Jakubovics N.S.,Oral Biology
Molecular Oral Microbiology | Year: 2010
Mature dental biofilms consist of towering microcolonies in which the resident bacterial cells interact with one another and exchange messages in the form of signalling molecules and metabolites. These structures have been compared with the bustling office blocks and apartment buildings of busy cities. Social and communication networks are the lifeblood of large communities, and there is mounting evidence that mutually beneficial interactions between microbial cells are essential to the development of biofilms in the oral cavity. This review discusses the mutualistic partnerships that form between oral bacteria, and the contribution of interspecies communication to the formation of mixed microbial communities. © 2010 John Wiley & Sons A/S.
Battacharya M.,Oral Biology |
Nandanoor A.,Oral Biology |
Osman M.,Pharmacology and Physiology |
Kasinathan C.,Oral Biology |
Frederikse P.,Oral Biology
Neurochemical Research | Year: 2014
Detailed parallels described between lens fiber cell and neuron morphology, sub-cellular structure, and molecular biology include striking similarities in the ultrastructure of their vesicle transport machinery and the membrane protrusions that occur along the lateral surfaces of both cell types. α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate receptor (NMDA) glutamate receptors (AMPARs/NMDARs) are the predominant receptors in neurons. These receptors have fundamental roles in neuron morphogenesis as well as neuron physiology and dynamic cell signaling, and specifically at dendritic spines. As a result, AMPAR and NMDAR dysregulation underlies several primary neural disorders that have also shown epidemiological associations with cataract. Previously, we demonstrated AMPAR GluA1 and REST (RE-1 silencing transcription factor)-regulated GluA2 subunits are expressed in the lens, and showed C-terminal phospho-tyrosine-GluA2, and striatal-enriched tyrosine phosphatase (STEP), as well as GluA2 Q/R RNA editing in lenses similar to neurons. Here, we demonstrated that REST-regulated NMDAR NR1, NR2A, and NR2B are also expressed in lenses and localize predominantly in fiber cell membranes, consistent with REST transcription factors, as well as miR-124 and other REST gene targets identified in the lens. We also showed NR2B Tyr-1472 phosphorylation occurs in lens. These p-Tyr-GluA2 and p-Tyr-NR2B phosphorylation events are linked with membrane insertion regulated by STEP. We next determined that NR1 transcripts that include exon 5 are produced in lens consistent with Fox-1 RNA binding protein isoforms linked with this alternative splicing event, and shown to be expressed in lens as well as brain. These findings provide further evidence that fundamental neuronal morphogenetic programs, and hallmark neuronal gene expression and modes of regulation, are shared with elongated fiber cells of the lens. © 2014, Springer Science+Business Media New York.
Frederikse P.H.,Oral Biology |
Nandanoor A.,Oral Biology |
Kasinathan C.,Oral Biology
Neurochemical Research | Year: 2015
Fmr1 and FMRP underlie Fragile X Syndrome (FXS) and are linked with related autism spectrum disorders (ASD). Fmr1 also has an essential role in eye and lens development. Lenses express FMRP along with γ-aminobutyric acid (GABA) receptors (GABARs), post-synaptic density protein 95 (PSD-95), Tyr-phosphatase STEP, CaMKIIα and Alzheimer’s disease Aβ precursor protein, which are verified targets of FMRP regulation in neurons and outline major topics in FXS/ASD research. PSD-95 as well as CaMKIIα transcripts undergo polypryimidine tract binding protein dependent alternative splicing in lens, consistent with PSD-95 translation in lens. At least 13 GABAR subunits and GAD25/65/67 GABA metabolism enzymes are expressed in lenses beginning in embryonic development, matching neural development. Interestingly, GABAergic drugs (e.g. baclofen) studied as FXS/ASD therapeutics are shown to resolve developmental vision defects in experimental myopia. Here, we demonstrated that FMRP co-localizes at fiber cell membranes with PSD-95, GABAAδ, GABAAβ3, GABBR1, STEP, CaMKIIα, and mGluR5 in young adult lenses. GAD65 and GABA detection was greatest at the peri-nuclear lens region where fiber cell terminal differentiation occurs. These findings add to an extensive list of detailed parallels between fiber cell and neuron morphology and their lateral membrane spine/protrusions, also reflected in the shared expression of genes involved in the morphogenesis and function of these membrane structures, and shared use of associated regulatory mechanisms first described as distinguishing the neuronal phenotype. Future studies can determine if GABA levels currently studied as a FXS/ASD biomarker in the brain, and generated by GAD25/65/67 in a comparable cell environment in the lens, may be similarly responsive to Fmr1 mutation in lens. The present demonstration of FMRP and key regulatory targets in the lens identifies a potential for the lens to provide a new research venue, in the same individual, to inform about Fmr1/FMRP pathobiology in brain as well as lens. © 2015, Springer Science+Business Media New York.