[The relationship between the amount of gingival crevicular fluid and periodontitis]

In this paper, we report the results of comparing the amount of GCF, collected from 100 patients suffering from periodontitis and 40 patients suffering from gingivitis with 64 normal control subjects. The results showed that the amount of GCF is independent of sex and where the GCF was collected, ie., either side of the maxillary or mandibular teeth. However, the fluid amount was closely related to inflammation of the periodontium and significantly related to the severity of inflammation and bone destruction. This study provide evidence that the determination of the GCF amount is an essential criteria for detecting periodontal activity.

Cellular localization and regulation of gene expression for components of the insulin-like growth factor ternary binding protein complex

Insulin-like growth factors (IGFs) are present in the circulation, largely as part of a high mol wt complex including IGF-binding protein-3 (IGFBP-3) and an acid-labile subunit (ALS). This study used in situ hybridization to investigate the cellular sites of synthesis of these factors in the rat and to evaluate changes in transcript levels during development and after hypophysectomy and GH treatment. IGFBP-3 transcripts are considerably more abundant and widely expressed than ALS at birth, but both are present in liver and kidney. Hepatic IGFBP-3 gene expression increases slightly, whereas ALS increases dramatically in the first few weeks after birth. IGFBP-3 mRNA is concentrated in portal venous and sinusoidal endothelium, but is not detected in hepatocytes, whereas ALS mRNA is diffusely expressed by hepatocytes, but is not detected in nonparenchymal cells. Both transcripts are localized in the renal cortex; however, IGFBP-3 mRNA is concentrated in interstitial cells, whereas ALS is expressed in proximal tubule epithelium. Hypophysectomy results in a 90% reduction in hepatic ALS and an approximately 50% decrease in IGFBP-3 mRNA level. ALS, but not IGFBP-3, transcripts were also reduced in the kidney. GH receptor mRNA is coexpressed with ALS in liver and kidney, suggesting that the effects of GH on ALS gene expression may be direct. In summary, the fact that IGFBP-3 gene expression is far more widespread than that of ALS in both spatial and temporal parameters suggests that IGFBP-3 has a role apart from contribution to the ternary complex. We have also shown that IGFBP-3 and ALS are synthesized by distinct hepatic cell types in an anatomical organization that may serve to ensure efficient formation of the ternary complex in the blood passing through the sinusoids. Finally, the present data suggest that regulation of ALS synthesis may be the primary site of GH regulation of ternary complex formation.

Chromium-induced early changes in renal function among ferrochromium-producing workers

Urinary biochemical indicators of renal injury were examined in 84 male and 38 female ferrochromium-producing workers exposed to water-soluble chromium compounds [Cr(VI)]. The indicators examined included urinary chromium (U-Cr), alkaline phosphatase (ALP), gamma-glutamyl transferase (gamma-GT), glutamic-oxalacetic and glutamic-pyruvic transaminases (GOT & GPT), lactate dehydrogenase (LDH), N-acetyl-beta-D-glucosaminidase (NAG), total protein (TPr) and beta 2-microglobulin (beta 2-MG). The U-Cr levels in the exposed group were approximately 1.8 times that of the control group. Compared to controls, the activities of gamma-GT, NAG, ALP, GOT and LDH in the urine of workers were significantly increased whenever U-Cr concentration exceeded 45 microgram/g creatinine. The activities of gamma-GT, GOT and NAG were elevated in workers employed for longer than ten years. However, no clear dose-response relationships nor time-effect relationships were found. The present results suggest that long-term exposure to water-soluble chromium [Cr(VI)] produces chronic renal injury. The site of the injury appears to mainly involve the proximal tubule. U-Cr concentrations of > 15 microgram/g creatinine can be proposed as a threshold dosage for nephrotoxicity, and gamma-GT, NAG and ALP are early sensitive indicators of the most valuable for evaluating the renal injury.

Complete primary structure of the sixth chain of human basement membrane collagen, alpha 6(IV). Isolation of the cDNAs for alpha 6(IV) and comparison with five other type IV collagen chains

Basement membranes were previously believed to contain five distinct type IV collagen subunits. We have recently isolated part of the cDNA for a novel type IV collagen, alpha 6(IV), and shown that COL4A6, the gene encoding this new chain, is deleted in Alport syndrome-associated leiomyomatosis (Zhou, J., Mochizuki, T., Smeets, H., Antignac, C., Laurila, P., de Paepe, A., Tryggvason, K., and Reeders, S. T. (1993) Science 261, 1167-1169). Here, we describe the entire human alpha 6(IV) cDNA and show that the gene encodes a classical type IV collagen with homology throughout its length to all the other five chains. There is a 21-residue signal peptide, a 1417-residue collagenous domain interrupted at 25 points, and a 228-residue carboxyl-terminal non-collagenous domain. When the complete primary structure of this new chain was compared with all the other known chains, it became clear that alpha 6(IV) has the most resemblance to alpha 2(IV) and alpha 4(IV). The evolution of the six chains was deduced, allowing a new classification of the type IV collagen family. The alpha 6(IV) chain is a candidate gene for X-linked Alport syndrome; knowledge of the complete structure of the chain will permit us to screen systematically for mutations in patients and to generate recombinant proteins and synthetic peptides for further study of cell-matrix interactions involving the alpha 6(IV) chain.

Expression of TrkA confers neuron-like responsiveness to nerve growth factor on an immortalized hypothalamic cell line

The result of nerve growth factor (NGF) actions depends upon the cells in which it signals. To define how signaling is influenced by cellular context, it would be useful to examine cells committed to different fates or cells of a single type at different developmental stages. Interest in NGF actions on neurons of the central nervous system led us to examine GT1-1 cells, an immortalized hypothalamic cell line. GT1-1 cells demonstrated neuronal properties but were unresponsive to NGF and other neurotrophins. Through transfection, trkA expression conferred NGF signaling leading to enhanced neuronal differentiation, including dose-dependent induction of neurite outgrowth and a rapid transient increase in c-fos and NGFI-A mRNA. Under serum-free culture conditions, NGF also delayed cell death. These findings suggest that trkA transfection of neurons and neuronal precursors can be used to better define NGF signaling.

[Prostaglandin E2 levels in gingival crevicular fluid and its relation to the depth of periodontal pocket in patients with periodontitis]

The prostaglandin E2(PGE2) levels in gingival crevicular fluid (GCF) of 46 normal controls and 90 patients suffering from periodontitis with periodontal pocket of different depth were measured by radioimmunoassay (RIA). The results demonstrated that the PGE2 levels in GCF of the periodontal pockets in periodontitis with different depth were higher than normal controls. The PGE2 levels increased with the depth of the periodontal pocket, particularly when the depth exceed over 6 mm. This study shows that the PGE2 levels are significantly related to the severity of bone destruction in periodontitis.

Structure of the human type IV collagen COL4A5 gene

The complete exon size and distribution pattern of the human alpha 5(IV) collagen gene COL4A5 has been determined. Seventeen genomic lambda phage clones, eight of which have been described previously (Zhou, J., Hostikka, S.L., Chow, L.T., and Tryggvason, K. (1991) Genomics 9, 1-9), spanning about 160 kilobases of DNA contained 140 kilobases of the gene itself. The clones covered the entire gene with the exception of exons 2 and 37 and their flanking regions so that the exact gene size could not be determined. The sequences of these two exons were, however, determined from polymerase chain reaction products. The COL4A5 gene has a structure highly homologous with that of COL4A1 which encodes the alpha 1(IV) chain. However, the COL4A5 gene contains 51 exons, or one less than COL4A1. The exon size pattern of the genes are similar, with 41 exons having identical sizes. All the exons were assigned to distinct EcoRI restriction fragments. The results may be useful for characterization of mutations in COL4A5 in patients with X chromosome-linked Alport syndrome.

Cellular distribution of insulin-degrading enzyme gene expression. Comparison with insulin and insulin-like growth factor receptors

Insulin-degrading enzyme (IDE) hydrolyzes both insulin and IGFs and has been proposed to play a role in signal termination after binding of these peptides to their receptors. In situ hybridization was used to investigate the cellular distribution of IDE mRNA and to compare it with insulin receptor (IR) and IGF-I receptor (IGFR) gene expression in serial thin sections from a variety of tissues in embryonic and adult rats. IDE mRNA is highly abundant in kidney and liver, tissues known to play a role in insulin degradation. IDE and IR mRNAs are highly coexpressed in brown fat and liver. The highest level IDE gene expression, on a per cell basis, is found in germinal epithelium. IDE and IGFR mRNAs are colocalized in oocytes, while IDE is colocalized with the IGF-II receptor in spermatocytes, suggesting that IDE may be involved with degradation of IGF-II in the testis. In summary, IDE expression demonstrates significant anatomical correlation with insulin/IGF receptors. These data are compatible with a role for IDE in degrading insulin and IGFs after they bind to and are internalized with their respective receptors and may also suggest a novel role for IDE in germ cells.

Prostaglandin E2 level in gingival crevicular fluid and its relation to the periodontal pocket depth in patients with periodontitis

Prostaglandin E2 (PGE2) levels in gingival crevicular fluid (GCF) of 46 normal controls and 90 patients suffering from periodontitis with different periodontal pocket depths were measured by radioimmunoassay (RIA). The results demonstrated that PGE2 levels in the GCF of the periodontal pockets are higher in patients with periodontitis. The PGE2 level rises as the periodontal pocket deepens, especially in cases where the periodontal pocket depth exceeds 6 mm. This study shows that the PGE2 level is significantly related to the severity of bone destruction in periodontitis.

Deletions in the COL4A5 collagen gene in X-linked Alport syndrome. Characterization of the pathological transcripts in nonrenal cells and correlation with disease expression

The type IV collagen alpha 5 chain (COL4A5) gene of 88 unrelated male patients with X-linked Alport syndrome was tested for major gene rearrangements by Southern blot analysis, using COL4A5 cDNA probes. 14 different deletions were detected, providing a 16% deletion rate in the COL4A5 gene in the patient population. The deletions are dispersed all over the gene with different sizes, ranging from 1 kb to the complete absence of the gene (> 250 kb) in one patient. In four patients with intragenic deletions, absence of the alpha 3 (IV) chain in the glomerular basement membrane was demonstrated by immunohistochemical studies. This finding supports the hypothesis that abnormalities in the alpha 5 (IV) chain may prevent normal incorporation of the alpha 3 (IV) chain into the glomerular basement membrane. Direct sequencing of cDNA amplified from lymphoblast mRNA of four patients with internal gene deletions, using appropriate combinations of primers amplifying across the predicted boundaries of the deletions, allowed us to determine the effect of the genomic rearrangements on the transcripts and, by inference, on the alpha 5 (IV) chain. Regardless of the extent of deletion and of the putative protein product, the 14 deletions occur in patients with juvenile-type Alport syndrome.

Interaction of human papillomavirus (HPV) type 16 capsid proteins with HPV DNA requires an intact L2 N-terminal sequence

Encapsidation of papillomavirus DNA involves DNA-protein and protein-protein interactions. We sought to define the role of each human papillomavirus (HPV) capsid protein in HPV DNA encapsidation. HPV16 major (L1) and minor (L2) capsid proteins purified from recombinant vaccinia virus-infected cells were compared for their ability to bind nucleic acids. L2 protein, but not L1 protein, could bind HPV DNA. To map the DNA-binding region of L2, a series of truncated or point-mutated L2 protein open reading frames were used to show that only the N terminal of L2 was required for L2-DNA binding. This interaction depends critically on charged amino acids (Lys or Arg) in the first 12 amino acids of the N terminal of the protein. Several techniques were used to show that L2 interaction with DNA did not require specific DNA sequences. We propose that HPV L2 protein may play a major role in papillomavirus capsid assembly by introducing HPV DNA to the virus particles formed by the self assembly of the L1 major structural protein.

Limitations of predictive motifs revealed by cytotoxic T lymphocyte epitope mapping of the human papilloma virus E7 protein

Human papilloma virus (HPV) type 16 is found in the majority of cervical cancer patients and the transforming protein E7 is consistently expressed in cancer cells, making it a potential target for immune attack. In this study we have investigated whether E7 gains access to the MHC class I processing pathway and provides cytotoxic T lymphocyte (CTL) stimulating peptide epitopes. CTL were induced in H-2b mice by immunization with recombinant vaccinia virus expressing E7 (Vac-E7). To map CTL recognition, natural peptides were purified from cells expressing either intact or truncated E7 protein. Following peptide separation by HPLC one major CTL epitope was detected and truncated constructs localized this epitope to the C-terminal region. Mapping with synthetic peptides indicated that residues 49-57 (RAHYNIVTF) were recognised by anti-E7 CTL. Synthetic 49-57 peptide was used to induce CTL, which recognized the same HPLC purified natural peptide fractions as anti-E7 CTL. Binding motifs for H-2b class I molecules did not predict residues 49-57 to be a CTL epitope, but instead the sequence 21-28 (DLYCYEQL) which contains a Kb anchor motif. Synthetic 21-28 peptide was found to bind to Kb class I molecules and readily induced CTL, indicating that the T cell repertoire of H-2b mice can recognize this epitope. However, these CTL did not recognize peptides isolated from E7 expressing cells, showing that natural processing did not produce detectable levels of the 21-28 epitope. Together, the data demonstrate that an unexpected E7 peptide can function as a major CTL epitope.

Overexpression of parathyroid hormone-related protein in the skin of transgenic mice interferes with hair follicle development

Parathyroid hormone-related peptide (PTHrP) was initially discovered as the cause of the syndrome of humoral hypercalcemia of malignancy. Subsequently, the PTHrP gene has been shown to be expressed in a wide variety of normal tissues, including skin. Because the biological function of PTHrP in skin remains unknown, we used the human keratin 14 promoter to target overexpression of PTHrP to the skin of transgenic mice. We achieved a 10-fold level of overexpression in skin, and human keratin 14 promoter-PTHrP transgenic mice displayed a disturbance in normal hair follicle development. These mice either failed to initiate follicle development or showed a delay in the initiation of follicles. These findings suggest that PTHrP normally plays a role in the early stages of hair follicle development and support previous speculation that the peptide may function in regulating cellular differentiation.

Heterochronic expression of an adult muscle actin gene during ascidian larval development

Adultation is a heterochronic mode of development in which adult tissues and organs differentiate precociously during the larval phase. We have investigated the expression of an adult muscle actin gene during adultation in the ascidian Molgula citrina. Ascidians contain multiple muscle actin genes which are expressed in the larva, the adult, or during both phases of the life cycle. In ascidian species with conventional larval development, the larval mesenchyme cells, which are believed to be progenitors of the adult mesoderm, remain undifferentiated and do not express the muscle actin genes. In M. citrina, the mesenchyme cells differentiate precociously during larval development, suggesting a role in adultation. An adult muscle actin gene from M. citrina was obtained by screening a mantle cDNA library with a probe containing the coding region of SpMA1, a Styela plicata adult muscle actin gene. The screen yielded a cDNA clone designated McMA1, which contained virtually the complete coding and 3' noncoding regions of a muscle actin gene. The deduced McMA1 and SpMA1 proteins exhibit 97% identity in amino acid sequence and may be encoded by homologous genes. The McMA1 gene is expressed in juveniles and adults, but not in larval tail muscle cells, suggesting that it is an adult muscle actin gene. In situ hybridization with a 3' non-coding region probe was used to determine whether the McMA1 gene is expressed during adultation in M. citrina. McMA1 mRNA was first detected exclusively in the mesenchyme cells during the late tailbud stage and continued to accumulate in these cells during their migration into the future body cavity and heart primordium in the hatched larva. The McMA1 transcripts persisted in mesenchyme cells after larval metamorphosis. It is concluded that an adult muscle actin gene shows a heterochronic shift of expression into the larval phase during adultation in M. citrina.

Significant species differences in local IGF-I and -II gene expression

Comparison of renal and ovarian IGF system gene expression in the rat and human has shown that IGF-I mRNA is predominant in rat and IGF-II in human tissues, and that the two IGFs demonstrate different cellular patterns of expression in the homologous organs. IGF-I receptor gene expression, however, describes an apparently identical pattern in the tissues of both rat and human, suggesting that, although local sources and presumably regulation of IGF expression vary between the species, the ultimate functions served might be the same.

Molecular analysis and functional expression of the human type E neuronal Ca2+ channel alpha 1 subunit

A human brain alpha 1 Ca2+ channel subunit was cloned and expressed in Xenopus laevis oocytes. The open reading frame, encoding 2,312 amino acids, has high homology to the marine ray doe-1, the rat E-type, and the rabbit brain BII alpha 1 subunits. The amino and carboxy termini of this human.E-type alpha 1 subunit (alpha 1E) are most similar to the rabbit BII-1 splice variant, the remainder being colinear with the BII alpha 1 with the exception of two insertions, one of 43 amino acids in the C-terminus and another of 7 amino acids, found also in the rat alpha 1E, between domains II and III. Two potential Ca2+ binding sites are predicted from its primary structure. The expression of inward Ba2+ currents reveals voltage-dependent activation and inactivation measured by the cut-open oocyte vaseline-gap technique, with kinetics that correspond to that of a high-voltage-activated neuronal Ca2+ channel, and pharmacologic properties that resemble those of some low-voltage-activated neuronal Ca2+ currents. The human alpha 1E currents are insensitive to omega-conotoxin-GVIA (1 microM), omega-agatoxin-IVA (200 nM), a synthetic funnel web spider toxin (FTX, 20 microM), and Bay-K8644 (0.5 microM); they are inhibited 20% by high concentrations of methoxyverapamil and diltiazem, 65% by 0.1% crude funnel web spider venom and 100% by Ni2+ (IC50 = 30 nM). Single-channel records show a complex activity pattern with several apparent conductance states, the largest having a conductance of 14 pS.