Preconditioning with whole-body or regional hyperthermia attenuates exercise-induced muscle damage in rodents

Our aim was to investigate whether hyperthermia before exercise protects against exercise-induced skeletal muscle damage. Two hyperthermia protocols were evaluated. In the first, male ICR mice were exposed to 30 min of whole-body heat in an environmental chamber at an ambient temperature of 42 °C. Heat-exposed and non-heat-exposed mice subsequently completed 60 min of downhill running on a treadmill, 24 h after exposure. Heat exposure significantly increased HSP70 and HSP25 content in the soleus muscle compared to controls. Plasma creatine kinase, muscle beta-glucuronidase, and histochemical (hematoxylin and eosin stain) analysis demonstrated that muscle damage was lower in the heat-exposed mice than in the non-heat-exposed mice. In the second, the effect of regional heating of the legs, by microwave diathermy, on the prevention of exercise-induced muscle damage was evaluated in male Wistar rats. Microwave-treated and non-microwave-treated rats again completed the running protocol 24 h after exposure. Microwave diathermy increased the muscle temperature to 40 °C, significantly increased HSP70 and HSP25 content in the soleus muscle, and significantly attenuated exercise-induced muscle damage. Therefore, hyperthermia before exercise increases skeletal muscle HSPs and attenuates the risk of exercise-induced muscle injury.

Primordial odontogenic tumor: Subepithelial expression of Syndecan-1 and Ki-67 suggests origin during early odontogenesis

Primordial odontogenic tumor (POT) is composed of variably cellular myxoid connective tissue, surrounded by cuboidal to columnar odontogenic epithelium resembling the inner epithelium of the enamel organ, which often invaginates into the underlying connective tissue. The tumor is delimited at least partially by a thin fibrous capsule. It derives from the early stages of tooth development. Syndecan-1 is a heparan sulfate proteoglycan that has a physiological role in several cellular functions, including maintenance of the epithelial architecture, cell-to-cell adhesion and interaction of cells with extracellular matrix, and with diverse growth factors, stimulating cell proliferation. Ki-67 is considered the gold standard as a cell proliferation marker. The aim of this study was to examine the expression of Syndecan-1 and Ki-67 proliferation index in POT and normal tooth germs to better understand the biological behavior of this tumor. Results showed that Syndecan-1 was more intensely expressed in subepithelial mesenchymal areas of POT, in a pattern that resembles the early stages of tooth development. The cell proliferation index (4.1%) suggests that POT is a slow growing tumor. Syndecan-1 expression in tooth germs in late cap and early bell stages was similar to POT, showing immunopositivity in subepithelial mesenchymal condensed areas. The immunohistochemical findings showed a pattern in which the population of subepithelial mesenchymal cells exhibited greater proliferative activity than the central portion of the dental papilla.

Expression of hMLH1 and hMSH2 proteins in ameloblastomas and tooth germs

BACKGROUND

Mismatch repair proteins (MMRPs) are a group of nuclear enzymes that participate in the repair of base mismatches that occur during DNA replication in all proliferating cells. The most studied MMRPs are hMSH2 and hMLH1, which are known to be highly expressed in normal tissues. A loss of MMRPs leads to the accumulation of DNA replication errors in proliferating cells. Ki-67 is a biomarker regarded to be the gold-standard tool for determining cell proliferation by immunohistochemical methods. The aim of this study was to investigate the immunohistochemical expression of hMLH1, hMSH2 and Ki-67 proteins in ameloblastomas and tooth germs, to contribute to the understanding of the development of this odontogenic neoplasm.

MATERIAL AND METHODS

Immunohistochemical assays to determine the presence of proteins hMSH2, hMLH1 and Ki-67 were performed in 80 ameloblastomas (40 solid and 40 unicystic) and five tooth germs.

RESULTS

Unicystic ameloblastomas showed higher MMRP expression (hMLH1: 62.5 ± 43.4; hMSH2: 83.3 ± 47.8) than did solid ameloblastomas (hMLH1: 59.4 ± 13.5; hMSH2: 75.8 ± 40.2). Additionally, the cell proliferation index assessed by Ki-67 was inversely proportional to the expression of MMRP. Comparison between tooth germs and ameloblastoma revealed significantly higher expression of hMLH1, hMSH2 and Ki-67 in tooth germs (p=0.02).

CONCLUSIONS

The differences of MMRP and Ki-67 immunoexpression between ameloblastomas and tooth germ suggest that alterations in the MMRP mechanisms could participate in the biological behavior of ameloblastomas.

Study of termination of postprandial gastric contractions in humans, dogs and Suncus murinus: role of motilin- and ghrelin-induced strong contraction

AIM

Stomach contractions show two types of specific patterns in many species, that is migrating motor contraction (MMC) and postprandial contractions (PPCs), in the fasting and fed states respectively. We found gastric PPCs terminated with migrating strong contractions in humans, dogs and suncus. In this study, we reveal the detailed characteristics and physiological implications of these strong contractions of PPC.

METHODS

Human, suncus and canine gastric contractions were recorded with a motility-monitoring ingestible capsule and a strain-gauge force transducer. The response of motilin and ghrelin and its receptor antagonist on the contractions were studied by using free-moving suncus.

RESULTS

Strong gastric contractions were observed at the end of a PPC in human, dog and suncus models, and we tentatively designated this contraction to be a postprandial giant contraction (PPGC). In the suncus, the PPGC showed the same property as those of a phase III contraction of MMC (PIII-MMC) in the duration, motility index and response to motilin or ghrelin antagonist administration. Ghrelin antagonist administration in the latter half of the PPC (LH-PPC) attenuated gastric contraction prolonged the duration of occurrence of PPGC, as found in PII-MMC.

CONCLUSION

It is thought that the first half of the PPC changed to PII-MMC and then terminated with PIII-MMC, suggesting that PPC consists of a digestive phase (the first half of the PPC) and a discharge phase (LH-PPC) and that LH-PPC is coincident with MMC. In this study, we propose a new approach for the understanding of postprandial contractions.

Uric acid contributes greatly to hepatic antioxidant capacity besides protein

Uric acid is the end-product of purine nucleotide metabolism and an increase in uric acid concentration in the body results in hyperuricemia, ultimately leading to gout. However, uric acid is a potent antioxidant and interacts with reactive oxygen species (ROS) to be non-enzymatically converted to allantoin. Uric acid accounts for approximately 60 % of antioxidant capacity in the plasma; however, its contribution to tissue antioxidant capacity is unknown. In this study, the contribution of uric acid to tissue antioxidant capacity and its conversion to allantoin by scavenging ROS in tissue were examined. The results showed that a decrease in hepatic uric acid content via allopurinol administration significantly reduced hepatic total-radical trapping antioxidant parameter (TRAP) content in protein-free cytosol. Additionally, treating protein-free cytosol with uricase led to a further reduction of hepatic TRAP content. Allantoin was also detected in the solution containing protein-free cytosol that reacted with ROS. These findings suggest that in the absence of protein, uric acid contributes greatly to antioxidant capacity in the liver, where uric acid is converted to allantoin by scavenging ROS.

Primordial odontogenic tumor: An immunohistochemical profile

BACKGROUND

Primordial Odontogenic Tumor (POT) is a recently described odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla, covered by cuboidal to columnar epithelium that resembles the internal epithelium of the enamel organ, surrounded at least partly by a delicate fibrous capsule. The purpose of this study was to investigate the possible histogenesis and biological behavior of this rare tumor by means of a wide immunohistochemical analysis of its epithelial and mesenchymal components.

MATERIAL AND METHODS

The immunoexpression of twenty-three different antibodies were evaluated in four cases of POT.

RESULTS

The epithelial cells that cover the periphery of the tumor showed immunopositivity for Cytokeratins 14 and 19, while Amelogenin, Glut-1, MOC-31, Caveolin-1. Galectin-3, PITX2, p53, Bax, Bcl-2, Survivin and PTEN were variably expressed in focal areas. The mesenchymal component of the tumor was positive for Vimentin, Syndecan-1, PITX2, Endoglin (CD105), CD 34, Cyclin D1, Bax, Bcl-2, Survivin and p53. PTEN and CD 90 showed a moderate positivity. BRAF V600E and Calretinin were negative in all samples. Cell proliferation markers (Ki-67, MCM-7) were expressed in <5% of the tumor cells.

CONCLUSIONS

According to these immunohistochemical findings, we may conclude that POT is a benign odontogenic tumor in which there is both epithelial and mesenchymal activity during its histogenesis, as there is expression of certain components in particular zones in both tissues that suggests this tumor develops during the immature (primordial) stage of tooth development, leading to its inclusion within the group of benign mixed epithelial and mesenchymal odontogenic tumours in the current World Health Organization classification of these lesions.

A two-dimensional random crystalline algorithm for Gauss curvature flow

We propose and study a random crystalline algorithm (a discrete approximation) of the Gauss curvature flow of smooth simple closed convex curves in ℝ2 as a stepping stone to the full understanding of such phenomena as the wearing process of stones on a beach.

The application of mass spectrometry to proteomics and metabolomics in biomarker discovery and drug development

Drugs are launched to market after the lengthy process of development. Despite careful preclinical assessment, there is still a significant risk that a drug candidate may elicit adverse effects or display a low level of efficacy during clinical trials. If a drug candidate fails in the latter stages of the clinical process, the overall loss, both in terms of time and money, is enormous. A major concern for the pharmaceutical companies is to improve the drug development process to make it faster and more cost-effective by adoption of new technologies. Biomarkers are emerging as a key tool in identifying potential drug failures at an early stage or in helping to make go/no-go decisions, which should significantly accelerate drug development. Omics technologies play an important role in biomarker discovery as well as in other stages of the drug discovery and development (e.g. target discovery, mechanism of action or predicting toxicity). In particular, recent progress in mass spectrometry techniques such as selected reaction monitoring (SRM) and novel high-resolution features have helped facilitate the realization of the inherent power of proteomics and metabolomics in biomarker discovery, validation and qualification. In this manuscript, we review the current state of proteomics and metabolomics in conjunction with recent technical advances in mass spectrometry with some examples of applications in biomarker research. In addition, we discuss the possible impact of biomarker research with these technologies in drug discovery and development.

N (α) Selective Acetylation of Peptides

A chemical tag at the peptide N-terminus, in combination with MS, can be useful for quantitative analysis, N-terminal peptide identification, or peptide sequencing. Here we report on the N (α) selective acetylation of a peptide using acetic anhydride, a popular reagent for the modification of amino groups, without the need for the blocking of lysine side-chain ε-amino groups, which is usually required for N (α) selective acetylation. By controlling the amount of acetic anhydride used and running the reaction at 0°C, it is possible to preferentially acetylate the α-amino group. As a typical application of the method, a tryptic digest of an N-terminally blocked protein, cytochrome c, was directly acetylated using the present method. When deuterated acetic anhydride was used as the reagent, the N-terminal blocked peptide could be easily identified as a non-labeled ion peak while the N (α)-acetyl groups of all the other peptides were deuterated.

Epidemiological classification of infectious bronchitis virus isolated in Korea between 1986 and 1997

Forty Korean isolates and four reference strains of infectious bronchitis virus (IBV) were classified by reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RFLP) analysis. Each Korean isolate was isolated from different types of commercial chicken flocks between 1986 and 1997. RFLP patterns of an amplified DNA fragment (1722 bp) containing the S1 gene of IBV digested by restriction enzyme HaeIII showed that the 40 Korean isolates were classified into five genotypes, I to V. Six of them belonged to genotype I which had the same HaeIII and XcmI cleavage patterns with Massachusetts type (H120 and M41) but the other four genotypes had a different HaeIII cleavage pattern from the four reference IBV strains used in this study. Genotype III seemed to be the major type as 29 of the 40 isolates belonged to this type which was consistently found in the chicken flocks since 1990. On the other hand, genotypes II, IV and V were found in the field only in 1986, 1995 and 1995, respectively. Five isolates selected from each of the five genotypes were inoculated into 1-day-old specific-pathogen-free chicks to evaluate their pathogenicity. Genotype III induced 50% mortality as well as severe renal urate deposition on the kidneys but the other four genotypes only showed respiratory distress at 1 to 2 days after inoculation. Live H120 vaccine protected chicks against challenge with isolates selected from genotype I, but not genotypes IV to V. A live KM91p120 strain selected from major genotype III did protect chicks against challenge with isolates from genotype III, in addition to other genotypes, including two recent isolates of genotypes IV and V.

Classification of lymphoscintigraphy and relevance to surgical indication for lymphaticovenous anastomosis in upper limb lymphedema

Upper limb lymphedema that develops after breast cancer surgery causes physical discomfort and psychological distress, and it can require both conservative and surgical treatment. Lymphaticovenous anastomosis has been reported to be an effective treatment; however the disease severity criteria that define indications for this treatment remain unclear. Here, we examined lymphoscintigraphic findings in 78 patients with secondary upper limb lymphedema and classified them into 5 major types (Type I-V) and 3 subtypes (Subtype E, L, and 0). Results revealed that this classification is related to the clinical stage scale of the International Society of Lymphology. Based on intraoperative examination findings in 20 of the 78 patients, lymphatic pressure is likely to be further elevated in Type II-V cases which are characterized by the presence of dermal back flow. Therefore, lymphaticovenous anastomosis should be considered as a treatment option for lymphedema in Type II-V cases. Furthermore, there are only limited lymph vessel sites usable for lymphaticovenous anastomosis in more severe lymphedema types [Types IV and Type V (which is characterized by dermal backflow only in the hand)]. The findings in Type IV-V cases suggest that therapeutic strategies for severe upper limb lymphedema need further consideration.

Adipokine ganglioside GM2 activator protein stimulates insulin secretion

Recently, we identified ganglioside GM2 activator protein (GM2AP) as a novel adipokine, and revealed that treatment of cultured cells with GM2AP impairs insulin signal transduction. The aim of this study was to examine the impact of GM2AP on glucose metabolism in vivo. Injection of recombinant GM2AP in mice significantly lowered blood glucose levels in glucose tolerance tests. Administration of GM2AP to mice for 10 days increased serum insulin levels, whereas the contents of glucose, leptin and FFA were significantly decreased. Stimulation of calcium influx and insulin secretion by GM2AP was observed in hamster insulinoma HIT-T15 cells. Blockage of GM2AP function by specific antibodies inhibited GM2AP-induced insulin secretion. These results provide novel insights into the physiological functions of GM2AP in obesity.

A novel small compound that promotes nuclear translocation of YB-1 ameliorates experimental hepatic fibrosis in mice

Transforming growth factor-β (TGF-β) is considered to be a major factor contributing to liver fibrosis. We have previously shown that nuclear translocation of YB-1 antagonizes the TGF-β/Smad3 signaling in regulating collagen gene expression. More recently, we have demonstrated that the novel small compound HSc025 promotes nuclear translocation of YB-1, resulting in the improvement of skin and pulmonary fibrosis. Here, we presented evidence as to the mechanism by which HSc025 stimulates nuclear translocation of YB-1 and the pharmacological effects of HSc025 on a murine model of hepatic fibrosis. A proteomics approach and binding assays using HSc025-immobilized resin showed that HSc025 binds to the amino acid sequence within the C-tail region of YB-1. In addition, immunoprecipitation experiments and glutathione S-transferase pulldown assays identified poly(A)-binding protein (PABP) as one of the cytoplasmic anchor proteins of YB-1. HSc025 directly binds to YB-1 and interrupts its interaction with PABP, resulting in accelerated nuclear translocation of YB-1. Transfection of cells with PABP siRNA promoted nuclear translocation of YB-1 and subsequently inhibited basal and TGF-β-stimulated collagen gene expression. Moreover, HSc025 significantly suppressed collagen gene expression in cultured activated hepatic stellate cells. Oral administration of HSc025 to mice with carbon tetrachloride-induced hepatic fibrosis improved liver injury as well as the degree of hepatic fibrosis. Altogether, the results provide a novel insight into therapy for organ fibrosis using YB-1 modulators.

A novel adipokine GM2AP impairs insulin signaling

In an attempt to discover novel adipokines, we performed proteomics analyses using culture medium from differentiated 3T3-L1 adipocytes, and first identified GM2AP. The levels of GM2AP mRNA and protein were augmented by adipogenesis in cultured adipocytes and expression in adipose tissue and serum of obese mice or human subjects was found to be significantly higher than in lean counterparts. Exposure of 3T3-L1 adipocytes to GM2AP protein accelerated dissociation of insulin receptor-beta (IRβ) from caveolin-1, and interrupted insulin signal transduction. Abrogation of GM2AP function by specific antibodies augmented glucose uptake. Furthermore, treatment of rat pheochromocytoma PC12 NS1 cells with GM2AP impaired NGF signal transduction. Taken together, these results provide novel insights into the physiological functions of GM2AP in obesity.

Cutaneous metastasis of pancreatic carcinoma as an initial symptom in the lower extremity with obstructive lymphedema treated by physiotherapy and lymphaticovenous shunt: a case report, review, and pathophysiological implications

Cutaneous metastasis from pancreatic cancer is relatively rare as an initial symptom, and it is generally localized on the periumbilical area that is known as Sister Mary Joseph's nodule. We report a rare case of a 49-year-old female who developed cutaneous metastasis of pancreatic cancer as an initial symptom. The patient was referred to our department for treatment of lymphedema due to surgical treatment of cervical cancer and underwent combined physiotherapy and, 2 months later, a lymph venous anastomosis (LVA) for treatment of the lymphedema. Two months after the operation, she developed erythema on her right leg which spread from the leg to the groin in series. This pattern corresponded to the direction of lymph drainage, which may have been enhanced by the conservative physiotherapy and LVA treatments. These facts suggest a possible relationship between cutaneous metastasis of carcinoma and treatment for lymphedema. Alternatively, the lymphedematous limb may be a privileged site for cancer growth, and metastatic seeding could have taken place from pre-existing hematogenous spread at the time of operation.

High expression of HSP47 in ulcerative colitis-associated carcinomas: proteomic approach

BACKGROUND

Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease, known to be associated with a markedly increased risk of colorectal carcinoma development.

METHODS

Using proteomic analysis with two-dimensional gel electrophoresis and mass spectrometry, differentially expressed proteins were assessed between UC-associated cancer and sporadic colon cancer cell lines. Western blot and immunostaining were performed for confirming the expression.

RESULTS

Heat-shock protein of 47 kDa (HSP47) was identified as one of the proteins expressed more highly in UC-associated cancer cell lines, and an immunohistochemical examination confirmed significantly higher levels of HSP47 in UC-associated colon cancers than in sporadic counterparts, the expression increasing with a progression of neoplastic lesions. Heat-shock protein of 47 kDa was further found to be coexpressed with type I collagen in the cytoplasm, and both HSP47 and type I collagen were released from cultured cells into the culture medium.

CONCLUSION

These results suggest that overexpression of HSP47 is a unique characteristic of UC-associated carcinoma related to type I collagen synthesis, with possible clinical applications.

Mixed-histologic-type submucosal invasive gastric cancer as a risk factor for lymph node metastasis: feasibility of endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

The clinicopathologic features of gastric cancers containing a mixture of differentiated-type and undifferentiated-type components remain uninvestigated. We evaluated the risk of lymph node metastasis and the feasibility of endoscopic submucosal dissection (ESD) for the treatment of mixed-histologic-type gastric cancers.

PATIENT AND METHODS

We histologically classified 376 cases of gastric cancer with submucosal invasion into four types (differentiated type, differentiated-type-predominant mixed type, undifferentiated-type-predominant mixed type, and undifferentiated type) and studied the clinicopathologic relations of each type to lymph node metastasis. Lymphatic invasion was evaluated by D2-40 immunostaining.

RESULTS

The overall prevalence of lymph node metastasis in gastric cancer with submucosal invasion was 16.5% (62/376). The prevalence of lymph node metastasis was 36.5% (23/63) in undifferentiated-type-predominant mixed type, which was significantly higher than those in the other three types (P < 0.001 vs. differentiated type, P = 0.013 vs. differentiated-type-predominant mixed type, and P = 0.003 vs. undifferentiated type). Lymphatic invasion, a depth of invasion of 500 microm or more from the lower margin of the muscularis mucosae (SM2), tumor size above 30 mm, and undifferentiated-type-predominant mixed histologic type were independent risk factors for lymph node metastasis. Submucosal cancers without these four risk factors were free of lymph node metastasis (0/41; 95 % confidence interval 0%-8.6%).

CONCLUSIONS

Undifferentiated-type-predominant mixed-type gastric cancer with submucosal invasion carries a high risk of lymph node metastasis. ESD can be indicated for gastric cancer with submucosal invasion provided that the following conditions indicating a low risk of metastasis are met: a depth of invasion of no more than 500 microm or more from the lower margin of the muscularis mucosae (SM1), no lymphatic invasion, a tumor size of no more than 30 mm, and a proportion of undifferentiated components below 50%.

Hepatocyte growth factor suppresses profibrogenic signal transduction via nuclear export of Smad3 with galectin-7

BACKGROUND & AIMS

Hepatocyte growth factor (HGF) and transforming growth factor-beta (TGF-beta) regulate diversified cellular functions and often act antagonistically against each other. For example, TGF-beta is the most potent factor accelerating liver fibrosis, whereas HGF treatment prevents its progression. Here, we propose a novel molecular mechanism by which HGF counter represses TGF-beta-stimulated profibrogenic signal transduction.

METHODS

Effects of HGF on TGF-beta-responsive gene transcription of type I collagen, the major matrix component of fibrotic liver, were examined by using cultured hepatic stellate cells (HSC) and transgenic mice harboring alpha2(I) collagen gene (COL1A2) promoter. Expression and subcellular localization of Smad3 were determined by Western blot analyses and immunofluorescence staining, respectively. A mass spectrometric analysis was employed to identify immunoprecipitated proteins with antiphospho-Smad2/3 antibodies.

RESULTS

Over expression of HGF inhibited COL1A2 transcription in cultured HSC and suppressed activation of COL1A2 promoter in liver tissue induced by carbon tetrachloride administration. A mass spectrometric analysis identified galectin-7 as one of the immunoprecipitated proteins with antiphospho-Smad2/3 antibodies following HGF treatment. HGF accelerated nuclear export of Smad3 by enhancing its interaction with galectin-7. Transfection of cells with galectin-7 small interfering RNA inhibited nuclear export of Smad3 and abolished suppressive effect of HGF on expression of TGF-beta-responsive genes such as COL1A2 and plasminogen activator inhibitor-1. On the other hand, over expression of galectin-7 suppressed TGF-beta-stimulated expression of those target genes.

CONCLUSIONS

These results reveal a novel function of intracellular galectin-7 as a transcriptional regulator via its interaction with Smad3 and provide a molecular basis for the antifibrotic effect of HGF.

Selective Isolation of N-Blocked Peptides by Isocyanate-Coupled Resin

We developed a method for selective isolation of N-blocked peptides from a complex mixture such as an enzymatic digest of a protein. The approach is based on a newly designed isocyanate-resin (resin-NCO), which specifically reacts with alpha-amino or imino groups. This method, then, permits the isolation of N-blocked peptides, even those containing Lys, from a peptide mixture as intact forms by trapping N-free peptides via covalent bonding to the resin-NCO. The present study demonstrates the performance of this method for the selective isolation of N-blocked peptides by applying it to several peptide mixtures, including proteolytic digests.

Expression pattern of adhesion molecules in junctional epithelium differs from that in other gingival epithelia

BACKGROUND AND OBJECTIVE

The gingival epithelium is the physiologically important interface between the bacterially colonized gingival sulcus and periodontal soft and mineralized connective tissues, requiring protection from exposure to bacteria and their products. However, of the three epithelia comprising the gingival epithelium, the junctional epithelium has much wider intercellular spaces than the sulcular epithelium and oral gingival epithelium. Hence, the aim of the present study was to characterize the cell adhesion structure in the junctional epithelium compared with the other two epithelia.

MATERIAL AND METHODS

Gingival epithelia excised at therapeutic flap surgery from patients with periodontitis were examined for expression of adhesion molecules by immunofluorescence.

RESULTS

In the oral gingival epithelium and sulcular epithelium, but not in the junctional epithelium, desmoglein 1 and 2 in cell-cell contact sites were more abundant in the upper than the suprabasal layers. E-cadherin, the main transmembranous molecule of adherens junctions, was present in spinous layers of the oral gingival epithelium and sulcular epithelium, but was scarce in the junctional epithelium. In contrast, desmoglein 3 and P-cadherin were present in all layers of the junctional epithelium as well as the oral gingival epithelium and sulcular epithelium. Connexin 43 was clearly localized to spinous layers of the oral gingival epithelium, sulcular epithelium and parts of the junctional epithelium. Claudin-1 and occludin were expressed in the cell membranes of a few superficial layers of the oral gingival epithelium.

CONCLUSION

These findings indicated that the junctional epithelium contains only a few desmosomes, composed of only desmoglein 3; adherens junctions are probably absent because of defective E-cadherin. Thus, the anchoring junctions connecting junctional epithelium cells are lax, causing widened intercellular spaces. In contrast, the oral gingival epithelium, which has a few tight junctions, functions as a barrier.