The Impact of Gene Therapy on Dentistry: a Revisiting After Six Years

Journal of the American Dental Association (1939). Jan, 2002  |  Pubmed ID: 11811741

Gene therapy is an emerging field of biomedicine that has commanded considerable scientific and popular attention. The procedure involves the transfer of genes to patients for clinical benefit. Transferred genes can b e used for either reparative or pharmacological purposes.

Integrin Clustering Induces Kinectin Accumulation

Journal of Cell Science. May, 2002  |  Pubmed ID: 11973345

Integrin receptors mediate the formation of adhesion complexes and play important roles in signal transduction from the extracellular matrix. Integrin-based adhesion complexes (IAC) contain proteins that link integrins to the cytoskeleton and recruit signaling molecules, including vinculin, paxillin, focal adhesion kinase, talin and alpha-actinin. In this study, we describe a approximately 160 kDa protein that is markedly enriched at IAC induced by clustering integrins with fibronectin-coated beads. Protein sequence analysis reveals that this approximately 160 kDa protein is kinectin. Kinectin is an integral membrane protein found in endoplasmic reticulum, and it serves as a receptor for the motor protein kinesin. Fibronectin-induced IAC sequestered over half of the total cellular content of kinectin within 20 minutes. In addition, two other ER-resident proteins, RAP [low-density lipoprotein receptor-related protein (LRP) receptor-associated protein] and calreticulin, were found to be clustered at IAC, whereas kinesin was not. Our results identify a novel class of constituents of IAC.

Differentiation of Human Bone Marrow-derived Cells into Buccal Epithelial Cells in Vivo: a Molecular Analytical Study

Lancet. Mar, 2003  |  Pubmed ID: 12672312

Adult bone marrow-derived (BMD) cells could be used to repair damaged organs and tissues, but the intrinsic plasticity of these cells has been questioned by results of in-vitro studies suggesting that such cells might fuse with other cells giving the appearance of differentiation. We aimed to determine whether fusion events are important in vivo.

Immune Responses Following Salivary Gland Administration of Recombinant Adeno-associated Virus Serotype 2 Vectors

The Journal of Gene Medicine. Apr, 2005  |  Pubmed ID: 15515118

Gene transfer to salivary glands (SGs) can be accomplished in a minimally invasive manner, resulting in stable, long-term secretion of the transgene product. Therefore, SGs provide a novel target site for several potentially useful clinical gene therapeutics applications. Previous studies have indicated that intravenous, intramuscular and intranasal administration of recombinant adeno-associated virus serotype 2 (rAAV2) vectors induce host immune responses. There are no reported studies on immune responsiveness of rAAV2 vector administration to SGs.

Transplanted Human Bone Marrow Cells Generate New Brain Cells

Journal of the Neurological Sciences. Jun, 2005  |  Pubmed ID: 15949500

Multiple studies have reported that adult cells of bone marrow origin can differentiate into muscle, skin, liver, lung, epithelial cells, and neurons. To determine whether such cells might produce neurons and other cells in the human brain, we examined paraffin sections from female patients who had received bone marrow transplants from male donors. Y-chromosomes were labeled using autoradiography and fluorescent in situ hybridization. Neurons and astrocytes were identified histologically and immunohistochemically in neocortex, hippocampus, striatum, and cerebellum. However, most labeled cells in both gray and white matter appeared to be glia. Others have suggested that such Y-labeling represents fusion between host and donor cells, rather than true transdifferentiation. The possibilities of fusion and microchimerism were therefore examined using buccal epithelial cells as a model system. The female patients in this study had received either bone marrow or stem cell (CD34+ enriched) transplants from their brothers. Double labeling for X- and Y-chromosomes showed that Y-labeled buccal cells could not be explained by fusion. Genotyping studies of one patient, her brother, and her son ruled out the possibility of microchimerism. Whether, and under what circumstances, some form of bone marrow transplantation might provide adequate number of cells capable of replacing lost brain cells or enhancing their function will require additional studies.

Synergy Between Genetic and Tissue Engineering: Creating an Artificial Salivary Gland

Periodontology 2000. 2006  |  Pubmed ID: 16686936

Comment on Papers by Chong Et Al., Nishio Et Al., and Suri Et Al. on Diabetes Reversal in NOD Mice

Science (New York, N.Y.). Nov, 2006  |  Pubmed ID: 17124308

Chong et al., Nishio et al., and Suri et al. (Reports, 24 March 2006, pp. 1774, 1775, and 1778) confirmed that treating nonobese diabetic (NOD) mice with an immune adjuvant and semisyngenic spleen cells can reverse the disease but found that spleen cells did not contribute to the observed recovery of pancreatic islets. We show that islet regeneration predominately originates from endogenous cells but that introduced spleen cells can also contribute to islet recovery.

Re-engineering Primary Epithelial Cells from Rhesus Monkey Parotid Glands for Use in Developing an Artificial Salivary Gland

Tissue Engineering. Oct, 2006  |  Pubmed ID: 17518661

There is no satisfactory conventional treatment for patients who experience irreversible salivary gland damage after therapeutic radiation for head and neck cancer or because of Sjögren's syndrome. Additionally, if most parenchyma is lost, these patients also are not candidates for evolving gene transfer strategies. To help such patients, several years ago we began to develop an artificial salivary gland. In the present study, we used a non-human primate tissue source, parotid glands from rhesus monkeys, to obtain potential autologous graft cells for development of a prototype device for in situ testing. Herein, we present 3 major findings. First, we show that primary cultures of rhesus parotid gland (RPG) cells are capable of attaining a polarized orientation, with Na(+)/K(+)-adenosine triphosphatase, zonula occludens-1, and claudin-1 distributed in specific domains appropriate for epithelial cells. Second, we show that RPG cells exhibit 2 essential epithelial functions required for graft cells in an artificial salivary gland device (i.e., an effective barrier to paracellular water flow and the generation of a moderate transepithelial electrical resistance). Third, we show that RPG cells can express functional water channels, capable of mediating directional fluid movement, after transduction by adenoviral and adeno-associated virus type 2 vectors. Together these results demonstrate that it is feasible to individually prepare RPG cells for eventual use in a prototype artificial salivary gland.

Reversal of Sjogren's-like Syndrome in Non-obese Diabetic Mice

Annals of the Rheumatic Diseases. Jun, 2007  |  Pubmed ID: 17179174

Non-obese diabetic (NOD) mice exhibit autoimmune diabetes and Sjögren's-like syndrome.

Distribution of Tight Junction Proteins in Adult Human Salivary Glands

The Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society. Dec, 2008  |  Pubmed ID: 18765838

Tight junctions (TJs) are an essential structure of fluid-secreting cells, such as those in salivary glands. Three major families of integral membrane proteins have been identified as components of the TJ: claudins, occludin, and junctional adhesion molecules (JAMs), plus the cytosolic protein zonula occludens (ZO). We have been working to develop an orally implantable artificial salivary gland that would be suitable for treating patients lacking salivary parenchymal tissue. To date, little is known about the distribution of TJ proteins in adult human salivary cells and thus what key molecular components might be desirable for the cellular component of an artificial salivary gland device. Therefore, the aim of this study was to determine the distribution of TJ proteins in human salivary glands. Salivary gland samples were obtained from 10 patients. Frozen and formalin-fixed paraffin-embedded sections were stained using IHC methods. Claudin-1 was expressed in ductal, endothelial, and approximately 25% of serous cells. Claudins-2, -3, and -4 and JAM-A were expressed in both ductal and acinar cells, whereas claudin-5 was expressed only in endothelial cells. Occludin and ZO-1 were expressed in acinar, ductal, and endothelial cells. These results provide new information on TJ proteins in two major human salivary glands and should serve as a reference for future studies to assess the presence of appropriate TJ proteins in a tissue-engineered human salivary gland.

Point of Care

Journal (Canadian Dental Association). Sep, 2008  |  Pubmed ID: 18789194

Adiposity and Gingival Crevicular Fluid Tumour Necrosis Factor-alpha Levels in Children

Journal of Clinical Periodontology. Apr, 2009  |  Pubmed ID: 19426176

To investigate whether adiposity is associated with gingival crevicular fluid (GCF) tumour necrosis factor-alpha (TNF-alpha) levels in children. We also examined whether this relationship is mediated through plasma fasting insulin.

Bone Marrow Cells Are a Source of Undifferentiated Cells to Prevent Sjögren's Syndrome and to Preserve Salivary Glands Function in the Non-obese Diabetic Mice

The International Journal of Biochemistry & Cell Biology. Nov, 2010  |  Pubmed ID: 20732442

Non-obese diabetic (NOD) mice develop Sjögren's-like syndrome (Ss) and a gradual loss of saliva secretory function. Our previous study showed that injections of matched normal spleen cells with Complete Freund's Adjuvant (CFA) reversed salivary gland dysfunction in 14-week-old NOD mice, which had established Ss. The spleen and bone marrow are closely related organs, and both are among the first sites of hematopoiesis during gestation. Noticing a rapidly increasing number of clinical trials using bone marrow (BM) cells treatments for autoimmune diseases, we tested if BM cells can prevent Ss and restore salivary glands' function. We injected CFA and MHC class I-matched normal BM cells in 7-week-old NOD mice, which had not yet developed Ss. We found at week 52 post-treatment that all NOD mice receiving BM cells and CFA had a recovery of salivary flow and were protected from Ss and diabetes. BM cells-treated mice had their salivary function restored quantitatively and qualitatively. Saliva flow was higher (p<0.05) in BM cells-transplanted mice when compared to control mice, which continued to deteriorate over time. Total proteins, epidermal growth factor, amylase, and electrolytes concentrations in saliva of BM cells-treated mice were not significantly changed at week 44 and 52 post-therapy when compared to pre-therapy (when the mice did not have Ss). Restoration of salivary flow could have resulted from a combination of rescue and paracrine effects from BM cells. This study suggests that a combined immuno- and cell-based therapy can permanently prevent Ss and restored salivary function in NOD mice.

Efficacy and Safety of an Intraoral Electrostimulation Device for Xerostomia Relief: a Multicenter, Randomized Trial

Arthritis and Rheumatism. Jan, 2011  |  Pubmed ID: 20882668

To evaluate the efficacy and safety of an intraoral electrostimulation device, consisting of stimulating electrodes, an electronic circuit, and a power source, in treating xerostomia. The device delivers electrostimulation through the oral mucosa to the lingual nerve in order to enhance the salivary reflex.

Bone Marrow-derived Cells Rescue Salivary Gland Function in Mice with Head and Neck Irradiation

The International Journal of Biochemistry & Cell Biology. Jan, 2011  |  Pubmed ID: 20933096

Treatment for most patients with head and neck cancers includes ionizing radiation. A consequence of this treatment is irreversible damage to salivary glands (SGs), which is accompanied by a loss of fluid-secreting acinar-cells and a considerable decrease of saliva output. While there are currently no adequate conventional treatments for this condition, cell-based therapies are receiving increasing attention to regenerate SGs. In this study, we investigated whether bone marrow-derived cells (BMDCs) can differentiate into salivary epithelial cells and restore SG function in head and neck irradiated mice. BMDCs from male mice were transplanted into the tail-vein of 18Gy-irradiated female mice. Salivary output was increased in mice that received BMDCs transplantation at week 8 and 24 post-irradiation. At 24 weeks after irradiation (IR), harvested SGs (submandibular and parotid glands) of BMDC-treated mice had greater weights than those of non-treated mice. Histological analysis shows that SGs of treated mice demonstrated an increased level of tissue regenerative activity such as blood vessel formation and cell proliferation, while apoptotic activity was increased in non-transplanted mice. The expression of stem cell markers (Sca-1 or c-kit) was detected in BMDC-treated SGs. Finally, we detected an increased ratio of acinar-cell area and approximately 9% of Y-chromosome-positive (donor-derived) salivary epithelial cells in BMDC-treated mice. We propose here that cell therapy using BMDCs can rescue the functional damage of irradiated SGs by direct differentiation of donor BMDCs into salivary epithelial cells.

Microchimerism in Salivary Glands After Blood- and Marrow-derived Stem Cell Transplantation

Biology of Blood and Marrow Transplantation : Journal of the American Society for Blood and Marrow Transplantation. Mar, 2011  |  Pubmed ID: 20940057

Blood- and marrow-derived stem cells (BMDSCs) provide disease-ameliorating effects for cardiovascular and autoimmune diseases. Microchimerism from donor BMDSCs has been reported in several recipient tissues. We hypothesized that this finding suggests a potential use of BMDSCs in the treatment of salivary dysfunctions. We investigated the presence of Y chromosome-positive cells in salivary gland biopsies of 5 females who had received a marrow or blood stem cell transplant from male donors. One to 16 years after transplantation, all recipients exhibited scattered Y chromosome-positive cells in the acini, ducts, and stroma of their salivary glands (mean of 1.01%). Potentially, these cells can be markers of transplantation tolerance, contribute to neoplastic epithelial tissues, or engraft at sites of injury. In addition, transplantation of BMDSCs could be used for treatment of Sjögren's syndrome and salivary glands damaged by therapeutic irradiation for cancers of the head and neck.

Bone Marrow-derived Cells: A Potential Approach for the Treatment of Xerostomia

The International Journal of Biochemistry & Cell Biology. Jan, 2011  |  Pubmed ID: 21035563

Transplantations of bone marrow-derived cells (BMDCs) are traditionally used for hematologic diseases, but there are increasing numbers of clinical trials using BMDC treatments for non-hematologic disorders, including autoimmune diseases. BMDCs are recently reported to improve organ functions. This paper will review available reports supporting the role of BMDCs in reducing xerostomia (i.e. re-establishing salivary gland functions) due to head and neck irradiation for cancer therapies and in Sjögren's syndrome. There are reports that BMDCs provide a beneficial effect on the saliva production. BMDCs positively affect blood vessels stability and regeneration in irradiated salivary glands. Also, BMDCs provide an immunomodulatory activity in mice with Sjögren's-like disease. While the exact mechanisms by which BMDCs improve organ functions remain controversial, there is preliminary evidence that a combination of them (such as cell transdifferentiation, vasculogenesis, and paracrine effect) occur in salivary glands.

Human Mesenchymal Stem Cells Cultured with Salivary Gland Biopsies Adopt an Epithelial Phenotype

Stem Cells and Development. Jun, 2011  |  Pubmed ID: 21187001

Sjogren's syndrome and radiotherapy for head and neck cancer result in severe xerostomia and irreversible salivary gland damage for which no effective treatment is currently available. Cell culture methods of primary human salivary gland epithelial cells (huSGs) are slow and cannot provide a sufficient number of cells. In addition, the majority of cultured huSGs are of a ductal phenotype and thus not fluid/saliva secretory cells. Some reports indicated that mesenchymal stem cells (MSCs) possessed the potential to differentiate into epithelial cells. To test this hypothesis with huSGs, a coculture system containing 2 chambers separated by a polyester membrane was used to study the capacity of human MSCs to adopt an epithelial phenotype when cocultured with human salivary gland biopsies. Results were that 20%-40% of cocultured MSCs expressed tight junction proteins [claudin-1 (CLDN-1), -2, -3, and -4; occludin; junctional adhesion molecule-A; and zonula occludens-1] as well as other epithelial markers [aquaporin-5, α-amylase (α-AMY), and E-cadherin], and generated a higher transepithelial electrical resistance. Electron microscopy demonstrated that these MSCs had comparable cellular structures to huSGs, such as tight junction structures and numerous secretory granules. Quantitative real time (RT)-polymerase chain reaction revealed an upregulation of several salivary genes (aquaporin-5, AMY, and CLDN-2). Moreover, the amounts of α-AMY detected in cocultured MSCs were comparable to those detected in huSGs control cultures. These data suggest that cocultured MSCs can demonstrate a temporary change into a salivary gland acinar phenotype.

Matrigel Improves Functional Properties of Primary Human Salivary Gland Cells

Tissue Engineering. Part A. May, 2011  |  Pubmed ID: 21189069

Currently, there is no effective treatment available to patients with irreversible loss of functional salivary acini caused by Sjogren's syndrome or after radiotherapy for head and neck cancer. A tissue-engineered artificial salivary gland would help these patients. The graft cells for this device must establish tight junctions in addition to being of fluid-secretory nature. This study analyzed a graft source from human salivary glands (huSG) cultured on Matrigel. Cells were obtained from parotid and submandibular glands, expanded in vitro, and then plated on either Matrigel-coated (2 mg/mL) or uncoated culture dish. Immunohistochemistry, transmission electron microscopy, quantitative real-time-polymerase chain reaction, Western blot, and transepithelial electrical resistance were employed. On Matrigel, huSG cells adopted an acinar phenotype by forming three-dimensional acinar-like units (within 24 h of plating) as well as a monolayer of cells. On uncoated surfaces (plastic), huSG cells only formed monolayers of ductal cells. Both types of culture conditions allowed huSG cells to express tight junction proteins (claudin-1, -2, -3, -4; occludin; JAM-A; and ZO-1) and adequate transepithelial electrical resistance. Importantly, 99% of huSG cells on Matrigel expressed α-amylase and the water channel protein Aquaporin-5, as compared to <5% of huSG cells on plastic. Transmission electron microscopy confirmed an acinar phenotype with many secretory granules. Matrigel increased the secretion of α-amylase two to five folds into the media, downregulated certain salivary genes, and regulated the translation of acinar proteins. This three-dimensional in vitro serum-free cell culture method allows the organization and differentiation of huSG cells into salivary cells with an acinar phenotype.

Matrigel Improves Functional Properties of Human Submandibular Salivary Gland Cell Line

The International Journal of Biochemistry & Cell Biology. Apr, 2011  |  Pubmed ID: 21216302

Sjogren's syndrome and radiotherapy for head and neck cancers result in irreversible damage to functional salivary tissue, for which no adequate treatment is available. The microenvironment for salivary gland cell cytodifferentiation is critical for the future development of salivary gland regeneration, repair and tissue engineering treatments. Results from this study indicate that human submandibular cell line (HSG) cultured on Matrigel (2mg/ml) could be induced to differentiate into polarized secretory acinar-like cells. The HSG cells grown on Matrigel were evaluated by physiological functional assays, molecular and immunohistochemistry, immunofluorescence, and morphological assessments. The results showed (1) a decrease in cell proliferation; (2) an increase in cell apoptosis; (3) cellular polarization evident by transepithelial electrical resistance (TER), expressions of tight junction proteins (claudin-1, -2, -3, -4, occludin, JAM-A, and ZO-1) and transmission electron microscopy (TEM); (4) an increase in the production and/or secretion of acinar cell proteins, i.e., alpha-amylase, aquaporin-5, cytokeratins, and mucin-1, that were not associated with increases in mRNA transcription; (5) a decrease in vimentin expression; and (6) expression of potential stem cell biomarkers CD44 and CD166. The data indicated that Matrigel provided a suitable microenvironment for morphological and functional differentiation of HSG cells into 3D acinar like cells. This study provides an in vitro model and baseline data on future developments of new strategies for salivary gland regeneration and replacement.