Interprofessional Collaboration in Improving Oral Health for Special Populations.

People with complex medical, physical, and psychological conditions are among the most underserved groups in receiving dental care and consequently have the most significant oral health disparities of any group. The traditional dental care delivery system is not able to deliver adequate services to these people with "special needs" for a variety of reasons. New systems of care are evolving that better serve the needs of these groups by using interprofessional teams to reach these individuals and integrate oral health services into social, educational, and general health systems.

The potential for telehealth technologies to facilitate charity care. Creating virtual dental homes.

The dramatic increase in broadband connectivity is opening up the possibility for using telehealth-connected teams in an improved system for charity care. The Virtual Dental Home demonstration taking place in California provides a model for the development and deployment of such teams. Teams using telehealth connections to provide oral health care can transform episodic or one-time visits into an ongoing system of care with a much greater emphasis on prevention and early intervention techniques and a greater likelihood of improved oral health for the population.

Promoting oral health through community engagement.

Persistent health disparities still exist in the U.S. despite decades of focus on the importance of prevention. Individual behaviors are the major contributor to oral health. By partnering and linking with community organizations, oral health professionals can expand their reach, overcome the obstacles to delivering effective prevention activities in dental offices and improve the oral health of the most underserved and vulnerable populations, who bear the greatest burden of dental disease.

SIMPL enhancement of tumor necrosis factor-α dependent p65-MED1 complex formation is required for mammalian hematopoietic stem and progenitor cell function.

Significant insight into the signaling pathways leading to activation of the Rel transcription factor family, collectively termed NF-κB, has been gained. Less well understood is how subsets of NF-κB-dependent genes are regulated in a signal specific manner. The SIMPL protein (signaling molecule that interacts with mouse pelle-like kinase) is required for full Tumor Necrosis Factor-α (TNFα) induced NF-κB activity. We show that SIMPL is required for steady-state hematopoiesis and the expression of a subset of TNFα induced genes whose products regulate hematopoietic cell activity. To gain insight into the mechanism through which SIMPL modulates gene expression we focused on the Tnf gene, an immune response regulator required for steady-state hematopoiesis. In response to TNFα SIMPL localizes to the Tnf gene promoter where it modulates the initiation of Tnf gene transcription. SIMPL binding partners identified by mass spectrometry include proteins involved in transcription and the interaction between SIMPL and MED1 was characterized in more detail. In response to TNFα, SIMPL is found in p65-MED1 complexes where SIMPL enhances p65/MED1/SIMPL complex formation. Together our results indicate that SIMPL functions as a TNFα-dependent p65 co-activator by facilitating the recruitment of MED1 to p65 containing transcriptional complexes to control the expression of a subset of TNFα-induced genes.

The virtual dental home: bringing oral health to vulnerable and underserved populations.

Large and increasing oral health disparities in the U.S. population led the Institute of Medicine to call for expanded research and demonstration of delivery systems that test new methods and technologies. These new methods include delivering oral health services in nontraditional settings, using nondental professionals, expanded roles for existing dental professionals and new types of dental professionals, and incorporating telehealth technologies. The virtual dental home is a system that demonstrates the characteristics called for by the IOM.

In-person versus "virtual" dental examination: congruence between decision-making modalities.

This study evaluated the agreement of a dentist's conclusions reached through an in-person versus a virtual examination. The dentist determined whether a patient was healthy enough to be treated only by allied dental personnel in a community setting or whether the patient needed to be seen by a dentist. The study concludes that a virtual examination is a strong substitute for an in-person examination and validates the application of telehealth-enabled examinations.

The virtual dental home: implications for policy and strategy.

Widely recognized problems with the U.S. health care system, including rapidly increasing costs and disparities in access and outcomes also exist in oral health. If oral health systems are to meet the "Triple Aim" of improving the experience of care, improving the health of populations, and reducing per capita costs of health care, new and innovative strategies will be needed including new regulatory, delivery, and financing systems. The virtual dental home is one such system.

The antibiotic gentamicin inhibits specific protein trafficking functions of the Arf1/2 family of GTPases.

Gentamicin is a highly efficacious antibiotic against Gram-negative bacteria. However, its usefulness in treating infections is compromised by its poorly understood renal toxicity. Toxic effects are also seen in a variety of other organisms. While the yeast Saccharomyces cerevisiae is relatively insensitive to gentamicin, mutations in any one of ∼20 genes cause a dramatic decrease in resistance. Many of these genes encode proteins important for translation termination or specific protein-trafficking complexes. Subsequent inspection of the physical and genetic interactions of the remaining gentamicin-sensitive mutants revealed a network centered on chitin synthase and the Arf GTPases. Further analysis has demonstrated that some conditional arf1 and gea1 alleles make cells hypersensitive to gentamicin under permissive conditions. These results suggest that one consequence of gentamicin exposure is disruption of Arf-dependent protein trafficking.

Properties of double-stranded oligonucleotides modified with lipophilic substituents.

We have synthesized a series of short, self-complementary oligonucleotide sequences modified at their 5'- and/or 3'- termini with a lipophilic dodecane (C12); these systems serve as models to assess the biophysical properties of double-stranded DNA (dsDNA) equipped with potentially stabilizing lipophilic substituents. Addition of C12 to the 5'-termini of self-complementary 10 nucleotide sequences increased their duplex melting temperatures (T(m)) by approximately 4-8 degrees C over their corresponding unmodified sequences. C12 functionalities added to both the 3'- and 5'-termini increased T(m) values by approximately 10-12 degrees C. The observed increases in T(m) correlated with greater duplex stabilities as determined by the free energy values (DeltaG) derived from T(m) plots. There is a greater degree of stabilization when C12 is positioned with a C.G base pair at the termini, and the stabilizing effect of lipophilic groups far exceeds the effect seen in adding an additional base pair to both ends of DNA. Stable, short dsDNA sequences are of potential interest in the development of transcription factor decoy oligonucleotides as possible therapeutic agents and/or biological tools. These results suggest that the stability of short dsDNA sequences are improved by lipophilic substituents and can be used as the basis for the design of dsDNAs with improved biological stabilities and function under physiological conditions.

Activation of NF-kappaB by fluid shear stress, but not TNF-alpha, requires focal adhesion kinase in osteoblasts.

When bone is mechanically loaded fluid shear stress (FSS) is generated as a result of the movement of interstitial fluid across the membranes of osteoblasts and osteocytes. This external mechanical loading stimulates changes in the activity of cytoplasmic signaling molecules and alters gene expression in bone cells. This process, referred to as mechanotransduction, is vital for maintaining bone health in vivo by regulating the balance between bone formation and bone resorption. This current study focuses on the role of focal adhesions, sites of integrin-mediated cellular attachment to the extracellular matrix, and their proposed function as mechanosensors in bone cells. We examined the role of a key component of focal adhesions and of mechanotransduction, focal adhesion kinase (FAK) in regulation of FSS- and tumor necrosis factor-alpha (TNF-alpha)-induced activation of nuclear factor-kappa B (NF-kappaB) signaling in osteoblasts. Immortalized FAK(+/+) and FAK(-)(/)(-) osteoblasts were exposed to periods of oscillatory fluid shear stress (OFF) and NF-kappaB activation was analyzed. We determined that FAK is required for OFF-induced nuclear translocation and activation of NF-kappaB in osteoblasts. In addition we found that OFF-induced phosphorylation of the IkappaB kinases (IKKalpha/beta) in both FAK(+/+) and FAK(-/-) osteoblasts, but only FAK(+/+) osteoblasts demonstrated the resulting degradation of NF-kappaB inhibitors IkappaBalpha and IkappaBbeta. OFF did not induce the degradation of IkappaBepsilon or the processing of p105 in either FAK(+/+) and FAK(-/-) osteoblasts. To compare the role of FAK in mediating OFF-induced mechanotransduction to the well characterized activation of NF-kappaB by inflammatory cytokines, we exposed FAK(+/+) and FAK(-/-) osteoblasts to TNF-alpha. Interestingly, FAK was not required for TNF-alpha induced NF-kappaB activation in osteoblasts. In addition we determined that TNF-alpha treatment did not induce the degradation of IkappaBbeta as did OFF. These data indicate a novel relationship between FAK and NF-kappaB activation in osteoblast mechanotransduction and demonstrates that the mechanism of FSS-induced NF-kappaB activation in osteoblasts differs from the well characterized TNF-alpha-induced activation.

Loss of SIMPL compromises TNF-alpha-dependent survival of hematopoietic progenitors.

OBJECTIVE: Emerging work has revealed an integral role of the tumor necrosis factor-alpha (TNF-alpha) nuclear factor (NF)-kappaB pathway in the regulation of hematopoiesis. TNF-alpha inhibition of hematopoietic stem/progenitor cell growth involves type I TNF-alpha receptor (TNF-RI) and type II TNF-alpha receptor (TNF-RII). However, the role of TNF-RI vs TNF-RII in mediating this response is less clear. Full induction of NF-kappaB-dependent gene expression through TNF-RI requires the transcriptional coactivator SIMPL (substrate that interacts with mouse pelle-like kinase). To address the role of SIMPL in TNF-alpha-dependent signaling in hematopoiesis, endothelial cells and hematopoietic progenitors expressing SIMPL short hairpin RNA were characterized. MATERIAL AND METHODS: In vitro gene expression and progenitor assays employing SIMPL short hairpin RNA were used to examine the requirement for SIMPL in TNF-alpha-dependent effects upon cytokine gene expression and hematopoietic progenitor cell growth. Competitive repopulation studies were used to extend these studies in vivo. RESULTS: SIMPL is required for full TNF-RI-dependent expression of NF-kappaB-controlled cytokines in endothelial cells. Hematopoietic progenitor cell expansion is not affected if progenitors lacked SIMPL or if progenitors are treated with human TNF-alpha, which signals through TNF-RI. In the absence of SIMPL, human TNF-alpha leads to a dramatic decrease in progenitor cell expansion that is not due to apoptosis. Loss of SIMPL does not affect the activity of transforming growth factor-beta1 and interferon-gamma, other known suppressors of hematopoiesis. CONCLUSIONS: Suppression of myeloid progenitor cell expansion requires signaling through TNF-RI and TNF-RII. Signals transduced through the TNF-alpha-TNF-RI-SIMPL pathway support hematopoietic progenitor cell survival, growth and differentiation.

Transient membrane recruitment of IRAK-1 in response to LPS and IL-1beta requires TNF R1.

The transcription factor NF-kappaB is an essential regulator of the innate immune response that functions as the first line of defense against infections. Activation of the innate immune response by bacterial lipopolysaccharide (LPS) triggers production of tumor necrosis factor-alpha (TNF-alpha) followed by interleukin-1 (IL-1). The IL-1 receptor associated kinase-1 (IRAK-1) is an integral component of the LPS, TNF-alpha, and IL-1 signaling pathways that regulate NF-kappaB. Thus we hypothesized that IRAK-1 coordinates cellular NF-kappaB responses to LPS, TNF-alpha, and IL-1. In contrast to TNF-alpha where IRAK-1 subcellular localization does not change, treatment with LPS or IL-1 leads to a loss in cytoplasmic IRAK-1 with a coordinate increase in plasma membrane associated modified IRAK-1. In fibroblasts lacking the type 1 TNF-alpha receptor (TNF R1), IRAK-1 turnover is altered and modification of IRAK-1 in the plasma membrane is decreased in response to LPS and IL-1, respectively. When NF-kappaB controlled gene expression is measured, fibroblasts lacking TNF R1 are hyperresponsive to LPS, whereas a more variable response to IL-1 is seen. Further analysis of the LPS response revealed that plasma membrane-associated IRAK-1 is found in Toll 4, IL-1, and TNF R1-containing complexes. The data presented herein suggest a model whereby the TNF R1-IRAK-1 interaction integrates the cellular response to LPS, TNF-alpha, and IL-1, culminating in a cell poised to activate TNF-alpha-dependent NF-kappaB controlled gene expression. In the absence of TNF R1-dependent events, exposure to LPS or IL-1 leads to hyperactivation of the inflammatory response.

Tumor Necrosis Factor-alpha- and interleukin-1-induced cellular responses: coupling proteomic and genomic information.

The pro-inflammatory cytokines, Tumor Necrosis Factor-alpha (TNFalpha) and Interleukin-1 (IL-1) mediate the innate immune response. Dysregulation of the innate immune response contributes to the pathogenesis of cancer, arthritis, and congestive heart failure. TNFalpha- and IL-1-induced changes in gene expression are mediated by similar transcription factors; however, TNFalpha and IL-1 receptor knock-out mice differ in their sensitivities to a known initiator (lipopolysaccharide, LPS) of the innate immune response. The contrasting responses to LPS indicate that TNFalpha and IL-1 regulate different processes. A large-scale proteomic analysis of TNFalpha- and IL-1-induced responses was undertaken to identify processes uniquely regulated by TNFalpha and IL-1. When combined with genomic studies, our results indicate that TNFalpha, but not IL-1, mediates cell cycle arrest.

The expression level of luciferase within tumour cells can alter tumour growth upon in vivo bioluminescence imaging.

In vivo bioluminescence imaging is becoming a very important tool for the study of a variety of cellular and molecular events or disease processes in living systems. In vivo bioluminescence imaging is based on the detection of light emitted from within an animal. The light is generated as a product of the luciferase-luciferin reaction taking place in a cell. In this study, we implanted mice with tumour cells expressing either a high or a low level of luciferase. In vivo bioluminescence imaging was used to follow tumour progression. Repeated luciferin injection and imaging of high and low luciferase-expressing tumours was performed. While low luciferase-expressing tumours grew similarly to vector controls, growth of the high luciferase-expressing tumours was severely inhibited. The observation that a high level of luciferase expression will inhibit tumour cell growth when an animal is subjected to serial in vivo bioluminescence imaging is potentially an important factor in designing these types of studies.

Phosphorylation of SIMPL modulates RelA-associated NF-kappaB-dependent transcription.

Epidemiological data have implicated perturbations in the regulation of NF-kappaB activity to diseases that affect a large number of Americans today. Specifically, chronic activation of genes involved in the inflammatory response is associated with the progression of and complications in diabetes, arthritis, atherosclerosis, and cancer. Insight into the mechanisms governing the regulation of NF-kappaB transcriptional activity will provide the molecular link between NF-kappaB and these pathological states. SIMPL (signaling molecule that associates with mouse Pelle-like kinase) is a component of a signaling pathway through which tumor necrosis factor-alpha (TNF-alpha) induces NF-kappaB-controlled gene transcription. SIMPL interacts with the nuclear pool of the NF-kappaB subunit, p65, in a TNF-alpha-dependent manner to enhance p65-dependent gene transcription. How SIMPL activity is regulated is unknown. Under basal as well as TNF-alpha-stimulated conditions, SIMPL phosphopeptides were identified. SIMPL mutants lacking sites that are phosphorylated under basal conditions diminished p65 transactivation activity but had no effect on SIMPL nuclear localization. SIMPL mutants lacking sites of TNF-alpha-enhanced phosphorylation impaired nuclear localization and prevented TNF-alpha-induced p65 transactivation activity. Together, these studies reveal that phosphorylation of the SIMPL protein plays a critical role in SIMPL regulation by affecting both SIMPL subcellular localization and the p65 coactivator function of SIMPL.

Alpha-lipoic acid modulates ovarian surface epithelial cell growth.

OBJECTIVE: The intracellular redox state plays an important role in controlling inflammation. Clinical and laboratory data suggest that inflammation can lead to tumor progression. We hypothesized that restoring intracellular redox control would inhibit inflammation and subsequently tumor progression. Our studies were designed to investigate the effect of alpha-lipoic acid (ALA), a naturally occurring antioxidant, on a key inflammatory signaling pathway and cell proliferation in normal and tumorigenic ovarian surface epithelial cells. METHODS: Normal and tumorigenic ovarian surface epithelial cells were isolated as described by Roby and coworkers [Roby KF, Taylor CC, Sweetwood JP, Cheng Y, Pace JL, Tawpik O, Persons DL, Smith PG, Terranova PF, Development of a syngeneic mouse model for events related to ovarian cancer. Carcinogen 2000;21 (4):585. [1]]. The effect of ALA on cellular function was measured in cell proliferation and apoptosis assays. p27(kip1) protein levels were measured by Western analysis. Activation of NF-kappaB dependent transcription was assessed in cell cultures transiently transfected with NF-kappaB controlled reporter constructs. RESULTS: Our results reveal that ALA selectively inhibits the growth of tumorigenic as compared to non-tumorigenic ovarian surface epithelial cells. The growth inhibitory effect of ALA is not due to induction of apoptosis but instead is associated with an increase in the half-life of the cyclin-dependent kinase inhibitor, p27(kip1). In parallel to the growth inhibitory effect, ALA also affects a key inflammatory signaling pathway by inhibiting TNFalpha-induced NF-kappaB signaling activity. CONCLUSIONS: Our studies are the first to show that ALA treatment has a growth inhibitory effect on malignant surface epithelial cells of ovarian origin. We have also confirmed the reproducibility of the immunocompetent mouse ovarian cancer model originally described by Roby and coworkers [Roby KF, Taylor CC, Sweetwood JP, Cheng Y, Pace JL, Tawpik O, Persons DL, Smith PG, Terranova PF, Development of a syngeneic mouse model for events related to ovarian cancer. Carcinogen 2000;21 (4):585].

The disordered amino-terminus of SIMPL interacts with members of the 70-kDa heat-shock protein family.

The p65 coactivator SIMPL is a small protein that lacks any conserved domains of known function. To better understand regulation of SIMPL activity, we sought to identify novel SIMPL interacting proteins using mass spectrometry analysis of SIMPL containing complexes. Two members of the 70-kDa heat-shock protein family, Hsp70 and Hsc70, were identified as SIMPL binding proteins. Subsequent immunocomplexing assays confirmed this interaction and demonstrated that the amino-terminus of SIMPL is required for this interaction. Using a combination of amino acid composition analysis, PONDR VL-XT prediction, charge-hydropathy plots, and cumulative distribution functions, the amino-terminal region of both mouse and human SIMPL proteins was predicted to be intrinsically disordered. These data, taken together, suggest that Hsp70/Hsc70 bind the intrinsically disordered amino-terminal region of SIMPL to stabilize the protein and thereby regulate its activity. Understanding the regulation of SIMPL through its interaction with Hsp70/Hsc70 may serve as a novel means of modulating tumor necrosis factor alpha signaling.

Phosphorylation of Ser24 in the pleckstrin homology domain of insulin receptor substrate-1 by Mouse Pelle-like kinase/interleukin-1 receptor-associated kinase: cross-talk between inflammatory signaling and insulin signaling that may contribute to insulin resistance.

Inflammation contributes to insulin resistance in diabetes and obesity. Mouse Pelle-like kinase (mPLK, homolog of human IL-1 receptor-associated kinase (IRAK)) participates in inflammatory signaling. We evaluated IRS-1 as a novel substrate for mPLK that may contribute to linking inflammation with insulin resistance. Wild-type mPLK, but not a kinase-inactive mutant (mPLK-KD), directly phosphorylated full-length IRS-1 in vitro. This in vitro phosphorylation was increased when mPLK was immunoprecipitated from tumor necrosis factor (TNF)-alpha-treated cells. In NIH-3T3(IR) cells, wild-type mPLK (but not mPLK-KD) co-immunoprecipitated with IRS-1. This association was increased by treatment of cells with TNF-alpha. Using mass spectrometry, we identified Ser(24) in the pleckstrin homology (PH) domain of IRS-1 as a specific phosphorylation site for mPLK. IRS-1 mutants S24D or S24E (mimicking phosphorylation at Ser(24)) had impaired ability to associate with insulin receptors resulting in diminished tyrosine phosphorylation of IRS-1 and impaired ability of IRS-1 to bind and activate PI-3 kinase in response to insulin. IRS-1-S24D also had an impaired ability to mediate insulin-stimulated translocation of GLUT4 in rat adipose cells. Importantly, endogenous mPLK/IRAK was activated in response to TNF-alpha or interleukin 1 treatment of primary adipose cells. In addition, using a phospho-specific antibody against IRS-1 phosphorylated at Ser(24), we found that interleukin-1 or TNF-alpha treatment of Fao cells stimulated increased phosphorylation of endogenous IRS-1 at Ser(24). We conclude that IRS-1 is a novel physiological substrate for mPLK. TNF-alpha-regulated phosphorylation at Ser(24) in the pleckstrin homology domain of IRS-1 by mPLK/IRAK represents an additional mechanism for cross-talk between inflammatory signaling and insulin signaling that may contribute to metabolic insulin resistance.

Tumor necrosis factor alpha induction of NF-kappaB requires the novel coactivator SIMPL.

A myriad of stimuli including proinflammatory cytokines, viruses, and chemical and mechanical insults activate a kinase complex composed of IkappaB kinase beta (IKK-beta), IKK-alpha, and IKK-gamma/N, leading to changes in NF-kappaB-dependent gene expression. However, it is not clear how the NF-kappaB response is tailored to specific cellular insults. Signaling molecule that interacts with mouse pelle-like kinase (SIMPL) is a signaling component required for tumor necrosis factor alpha (TNF-alpha)-dependent but not interleukin-1-dependent NF-kappaB activation. Herein we demonstrate that nuclear localization of SIMPL is required for type I TNF receptor-induced NF-kappaB activity. SIMPL interacts with nuclear p65 in a TNF-alpha-dependent manner to promote endogenous NF-kappaB-dependent gene expression. The interaction between SIMPL and p65 enhances p65 transactivation activity. These data support a model in which TNF-alpha activation of NF-kappaB dependent-gene expression requires nuclear relocalization of p65 as well as nuclear relocalization of SIMPL, generating a TNF-alpha-specific induction of gene expression.