Prevalence of anterior open bite in children and adolescents: a systematic review and meta-analysis.

PURPOSE: Anterior open bite is defined by the lack of incisal contact between the teeth in centric relation. The aim of this study was to determine the prevalence of anterior open in children and adolescents. METHODS: This systematic review included a search in the databases: PubMed, Scopus, Web of Science, LILACS, Google Scholar, and ProQuest. The acronym PECOS was considered: (P) children and adolescents, (E) presence of anterior open bite, (C) not applicable, (O) prevalence, and (S) observational studies. The risk of bias assessment was carried out using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. The prevalence meta-analyses were performed using MedCalc® software. The certainty of the evidence was determined with the GRADE approach. RESULTS: 26 studies were included. Eleven studies were judged at low, seven at moderate, and eight at high risk of bias. The overall prevalence of anterior open bite was 16.52% (95% CI 12.34-21.17) in children and adolescents. The prevalence was 19.38% (95% CI 13.77-25.69) in South America. The prevalence of anterior open bite was 22.67% (95% CI 16.56-29.43) among females and 16.99% (95% CI 11.77-22.94) among males. The prevalence of anterior open bite was 18.84% (95% CI 13.88-24.38) in the primary dentition, and 14.26% (95% CI 7.67-22.46) in the mixed dentition. The overall certainty of the evidence was very low. CONCLUSION: The overall prevalence of anterior open bite was 16.52% in children and adolescents aged 2-16 years. Giving the limitations of a prevalence meta-analysis, the extrapolation of the results should be cautious. REGISTRATION NUMBER: CRD42020183162, 10 July 2020.

A multicentre phase II trial of gemcitabine for the treatment of patients with newly diagnosed, relapsed or chemotherapy resistant mantle cell lymphoma: SAKK 36/03.

Mantle cell lymphoma (MCL) has a poor prognosis with often short and incomplete remissions. We aimed to test the efficacy and tolerability of gemcitabine in treating MCL. Gemcitabine was given in doses of 1000 mg/m(2) as a 30 min infusion on days 1 and 8 of each 3 week cycle for a maximum of nine cycles. Eighteen patients with a median age of 70 years were recruited. MCL was newly diagnosed in half of patients and relapsed in the remainder. Fifteen patients had Ann Arbor stage IV. The best-recorded responses were 1 CR (complete remission), 4 PRs (partial responses), 8 SDs (stable diseases) and 4 PDs (diseases progression). The response rate (RR) (CR + PR) was 5 (28%; 95% confidence interval: 7.1, 48.5). The patient achieving a CR had stage IV disease. Most haematological adverse events occurred during the first chemotherapy cycle. Three patients developed non-haematological serious adverse events: dyspnea, glomerular microangiopathy with haemolytic uremic syndrome (HUS) and hyperglycaemia. The median time-to-progression and treatment response duration (TRD) was 8.0 (95% confidence interval: 5.5, 9.3) and 10.6 (95% confidence interval: 5.5, 10.9) months, respectively. We conclude that Gemcitabine is well tolerated, moderately active and can induce disease stabilization in patients with MCL.

Molecular evidence for chlamydial infections in the eyes of sheep.

Ocular infections by chlamydiae are associated with ocular disease manifestations such as conjunctivitis and keratitis in humans and animals. Limited evidence exists that members of the order Chlamydiales can also cause ocular disease in sheep. In the current study, the prevalence of chlamydiae in the eyes of sheep was investigated by using PCR methods. Data obtained in sheep by broad-range 16S rRNA order Chlamydiales-specific PCR were compared to the prevalence of antibodies against chlamydiae detected by a competitive enzyme-linked immunosorbent assay (cELISA). Flocks tested included a clinically healthy flock and two flocks suffering from ocular disease and with histories of Ovine Enzootic Abortion (OEA). PCR detected DNA of Chlamydophila (Cp.) abortus and Cp. pecorum in the eyes of both healthy and sick animals but also identified Chlamydia (C.) suis and a variety of uncultured chlamydia-like organisms. Good correlation was found between the presence of Cp. abortus DNA in sheep conjunctival samples and seropositivity detected by cELISA. Despite these findings, no association was found between the presence of chlamydial DNA in the sheep conjunctival samples and the onset of clinical disease. These results suggest that the biodiversity of chlamydiae in the eyes of sheep is greater than that previously thought. Further investigations are needed to determine whether a causal relationship between infection by chlamydiae and ocular disease exists in these animals.

Exploration of the APC/beta-catenin (WNT) pathway and a histologic classification system for pulmonary artery intimal sarcoma. A study of 18 cases.

APC, a tumor suppressor gene in the Wnt pathway, stabilizes beta-catenin and controls cell growth. Mutation of APC or beta-catenin leads to nuclear accumulation of beta-catenin and transcription of cyclin D1/cyclin A. Pulmonary artery sarcoma (PAS) were studied by morphologic, immunohistochemical, and molecular genetic methods of the Wnt pathway. Eighteen cases were included: mean age 52 years, primary intraluminal location with typical clinical presentation. PAS were classified as epithelioid (n = 4) or malignant fibrous histiocytoma (MFH; spindled/pleomorphic, n = 4), myxofibrosarcoma (n = 8), and one each hemangiopericytoma-like or malignant inflammatory myofibroblastic tumor-like. The tumor cells demonstrated vimentin, focal actins, and rare focal desmin positivity. All but one were grade 2 or 3 by FNCLCC grading. Alteration in chromosome 5q21 (APC) was found in 4/14 PAS by LOH, mostly epithelioid-type; an MFH-type case demonstrated microsatellite instability (MSI) and nuclear beta-catenin. Cyclin D1 was expressed in seven tumors, all myxofibrosarcoma-type. No mutations were detected in APC or beta-catenin. In summary, PAS are predominantly intermediate grade myxofibrosarcoma in middle-aged males, and fatal in two-thirds of patients. Despite myofibroblastic phenotype, APC/beta-catenin pathway changes are rare. Cyclin D1, only expressed in the myxofibrosarcoma-type, is likely transcribed via factors other than beta-catenin.

Relevance of translocation type in myxoid liposarcoma and identification of a novel EWSR1-DDIT3 fusion.

The clinical course of myxoid/round cell liposarcoma (MRCL) is characterized by frequent local recurrences and metastases at unusual sites. MRCLs carry specific translocations, t(12;16) or rarely t(12;22), linking the FUS or the EWSR1 gene with the DDIT3 gene, respectively. Nine FUS/DDIT3 and three EWSR1/DDIT3 variants of fusion transcripts have been described thus far. In search of prognostic markers for MRCL, we analyzed the translocation types of 31 patients and related them to the event free and overall survival. Using break-apart FISH and RT-PCR combined with DNA sequencing, we detected FUS/DDIT3 fusions in 30 sarcomas, while an EWSR1/DDIT3 translocation was identified in one tumor. FUS/DDIT3 type II (exons 5-2) was most commonly detected (20 cases), followed by type I (7-2) (7 cases) and type III (8-2) (3 cases). A single tumor carrying a t(12;22) translocation expressed a hitherto unknown EWSR1-DDIT3 fusion transcript (13-3) linking the complete RNA-binding domain of EWSR1 with a short piece of the 5'-UTR and the entire open reading frame of the DDIT3 gene. Interestingly, five of six patients with type I (7-2) FUS/DDIT3 fusions displayed local recurrences and/or metastatic spread within the first 3 years, generally requiring chemotherapeutical treatment (median disease-free survival 17 months). In contrast, 9 of 13 patients with type II FUS/DDIT3 translocations remained at 3 years disease-free (median disease-free survival 75 months). Since the total number of patients is still limited, further studies are required to verify a putative association of type I FUS/DDIT3-fusion transcripts with a prognosis of MRCL.

Intensively kept pigs pre-disposed to chlamydial associated conjunctivitis.

In the present study, ocular chlamydial infections in pigs that originate from two different farming systems were investigated. In particular, the aim was to test pigs with and without clinical ocular symptoms for the presence of Chlamydiaceae and for linked infections with Acanthamoebae spp. possibly acting as vectors for Chlamydia or Chlamydia-like organisms. In a total of 181 pigs, 102 from Germany (GER), representing the intensively kept animals and 79 from Switzerland (CH), which were kept extensively, were screened for the presence of different pathogens by PCR, including a new Chlamydiaceae-specific intergenic spacer rRNA gene PCR. Additionally, results of clinical examination and cytology were compared between the symptomatic and asymptomatic pigs of the two groups. Ocular symptomatic pigs showed a high prevalence of Chlamydia suis in both groups: CH 79%, GER 90%. Only 23% asymptomatic pigs from CH, but 88% asymptomatic pigs from GER were positive for C. suis by PCR. DNA of Chlamydia-like organisms were detected in 19% CH, but only in 2% GER pigs, whereas only 4% CH and 1% GER pigs were also positive for Acanthamoebae spp. A co-infection of Acanthamoebae spp. and C. suis was present in only 3% of the CH but 28% of the GER pigs. In general, the intensively kept pigs in our study seemed to be pre-disposed to ocular chlamydial infection and associated conjunctivitis. Infections with Chlamydia-like organisms alone and in combination with Acanthamoebae played no role for clinical findings within the tested pig groups, whereas a co-infection of Acanthamoebae and C. suis was able to cause serious ocular manifestations in half of the cases of intensively kept pigs being positive for these microorganisms.

Chlamydiae in free-ranging and captive frogs in Switzerland.

A total of 210 frog samples originating either from a mass mortality (1991/1992) or from routine postmortem investigations of the years 1990 to 2004 were examined retrospectively for a possible involvement of Chlamydiae. For a prevalence study of Chlamydia in a selected Swiss amphibian population, 403 samples from free-ranging Rana temporaria were examined. Histopathology, immunohistochemistry using a monoclonal antibody against chlamydial lipopolysaccharide, and a 16S rRNA polymerase chain reaction (PCR) followed by DNA sequencing were performed on the formalin-fixed and paraffin-embedded tissues. Using PCR, 8 of 54 (14.8%) frog samples from the mass mortality (1991/1992) were positive for Chlamydia suis S45. A control group of healthy Xenopus laevis had 3 of 38 positive samples, sequenced as C suis S45 (2/3) and an endosymbiont of Acanthamoeba species UWE1 (1/3). Chlamydophila pneumoniae TW-183 was detected from exotic frogs kept in a zoo. Of the frogs collected for the prevalence study, 6 of 238 (2.5%) tested positive, 1 each for C suis S45, Cp pneumoniae TW-183, and uncultured Chlamydiales CRG22, and the remaining 3 revealed Chlamydophila abortus S26/3. In immunohistochemistry, there were 2 positive labeling reactions, 1 in intestine and the other in the epithelium coating the body cavity, both testing positive for Cp pneumoniae TW-183 in PCR. Histologically there were no lesions recorded being characteristic for Chlamydia. Although there is a prevalence of Chlamydia in Swiss frogs, no connection to a mass mortality (1991/1992) could be established. For the first time, C suis S45 and Cp abortus S26/3 were detected in frog material.

Prevalence of chlamydiae in semen and genital tracts of bulls, rams and bucks.

Chlamydiae infect male genital organs of ruminants. However, little is known about their prevalence. Hence, we investigated fresh and cryopreserved semen (bulls: n=304; rams: n=78; bucks: n=44) by polymerase chain reaction (PCR), as well as genital organs (bulls: n=13; rams: n=10; bucks: n=6) by immunohistochemistry (IHC) and PCR. Sera from bulls (n=104) and small ruminants (n=61) were tested by LPS and rMOMP (recombinant major outer membrane protein) ELISA and competitive ELISA (cELISA), respectively. Three PCR assays were compared in this study for detection of chlamydial DNA in semen: 16S rRNA, IGS-S (intergenic spacer 16S/23S-short), and IGS-L (intergenic spacer 16S/23S-long) PCRs. PCR sensitivity and inhibitory effects were determined by spiking semen with Chlamydophila (Cp.) abortus DNA. In bull semen, detection limits of the 16S, IGS-S and IGS-L PCRs were 10, 10, 100 templates, respectively. However, PCR sensitivity was reduced in ram and buck semen suggesting the presence of potential PCR inhibitors. Of 304 bull semen samples, the 16S PCR revealed DNA of chlamydiae in 20 samples (6.6%), including Cp. abortus (n=2), Cp. psittaci (n=1), Chlamydia suis (n=2), and Chlamydia-like organisms (n=15). In rams, one semen sample was positive for Chlamydia-like organism. All investigated male genital organs were negative for Chlamydia. Serology revealed 47.1% (49/104) positive bulls by LPS ELISA. Of these, 30 samples were positive by rMOMP ELISA, predominantly for Cp. pecorum. In small ruminants, cELISA displayed 34.8% (16/46) and 60% (9/15) positivity for Cp. abortus in rams and bucks, respectively. There was no correlation between serology and PCR of semen. The presence of chlamydiae in semen suggests the possibility of venereal transmission, although risk may be low in Switzerland.

Chlamydia-related abortions in cattle from Graubunden, Switzerland.

In 2001, the first case of bovine chlamydial abortion was reported in canton Graubunden, Switzerland. In this region, Chlamydophila (Cp.) abortus is endemic in small ruminants. Hence, we aimed to investigate the incidence of chlamydia-related abortions in cattle from Graubunden. During breeding seasons of 2003-2004, formalin-fixed and paraffin-embedded placenta specimens (n = 235) from late-term abortions in cattle were analyzed by histopathology, immunohistochemistry with a Chlamydiaceae-specific monoclonal antibody against chlamydial lipopolysaccharide (LPS), and 2 different polymerase chain reaction (PCR) methods (16 S ribosomal ribonucleic acid [rRNA] PCR, intergenic spacer [IGS-S] PCR), followed by PCR product sequencing. In 149 of 235 cases (63.4%), histopathologic lesions such as purulent and/or necrotizing placentitis were observed. Chlamydial antigen was clearly demonstrated in immunohistochemistry in only 1 of 235 cases (0.4%). Cp. abortus or Cp. psittaci was found in 12 of 235 (5.1%) and 10 of 235 cases (4.2%) by 16 S rRNA PCR and IGS-S PCR, respectively. However, we detected, by 16 S rRNA PCR, 43 of 235 cases (18.3%) to be positive for chlamydia-like organisms. In contrast to the situation in small ruminants in the canton Graubunden, bovine abortion from Cp. abortus seems not to play an important role. Nevertheless, zoonotic potential should be taken into account when handling abortion material from cattle. The significance of chlamydia-like isolates other than Waddlia chondrophila remains an open question in abortion and needs further investigation.

Detection of chlamydiae in boar semen and genital tracts.

Chlamydiae cause abortion and reproductive disorders in sows. Although organisms can infect the male genital tract, little is known about the disease situation in boars. Hence, we examined the prevalence of chlamydial infection in semen and genital tracts of boars. Samples collected from Swiss boars (group A: n=42), and boars from Germany (group B: n=39) were examined by bacteriology, LPS-ELISA, immunohistochemistry (IHC) and polymerase chain reaction (PCR). The latter methodology involved use of three PCR assays including 16Sig rDNA, IGS-S (intergenic spacer 16S/23S-Short) and IGS-L (intergenic spacer 16S/23S-Long) PCR for comparison methods. PCR sensitivity and the presence of potential PCR inhibitors were determined by spiking semen with Chlamydophila (Cp.) abortus DNA. Detection limits of the 16Sig and IGS-S PCR were 10 templates, while the IGS-L PCR was less sensitive (100 templates). Of 25 semen samples that were collected from group A, one semen sample was positive for Cp. psittaci and two were positive for Chlamydia-like organisms by 16Sig PCR. Screening of sera from Swiss boars revealed three animals with positive reactions in the LPS-ELISA, although we failed to detect chlamydiae within organs of these or sera-negative animals by IHC or IGS-S PCR. In group B, 10 ejaculates were positive for Chlamydia (C.) suis and two were positive for Chlamydia-like organisms by 16S PCR. The identification of DNA from Chlamydia-like organisms in semen from both groups of boars was surprising and a role for these bacteria in reproductive diseases requires further assessment. In conclusion, the prevalence of chlamydial infection was low in group A animals indicating that venereal transmission may not be significant for Chlamydia-associated reproductive diseases in pigs, although rare cases may occur.

Lesion-induced differential expression and cell association of Neurocan, Brevican, Versican V1 and V2 in the mouse dorsal root entry zone.

Lack of regeneration in the CNS has been attributed to many causes, including the presence of inhibitory molecules such as chondroitin sulfate proteoglycans (CSPGs). However, little is known about the contribution of CSPGs to regeneration failure in vivo, in particular at the dorsal root entry zone (DREZ), a unique CNS region that blocks regeneration of sensory fibers following dorsal root injury without glial scar formation. The goal of the present study was to evaluate the presence, regulation, and cellular identity of the proteoglycans Brevican, Neurocan, Versican V1 and Versican V2 in the DREZ using CSPG-specific antibodies and nucleic acid probes. Brevican and Versican V2 synthesized before the lesion were still present at high levels in the extracellular matrix of the DREZ several weeks after injury. In addition, Brevican was transiently expressed by reactive oligodendrocytes, and by a subset of astrocytes thereafter. Versican V2 mRNA appeared in NG2-positive cells with the morphology of oligodendrocyte precursor cells. Neurocan and Versican V1 levels were low before injury, and appeared in nestin-positive astrocytes and in NG2-positive cells, respectively, following lesion. Versican V1, but not V2, was also transiently increased in the peripheral dorsal root post-lesion. This is the first thorough description of the expression and cell association of individual proteoglycans following dorsal root lesion. It demonstrates that the proteoglycans Brevican, Neurocan, Versican V1, and Versican V2 are abundant in the DREZ at the time regenerating sensory fibers reach the PNS/CNS border and may therefore participate in growth-inhibition in this region.

Diagnostic investigation into the role of Chlamydiae in cases of increased rates of return to oestrus in pigs.

Cervical swabs and serum samples were taken from Swiss herds of sows with high rates of irregular return to oestrus (group A) and from control herds without reproductive problems (group B. The genital tracts of 21 slaughtered sows of group A were also examined. The swabs and genital tracts were screened for Chlamydiae by a new 16S rRNA PCR and the sera by an ELISA for Chlamydiaceae lipopolysaccharide. Chlamydophila (Cp) abortus was isolated from seven of the 65 swabs taken from group A but from none of the 128 swabs taken from group B. Chlamydia suis was present in swabs from both groups A (1.5 per cent) and B (2.3 per cent). In addition, Cp abortus was detected in 33.3 per cent of the genital tracts. Of the 193 sera tested, 61.7 per cent were positive, with no significant difference between group A (52.3 per cent) and group B (66.4 per cent). Chlamydia-like organisms were detected in 28.2 per cent of the swabs from group A and in 22 per cent of those from group B.

Detection of mycobacteria and chlamydiae in granulomatous inflammation of reptiles: a retrospective study.

A retrospective study on reptile tissues presenting with granulomatous inflammation was performed to detect the possible presence of mycobacteria and chlamydiae in these lesions. Ninety cases including 48 snakes, 27 chelonians, and 15 lizards were selected. Mycobacteria were detected by Ziehl-Neelsen (ZN) staining and a broad-range polymerase chain reaction (PCR) followed by DNA sequencing. To detect chlamydiae, immunohistochemistry with monoclonal antibodies against chlamydial lipopolysaccharide (LPS) and a Chlamydiales order-specific PCR and sequencing were applied. Acid-fast bacilli were found in 14 cases (15.6%) by ZN staining and in 23 cases (25.6%) by PCR. Sequence analysis revealed the presence of Mycobacteria other than Mycobacterium tuberculosis complex (MOTT). Chlamydial LPS antigen was observed within granulomas from five samples (5.6%), whereas the PCR screen revealed 58 positive cases (64.4%). Of these, 9 cases (10%) showed 98-99% similarity to Chlamydophila (Cp.) pneumoniae and 49 cases (54.4%) displayed a high similarity (88-97%) to the newly described "Chlamydia-like" microorganisms Parachlamydia acanthamoebae and Simkania negevensis. Results from this study confirm, on the one hand, that MOTT are probably the most important infectious etiology for granulomatous inflammation in reptiles. On the other hand, they indicate that chlamydia infects reptiles and that Cp. pneumoniae should be considered an etiological agent of granulomatous lesions of reptiles. Because both MOTT and Cp. pneumoniae are human pathogens, the potential of zoonotic transmission from reptiles to humans has to be considered. In contrast, the significance of Chlamydia-like isolates remains completely open, and further studies are needed to evaluate their role.

Versican V1 proteolysis in human aorta in vivo occurs at the Glu441-Ala442 bond, a site that is cleaved by recombinant ADAMTS-1 and ADAMTS-4.

Mature human aorta contains a 70-kDa versican fragment, which reacts with a neoepitope antiserum to the C-terminal peptide sequence DPEAAE. This protein therefore appears to represent the G1 domain of versican V1 (G1-DPEAAE(441)), which has been generated in vivo by proteolytic cleavage at the Glu(441)-Ala(442) bond, within the sequence DPEAAE(441)-A(442)RRGQ. Because the equivalent aggrecan product (G1-NITEGE(341)) and brevican product (G1-EAVESE(395)) are generated by ADAMTS-mediated cleavage of the respective proteoglycans, we tested the capacity of recombinant ADAMTS-1 and ADAMTS-4 to cleave versican at Glu(441)-Ala(442). Both enzymes cleaved a recombinant versican substrate and native human versican at the Glu(441)-Ala(442) bond and the mature form of ADAMTS-4 was detected by Western analysis of extracts of aortic intima. We conclude that versican V1 proteolysis in vivo can be catalyzed by one or more members of the ADAMTS family of metalloproteinases.

Significantly different bcl-2 expression profiles in gastric and non-gastric primary extranodal high-grade B-cell lymphomas.

Fifty-five cases of primary extranodal high-grade B-cell non-Hodgkin's lymphoma were investigated for bcl-2 and p53 protein expression as well as for t(14;18) translocations and p53 mutations. Phenotypic and genotypic profiles were compared between tumours of gastric (27 cases) and non-gastric (28 cases) origin. bcl-2 protein expression was significantly lower in gastric (11/27) than in non-gastric (28/28) lymphomas (p<0.0001), while nuclear p53 protein expression did not differ significantly between these two groups. In the stomach, there were no significant differences in either bcl-2 or p53 expression profiles between high-grade lymphomas with (n=14) and without (n=13) evidence of a low-grade component of MALT type. However, secondary high-grade lymphomas showed a significant down-regulation of bcl-2 protein (p<0.0001) and, conversely, an up-regulation of p53 protein (p<0.0001) as compared with their low-grade tumour components. In extranodal high-grade B-cell lymphomas, bcl-2 protein expression was not associated with t(14;18) translocation. Only one gastric lymphoma had a p53 point mutation with potential alteration of the amino acid sequence. These findings indicate that primary gastric high-grade B-cell lymphomas are immunohistologically distinct from primary extranodal high-grade B-cell lymphomas of an origin other than in the stomach.

Proteoglycans in the developing brain: new conceptual insights for old proteins.

Proteoglycans are a heterogeneous class of proteins bearing sulfated glycosaminoglycans. Some of the proteoglycans have distinct core protein structures, and others display similarities and thus may be grouped into families such as the syndecans, the glypicans, or the hyalectans (or lecticans). Proteoglycans can be found in almost all tissues being present in the extracellular matrix, on cellular surfaces, or in intracellular granules. In recent years, brain proteoglycans have attracted growing interest due to their highly regulated spatiotemporal expression during nervous system development and maturation. There is increasing evidence that different proteoglycans act as regulators of cell migration, axonal pathfinding, synaptogenesis, and structural plasticity. This review summarizes the most recent data on structures and functions of brain proteoglycans and focuses on new physiological concepts for their potential roles in the developing central nervous system.

Brain derived versican V2 is a potent inhibitor of axonal growth.

In this paper, we identify the chondroitin sulfate proteoglycan versican V2 as a major inhibitor of axonal growth in the extracellular matrix of the mature central nervous system. In immunohistochemical and in situ hybridization experiments we show that this tissue-specific splice variant of versican is predominantly present in myelinated fiber tracts of the brain and in the optic nerve, most likely being expressed by oligodendrocytes. We demonstrate that isolated versican V2 strongly inhibits neurite outgrowth of central and peripheral neurons in stripe-choice assays using laminin-1 as permissive substrate. The inhibitory character of versican V2 is maintained after removal of chondroitin sulfate and N- and O-linked oligosaccharide side chains, but it is abolished after core protein digestion with proteinase-K. Our data support the notion, that intact versican V2 prevents excessive axonal growth during late phases of development and hereby participates in the structural stabilization of the mature central nervous system.

Bovine CNS myelin contains neurite growth-inhibitory activity associated with chondroitin sulfate proteoglycans.

The absence of fiber regrowth in the injured mammalian CNS is influenced by several different factors and mechanisms. Besides the nonconducive properties of the glial scar tissue that forms around the lesion site, individual molecules present in CNS myelin and expressed by oligodendrocytes, such as NI-35/NI-250, bNI-220, and myelin-associated glycoprotein (MAG), have been isolated and shown to inhibit axonal growth. Here, we report an additional neurite growth-inhibitory activity purified from bovine spinal cord myelin that is not related to bNI-220 or MAG. This activity can be ascribed to the presence of two chondroitin sulfate proteoglycans (CSPGs), brevican and the brain-specific versican V2 splice variant. Neurite outgrowth of neonatal cerebellar granule cells and of dorsal root ganglion neurons in vitro was strongly inhibited by this myelin fraction enriched in CSPGs. Immunohistochemical staining revealed that brevican and versican V2 are present on the surfaces of differentiated oligodendrocytes. We provide evidence that treatment of oligodendrocytes with the proteoglycan synthesis inhibitors beta-xylosides can strongly influence the growth permissiveness of oligodendrocytes. beta-Xylosides abolished cell surface presentation of brevican and versican V2 and reversed growth cone collapse in encounters with oligodendrocytes as demonstrated by time-lapse video microscopy. Instead, growth cones were able to grow along or even into the processes of oligodendrocytes. Our results strongly suggest that brevican and versican V2 are additional components of CNS myelin that contribute to its nonpermissive substrate properties for axonal growth. Expression of these CSPGs on oligodendrocytes may indicate that they participate in the restriction of structural plasticity and regeneration in the adult CNS.

Versican V2 is a major extracellular matrix component of the mature bovine brain.

We have isolated and characterized the proteoglycan isoforms of versican from bovine brain extracts. Our approach included (i) cDNA cloning and sequencing of the entire open reading frame encoding the bovine versican splice variants; (ii) preparation of antibodies against bovine versican using recombinant core protein fragments and synthetic peptides; (iii) isolation of versican isoforms by ammonium sulfate precipitation followed by anion exchange and hyaluronan affinity chromatography; and (iv) characterization by SDS-polyacrylamide gel electrophoresis and Coomassie Blue staining or immunoblotting. Our results demonstrate that versican V2 is, together with brevican, a major component of the mature brain extracellular matrix. Versicans V0 and V1 are only present in relatively small amounts. Versican V2 migrates after chondroitinase ABC digestion with an apparent molecular mass of about 400 kDa, whereas it barely enters a 4-15% polyacrylamide gel without the enzyme treatment. The 400-kDa product is recognized by antibodies against the glycosaminoglycan-alpha domain and against synthetic NH2- and COOH-terminal peptides. Our preparations contain no major proteolytic products of versican, e.g. hyaluronectin or glial hyaluronate-binding protein. Having biochemical quantities of versican V2 available will allow us to test its putative modulatory role in neuronal cell adhesion and axonal growth.