Regulation by estrogen through the 5'-flanking region of the transforming growth factor alpha gene

Expression of transforming growth factor alpha (TGF alpha) mRNA and protein can be stimulated by estrogens such as 17 beta-estradiol (E2) in estrogen-responsive rodent and human breast cancer cells. To ascertain if E2 can directly regulate TGF alpha expression through the 5'-flanking region of the human TGF alpha gene, E2-responsive MCF-7 or ZR-75-1 human breast cancer cells or E2-nonresponsive MDA-MB-231 breast cancer cells were transiently transfected with a plasmid containing an 1140-base pair (bp) Sac-I fragment of the TGF alpha 5'-flanking region ligated to the chloramphenicol acetyltransferase (CAT) gene. Cells that were transfected and subsequently treated with physiological concentrations of E2 (10(-11)-10(-8) M) for 24 h exhibited a 2- to 10-fold increase in CAT activity. The E2 stimulation of CAT activity was dose-dependent with an increase first found at 10(-10) M E2. The increase in CAT activity could be detected within 24-36 h after the addition of E2. There was no significant change in CAT activity in transiently transfected MDA-MB-231 cells as mediated through the TGF alpha 5'-flanking region after E2 treatment. MCF-7 cells were also transiently transfected with different fragments of the TGF alpha 5'-flanking region ligated to the luciferase gene. In the absence of E2 treatment, no detectable luciferase activity was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Trabecular myocytes of the embryonic heart require N-cadherin for migratory unit identity

The myocardial wall of the vertebrate heart changes from a simple epithelium to a trabeculated structure during embryogenesis. This process occurs when epithelioid cardiomyocytes migrate toward the endocardium, which we show is coincident with up-regulation of the cell adhesion molecule, N-cadherin. To study the role of N-cadherin expressed at the trabeculation stage, a replication-defective retrovirus expressing a dominant negative mutant of N-cadherin (delta N-cadherin) was engineered. Control viruses were designed to express beta-galactosidase or a full-length N-cadherin. Viruses were introduced into epithelioid presumptive myocytes at the time they initiate the epithelial-mesenchymal transformation. Individual cells infected with control viruses generated daughter myocytes which migrated toward endocardium as a tight cluster, thereby generating a clone that forms a single or at most two trabeculae. In contrast, myocytes expressing delta N-cadherin were sparsely distributed within the myocardium and failed to form the ridge-shaped clone. Thus, in addition to its known roles in myocyte epithelialization and intercalated disc formation, N-cadherin appears to play a role in homotypic interactions between nonepithelial migratory myocytes during trabecular formation of the embryonic heart.

Computed tomography assessment of abdominal aortic aneurysm morphology after endograft exclusion

OBJECTIVES

Assessment of the long-term function of endografts to exclude abdominal aortic aneurysm (AAA) includes determination of aneurysm dimensions and morphologic changes that occur after implantation. This study reports the dimensional analysis of patients treated with AneuRx bifurcated endoprostheses with postintervention, 1-year (n = 51), 2-year (n = 28), and 3-year (n = 10) postimplantation contrast computed tomography data.

METHODS

Maximal diameter (D) and cross-sectional area (CSA) of the AAA were measured from axial computed tomography images. Total volume, AAA thrombus volume (AAA volume minus the volume of the device and luminal blood flow), diameter of the aorta at the level of the renal arteries and within the device, distance from the renal arteries to the device, length of the device limbs, and the angle of the proximal neck were also determined at the same follow-up intervals after deployment with computed tomography angiograms reconstructed in an interactive environment.

RESULTS

Fifty-one of 98 consecutively treated patients with the AneuRx bifurcated prosthesis (29 "stiff" and 22 "flexible" body devices) had complete data from the postprocedure and follow-up computed tomography studies available for analysis. Max D, CSA, total volume of the AAA, and AAA thrombus volume decreased sequentially from year to year compared with the postimplantation values. D and CSA decreased or were unchanged in all except four patients, two who had unrestricted enlargement of the aneurysm with eventual rupture and one who had surgical conversion for continued expansion despite four diagnostic angiograms and attempted embolizations. Total volume of the AAA increased in 11 of 51 patients at 1 year, eight of whom had endoleaks at some interval during the follow-up. Thrombus volume increased more than 5% in four of these patients, including the two with eventual rupture and the one conversion. Patients with endoleaks who had spontaneous thrombosis or were successfully treated either remained at the same volume or had decreased volume on subsequent examinations. D at the renal arteries increased an average of 0.9 mm during the first year, with a concomitant increase of 2.8 mm within the proximal end of the device related to the self-expanding nature of the Nitinol suprastructure. Subsequent enlargement of the proximal neck continued at a slow rate in some cases but never exceeded the diameter of the endoluminal device. The distance from the renal arteries to the device increased by an average of 3 mm over the first year, with the greatest increases occurring in patients with a "stiff" body device and those with rapid regression (>10% total volume) in 1 year. As regression of the AAA occurred, the angle of the proximal neck varied from -5 degrees to +25 degrees from the original alignment. Limb length varied from -8 mm to +10 mm, with no consistent pattern for the change, that is, ipsilateral or contralateral limb.

CONCLUSION

Significant variation in the quantitation of aneurysm size occurs depending on the technique of computed tomography assessment used. In most patients diameter assessment is adequate, although volumetric analysis appears to be very helpful in certain patients who do not show aneurysm regression, or in whom the diameter increases or where endoleaks persist. Three-dimensional reconstruction and volumetric analysis are also useful to assess the mechanism by which the endovascular device accommodates to morphology changes and to determine criteria for reintervention.

Analysis of polymorphisms affecting immune complex handling in systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) is a polygenic disorder of dysregulated inflammation. Numerous specific candidate genes have been identified and most relate to the handling of immune complexes or antigen presentation. This is consistent with the classic finding of immune complex deposition in affected end organs. We wished to examine combinatorial effects of polymorphic variants of genes involved in immune complex clearance in susceptibility to lupus.

METHODS

This study examined the occurrence of polymorphisms in genes which encode proteins known to be involved in immune complex handling and clearance. Each polymorphic variant of a complement protein (C2, mannose binding protein and C4), complement receptor (CR1) or Fc receptor (FcgammaRIIA and FcgammaRIIIA) gene is known to affect function adversely. One hundred and sixty SLE patients and 212 control subjects were genotyped using polymerase chain reaction methods.

RESULTS

We found an increasing association of SLE with increasing numbers of gene defects. Combinations of severe defects in FcgammaRIIA and FcgammaRIIIA were particularly deleterious for both African American and Caucasian patients, even though only one defective variant was individually statistically significantly associated with SLE.

CONCLUSIONS

The results of the study suggest that genes may interact in ways that either synergize or modify the effect of a single genetic effect and imply that association studies must be interpreted within the genetic background of the populations.

Localization of telomerase hTERT protein and hTR in benign mucosa, dysplasia, and squamous cell carcinoma of the cervix

Telomerase has been detected by telomerase repeat amplification protocol (TRAP) assay in cervical dysplasia and squamous cell carcinoma but not in most normal cervical tissues. In the present study, the cellular localization of the protein catalytic subunit of telomerase (hTERT) and the RNA component (hTR) were investigated by a sensitive immunohistochemical technique and by in situ hybridization, respectively. hTERT protein was detected in all diagnostic categories of cervical specimens. hTERT was localized predominantly to the lower suprabasal levels of normal squamous mucosa but was detected throughout virtually all levels of the lesional epithelium in low-grade squamous intraepithelial lesions (LSILs), high-grade squamous intraepithelial lesions (HSILs), and squamous cell carcinoma (SCC). Telomerase expression correlated with hTERT detection in SCC and HSIL but was not detected by TRAP assay in most samples of normal mucosa or LSIL. The distribution of hTR correlated with the localization of hTERT in HSIL and SCC but was restricted to the basal and suprabasal cell layers in normal mucosa and LSIL.

Somatic hypermutation of immunoglobulin and non-immunoglobulin genes

Somatic hypermutation (SHM) of immunoglobulin (Ig) genes is a highly specific mechanism restricted to B lymphocytes during only a few cell generations. Data presented here suggest that transcription of the target genes is required, but not sufficient for SHM. Presumably, cis-acting elements, such as those present in the Ig enhancers, are required to target a mutator factor (MuF) to Ig and human BCL-6 genes. It is postulated that the MuF travels with the transcribing RNA polymerase and is deposited on the target gene when the polymerase pauses. Point mutations, and rare deletions and insertions, are created by the combined actions of MuF and certain DNA polymerases. A subset of the mutations is corrected during SHM by DNA mismatch repair.

Rapamycin-insensitive companion of mTOR (RICTOR) amplification defines a subset of advanced gastric cancer and is sensitive to AZD2014-mediated mTORC1/2 inhibition

Background

Targeting oncogenic genomic aberrations is an established therapeutic strategy in multiple tumor types. Molecular classification has uncovered a number of novel targets, and rapamycin-insensitive companion of mTOR (RICTOR) amplification has been identified in lung cancer. Further investigation assessing the therapeutic potential of RICTOR amplification as a novel target across advanced cancers is needed.

Patients and methods

Tumor samples from 640 patients with metastatic solid tumors, primarily gastrointestinal and lung cancers were prospectively subjected to a next-generation sequencing (NGS) assay to identify molecular targets. Samples with NGS-detected RICTOR amplification were confirmed with FISH. A RICTOR-amplified patient-derived cell (PDC) line was generated and used to investigate the effectiveness of selective AKT, mTORC1, and mTORC1/2 inhibition.

Results

NGS identified 13 (2%) of 640 patients with RICTOR-amplified tumors (6 gastric, 3 NSCLC, 1 SCLC, 1 CRC, 1 sarcoma, 1 MUO). Of the 13 patients, seven patients had RICTOR protein overexpression by IHC. The prevalence of RICTOR amplification in gastric cancer by NGS was 3.8% (6/160). FISH testing confirmed amplification (RICTOR/control >2) in 5/13 (38%) of samples, including four gastric cancers and one lung cancer. Treatment of a RICTOR amplified PDC with a selective AKT (AZD5363), selective mTORC1 (everolimus), dual mTORC1/2 (AZD2014), and the multi-target kinase inhibitor pazopanib demonstrated preferential sensitivity to the mTORC1/2 inhibitor (AZD2014). Knockdown of RICTOR reversed PDC sensitivity to AZD2014, validating the importance of RICTOR amplification to the PDC line.

Conclusions

RICTOR amplification is a rare but therapeutically relevant genomic alteration across solid tumors. Our results support further pre-clinical and clinical investigation with AZD2014 in RICTOR amplified gastric cancer and highlights the importance of genomic profiling.

Measurement of the mitochondrial membrane potential and pH gradient from the redox poise of the hemes of the bc1 complex

The redox potentials of the hemes of the mitochondrial bc(1) complex are dependent on the proton-motive force due to the energy transduction. This allows the membrane potential and pH gradient components to be calculated from the oxidation state of the hemes measured with multi-wavelength cell spectroscopy. Oxidation states were measured in living RAW 264.7 cells under varying electron flux and membrane potential obtained by a combination of oligomycin and titration with a proton ionophore. A stochastic model of bc(1) turnover was used to confirm that the membrane potential and redox potential of the ubiquinone pool could be measured from the redox poise of the b-hemes under physiological conditions assuming the redox couples are in equilibrium. The pH gradient was then calculated from the difference in redox potentials of cytochrome c and ubiquinone pool using the stochastic model to evaluate the ΔG of the bc(1) complex. The technique allows absolute quantification of the membrane potential, pH gradient, and proton-motive force without the need for genetic manipulation or exogenous compounds.

Induction of transforming growth factor alpha expression in mouse mammary epithelial cells after transformation with a point-mutated c-Ha-ras protooncogene

NOG-8 ras cells are a normal mouse mammary epithelial cell line transfected with a plasmid containing a glucocorticoid-inducible mouse mammary tumor virus long terminal repeat linked to the activated c-Ha-ras protooncogene. After addition of dexamethasone, there is a rapid induction (within 1-3 h) of p21ras protein that is concomitant with a parallel induction of the c-Ha-ras specific mRNA. After 4-6 days of dexamethasone treatment, NOG-8 ras cells are able to grow as colonies in semisolid medium. Between 9 and 12 days of dexamethasone treatment, there is a 5- to 6-fold increase of transforming growth factor alpha (TGF alpha) activity in the conditioned medium from NOG-8 ras cells. A 60-65% reduction in epidermal growth factor cell surface receptors on NOG-8 ras cells also occurs during this time interval. A 3- to 4-fold increase of the expression of a specific TGF alpha mRNA can be detected within 2 days of dexamethasone treatment, preceding the increase in TGF alpha protein found in the conditioned medium. Exogenous TGF alpha is able to stimulate in a dose-dependent fashion the anchorage-dependent and anchorage-independent growth of NOG-8 ras cells to a level comparable to that observed in dexamethasone treated ras-transformed NOG-8 ras cells. These results suggest that the enhanced expression of TGF alpha after induction of an activated ras protooncogene may be necessary for the anchorage-independent growth and subsequent morphological changes and the enhanced growth rate observed in ras-transformed mammary epithelial cells.

Expression of transforming growth factor alpha (TGF alpha) in breast cancer

Transforming growth factor alpha (TGF alpha) is one growth factor that has been circumstantially implicated in regulating the autocrine growth of breast cancer cells. Expression of TGF alpha can be modulated by activated cellular protooncogenes such as ras and by estrogens. For example, the epidermal growth factor (EGF)-responsive normal NOG-8 mouse and human MCF-10A mammary epithelial cell lines can be transformed with either a point-mutated c-Ha-ras protooncogene or with a normal or point-mutated c-neu (erbB-2) protooncogene. In ras transformed NOG-8 and MCF-10A cells but not in neu transformed cells there is a loss in or an attenuated response to the mitogenic effects of EGF. This response may be due in part to an enhanced production of endogenous TGF alpha that is coordinately and temporally linked to the expression of the activated ras gene and to the acquisition of transformation-associated properties in these cells. TGF alpha mRNA and TGF alpha protein can also be detected in approximately 50-70% of primary human breast tumors. In addition, approximately 2- to 3-fold higher levels of biologically active and immunoreactive TGF alpha can also be detected in the pleural effusions from breast cancer patients as compared with the TGF alpha levels in the serous effusions of noncancer patients. Over-expression of a full-length TGF alpha cDNA in NOG-8 and MCF-10A cells is capable of transforming these cells. Finally, expression of TGF alpha mRNA and production of biologically active TGF alpha protein is also found in normal rodent and human mammary epithelial cells.

B lymphocytes of xeroderma pigmentosum or Cockayne syndrome patients with inherited defects in nucleotide excision repair are fully capable of somatic hypermutation of immunoglobulin genes

Recent experiments have strongly suggested that the process of somatic mutation is linked to transcription initiation. It was postulated that a mutator factor loads onto the RNA polymerase and, during elongation, causes transcriptional arrest that activates DNA repair, thus occasionally causing errors in the DNA sequence. We report the analysis of the role of one of the known DNA repair systems, nucleotide excision repair (NER), in somatic mutation. Epstein-Barrvirus-transformed B cells from patients with defects in NER (XP-B, XP-D, XP-V, and CS-A) were studied. Their heavy and light chain genes show a high frequency of point mutations in the variable (V), but not in the constant (C) regions. This suggests that these B cells can undergo somatic hypermutation despite significant defects in NER. Thus, it is doubtful that NER is an essential part of the mechanism of somatic hypermutation of Ig genes. As an aside, NER seems also not involved in Ig gene switch recombination.

Comparison of risk factors and clinical responses to proton pump inhibitors in patients with erosive oesophagitis and non-erosive reflux disease

BACKGROUND

There has been no report on the response to proton pump inhibitor (PPI) therapy and on-demand or the relapse rate of non-erosive reflux disease (NERD) and erosive oesophagitis in Korea.

AIM

To compare the risk factors, clinical symptoms and PPI responses between patients with erosive oesophagitis and NERD patients.

METHODS

A survey was performed prospectively in the erosive oesophagitis (205 patients) and NERD group (200 patients). Clinical symptoms, risk factors and PPI responses were analysed. On-demand therapy and the relapse rate of GERD symptoms were investigated during a one-year follow-up.

RESULTS

BMI > or = 25 (OR 3.0, 95% CI 1.1-8.3), alcohol use (OR 2.9, 95% CI 1.0-8.3), hiatal hernia (OR 5.0, 95% CI 1.2-20) and triglyceride > or =150 mg/dL (OR 4.0, 95% CI 1.7-10) were more common in the erosive oesophagitis group than in the NERD group by multivariate analysis. The ratio of oesophageal to extra-oesophageal symptoms was higher in the erosive oesophagitis group compared with the NERD group (P < 0.001). The PPI response rates at 8 weeks were different (P = 0.02); refractory rates were higher in the NERD group (16.7%) compared with the erosive oesophagitis group (6.0%). However, there was no significant difference between the two groups in on-demand therapy or the relapse rate.

CONCLUSION

These results suggest that the underlying pathogenic mechanisms of erosive oesophagitis and NERD are distinct.

Multi-valvular endocarditis

OBJECTIVE

Seventy-seven cases of native valve infective endocarditis as determined by the Duke criteria, were reviewed to determine the incidence and clinical features of multi-valvular endocarditis.

METHODS

Fourteen of 77 patients (18%) had multi-valvular endocarditis most commonly involving the mitral and aortic valves. Staphylococcus aureus (43%) and viridans streptococci (36%) were the most common organisms causing multi-valvular endocarditis.

RESULTS

Definite or probable vegetations were found in 50% of the patients by two-dimensional transthoracic echocardiograph and/or transesophageal echocardiograph, and possible vegetations were detected in 21%. The overall mortality in our series was 21%; 29% underwent valve replacement and 50% were treated medically. The major complications of multi-valvular endocarditis were congestive heart failure (64%), acute renal failure (50%), embolic events (21%), and splenic abscess/infarcts (21%).

CONCLUSIONS

Our data suggests complications of multi-valvular endocarditis, compared with uni-valvular endocarditis are similar except for heart failure. Heart failure is statistically more common in multi-valvular endocarditis (P < or = 0.002).

Expression of transforming growth factor alpha antisense mRNA inhibits the estrogen-induced production of TGF alpha and estrogen-induced proliferation of estrogen-responsive human breast cancer cells

To ascertain if 17 beta-estradiol (E2)-induced proliferation could be attenuated by blocking the expression of endogenous transforming growth factor alpha (TGF alpha), estrogen receptor (ER)-positive, estrogen-responsive MCF-7 or ZR-75-1 cells and ER-negative, estrogen-nonresponsive MDA-MB-468 or HS-578T cells were infected with a recombinant amphotropic, replication-defective retroviral expression vector containing a 435 base pair (bp) Apa1-Eco R1 coding fragment of the human TGF alpha cDNA oriented in the 3' to 5' direction and under the transcriptional control of an internal heavy metal-inducible mouse metallothionein (MT-1) promoter and containing the neomycin (neo) resistance gene. E2-stimulated expression of endogenous TGF alpha mRNA was inhibited by 4-5-fold, and the production of TGF alpha protein was inhibited by 50-80% when M-1 mass-infected MCF-7 or MZ-1 mass-infected ZR-75-1 cells were treated with 0.75-1 microM CdCl2, whereas in comparably treated parental MCF-7 or ZR-75-1 cells there was no significant effect upon these parameters. E2-stimulated anchorage-dependent growth (ADG) and anchorage-independent growth (AIG) of the M-1 or MZ-1 cells was inhibited by 60-90% following CdCl2 treatment. In contrast, neither the ADG nor AIG of the parental noninfected MCF-7 or ZR-75-1 cells that were maintained in the absence or presence of E2 was affected by comparable concentrations of CdCl2. The ADG and AIG of TGF alpha antisense MD-1 mass-infected MDA-MB-468 cells that express high levels of endogenous TGF alpha mRNA were also inhibited by 1 microM CdCl2, whereas the ADG and AIG of MH-1 mass-infected HS-578T cells, a TGF alpha-negative cell line, were unaffected by CdCl2 treatment. These results suggest that TGF alpha may be one important autocrine intermediary in regulating estrogen-induced cell proliferation.

The TATA binding protein, c-Myc and survivin genes are not somatically hypermutated, while Ig and BCL6 genes are hypermutated in human memory B cells

Immunoglobulin (IG:) genes are hypermutated in mature B cells after interaction with antigen and T cells in a germinal center reaction. We and others have recently shown that the human BCL6 gene is also hypermutated in human peripheral blood memory B cells and tonsils. A preliminary analysis of other non-Ig genes (c-MYC:, S14 and AFP) suggested that they were not mutated in memory B cells. We have now performed an in-depth analysis of three non-Ig genes that are expressed in germinal center B cells in two human donors in whom BCL6 is highly mutated. It was found that the TATA binding protein (TBP), c-MYC: and survivin genes are not hypermutated. This lack of targeting by the Ig hypermutation mechanism must be due to the lack of regulatory DNA elements, since the primary sequences of the three tested genes have at least as high intrinsic mutability indices as the BCL6 gene.

Telomerase activity in ductal carcinoma in situ and invasive breast cancer

The increasing number of breast carcinoma in situ detected by screening procedures makes it imperative to develop improved markers to stratify the risk of invasive cancer. Telomerase is detectable in invasive cancer, but not in normal tissues. We have microdissected frozen tissue blocks containing both DCIS and invasive cancer to assay the telomerase activity of these two lesions. The 46 available cases of concurrent DCIS and invasive breast cancer resulted in 43 DCIS samples and 38 invasive cancer samples adequate for analysis. Seventy per cent of the DCIS and all invasive cancer samples tested had detectable telomerase activity. In addition, we analysed telomerase activity in ten cases of DCIS that were not associated with invasive cancer, and detected telomerase activity in seven (70%). Mixing experiments showed no evidence of telomerase inhibitors in telomerase negative samples. Furthermore, periductal inflammatory infiltrates were shown to be a potential confounding source of telomerase activity. Since DCIS lesions appear to be heterogeneous with respect to telomerase activity, and telomerase activation appears to precede the development of invasive cancer, telomerase activity may be a useful adjunct in stratifying the risk of developing invasive breast cancer in patients with DCIS.

mRNA expression of transforming growth factor alpha in human breast carcinomas and its activity in effusions of breast cancer patients

Transforming growth factor alpha (TGF alpha) mRNA expression was measured by Northern blot analysis in 18 human, primary, infiltrating, ductal breast carcinomas. Expression of a 4.8-kilobase TGF alpha mRNA transcript was detected in nine of 18 tumors. No evidence was observed of any gross amplifications or major rearrangements of the TGF alpha gene in the breast carcinoma specimens. Biologically active and immunoreactive TGF alpha was measured in the pleural effusions or in the ascitic fluids from 37 noncancer and 63 cancer patients. The TGF alpha activity detected ranged from 0.2 to 26 ng/mL in most effusions from both groups. However, 29 of 63 (46%) of the effusions from cancer patients exhibited TGF alpha levels that were 6 ng/mL or higher, whereas only seven of 37 (19%) of those from noncancer patients exceeded this level (P less than .03). In particular, effusions obtained from breast cancer patients showed a significantly higher level of TGF alpha, compared with those from noncancer patients (P less than .001). Effusions from 14 cancer patients also contained elevated levels of two tumor-associated antigens, CEA and/or TAG-72, and within this group, nine also had elevated levels of TGF alpha.

Evaluation of the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch via a double-blind, placebo-controlled clinical study

OBJECTIVE

Although an ascorbic acid-loaded dissolving microneedle patch has been developed to improve anti-wrinkle effects, an efficacy evaluation with a control group has not yet been performed. In this study, the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch was evaluated in a double-blind clinical study with a control group. In addition, a cumulative skin irritation and sensitization potential of the ascorbic acid-loaded dissolving microneedle patch was performed.

METHODS

Twenty-three subjects were selected for anti-wrinkle effect evaluation in a double-blind clinical study. Subjects were divided into two groups. Group I subjects applied an ascorbic acid-loaded dissolving microneedle patch on a crow's feet area on the left side of the face and a control sample on a crow's feet area on the right side of the face every 4 days. Group II subjects placed the same patches on opposite sides of the face. Global Photodamage Score and skin replica analysis were conducted by visual inspection and skin visiometer, respectively. A skin irritation and sensitization assessment was performed on 51 subjects using the modified Shelanski & Shelanski procedure. Cumulative skin irritation potential and skin sensitization of the ascorbic acid-loaded dissolving microneedle patch and control sample were evaluated.

RESULTS

Skin treated with the ascorbic acid-loaded dissolving microneedle patch showed a statistically significant improvement in both the Global Photodamage Score and visiometer R values (P < 0.05) compared with the control sample. The R2 value (maximum roughness), in particular, showed a highly significant improvement (P < 0.01). The skin irritation and sensitization assessment demonstrated that the ascorbic acid-loaded dissolving microneedle patch did not induce any cumulative skin irritation potential or skin sensitization.

CONCLUSIONS

An ascorbic acid-loaded dissolving microneedle patch produced a significant anti-wrinkle effect without skin irritation and sensitization problems. This cosmetic dissolving microneedle patch can be used efficiently in the anti-wrinkle cosmetic field with patient convenience.

Formation of vitamin A lipid droplets in pancreatic stellate cells requires albumin

OBJECTIVE

Quiescent pancreatic stellate cells (PSCs) store vitamin A as cytoplasmic lipid droplets, and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells characterised by the loss of vitamin A droplets. Activation of stellate cells is central to fibrogenesis, but the mechanism for the formation of vitamin A droplets and its relationship to stellate cell activation remain unclear.

METHODS

With use of cultured PSCs, an attempt was made to characterise the function of albumin endogenously expressed in stellate cells.

RESULTS

Albumin is endogenously expressed in quiescent PSCs, localised in cytoplasmic lipid droplets, and its levels are markedly reduced after stellate cell activation. Continuous albumin expression in stellate cells is sufficient to maintain their fat-storing phenotype even after cell passages and renders cells resistant to the activating effects of transforming growth factor beta (TGFbeta). Forced expression of albumin in PSCs after passage 2 (activated PSCs) induced the re-appearance of lipid droplets and phenotypic changes, which were previously reported with retinol treatment. Retinol increases albumin synthesis in activated PSCs and the suppression of albumin expression using small interfering RNA (siRNA) abolishes retinol-induced effects.

CONCLUSIONS

The data demonstrate a novel role for albumin in the formation of cytoplasmic vitamin A lipid droplets in stellate cells, and suggest that albumin may have a direct influence on stellate cell activation.

TDAG51 is not essential for Fas/CD95 regulation and apoptosis in vivo

Fas/CD95 is a key regulator of apoptotic signaling, which is crucial for the maintenance of homeostasis in peripheral lymphoid organs. TDAG51 has been shown to play critical roles in the up-regulation of Fas gene expression and T-cell apoptosis in vitro. In order to identify the role of TDAG51 in vivo, we generated TDAG51-deficient (TDAG51-/-) mice. Northern blotting revealed no expression of TDAG51 in TDAG51-/- mice, indicating that the TDAG51 gene was successfully targeted. TDAG51-/- mice were healthy and showed no gross developmental abnormalities. While Fas-deficient mice display marked lymphadenopathy, splenomegaly, and lymphocytosis, TDAG51-/- mice had no apparent defects in secondary lymphoid organs. Although TDAG51 is required for up-regulation of Fas expression in T-cell hybridomas, TDAG51-/- mice expressed normal levels of Fas and had normal T-cell apoptosis. Therefore, we conclude that TDAG51 is not essential for Fas up-regulation and T-cell apoptosis in vivo. There are several known homologs of TDAG51, and these homologs may substitute for TDAG51 in TDAG51-/- mice.

Regulation of the Expression of the Prostate-specific Antigen by Claudin-7

Claudins are a family of proteins involved in forming tight junctions between cells. Here we describe two forms of claudin-7 (CLDN-7), a full-length form of CLDN-7 with 211 amino-acid residues and a C-terminal truncated form with 158 amino-acid residues. These two forms of CLDN-7 are able to regulate the expression of a tissue-specific protein, the prostate-specific antigen (PSA), in the LNCaP prostate cancer cell line. We also found that the expression of CLDN-7 is responsive to androgen stimulation in the LNCaP cell line, suggesting that this protein is involved in the regulatory mechanism of androgen. Both forms of claudin-7 are expressed in human prostate, kidney and lung samples, and in most samples, the full-length form of claudin-7 was predominant. However, in some prostate samples from healthy individuals, the truncated form of claudin-7 is predominantly expressed. Our results demonstrated that unlike other claudins, CLDN-7 has both structural and regulatory functions, and the two forms of CLDN-7 may be related to cell differentiation in organ development.