Marzia Arlotti

Genes causing clefting syndromes as candidates for non‐syndromic cleft lip with or without cleft palate: a family‐based association study

Clefts of the orofacial region are among the most common congenital defects, caused by abnormal facial development during gestation. Non-syndromic cleft lip with or without cleft palate (NSCLP) is a complex trait most probably caused by multiple interacting loci, with possible additional environmental factors. As facial clefts form part of more than 300 syndromes, one strategy for identifying the genetic causes of NSCLP could be to study candidate genes responsible for clefting syndromes. Three genes were selected for this investigation: TP63, which codes for the tumour protein p63 and causes Ectrodactyly-Ectodermal dysplasia-orofacial Cleft syndrome; JAG2, a downstream gene of TP63; and MID1, which is responsible for Opitz syndrome. A linkage disequilibrium investigation was performed with intragenic single nucleotide polymorphisms on each of these genes in a sample study of 239 patients/parents trios. Evidence which suggests that JAG2 and MID1 may play a role in NSCLP was obtained.

PerioGlas regulates osteoblast RNA interfering.

PURPOSE PerioGlas (PG) is an alloplastic material that has been used for grafting periodontal osseous defects since the 1990s. In animal models, it has been proven that PG achieves histologically good repairs of surgically created defects. In clinical trials, PG is effective as an adjunct to conventional surgery in the treatment of intrabony defects; however, how PG alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microRNA (miRNA) microarray techniques to investigate the translation process in osteoblasts exposed to PG. MATERIALS AND METHODS By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we identified several miRNA whose expression was significantly modified in osteoblast-like cell lines (MG-63) cultured with PG. RESULTS There were ten up-regulated miRNA (mir-337, mir-377, mir-9, mir-516, mir-515-3p, mir-496, mir-200b, mir-489, mir-25, mir-423) and two down-regulated miRNA (mir-26a, mir-30d). CONCLUSION PG acts on miRNAs, which in turn regulate several messengers. Among them there are mRNAs related to bone formation and skeletal and cartilage development. The vast majority of detected genes are down-regulated, and some are homeobox genes like NOG, EN1, and CHRD. Other down-regulated genes are receptors (like GHRHR) and extracellular matrix proteins (like COMP). Although the exact mechanism of PG action on osteoblasts is still incompletely understood, these data demonstrate that PG has not only an osteoconductive effect, but also regulates bone formation.

Zirconium oxide regulates RNA interfering of osteoblast-like cells.

Zirconium oxide (ZO) has outstanding mechanical properties, high biocompatibility and high resistance to scratching. Since dental implants are made with ZO and the genetic effects of ZO on osteoblasts are incompletely understood, we used microRNA microarray techniques to investigate the translation process in osteoblasts exposed to ZO. By using miRNA microarrays containing 329 probes designed from Human miRNA sequences, we identified in osteoblast-like cells line (MG-63) cultured on ZO disks several miRNA whose expression was significantly modified. The most notable regulated genes acting on osteoblasts are: NOG, SHOX, IGF1, BMP1 and FGFR1. The data reported below represent the first study on translation regulation in osteoblasts exposed to zirconium and one in which the effect of ZO on bone formation has been detected.

Anatase Nanosurface Regulates Micrornas

Titanium is the criterion standard among materials used for prosthetic devices because of its good mechanical and chemical properties. When exposed to oxygen, titanium becomes an oxide that is biocompatible and able to induce osseointegration. There are 3 allotropic forms of titanium dioxide: brookite, rutile, and anatase. Anatase can be prepared as a colloidal suspension and then used to coat surfaces. Anatase coating (AC) can potentially have specific biologic effects and specifically induce bone formation. To get more information as regards the osteogenic effect of AC, we used microRNA (miRNA) microarray techniques to investigate translation regulation in osteoblasts exposed to AC. Transduction, transcription, and translation are the 3 levels of regulation of cell activity. Recently, a new type of translation regulation has been identified: RNA interference. RNA interference is a process in which miRNA (i.e., noncoding RNAs of 19-23 nucleotides) can induce sequence-specific mRNA degradation and/or translational repression. The human genome encodes a few hundred miRNAs that can posttranscriptionally repress thousands of genes. miRNA oligonucleotide microarray provides a novel method of carrying out genome-wide miRNA profiling in human samples. By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we identified in osteoblast-like cell line (MG-63) cultured with AC several miRNA whose expression had been significantly modified. The data reported constitute, to our knowledge, the first study on translation regulation in osteoblasts exposed to AC. They can be relevant to a better understanding of the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects.

Medpor ® regulates osteoblast's microRNAs

Porous polyethylene (PP or Medpor) is an alloplastic material worldwide used for craniofacial reconstruction. Although several clinical studies are available, there is a lack as regard the genetic effects. Because PP is always fixed on bone and the mechanism by which PP acts on osteoblasts is unknown, we therefore attempted to address this question by using microRNA microarray techniques to investigate the translation regulation in osteoblasts exposed to PP. The miRNA oligonucleotide microarray provides a novel method to carry out genome-wide microRNA profiling in human samples. By using miRNA microarrays containing 329 probe designed from Human miRNA sequence, we identified in osteoblast-like cells line (MG-63) cultured with Medpor (Porex Corporation, Fairburn, Georgia, USA) several miRNA which expression is significantly modified. We identified 16 up-regulated miRNA (i.e. mir-337, mir-515-3p, mir-377, mir-153, mir-367, mir-152, let-7b, mir-92, mir-155, mir-424, mir-148b, mir-368, mir-18b, mir-520d, mir-20b, mir-128a) and 2 down-regulated miRNA (i.e. mir-143, mir-32). The data reported are, to our knowledge, the first study on translation regulation in osteoblasts exposed to PP. They can be relevant to better understand the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects.

Short-period Effects of Zirconia and Titanium on Osteoblast MicroRNAs

BACKGROUND MicroRNAs (miRNAs) are a class of small, functional, noncoding RNAs of 19 to 23 nucleotides which induce degradation of specific messenger RNAs (mRNAs), thus controlling the translational process (ie, synthesis of proteins from mRNAs). In addition, mRNAs regulate the promoter of specific miRNAs activating an autoregulatory feedback loop. PURPOSE Titanium and zirconium dioxide ceramics (ZDCs) are used to make dental implants. Because the molecular mechanism by which ZDC and Ti act on osteoblasts is incompletely understood, we attempted to get more information by comparing the effect of ZDC and Ti on osteoblast miRNAs. MATERIALS AND METHODS By using miRNA microarray technique, we identified in osteoblast-like cell line (MG63) grown on grade 3 Ti and ZDC disks several miRNAs whose expression was modified. We collected mRNAs after 24 hours of cell culturing to better understand molecular events related to early bone healing around inserted implants. An mRNA microarray technique was then performed as a control. RESULTS There were six up- and four down-regulated miRNAs. Because every miRNA regulates hundreds of genes, we focused only on those related to bone formation. Among them, the most notable are BMP4 and 7, which are both up-regulated in osteoblasts cultured on Ti disks. CONCLUSION The detected miRNAs differentially expressed in osteoblast-like cells grown on ZDC versus Ti act on a limited number of miRNAs and bone-related genes. The most notable are BMP4 and 7, which are more expressed in osteoblasts exposed to Ti surface. Consequently, we suggest that Ti surfaces could provide some advantages to immediate load implantology.

Genetic Portrait of Osteoblast-Like Cells Cultured on PerioGlas

PerioGlas (PG) is an alloplastic material used for grafting periodontal osseous defects since 1995. In animal models it has been histologically proven that PG achieves good repair of surgically created defects. In clinical trials, PG has been shown to be effective as an adjunct to conventional surgery in treating intrabony defects. Because the molecular events by which PG is able to alter osteoblast activity to promote bone formation are poorly understood, we investigated genes that are differently regulated in osteoblast-like cells exposed to PG. Bone formation can be attributable to ostegenesis (ie, direct stimulation of osteoblast to produce new bone), osteoconduction (which operates like a scaffold), or both processes. By using DNA microarrays containing 20 000 oligonucleotides, we identified several genes in which expression was significantly downregulated in a MG63 cell line cultured with PerioGlas (US Biomaterials Corp, Alachua, Fla). Specifically, PG is able to downregulate some functional activities of osteoblast-like cells: it acts on signal transduction, especially on the transforming growth factor beta (TGFB) paracrine network; it inhibits apoptosis; it decreases cell adhesion with consequent enhancement of cell mobility and migration; and it acts on bone marrow stem cells (ie, CD34). In conclusion, PG acts on bone formation by determining both osteoconduction (as demonstrated by the reduced cell adhesion) and ostegenesis (as shown by TGFB-related proteins and stem cell markers).

Titanium Acts on Osteoblast Translational Process

Titanium is a highly biocompatible material and very osteogenic in vivo. However, how titanium regulates osteoblast activity to promote bone formation is incompletely characterized. We, therefore, attempted to get more information by using microRNA (miRNA) microarray techniques to investigate translation regulation in osteoblasts grown on titanium disks. The miRNA oligonucleotide microarray provides a novel method to carry out genome-wide miRNA profiling in human samples. By using miRNA microarrays containing 329 probes designed from the human miRNA sequence, several miRNA were identified in osteoblast-like cell line (MG 63) grown on titanium disks. There were 13 upregulated miRNAs (ie, mir-23a, mir-222, mir-523, mir-22, mir-23b, mir-143, mir-377, mir-24, mir-422b, mir-26a, mir-29a, mir-17-5p, mir-182) and 2 down-regulated miRNAs (ie, mir-187, mir-339). The data reported are, to our knowledge, the first study on translation regulation in osteoblasts exposed to titanium. The data can be relevant to understand better the molecular mechanism of osteoblast activation and as a model for comparing other materials with similar clinical effects.

Comparison between osteoblasts derived from human dental pulp stem cells and osteosarcoma cell lines

Stem cells derived from human dental pulp are able to differentiate into osteoblasts and are a potential source of autologous bone. The aim of this study was to compare genes differentially expressed in osteoblastoids from human dental pulp (OHDP) to osteosarcoma cells (OCs).

Genetic effects of Medpor on osteoblast-like cells.

Porous polyethylene (PP or Medpor®) is an alloplastic material used worldwide for craniofacial reconstruction. Although several clinical studies are available, there is a lack as regard the genetic effects. Because PP is always fixed on bone and the mechanism by which PP acts on osteoblasts is unknown, we therefore attempted to address this question by using microarray techniques to identify genes that are differently regulated in osteoblasts exposed to PP. By using DNA microarrays containing 19,200 genes, we identified in osteoblast-like cell lines (i.e. MG-63) cultured on PP several genes where expression was differentially regulated. The differentially expressed genes cover a broad range of functional activities: 1) signal transduction, 2) transcription, 3) translation, 4) cell cycle regulation, 5) vesicular transport, and 6) production of cytoskeletal elements, cell-adhesion molecules and extracellular matrix components. The data reported are, to our knowledge, the first genetic portrait of osteoblast-like cells cultured on PP. They are relevant to better understanding of the molecular mechanism of bone-PP interaction and as a model for comparing other materials used for bone reconstruction.