed in psoriatic epithelium. In this study, the effects of cyclosporine on cultured human keratinocytes were examined. Cyclosporine specifically inhibited keratinocyte cell-cycle progression in the G1 phase without causing keratinocytes to terminally differentiate. Cyclosporine did not decrease the expression of TGF-alpha or epidermal growth factor receptors. These results suggest that the effects of cyclosporine on psoriatic skin are unrelated to direct effects on autocrine growth regulation of keratinocytes via TGF-alpha production or of epidermal growth factor receptor modulation.

Chemokine CXCL10↗

PubMed1991

Impact of exogenous growth hormone on host preservation and tumor cell-cycle distribution in a rat sarcoma model.

Growth hormone (hGH) has been reported to improve nitrogen balances and accrue lean mass tissue in stable subjects. However, the ability of hGH to positively influence host preservation in stressed catabolic states such as cancer-induced cachexia remains unproven. Thirty-seven sham or tumor implanted Fischer 344 rats were randomized to receive either 0.5 mg/kg/day hGH or saline (SAL) subcutaneously from Days 14 to 23 postimplantation. Plasma levels of hGh and somatomedin C/insulin-like growth factor I (IGF I) as well as IGF I bioactivity were determined at sacrifice. Gastrocnemius muscle protein content was used as a index of host lean tissue mass and the tumor response was evaluated via flow cytometry for analysis of cell-cycle distribution. Host cachexia was not attenuated by hGH as muscle protein content was similar in hGH and saline-treated groups. Despite elevated hGH levels (range, 77-222 ng/ml (GH) vs less than 2 ng/ml (SAL], IGF I levels and bioactivity were not elevated in GH-treated groups. In contrast, cancer-induced anorexia markedly decreased IGF I levels (4 U/ml vs 9 U/ml, NTB; P less than 0.01) and this response remained refractory to hGH administration. While final tumor weights were similar between GH- and SAL-treated groups, hGH treatment caused a twofold increase in the proportion of aneuploid cells (P less than 0.05). In conclusion, hGH failed to attenuate lean mass dissolution in the tumor bearing host and this response may be related to the failure of IGF I induction. Conversely, the altered proportion of tumor aneuploid cells suggests a direct influence on tumor cell-cycling populations.

Animals↗

PubMed1990

Epidermal cell-shape regulation and subpopulation kinetics during butyrate-induced terminal maturation of normal and SV40-transformed human keratinocytes: epithelial models of differentiation therapy.

Recent data indicate that malignant human epidermal cells may be appropriate targets for sodium butyrate (NaB)-mediated differentiation therapy. The response of pre- and post-crisis populations of SV40-transformed human keratinocytes (SVKs) to this differentiation-inducing agent was assessed, therefore, within the framework of NaB-directed normal human keratinocyte (NHK) maturation. NaB augmented cornified envelope (CE) production in NHK and pre-crisis SVK cultures; the time-course and efficiency of induced maturation were similar in the 2 cell systems. In NHKs, the percentage of amplifying ("B" substate) cells decreased with time in NaB correlating with increases in both "C" stage keratinocytes and CEs. The latter formed over one or 2 layers of nucleated basal-like cells. Inductions were accompanied by immediate cell cycle blocks (in both the G1 and G2/M phases), reorganization within the actin cytoskeleton, and transient early increases in cellular actin content. Increased NHK and pre-crisis SVK cytoskeletal-associated actin reached a maximum approximately 48 hr after NaB addition and preceded development of CEs. The CE precursors, thus, probably reside in the "B" substate. Post-crisis SVKs, in contrast, were refractive to NaB-induced terminal maturation or cell-cycle perturbation, failed to initiate actin filament rearrangements, and retained a basal cell-like phenotype. Stable transformation of human SVKs in post-crisis phase, therefore, appears to be associated with loss of maturation "competence" within the "B" keratinocyte subpopulation.

Actin Cytoskeleton↗

PubMed1990

Abnormal DNA ploidy and proliferative patterns in superficial colonic epithelium adjacent to colorectal cancer.

Superficial colonic cells were taken from normal-appearing mucosa at 2, 5, and 10 cm proximal and distal to colorectal cancer margins in 37 patients. The DNA ploidy and proliferative pattern of each sample were determined using flow cytometry. In 11 patients, histology of mucosal sections from the same sites also was analyzed. We found a higher frequency of aneuploidy than previously reported in mucosa up to 10 cm from a colorectal cancer; 62% (23/37) of the primary cancers were aneuploid, and of these, 48% (11/23) were associated with adjacent aneuploid mucosa. The mucosa adjacent to the 14 diploid cancers had only diploid characteristics. The proliferative activity (as reflected by synthetic (S) phase fraction) of aneuploid cancers (21.1 +/- 2.0% SEM) and aneuploid mucosa as far as 10 cm away (21.2 +/- 2.1% SEM) was higher than in normal controls (10.2 +/- 0.7% SEM) (P less than 0.0005). Parallel cytology excluded shed cancer cells as an explanation for these findings. Histology showed diffuse, generally mild and reactive, mucosal abnormalities in eight of 11 patients. Ploidy did not correlate with histologic abnormalities. The findings of aneuploidy and high S-phase fraction in uninvolved superficial mucosa provide evidence for a field defect in mucosa adjacent to colorectal cancer and support the concept that the large bowel mucosa behaves as a unit in carcinogenesis.

Adult↗

PubMed1990

TGF-alpha and TGF-beta expression during sodium-N-butyrate-induced differentiation of human keratinocytes: evidence for subpopulation-specific up-regulation of TGF-beta mRNA in suprabasal cells.

Sodium-N-butyrate (NaB) induces terminal differentiation and cornified envelope formation in cultured human keratinocytes. In the present study we explored the question of whether NaB-induced maturation could be mediated through changes in TGF-alpha and TGF-beta expression in normal keratinocytes. NaB induced a four-fold increase in TGF-beta mRNA transcript levels. This increase in TGF-beta mRNA abundance occurred only within the nonbasal keratinocyte subpopulation which maximally responds to NaB treatment by progression to cornified envelopes. Basal keratinocytes, which are relatively refractive to cornified envelope formation, did not show any increase in TGF-beta mRNA abundance after NaB treatment. By comparison, TGF-alpha mRNA transcript and extracellular TGF-alpha protein levels were unaffected by NaB treatment. A 50% decrease in EGF receptor binding was observed in NaB-treated keratinocyte cultures, rendering the cells less responsive to proliferation induction.

Butyrates↗

PubMed1990

Occlusive hydrocolloid dressings decrease keratinocyte population growth fraction and clinical scale and skin thickness in active psoriatic plaques.

Clinical studies suggest a therapeutic role for occlusion in the treatment of psoriasis. Previous studies, using multiparameter RNA/DNA flow cytometric analysis of epidermal suspensions obtained from active plaques, demonstrated increased keratinocyte growth fraction which reversed with successful medical treatment. Because keratinocyte growth fraction reflected disease activity, it was used in this study in addition to clinical evaluations in order to determine the efficacy of occlusion in the treatment of psoriatic plaques. In each of 9 patients, scale, skin thickness and erythema were compared in one occluded and one control plaque using an analog scale. Both scale and skin thickness, but not erythema, were decreased after 2 weeks of occlusion. However after 10 weeks, no additional differences were seen when compared with assessments made after 2 weeks, suggesting that the benefits of occlusive therapy occurred early. After 10 weeks of occlusion, the keratinocyte growth fraction was significantly decreased in occluded plaques. This study demonstrates that occlusion plays a synergistic role with other therapeutic modalities in ameliorating psoriatic plaques.

Bandages, Hydrocolloid↗

PubMed1990

Growth of melanocytes in human epidermal cell cultures.

Epidermal cell cultures were grown in keratinocyte-conditioned medium for use as burn wound grafts; the melanocyte composition of the grafts was studied under a variety of conditions. Melanocytes were identified by immunohistochemistry based on a monoclonal antibody (MEL-5) that has previously been shown to react specifically with melanocytes. During the first 7 days of growth in primary culture, the total number of melanocytes in the epidermal cultures decreased to 10% of the number present in normal skin. Beginning on day 2 of culture, bipolar melanocytes were present at a mean cell density of 116 +/- 2/mm2; the keratinocyte to melanocyte ratio was preserved during further primary culture and through three subpassages. Moreover, exposure of cultures to mild UVB irradiation stimulated the melanocytes to proliferate, suggesting that the melanocytes growing in culture maintained their responsiveness to external stimuli. When the sheets of cultured cells were enzymatically detached from the plastic culture flasks before grafting, melanocytes remained in the basal layer of cells as part of the graft applied to the patient.

Antibodies, Monoclonal↗

PubMed1989

DNA content of rectal scrapings from individuals at low and high risk for the development of colorectal cancer. A feasibility study.

Scrapings of superficial rectal mucosa were collected from 31 patients with colorectal carcinoma, 66 patients with sporadic adenoma, and 53 control subjects with no personal or family history of colorectal cancer. The DNA ploidy level and proliferative patterns of each specimen were analyzed by flow cytometry (FCM). A GMS index, calculated as the ratio of G2 + M:S, was found to be significantly lower in control subjects than in any of the high-risk groups studied. Aneuploidy was more prevalent in rectal scrapings from cancer patients and adenoma patients than in those from control subjects. Aneuploid cell populations were detected in apparently normal rectal scrapings from two control subjects. Some high-risk individuals (i.e., cancer patients and patients with adenomas and a family history of cancer) exhibited higher proportions of tetraploid (designated G2/M) cells and a higher G2/M:S phase ratio than control subjects. The results accumulated thus far show that the rectal scraping procedure is safe and easy to perform. Our limited findings give hope that the DNA content analysis of cells obtained by rectal scraping may eventually prove useful in mass screening for colorectal cancer risk. However, definitive evaluation will require further refinement and elaboration of analytic technique and testing on more patients at various levels of predetermined risk.

Adenoma↗

PubMed1989

Comparison of an occlusive and a semi-occlusive dressing and the effect of the wound exudate upon keratinocyte proliferation.

Three consecutive studies were performed in 58 patients evaluating the effect of occlusion on the healing of partial-thickness wounds. Mirror-image donor sites were covered with the occlusive hydrocolloid dressing (HCD) (DuoDerm) and compared to fine mesh gauze, and the HCD was subsequently compared to a semi-occlusive dressing of polyurethane film, (Op-site). In addition, partial-thickness burn wounds were covered with the HCD and the remaining burn wound was treated with silver sulfadiazine. The donor sites and burn wounds treated with HCD healed significantly faster than those covered with fine mesh gauze or silver sulfadiazine (p less than 0.001) and with less pain. The HCD and polyurethane film were equivalent. There were no clinical infections with the wounds that were occluded. The exudate collected beneath the DuoDerm and Op-site on donor sites was added to the tissue culture system and resulted in a modest increase in keratinocyte proliferation. However, the exudate from burn wounds under HCD resulted in a marked increase in cell proliferation (p less than 0.001).

Adolescent↗

PubMed1989

Cultured human keratinocytes: discrimination of different cell cycle compartments based upon measurement of nuclear RNA or total cellular RNA content.

Correlated measurements of total cellular RNA and DNA of cultured human keratinocytes by flow cytometry, followed by multivariate analysis, discriminate three distinct subpopulations of cells differing in RNA content. The first subpopulation is comprised of small cells resembling basal cells of epidermis, with low RNA content and long (100-300 h) generation times. The second subpopulation consists of keratinocytes resembling cells in the spinous layer of epidermis, characterized by increased RNA content and shorter (35-40 h) generation times. The third subpopulation consists of the largest, keratinohyalin-containing cells which remain in G1 and undergo terminal differentiation. In contrast to total cellular RNA, correlated measurements of DNA and nuclear RNA reveal that: (1) entrance of all cultured cells from G1 into S phase occurs only after accumulation of the same, threshold amount of nuclear RNA; hence there is only a single population of S + G2 + M-phase cells; (2) there are two distinct subpopulations in G1, one with minimal nuclear RNA content and another with increased RNA. Stathmokinetic experiments indicate that the G1-phase cells with low nuclear RNA have distinctly longer residence times in G1 compared to cells with high nuclear RNA content. Thus, measurements of the total cellular RNA versus nuclear RNA content reveal kinetically distinct cell subpopulations. Whereas total cellular RNA content correlates more with differentiation, nuclear RNA content reflects primarily the kinetic properties of the cell.

Acridine Orange↗

PubMed1989

Sodium-N-butyrate induces cytoskeletal rearrangements and formation of cornified envelopes in cultured adult human keratinocytes.

The technique developed in our laboratory allows us to culture multilayered, stratified sheets of human keratinocytes, which can be used to cover the burn wounds of patients. Organization of cells in these cultures resembles stratum germinativum and stratum spinosum but there are only a few fully keratinized cells and the stratum corneum is not developed. Since the fully differentiated sheets may offer additional advantages as epidermal transplants, attempts were made to enhance the degree of differentiation in vitro. In the present study sodium-N-butyrate (NaB) was used as a differentiating agent and its effect on the cell cycle and cytoarchitecture of epidermal cells was investigated. Incubation of keratinocytes in the presence of 2.5 mM NaB induced the appearance of enucleated cornified envelopes, covering approximately 70-80% of the surface of the cultures. Their appearance correlated with a decrease in expression of keratin K13, previously shown to be inhibited during terminal differentiation of human keratinocytes. An increase in transglutaminase transferase activity was also observed. The induction of cornified layers also correlated with an increase in the amount of microfilament (MF)-associated actin. NaB also induced changes in the cell cycle distribution of the keratinocyte cultures. A decrease in the proportion of S and G1B phase cells was paralleled by an increase in G1A cells, maximally expressed 30-48 h following addition of the inducer. Interestingly, NaB also induced a cell arrest in G2 phase. These cell cycle perturbations preceded the onset of keratinocyte differentiation. The results indicate that the enhanced differentiation of human keratinocytes in the presence of NaB may serve as a means to produce epidermal sheets with improved properties for transplantation in a clinical setting. It also serves as an in vitro model system to study the interrelationships between biochemical events and cell cycle changes accompanying differentiation.

Butyrates↗

PubMed1988

Effects of tobacco glycoprotein (TGP) on the immune system. II. TGP stimulates the proliferation of human T cells and the differentiation of human B cells into Ig secreting cells.

We have been studying the effects of tobacco glycoprotein (TGP), a polyphenol-rich glycoprotein isolated from cured tobacco leaves, on the immune system. We have shown previously that mice immunized with TGP produce preferentially antibodies of the IgE isotype and that TGP is a T cell-independent B cell mitogen for mice, which stimulates B cell proliferation and B cell differentiation into Ig-secreting cells. We report herein that TGP stimulates a significant increase in [3H]TdR incorporation by human PBL and by human cord blood lymphocytes. The magnitude of the proliferative response of PBL to TGP does not correlate with the donor's titer of IgE antibodies to TGP, as assayed by a wheal and flare response after an i.d. injection of TGP, neither does it correlate with the donor's smoking history. [3H]TdR uptake is not observed before day 5 of culture, and the response peaks between days 5 and 10 of culture. Analysis of the cellular basis for the proliferative response suggests that T cells are proliferating. Two-parameter analysis by flow cytometry shows that CD3+, CD4+, and CD8+ cells are in the S + G2 + M phases, but not Ig-bearing cells or monocytes. A significant increase in HLA-DR (Ia)-bearing cells is observed on cells in all of the cell cycle phases. This increase coincides with cells entering the S phase. No increase is observed in the expression of the IL-2-R as assayed by the anti-Tac antibody. TGP also stimulates human PBL to differentiate and to produce Ig of the IgM, IgG, and IgA isotypes, without stimulating a detectable B cell proliferative response. The proliferative response of PBL is clearly due to TGP and not to contamination with LPS, because by the limulus amebocyte assay the TGP preparation contains less than 2% LPS, which could not account for the stimulation observed.

Adult↗

PubMed1988

Interactions of arterial cells: III. Stathmokinetic analyses of smooth muscle cells cocultured with endothelial cells.

Arterial endothelial cells (EC) or their conditioned medium (ECCM) can alter the proliferation of cocultured arterial smooth muscle cells (SMC). Previously, we have shown, as have others, that EC regulate the growth of cocultured SMC depending on the density of both cell types. To ascertain the rate of cell-cycle traverse in preconfluent arterial SMC cocultured with arterial EC or ECCM (derived from preconfluent EC), we have conducted a series of stathmokinetic experiments using flow cytometry to determine where specific changes may occur in the cell cycle. Results of our experiments indicate for the first time that ECCM stimulates the proliferation of preconfluent SMC by significantly shortening the residence times in the G1 and S phases of the cell cycle. The predominant relative effect occurs within the early G1 (G1A) compartment where pretreatment with ECCM shortens the residence time by approximately 55%. Furthermore, we have observed that preincubation of serum-free ECCM with antiplatelet-derived growth factor (PDGF) antibody abolishes any mitogenic effect on SMC. This suggests that EC secrete PDGF-like molecules which enhance the proliferation rate of preconfluent, cocultured SMC. These findings support the hypothesis that arterial EC may secrete mitogens which stimulate arterial SMC proliferation in the vascular wall.

Animals↗