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Introduction: A rational way of nourishment, combined with adequate physical activity, are the basic components of maintaining proper body condition. Objective: The aim of the study was to evaluate nutritional status among children and adolescents with different levels of physical activity. Methods: The study group consisted of 1,013 students of both genders aged between 7 and 18 years attending elementary and post-primary schools (general and sports profile) in Siemianowice Slaskie. Results: The crude body mass index (BMI) values ranged from 12.78 to 35.3. Body mass within the limits of arbitrary standard referred to 70% of the examined group, overweight or obesity was found in over 25%. Percentage of body fat (FATP) values ranged from 5.7 to 45.2%. Conclusions: A significant number of children and adolescents were overweight or obese based on BMI categories and FATP values. Overweight and obesity were most common among younger children, particularly boys. Higher torso FATP levels were more common among sports-oriented class students. BMI is not a good tool for the determination of the nutritional status of children and adolescents, while the bioelectric impedance method enables one to conduct a precise analysis of adipose tissue content and location. Sports-oriented elementary school students from the study group were characterized by higher FATP values.

Background Bacterial reinfection of dental cavities remains an unsolved clinical problem. The search for methods enabling the limitation of the bacterial factor has become the fundamental goal of the dental materials research. Silver nanoparticles (AgNPs) are used as disinfection agents. An incomplete polymerization of the polymer resins combined with AgNPs, along with the increase of the release of the unbound monomers, have been found. Objectives The aim of this study was to evaluate the vitality of the human dental pulp stem cells (DPSCs) in response to a disinfection agent containing silver and gold nanoparticles (NPs), different bonding systems, glass-ionomer cement (GIC), and their combinations with the disinfection agent. Also, the influence of these materials both on the secretory function of DPSCs and on their antibacterial properties was established. Material and methods Cytotoxicity (MTT assay) and genotoxicity (enzyme-linked immunosorbent assay - ELISA) assays were used in the study. Antibacterial features were assessed with the optical density (OD) measurement of the bacteria (Streptococcus mutans, Streptococcus salivarius and Lactobacillus acidophilus) kept in dental materials. Results The disinfection liquid proved to be biocompatible. However, it relevantly interfered with the total-etch bonding system in terms of vitality, which may have serious clinical implications. Its combination with the self-etching system was biocompatible, yet it impaired the antibacterial action of the system. An enhancement of antibacterial action of GIC with AgNPs was found. Conclusions The disinfection liquid and GIC were biocompatible toward the DPSCs in terms of cytotoxicity and genotoxicity. Simultaneous usage of AgNPs with other dental materials did not affect the biocompatibility of the used materials. The disinfection liquid and GIC acted as antibacterial agents against all studied bacteria species. Used together with GIC and the total-etch bonding system, the disinfection liquid seemed to be efficient toward bacteria, yet it relevantly impaired the antibacterial action of self-etching systems.

An early stage of dentine formation and its later appropriate mineralization require the deposition of collagen type I and subsequent deposition of multiple non-collagenous proteins. The most critical non-collagenous proteins for dentineogenesis belong to two families, the Small Leucine Rich Proteoglycans (SLRP) and the Small Integrin-Binding Ligands (SIBLING). The threepart manuscript summarizes current knowledge of the molecular mechanism of dentineogenesis. It argues the confirmed but also speculative theses about the function of non-collagenous proteins and their potential role in the formation of sclerotic dentine. In the opinion of the authors this may play a key role in the planning of prosthetic treatment. Considering the current knowledge of dentine a number of opponents speculate that long-lasting teeth grinding and clenching might modify the level of expression of the non-collagenous proteins in dentine, and thus invalidate or impair further prosthetic treatment. The first part of the manuscript contains a short introduction to dentine formation and roles of the SLRP family proteoglycans in the process of�dentineogenesis. The emphasis has been put on two proteoglycans: decorin and biglycan and their ability to interfere with the process of spatial orientation of the collagenous fibres in dentine.

Turner syndrome (TS) is characterized by the partial or complete loss of one sex chromosome and results in growth failure, gonadal insufficiency and cardiac anomalies. Treatment with growth hormone (GH) during childhood has indisputable benefits when taking into account the low stature of TS women. Medical records and biochemical findings of 33 TS women treated with GH in childhood (GH+) were compared to those of 124 TS women who did not receive GH (GH−). It seems that the GH-treated group might have had a more severe initial phenotype than the untreated group, as evidenced by higher FSH, more feeding issues in infancy, more lymphedema cases and urinary system malformations. GH+ women were significantly taller and had a better lipid profile and lower prevalence of arterial hypertension than GH− . However, they also had lower thrombocyte counts, a greater prevalence of retrognathism and nail anomalies, especially when the GH treatment was delayed. Long-term GH use was not as effective for growth as GH treatment during the initial period and seemed to have resulted in elevated creatinine levels. GH treatment in childhood has benefits in adulthood; however, adverse effects may occur, especially in individuals with treatment that is delayed or is too long.

Multiple studies showed that the cessation of TWIST1 expression is the prerequisite for osteoblasts' maturation. However, recent reports revealed that the function of TWIST1 is different in the dental pulp stem cells (DPSCs), where a high level of TWIST1 expression promoted DPSCs' differentiation. The aim of the study was to investigate the impact of TWIST1 and ID1 on the differentiation process in the human DPSCs. Methods TWIST1 and ID1 expression in the DSPCs was modulated by lentivirus transduction. Genes expression was assessed with qRT-PCR. The proteins level was evaluated by Western blot. The DPSCs differentiation was assessed with the proliferation, alkaline phosphatase (ALP) activity, and calcium concentration assays. Results TWIST1 silencing suppressed the expression of ID1 and both the early and late markers of odontoblasts' differentiation detected at the transcript and protein level. The forced overexpression of ID1 increased the expression of the late markers of odontoblasts differentiation but diminished the expression of the early markers. DPCSs with the silenced TWIST1 and subsequent ID1 overexpression displayed an increase in the expression of the late markers of odontoblasts differentiation. Cells with silenced TWIST1 and overexpressing ID1 had increased activity of ALP, higher calcium concentration and decreased proliferation rate. The high level of ID1 expression might be a critical factor stimulating DPSCs differentiation and it might compensate the repressed differentiation of DPSCs caused by TWIST1 silencing. Conclusion The mutual correlation between the expression level of TWIST1 and ID1 might be a critical factor driving the process of the human odontoblasts' differentiation.

Background/Aim: Currently, it has been proposed that combination of 5-fluorouracil (5FU) with inhibitors of the mitogen-activated protein kinases (MAPKs) signaling pathway might enhance the efficacy of 5FU-based chemotherapy in colon cancer. Our study aimed to investigate an impact of TWIST1 silencing on the sensitivity of cancer cells to 5FU and selected MAPK inhibitors. Materials and Methods: The suppression of TWIST1 expression in human colon cancer HT29 and HCT116 cell lines was achieved by transduction with lentiviral vector carrying the TWIST1 silencing sequence (pLL3.7-sh TWIST1). The statistical calculation was performed with analysis of variance or Dunnett's test for comparison to control group. Paired Student's t-test was performed when two groups were analyzed. Results: Suppression of TWIST1 reduced the proliferation rate of colon cancer cells and enhanced their sensitivity to 5FU and MAPKs inhibitors. The sensitivity of HT29 cells to examined compounds was more dependent on TWIST1 expression level compared to HCT116 cells. The most noticeable effect of TWIST1 suppression on sensitivity of both colon cancer cell lines to combined treatment of 5FU and the MAPKs inhibitors was observed for inhibitors of p38α/β and JNK1-3. We also noted that the suppression of TWIST1 significantly sensitized both cell lines to combined treatment of 5FU and Rac inhibitor. Conclusions: Our observations point to TWIST1 expression level as a marker of colon cancer sensitivity to combined treatment of 5FU and MAPKs inhibitors.

Wstep: Leptyna reguluje odpowiedź immunologiczną organizmow. Mlodziencze idiopatyczne zapalenie stawow (MIZS) jest przewleklą chorobą stawow u dzieci prowadzącą do przewleklych zmian w narządach ukladu ruchu. Material i metody: U dzieci z MIZS (n = 42) i zdrowych osobnikow (n = 28) analizowano nastepujące parametry: stezenie leptyny (LEP), wskaźnik masy ciala (BMI), hematokryt (HTC), zawartośc hemoglobiny (HB), liczba elementow morfotycznych krwi (WBC, LYMPH), odczyn OB i obecnośc przeciwcial ANA Hep-2. Grupe MIZS podzielono na: dzieci dluzej chorujące (51–148 miesiecy) n = 22 (IA) i krocej chorujące (2–18 miesiecy) n = 20 (IB). Wyniki: Tylko u 58,3% dzieci grupy IA i 50% dzieci grupy IB potwierdzono obecnośc przeciwcial przeciwjądrowych ANA Hep-2. U chorych dzieci wykazano wyzsze poziomy LYMPH i OB oraz wieksze zroznicowanie wynikow, w porownaniu do dzieci zdrowych. Najwyzsze stezenie LEP dla grupy IA wynosilo 37,50 ng/cm3, (Me 5,85) dla IB 40,10 ng/cm3, (Me2,46), w porownaniu z IC, gdzie wynosilo odpowiednio 3,74 ng/cm3 (Me 2,85). Średnia wartośc BMI dla grupy IA wynosila 16,61 kg/m2, dla IC 18,91 kg/m2, a mediana dla IB 15,89 kg/m2 . U dzieci z BMI l 23 kg/m2, grupy IA i IB, stwierdzono nizsze stezenia leptyny w porownaniu z grupą kontrolną (p = 0,04). Stwierdzono wplyw schorzenia na zroznicowanie stezenia leptyny w przeliczeniu na BMI w obu grupach dzieci chorych. U chorych dzieci, z krotszym czasem trwania choroby, wykazano wieksze zroznicowanie wartości stezenia leptyny w przeliczeniu na BMI, niz u zdrowych. Wnioski: Dzieci z mlodzienczym idiopatycznym zapaleniem stawow z BMIl23 kg/m2 mają nizsze stezenie leptyny niz dzieci grupy kontrolnej. Dzieci z MIZS z krotszym czasem trwania choroby, charakteryzują sie wiekszym zroznicowaniem stezenia leptyny w przeliczeniu na jednostke BMI, w porownaniu ze zdrowymi dziecmi. (Endokrynol Pol 2015; 66 (5): 417–421)

Objective To assess possible changes in leptin and ghrelin secretion due to etanercept in juvenile idiopathic arthritis (JIA). Methods 50 patients with JIA and 16 age-matched controls were enrolled into this prospective, cross-sectional study. Serum leptin, total and acyl ghrelin were measured in addition to white blood cell (WBC) and lymphocyte counts. Results 25 patients received etanercept and 25 conventional therapies (including methotrexate) for JIA. There was no difference between treatment and control groups in leptin or ghrelin levels and no evidence of a relationship between leptin and ghrelin in patients with JIA. In all children with JIA there was a correlation between leptin and body mass index (BMI). However, compared with children in the conventional treatment group, children in the etanercept group showed a positive correlation between total ghrelin and BMI and those with a low BMI showed a negative correlation between acyl ghrelin and BMI. Conclusion No differences in leptin and ghrelin concentrations were found when patients with JIA and controls were compared or when patients who received etanercept were compared with those who received conventional treatment for JIA.

TWIST1 plays a crucial role in dentinogenesis, and its activity depends on both a dimerization partner selection and phosphorylation. Other factors, like Id proteins, can affect the availability of dimerization partners for TWIST1, subsequently leading to diverse biological outcomes. The purpose of this study was to evaluate an impact of Id1 expression on differentiation of dental pulp stem cells (DPSCs). The altered expression of Id1 was achieved by transfection of human DPSCs with lentiviral vectors either driving an entire sequence of Id1, hence leading to Id1 overexpression, or carrying the Id1 silencing sequence. We observed that both overexpression and silencing of Id1 modulated human DPSC differentiation. Id1 overexpression resulted in a prevailing formation of TWIST1 homodimer and increased expression of genes encoding dentin sialophosphoprotein and dentin matrix protein 1, which confirm an enhanced odontogenic differentiation of DPSCs. Concurrently, Id1 silencing produced an opposite effect, slowing DPSC differentiation. These results highlight Id1 as an important modulator of molecular events during DPSC commitment and differentiation, which should be considered in dental research on tissue engineering. Moreover, we assume that the balance between TWIST1 dimerization forms in DPSCs might function in a cell-type-specific manner.

Streszczenie Wprowadzenie. Dentinogenesis imperfecta typu II (DGI) oraz dysplazja zebiny (DD) są rzadkimi, izolowanymi wrodzonymi wadami rozwojowymi polegającymi na nieprawidlowym formowaniu zebiny zarowno w zebach mlecznych jak i stalych. Poza istotną zmianą koloru zebow dochodzi do ich szybkiego starcia, a nastepnie utraty. Leczenie zachowawcze jak i protetyczne pacjentow chorujących na DGI/DD niejednokrotnie jest nieskuteczne. Przy planowaniu leczenia pacjentow z DGI/DD niezbednym jest potwierdzenie rozpoznania metodami diagnostyki molekularnej. Za fenotyp DGI/DD odpowiedzialne są mutacje w genie DSPP, ktory wykazuje wysoki stopien polimorfizmu oraz posiada dlugie sekwencje repetywne, co utrudnia jego sekwencjonowanie. Cel pracy. Analiza molekularna genu DSPP u przypadkowych osob nie wykazujących cech klinicznych fenotypu dentinogenesis imperfecta typu II bądź dysplazji zebiny. Mutacje w genie kodującym bialko sialofosforowe zebiny (DSPP) nie zawsze skutkujące fenotypem dentinogenesis imperfecta typu II bądź dysplazją zebiny*

Adjuvant chemotherapy with 5-fluorouracil remains the basic treatment for patients with advanced colorectal carcinoma. The major obstacle in successful treatment is an ability of CRC cells to acquire chemoresistance. Here we examined the impact of ID1 silencing on the sensitivity of CRC cells to 5-FU. To suppress ID1 expression in HT-29 and HCT-116 cells the cells were transduced with a lentiviral vector carrying the ID1 silencing sequence. Cells with silenced ID1 showed altered expression of epithelial and mesenchymal markers and exhibited increased proliferation rate compared to the parental cells. HCT-116 cells with suppressed ID1 became sensitized to 5-FU and this was not observed in HT-29 cells. Silencing ID1 resulted in altered expression of genes encoding enzymes metabolizing 5-FU. HT-29 cells with suppressed ID1 had significantly reduced mRNA level for thymidine phosphorylase, uridine-cytydine kinase 2 and dihydropyrimidine dehydrogenase. ID1 suppression in HCT-116 cells resulted in an increase of mRNA level for thymidine phosphorylase, thymidyne kinase and uridine-cytydine kinase 2 with concurrent drop of dihydropyrimidine dehydrogenase and thymidylate synthetase mRNA levels. In conclusion ID1 expression impacts the sensitivity of colon cancer cells to 5-FU and may be considered as potential predictive marker in CRC treatment.

Dentinogenesis imperfecta (DGI) is a hereditary defect of dentin, a calcified tissue that is the most abundant component of teeth. Most commonly, DGI is manifested as a part of osteogenesis imperfecta (OI) or the phenotype is restricted to dental findings only. In the latter case, DGI is caused by mutations in the DSPP gene, which codes for dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). Although these two proteins together constitute the majority of noncollagenous proteins of the dentin, little is known about their transcriptional regulation. Here we demonstrate that mice overexpressing the Trps1 transcription factor (Col1a1-Trps1 mice) in dentin-producing cells, odontoblasts, present with severe defects of dentin formation that resemble DGI. Combined micro–computed tomography (µCT) and histological analyses revealed tooth fragility due to severe hypomineralization of dentin and a diminished dentin layer with irregular mineralization in Col1a1-Trps1 mice. Biochemical analyses of noncollagenous dentin matrix proteins demonstrated decreased levels of both DSP and DPP proteins in Col1a1-Trps1 mice. On the molecular level, we demonstrated that sustained high levels of Trps1 in odontoblasts lead to dramatic decrease of Dspp expression as a result of direct inhibition of the Dspp promoter by Trps1. During tooth development Trps1 is highly expressed in preodontoblasts, but in mature odontoblasts secreting matrix its expression significantly decreases, which suggests a Trps1 role in odontoblast development. In these studies we identified Trps1 as a potent inhibitor of Dspp expression and the subsequent mineralization of dentin. Thus, we provide novel insights into mechanisms of transcriptional dysregulation that leads to DGI. © 2012 American Society for Bone and Mineral Research.

Dentin matrix protein 1 (DMP1) has been shown to be critical for the formation of dentin and bone. However, the precise pathway by which DMP1 participates in dentinogenesis and osteogenesis remains to be clarified. DMP1 is present in the extracellular matrix of dentin and bone as processed NH2- and COOH-terminal fragments. The NH2-terminal fragment occurs as a proteoglycan, whereas the COOH-terminal fragment is highly phosphorylated. The differences in biochemical properties suggest that these fragments may have different tissue and cell distribution in association with distinct functions. In this study, we analyzed the distribution of the NH2- and COOH-terminal fragments of DMP1 in tooth, bone, osteocytes as well as MC3T3-E1 and HEK-293 cells. Immunohistochemical analyses were performed using antibodies specific to the NH2- or COOH-terminal region of DMP1. Clear differences in the distribution of these fragments were observed. In the teeth and bone, the NH2-terminal fragment was primarily located in the nonmineralized predentin and cartilage of the growth plate, while the COOH-terminal fragment accumulated in the mineralized zones. In osteocytes, the NH2-terminal fragment appeared more abundant along cell membrane and processes of osteocytes, while the COOH-terminal fragment was often found in the nuclei. This pattern of distribution in cellular compartments was further confirmed by analyses on MC3T3-E1 and HEK-293 cells transfected with a construct containing DMP1 cDNA. In these cell lines, the COOH-terminal fragment accumulated in cell nuclei, while the NH2-terminal fragment was in the cytosol. The different distribution of DMP1 fragments indicates that these DMP1 variants must perform distinct functions.

I. Maciejewska-Paszek, E. Grochowska-Niedworok, M. Wardas, M. Skiba:Iron, Zinc and Copper in Selected Tissues of Rabbits under Increasing Exposure to Iron. Acta Vet. Brno 2005, 74: 551-555. The aim of this study was to demonstrate the disturbance of zinc/copper balance in tissues as the possible accelerating factor of liver damage after short- and long-term exposure to high doses of iron in case of its accidental overdosing or experimental haemochromatosis. Thirty chinchilla rabbits were administered Jectofer /iron (III) - sorbitol iron complex/ Short-term administration was given to groups A and B, respectively. Long term administration was given to groups C, D and E, respectively. The contents of metals in the fur, muscles, skin and liver were determined by atomic absorption spectrometry (AAS). After short-term administration the highest concentrations of iron in comparison to the control group were observed in liver (about 42-46%) at each collection (p < 0.05), copper concentration in liver slightly decreased (≈23%), but increased in other tissues (by a maximum of 55%). Accumulation of zinc in fur was stable, but a decrease in other tissues like liver, muscles and skin was observed (4 - 35%). After long-term administrations changes in zinc concentration were found (higher in the fur of groups C and D and in the liver in group E; lower in the skin of groups: C and E). On the other hand, the long-term administration of Jectofer caused a decrease in copper concentration in fur (23-70%) but caused a 3-to-5 fold increase in the skin of experimental rabbits. Short-term as well as long-term administration of iron affect changes of copper/zinc equilibrium concentrations in different tissues and in livers of rabbits.

Background: Ghrelin is a stomach-produced polypeptide hormone that stimulates hunger and secretion of growth hormone. Abnormalities in ghrelin secretion are well documented in obese patients, but explored little in patients with various forms of hypertension. Notably, ghrelin is indirectly involved in blood pressure regulation in pregnancy induced hypertension. Material and methods: The present study aimed to assess ghrelin concentration in venous blood of 19 nonpregnant (NP), 20 healthy pregnant (HP) and 20 hypertensive pregnant (PIH). It also included assessing blood ghrelin concentration of 21 obese hypertensive pregnant (OPIH) women before and one hour after eating. Ghrelin secretion was estimated 1-3 days before delivery. Results: All experimental groups of pregnant women (HP, PIH, and OPIH) showed significantly reduced ghrelin plasma level as compared with NP (812 ± 83, 716 ± 66, and 717 ± 52 vs 1057 ± 74, respectively). We found no significant ghrelin reduction after eating in obese hypertensive pregnant women. The blood ghrelin concentration in pregnant women negatively correlated with mean arterial pressure. In spite of the differences in ghrelin concentration in women, whom a decrease in ghrelin concentration after a standard meal was observed compared to women, who didn’t reduce of ghrelin secretion no differences were found in mean arterial pressure. Conclusion: The relationship between arterial hypertension and ghrelin secretion disorders during hypertensive pregnancy is uncertain and requires further examination.

Leptin regulates the organism's immune response. Juvenile idiopathic arthritis (JIA) is a chronic joint disease in children, leading to chronic changes in motor organs.In children with JIA (n = 42) and healthy subjects (n = 28), leptin concentration (LEP), body mass index (BMI), haematocrit (HTC), haemoglobin (HB), morphotic elements (WBC,LYMPH), erythrocyte sedimentation rate (ESR), and ANA Hep-2 antibodies were analysed. JIA group was divided into: children with a longer (51-148 months) (IA) n = 22 and a shorter disease period (2-18 months) (IB) n = 20.Only 58.3% of the IA and 50% of the IB group had ANA Hep-2 confirmed. The ill children had higher and more diversified LYMPH and ESR levels compared to the healthy children. The highest LEP for the IA group was 37.5 ng/cm3, (Me 5.85), for IB - 40.10 ng/cm3, (Me 2.46) as compared to the IC - 3.74 ng/cm3 (Me 2.85), respectively. The average BMI value for the IA group was 16.61 kg/m2, for IC it was 18.91 kg/m2, and the median for IB was 15.89 kg/m2. Children with BMI values23 kg/m2 from the IA and IB group had a reduction in LEP as compared to control group (p = 0.04). The relationship between the illness and LEP diversification per BMI unit was found in both groups. Children with a shorter illness period had higher LEP differentiation per BMI unit compared to the healthy children.Children with juvenile idiopathic arthritis with BMI23 kg/m2 had lower leptin concentrations than healthy subjects. Ill children with a shorter-term disease had a higher diversification of leptin concentration per BMI unit as compared to healthy controls.

Multiple studies have shown that dentin matrix protein 1 (DMP1) is essential for bone and dentin mineralization. After post-translational proteolytic cleavage, DMP1 exists within the extracellular matrix of bone and dentin as an NH2-terminal fragment, a COOH-terminal fragment, and the proteoglycan form of the NH2-terminal fragment (DMP1-PG). To begin to assess the biological function of each fragment, we evaluated the distribution of both fragments in the rat tooth and bone using antibodies specific to the NH2-terminal and COOH-terminal regions of DMP1 and confocal microscopy. In rat first molar organs, the NH2-terminal fragment localized to predentin, whereas the COOH-terminal fragment was mainly restricted to mineralized dentin. In the growth plate of bone, the NH2-terminal fragment appeared in the proliferation and hypertrophic zones, whereas the COOH-terminal fragment occupied the ossification zone. Forster resonance energy transfer analysis showed colocalization of both fragments of DMP1 in odontoblasts and predentin, as well as hypertrophic chondrocytes within the growth plates of bone. The biochemical analysis of bovine teeth showed that predentin is rich in DMP1-PG, whereas mineralized dentin primarily contains the COOH-terminal fragment. We conclude that the differential patterns of expression of NH2-terminal and COOH-terminal fragments of DMP1 reflect their potentially distinct roles in the biomineralization of dentin and bone matrices.

Dentin matrix protein 1 (DMP1) has been identified in the extracellular matrix (ECM) of dentin and bone as the processed NH(2)-terminal and COOH-terminal fragment. However, the full-length form of DMP1 has not been identified in these tissues. The focus of this investigation was to search for the intact full-length DMP1 in dentin and bone. We used two types of anti-DMP1 antibodies to identify DMP1: one type specifically recognizes the NH(2)-terminal region and the other type is only reactive to the COOH-terminal region of the DMP1 amino acid sequence. An approximately 105-kDa protein, extracted from the ECM of rat dentin and bone, was recognized by both types of antibodies; and the migration rate of this protein was identical to the recombinant mouse full-length DMP1 made in eukaryotic cells. We concluded that this approximately 105-kDa protein is the full-length form of DMP1, which is considerably less abundant than its processed fragments in the ECM of dentin and bone. We also detected the full-length form of DMP1 and its processed fragments in the extract of dental pulp/odontoblast complex dissected from rat teeth. In addition, immunofluorescence analysis showed that in MC3T3-E1 cells the NH(2)-terminal and COOH-terminal fragments of DMP1 are distributed differently. Our findings indicate that the majority of DMP1 must be cleaved within the cells that synthesize it and that minor amounts of uncleaved DMP1 molecules are secreted into the ECM of dentin and bone.