Tooth retention, health, and quality of life in older adults: a scoping review.

OBJECTIVE: This scoping review describes the relationship between tooth retention, health, and quality of life in older adults. METHODS: Seven databases were searched for English language articles for subjects ≥ 65 y from 1981 to 2021. Exposure was tooth retention (≥ 20), and outcomes were general/systemic health and quality of life. Methodological quality was assessed using the Newcastle-Ottawa Scale and Cochrane Risk of Bias 2.0 tool. RESULTS: 140 articles were included, only four were randomized trials. Inter-rater agreement (κ) regarding study inclusion was 0.924. Most were assessed with low risk of bias (n = 103) and of good quality (n = 96). Most studies were conducted in Japan (n = 60) and Europe (n = 51) and only nine in the US. Tooth retention was referred to as "functional dentition" in 132 studies and "shortened dental arch" in 19 studies. Study outcomes were broadly synthesized as (1) cognitive decline/functional dependence, (2) health status/chronic diseases, (3) nutrition, and (4) quality of life. DISCUSSION: There is a positive relationship between tooth retention, overall health, and quality of life. Older adults retaining ≥ 20 teeth are less likely to experience poorer health. Having < 20 teeth increases the likelihood for functional dependence and onset of disability, and may affect successful ageing. This review supports the general finding that the more teeth older adults retain as they age, the less likely they are to have adverse health outcomes. However, significant knowledge gaps remain which can limit decision-making affecting successful ageing for many older adults. This review highlights the need to consider, as an important marker of oral health and function, the retention of a functional minimum of a natural dentition, rather than a simple numeric score of missing teeth.

The Teaching of Personalized Dentistry in North American Dental Schools: Changes from 2014 to 2017.

The aim of this study was to assess the development of personalized dentistry in the curricula of North American dental schools from 2014 to 2017. In 2014, a web-based survey on personalized medicine/dentistry (PM/PD) was distributed to academic deans of all U.S. (n=65) and Canadian (n=10) dental schools with graduating classes. The results (n=42; 56% response rate) showed that few schools had plans for implementation of PM/PD at the time, even though the majority of respondents reported feeling that PM/PD should be taught in the curriculum and will impact clinical practice in the future. A three-year followup survey in 2017, sent to the same 75 schools, was designed to reassess the teaching/practice of PM/PD in dental schools in both didactic and clinical curricula. In the results of the 2017 survey (n=30; 40% response rate), the majority of respondents reported feeling that PM/PD should be taught in dental curricula. However, while most respondents indicated their schools did not teach PM/PD as a portion of their didactic curricula, they reported that specific pertinent PM/PD topics were taught as part of other courses in their curricula. The 2017 survey also evaluated the use of seven genetics-based and eight non-genetics-based PM/PD diagnostics in the schools' clinical curricula. Overall, non-genetics-based diagnostics were used more often than genetics-based diagnostics, and the use of genetics-based diagnostics was more prevalent in postgraduate than predoctoral clinics. Personalized dentistry will inevitably be part of the dental professional's future and should be reflected in basic science research, clinical settings, and dental school curricula in both predoctoral and postgraduate programs.

Salivary gland immunization via Wharton's duct activates differential T-cell responses within the salivary gland immune system.

Salivary glands are a major component of the mucosal immune system that confer adaptive immunity to mucosal pathogens. As previously demonstrated, immunization of the submandibular gland with tissue culture-derived murine cytomegalovirus (tcMCMV) or replication-deficient adenoviruses expressing individual murine cytomegalovirus (MCMV) genes protected mice against a lethal MCMV challenge. Here, we report that salivary gland inoculation of BALB/cByJ mice with tcMCMV or recombinant adenoviruses differentially activates T helper (Th)1, -2, and -17 cells in the salivary glands vs. the associated lymph nodes. After inoculation with tcMCMV, lymphocytes from the submandibular gland preferentially express the transcription factor T-cell-specific T-box transcription factor (T-bet), which controls the expression of the hallmark Th1 cytokine, IFN-γ. Lymphocytes from the periglandular lymph nodes (PGLNs) express both T-bet and GATA-binding protein 3 (GATA3), which promotes the secretion of IL-4, -5, and -10 from Th2 cells. In contrast, after inoculation with replication-deficient adenoviruses, lymphocytes from the submandibular gland express T-bet, GATA3, and RAR-related orphan receptor γ, thymus-specific isoform (RORγt) (required for differentiation of Th17 cells) and forkhead box P3 (Foxp3) (required for the differentiation of regulatory T cells). Lymphocytes from the PGLNs were not activated. The differential induction of Th responses in the salivary gland vs. the PGLNs after inoculation with attenuated virus vs. a nominal protein antigen supports the use of the salivary as an alternative mucosal route for administering vaccines.-Liu, G., Zhang, F., Wang, R., London, S. D., London, L. Salivary gland immunization via Wharton's duct activates differential T-cell responses within the salivary gland immune system.

Protective MCMV immunity by vaccination of the salivary gland via Wharton's duct: replication-deficient recombinant adenovirus expressing individual MCMV genes elicits protection similar to that of MCMV.

Salivary glands, a major component of the mucosal immune system, confer antigen-specific immunity to mucosally acquired pathogens. We investigated whether a physiological route of inoculation and a subunit vaccine approach elicited MCMV-specific and protective immunity. Mice were inoculated by retrograde perfusion of the submandibular salivary glands via Wharton's duct with tcMCMV or MCMV proteins focused to the salivary gland via replication-deficient adenovirus expressing individual MCMV genes (gB, gH, IE1; controls: saline and replication deficient adenovirus without MCMV inserts). Mice were evaluated for MCMV-specific antibodies, T-cell responses, germinal center formation, and protection against a lethal MCMV challenge. Retrograde perfusion with tcMCMV or adenovirus expressed MCMV proteins induced a 2- to 6-fold increase in systemic and mucosal MCMV-specific antibodies, a 3- to 6-fold increase in GC marker expression, and protection against a lethal systemic challenge, as evidenced by up to 80% increased survival, decreased splenic pathology, and decreased viral titers from 10(6) pfu to undetectable levels. Thus, a focused salivary gland immunization via a physiological route with a protein antigen induced systemic and mucosal protective immune responses. Therefore, salivary gland immunization can serve as an alternative mucosal route for administering vaccines, which is directly applicable for use in humans.

Curcumin modulates the inflammatory response and inhibits subsequent fibrosis in a mouse model of viral-induced acute respiratory distress syndrome.

Acute Respiratory Distress Syndrome (ARDS) is a clinical syndrome characterized by diffuse alveolar damage usually secondary to an intense host inflammatory response of the lung to a pulmonary or extrapulmonary infectious or non-infectious insult often leading to the development of intra-alveolar and interstitial fibrosis. Curcumin, the principal curcumoid of the popular Indian spice turmeric, has been demonstrated as an anti-oxidant and anti-inflammatory agent in a broad spectrum of diseases. Using our well-established model of reovirus 1/L-induced acute viral pneumonia, which displays many of the characteristics of the human ALI/ARDS, we evaluated the anti-inflammatory and anti-fibrotic effects of curcumin. Female CBA/J mice were treated with curcumin (50 mg/kg) 5 days prior to intranasal inoculation with 10(7)pfu reovirus 1/L and daily, thereafter. Mice were evaluated for key features associated with ALI/ARDS. Administration of curcumin significantly modulated inflammation and fibrosis, as revealed by histological and biochemical analysis. The expression of IL-6, IL-10, IFNγ, and MCP-1, key chemokines/cytokines implicated in the development of ALI/ARDS, from both the inflammatory infiltrate and whole lung tissue were modulated by curcumin potentially through a reduction in the phosphorylated form of NFκB p65. While the expression of TGFß1 was not modulated by curcumin, TGFß Receptor II, which is required for TGFß signaling, was significantly reduced. In addition, curcumin also significantly inhibited the expression of α-smooth muscle actin and Tenascin-C, key markers of myofibroblast activation. This data strongly supports a role for curcumin in modulating the pathogenesis of viral-induced ALI/ARDS in a pre-clinical model potentially manifested through the alteration of inflammation and myofibroblast differentiation.

Factors associated with toothache among African American adolescents living in rural South Carolina.

The aim of this study is to explore behavioral factors associated with toothache among African American adolescents living in rural South Carolina. Using a self-administered questionnaire, data were collected on toothache experience in the past 12 months, oral hygiene behavior, dental care utilization, and cariogenic snack and nondiet soft drink consumption in a convenience sample of 156 African American adolescents age 10 to 18 years living in rural South Carolina. Univariable and multivariable logistic regression analyses were used to assess the associations between reported toothache experience and sociodemographic variables, oral health behavior, and snack consumption. Thirty-four percent of adolescents reported having toothache in the past 12 months. In univariable modeling, age, dental visit in the last 2 years, quantity and frequency of cariogenic snack consumption, and quantity of nondiet soft drink consumption were each significantly associated with experiencing toothache in the past 12 months (all p values < 0.05). Multivariable logistic regression analysis indicated that younger age, frequent consumption of cariogenic snacks, and number of cans of nondiet soft drink consumed during the weekend significantly increased the odds of experiencing toothache in the past 12 months (all p values ≤ 0.01). Findings indicate age, frequent consumption of cariogenic snacks, and number of cans of nondiet soft drinks are related to toothache in this group. Public policy implications related to selling cariogenic snacks and soft drink that targeting children and adolescents especially those from low income families are discussed.

Salivary glands act as mucosal inductive sites via the formation of ectopic germinal centers after site-restricted MCMV infection.

We investigated the hypothesis that salivary gland inoculation stimulates formation of ectopic germinal centers (GCs), transforming the gland into a mucosal inductive site. Intraglandular infection of mice with murine cytomegalovirus (MCMV; control: UV-inactivated MCMV) induces salivary gland ectopic follicles comprising cognate interactions between CD4(+) and B220(+) lymphocytes, IgM(+) and isotype-switched IgG(+) and IgA(+) B cells, antigen presenting cells, and follicular dendritic cells. B cells coexpressed the GC markers GCT (57%) and GL7 (52%), and bound the lectin peanut agglutinin. Lymphoid follicles were characterized by a 2- to 3-fold increase in mRNA for CXCL13 (lymphoid neogenesis), syndecan-1 (plasma cells), Blimp-1 (plasma cell development/differentiation), and a 2- to 6-fold increase for activation-induced cytidine deaminase, PAX5, and the nonexcised rearranged DNA of an IgA class-switch event, supporting somatic hypermutation and class-switch recombination within the salivary follicles. Intraglandular inoculation also provided protection against a systemic MCMV challenge, as evidenced by decreased viral titers (10(5) plaque-forming units to undetectable), and restoration of normal salivary flow rates from a 6-fold decrease. Therefore, these features suggest that the salivary gland participates in oral mucosal immunity via generation of ectopic GCs, which function as ectopic mucosal inductive sites.

An oleate-stimulated, phosphatidylinositol 4,5-bisphosphate-independent phospholipase D in Schizosaccharomyces pombe.

Phospholipase D1 (PLD1) is an important enzyme involved in lipid-mediated signal transduction and membrane dynamics in eukaryotes. PLD1 preferentially hydrolyzes phosphatidylcholine to phosphatidic acid. This potent second messenger is involved in cytoskeletal reorganization, secretion, and membrane trafficking in eukaryotic cells. In Saccharomyces cerevisiae, PLD1 is involved in polarized growth and morphogenesis during pheromone response and sporulation. The presence of a PLD activity in Schizosaccharomyces pombe is demonstrated. PLD activity was able to hydrolyze a fluorescently labeled analog of phosphatidylcholine and was capable of performing the transphosphatidylation reaction characteristic of PLDs. Schizosaccharomyces pombe PLD activity was unaffected by phosphatidylinositol 4,5 bisphosphate (PIP(2)), but was slightly stimulated by oleate. PLD activity was shown to increase when the S. pombe cells underwent mating and sporulation. Here, we also report the molecular cloning of the first phospholipase D isoform from an S. pombe genomic DNA library (EMBL accession no. FN547388). Comparisons of three divergent yeasts, S. pombe, S. cerevisiae, and Candida albicans, with respect to the PLD enzymes revealed differences in regulation by oleate and PIP(2). Even with high homology in the protein sequences between the PLD1 enzymes of S. cerevisiae, C. albicans, and S. pombe, there was variation with the effects of the regulators.

Role of CXC chemokine ligand 13 in oral squamous cell carcinoma associated osteolysis in athymic mice.

Oral squamous cell carcinomas (OSCC) are malignant tumors with a potent activity of local bone invasion; however, the molecular mechanisms of tumor osteolysis are unclear. In this study, we identified high level expression of chemokine ligand, CXCL13 and RANK ligand (RANKL) in OSCC cells (SCC1, SCC12 and SCC14a). OSCC cell-conditioned media (20%) induced osteoclast differentiation which was inhibited by OPG in peripheral blood monocyte cultures indicating that OSCC cells produce soluble RANKL. Recombinant hCXCL13 (10 ng/ml) significantly enhanced RANKL-stimulated osteoclast differentiation in these cultures. Trans-well migration assay identified that CXCL13 induces chemotaxis of peripheral blood monocytes in vitro which was inhibited by addition of anti-CXCR5 receptor antibody. Zymogram analysis of conditioned media from OSCC cells revealed matrix metalloproteinase-9 (MMP-9) activity. Interestingly, CXCL13 treatment to OSCC cells induced CXCR5 and MMP-9 expression suggesting an autocrine regulatory function in OSCC cells. To examine the OSCC tumor cell bone invasion/osteolysis, we established an in vivo model for OSCC by subcutaneous injection of OSCC cells onto the surface of calvaria in NCr-nu/nu athymic mice, which developed tumors in 4-5 weeks. muCT analysis revealed numerous osteolytic lesions in calvaria from OSCC tumor-bearing mice. Histochemical staining of calvarial sections from these mice revealed a significant increase in the numbers of TRAP-positive osteoclasts at the tumor-bone interface. Immunohistochemical analysis confirmed CXCL13 and MMP-9 expression in tumor cells. Thus, our data implicate a functional role for CXCL13 in bone invasion and may be a potential therapeutic target to prevent osteolysis associated with OSCC tumors in vivo.

Oral health knowledge and behavior among adults with diabetes.

The purpose of this study was to determine levels of oral health knowledge and factors associated with adequate oral health knowledge in adults with diabetes. A convenience sample of 253 adult US residents with diabetes completed an oral health survey to assess their knowledge. Results showed that only 47% of the participants answered five or more (out of a maximum of seven) oral health knowledge items related to diabetes correctly. Participants who received oral health information related to diabetes have 2.9 times the odds of possessing adequate oral health knowledge (i.e., answered five or more items correctly) compared to participants who did not received that information controlling for education and race (OR=2.86, 95% CI 1.31-6.24, P=0.008). Given that oral health information provided by health professionals (dental and/or medical) contributes to improve oral health knowledge among adults with diabetes, health professionals should take the opportunity to educate patients with diabetes about the oral manifestations (e.g., dry mouth) and complications (e.g., periodontitis and oral candidiasis) of diabetes and to promote proper oral health behaviors.

Dental health knowledge in a group of Black adolescents living in rural South Carolina.

This study investigated levels of dental health knowledge and factors associated with adequate dental health knowledge in a group of black adolescents living in rural areas. Using a self-administered questionnaire, data were collected on a convenience sample of 151 black adolescents aged 10 to 18 yrs living in rural South Carolina. The mean percent correct on the dental health knowledge questions was 55.0%. Using 75% as the cutoff for adequate dental health knowledge, only 7.9% of the respondents achieved this level. Two thirds of the younger adolescents (aged 10-12 yrs) were below the median on dental health knowledge. Respondents selected dental health professionals, family, and school as the three main sources of dental health information. Results from univariate logistic regression analyses indicated that being older, having a regular dentist for routine care, and having learned about dental health from dental health professionals, family, mass media, and friends were significantly associated with adequate dental health knowledge. After adjusting for other explanatory factors, adequate dental health knowledge was associated with being older and having learned about dental health from friends. This group of adolescents seems to have limited dental health knowledge with misconceptions concerning periodontal health and caries prevention. This was especially evident in younger adolescents. Incorporation of peer dental health education in school is worthwhile to investigate as a means to enhance the dental health knowledge of these adolescents.

High glucose enhances lipopolysaccharide-stimulated CD14 expression in U937 mononuclear cells by increasing nuclear factor kappaB and AP-1 activities.

We have demonstrated recently that high glucose augments lipopolysaccharide (LPS)-stimulated matrix metalloproteinase (MMP) and cytokine expression by U937 mononuclear cells and human monocyte-derived macrophages. Since CD14 is a receptor for LPS, one potential underlying mechanism is that high glucose enhances CD14 expression. In the present study, we determined the effect of high glucose on CD14 expression by U937 mononuclear cells. After being chronically exposed to normal or high glucose for 2 weeks or longer, cells were treated with LPS for 24 h. Real-time PCR showed that although high glucose by itself did not increase CD14 expression significantly, it augmented LPS-stimulated CD14 expression by 15-fold. Immunoassay showed a marked enhancement of both membrane-associated and soluble CD14 protein levels by high glucose. Further investigations using transcription factor activity assays and gel shift assays revealed that high glucose augmented LPS-stimulated CD14 expression by enhancing transcription factor nuclear factor kappaB (NFkappaB) and activator protein-1 (AP-1) activities. Finally, studies using anti-CD14 neutralizing antibody showed that CD14 expression is essential for the enhancement of LPS-stimulated MMP-1 expression by high glucose. Taken together, this study has demonstrated a robust augmentation by high glucose of LPS-stimulated CD14 expression through AP-1 and NFkappaB transcriptional activity enhancement, elucidating a new mechanism by which hyperglycemia boosts LPS-elicited gene expression involved in inflammation and tissue destruction.

An upstream regulator and downstream target of phospholipase D1 activity during pheromone response in Saccharomyces cerevisiae.

Phospholipase D1 (PLD1), which is the product of the SPO14 gene, has been shown to play a role in the process of polarized cell growth (PCG) during the pheromone response in Saccharomyces cerevisiae. PLD1 hydrolyzes phosphatidylcholine to produce phosphatidic acid (PA) and a free choline headgroup. This study investigated the interactions of PLD1 and PA with two proteins known to be involved in the cellular signaling leading to PCG in yeast, the small GTPase Cdc42p and the PAK family kinase Ste20p. Constitutively activated Cdc42p stimulates PLD1 activity. Protein-lipid binding blots confirmed the specific binding of Ste20p to the PLD1 product, PA. Finally, kinase activity assays provided evidence for the stimulation of Ste20p by PA. These findings highlight the important interactions among PLD1, Cdc42p and Ste20p during PCG in S. cerevisiae.

Comprehensive phenotypic analysis of the gut intra-epithelial lymphocyte compartment: perturbations induced by acute reovirus 1/L infection of the gastrointestinal tract.

Intestinal intra-epithelial lymphocytes (IELs) form a highly specialized lymphoid compartment. IELs consist primarily of T cells that are dispersed as single cells within the epithelial cell layer that surrounds the intestinal lumen. These lymphocytes along with lamina propria lymphocytes are considered to play an important role in the regulation of immune responses. IELs are heterogeneous with regard to phenotype, and they contain sub-populations with diverse functions. In our most recent study, we found that intra-duodenal inoculation of mice with reovirus serotype 1/strain Lang (reovirus 1/L) induced expression of both germinal center and T cell antigen and CD11c on IELs suggesting these cells to be the recently stimulated cells in gut mucosal tissue. We also demonstrated that IELs from these mice when cultured in vitro in the presence of reovirus 1/L-pulsed antigen-presenting cells generated reovirus 1/L-specific MHC-restricted CTL whose function was mediated utilizing perforin, Fas-FasL and TRAIL mechanisms. This present study provides a comprehensive analysis of the diverse subsets of IELs, which function with other mucosal cells to provide a strong, protective immunity in a highly regulated fashion inside the microenvironment of the intestinal epithelium. We demonstrated that the IEL population contains both thymus-dependent (TD) and thymus-independent (TI) lymphocytes in mice and that a complex phenotype is present when sub-populations are analyzed for TCR, Thy-1, CD4, CD8 and B220 expression in a comprehensive manner. In reovirus 1/L-inoculated mice, we found a decrease in the TI population and an increase in the TD population characterized by significant alterations in various sub-populations. This increase was largely due to an increase in CD4(+), CD8(+) and CD4/CD8 double-positive sub-populations of TD IELs. Intracellular cytokine analysis demonstrated induction of IFN-gamma and an increase in effector/cytotoxic CD8 and CD4 cells after reovirus 1/L infection. These results suggest that TD IELs may play an important role in the clearance of reovirus 1/L infection from gut.

A focused salivary gland infection with attenuated MCMV: an animal model with prevention of pathology associated with systemic MCMV infection.

While the salivary gland has been recognized as an important effector site of the common mucosal immune system, a useful model for studying anti-viral salivary gland immune responses in vivo and for exploring the role of the salivary gland within the common mucosal system has been lacking. Murine cytomegalovirus (MCMV) is a beta-herpesvirus that displays a strong tropism for the salivary gland and produces significant morbidity in susceptible mice when introduced by intraperitoneal (i.p.) inoculation. This study tested the hypothesis that MCMV morbidity and pathology could be reduced by injecting the virus directly the submandibular salivary gland (intraglandular (i.g.)), using either in vivo derived MCMV or the less virulent, tissue-culture-derived MCMV (tcMCMV). Peak salivary gland viral titers were completely unaffected by infection route (i.p vs. i.g.) after inoculation with either MCMV or tcMCMV. However, i.g. tcMCMV inoculation reduced viremia in all systemic tissues tested compared to i.p. inoculation. Furthermore, systemic organ pathology observed in the liver and spleen after i.p. inoculation with either MCMV or tcMCMV was completely eliminated by i.g. inoculation with tcMCMV. Cellular infiltrates in the salivary glands, after i.p. or i.g. inoculation were composed of both B and T cells, indicating the potential for a local immune response to occur in the salivary gland. These results demonstrate that a focused MCMV infection of the salivary gland without systemic organ pathology is possible using i.g. delivery of tcMCMV.

RANK ligand signaling modulates the matrix metalloproteinase-9 gene expression during osteoclast differentiation.

Osteoclast differentiation is tightly regulated by receptor activator of NF-kappaB ligand (RANKL) signaling. Matrix metalloproteinase-9 (MMP-9), a type IV collagenase is highly expressed in osteoclast cells and plays an important role in degradation of extracellular matrix; however, the molecular mechanisms that regulate MMP-9 gene expression are unknown. In this study, we demonstrate that RANKL signaling induces MMP-9 gene expression in osteoclast precursor cells. We further show that RANKL regulates MMP-9 gene expression through TRAF6 but not TRAF2. Interestingly, blockade of p38 MAPK activity by pharmacological inhibitor, SB203580 increases MMP-9 activity whereas ERK1/2 inhibitor, PD98059 decreases RANKL induced MMP-9 activity in RAW264.7 cells. These data suggest that RANKL differentially regulates MMP-9 expression through p38 and ERK signaling pathways during osteoclast differentiation. Transient expression of MMP-9 gene (+1 to -1174 bp relative to ATG start codon) promoter-luciferase reporter plasmids in RAW264.7 cells and RANKL stimulation showed significant increase (20-fold) of MMP-9 gene promoter activity; however, there is no significant change with respect to +1 bp to -446 bp promoter region and empty vector transfected cells. These results indicated that MMP-9 promoter sequence from -446 bp to -1174 bp relative to start codon is responsive to RANKL stimulation. Sequence analysis of the mouse MMP-9 gene promoter region further identified the presence of binding motif (-1123 bp to -1153 bp) for the nuclear factor of activated T cells 1 (NFATc1) transcription factor. Inhibition of NFATc1 using siRNA and VIVIT peptide inhibitor significantly decreased RANKL stimulation of MMP-9 activity. We further confirm by oligonucleotide pull-down assay that RANKL stimuli enhanced NFATc1 binding to MMP-9 gene promoter element. In addition, over-expression of constitutively active NFAT in RAW264.7 cells markedly increased (5-fold) MMP-9 gene promoter activity in the absence of RANKL. Taken together, our results suggest that RANKL signals through TRAF6 and that NFATc1 is a downstream effector of RANKL signaling to modulate MMP-9 gene expression during osteoclast differentiation.

Sodium lactate increases LPS-stimulated MMP and cytokine expression in U937 histiocytes by enhancing AP-1 and NF-kappaB transcriptional activities.

The plasma lactate concentration in patients with obesity and type 2 diabetes is often higher than that in nondiabetic individuals. Although it is known that increased lactate concentration is an independent risk factor for developing type 2 diabetes, the underlying mechanisms are not well understood. Because inflammation plays an important role in the development of type 2 diabetes, we postulated that increased lactate level might contribute to the pathogenesis of type 2 diabetes by enhancing inflammation. In the present study, we demonstrated that preexposure of U937 macrophage-like cells to sodium lactate increased LPS-stimulated matrix metalloproteinase (MMP)-1, IL-1beta, and IL-6 secretion. Augmentation of LPS-stimulated MMP-1 secretion was diminished when sodium lactate was replaced by lactic acid that reduced pH in the culture medium. Furthermore, quantitative real-time PCR indicated that the increased secretion of MMP-1, IL-1beta, and IL-6 was due to increased mRNA expression. To explore the underlying signaling mechanism, blocking studies using specific inhibitors for NF-kappaB and MAPK cascades were performed. Results showed that blocking of either NF-kappaB or MAPK pathways led to the inhibition of MMP-1, IL-1beta, and IL-6 expression stimulated by sodium lactate, LPS, or both. Finally, electrophoretic mobility shift assays showed a synergy between sodium lactate and LPS on AP-1 and NF-kappaB transcriptional activities. In conclusion, this study has demonstrated for the first time that sodium lactate and LPS exert synergistic effect on MMP and cytokine expression through NF-kappaB and MAPK pathways and revealed a novel mechanism potentially involved in the development of type 2 diabetes and its complications.

Reovirus serotype 1/strain Lang-stimulated activation of antigen-specific T lymphocytes in Peyer's patches and distal gut-mucosal sites: activation status and cytotoxic mechanisms.

Intraduodenal priming of mice with reovirus serotype 1/strain Lang (reovirus 1/L) stimulates gut lymphocytes and generates precursor and effector CTLs. Our earlier studies demonstrated that germinal center and T cell Ag (GCT) is a marker which identifies reovirus 1/L-specific precursor CTL and effector CTL in Peyer's patches (PP) of reovirus 1/L-inoculated mice. In this study, we characterized the expression of the activation markers, GCT and CD11c, on reovirus 1/L-stimulated gut lymphocytes and the effector mechanisms involved in reovirus 1/L-specific cytotoxicity. We found that intraduodenal reovirus 1/L inoculation of mice induced the expression of both GCT and CD11c on PP lymphocytes (PPL), intraepithelial lymphocytes (IEL), and lamina propria lymphocytes (LPL), and these activated cells expressed Fas ligand (FasL). The majority of the GCT+ CD11c+ IEL and LPL expressed a phenotype, TCRalphabeta+ Thy-1+ CD8+ similar to that expressed on reovirus 1/L-stimulated PPL. However, splenic lymphocytes expressed GCT but not CD11c after stimulation with reovirus 1/L. Perforin, Fas-FasL, and TRAIL pathways were found to be involved in PPL, IEL, and LPL cytotoxic activity against reovirus 1/L-infected targets. In PPL, perforin and Fas-FasL pathways were more effective than TRAIL. In IEL, all three cytotoxic mechanisms were equally as effective. However, LPL prefer Fas-FasL and TRAIL over perforin. Further, we demonstrated the preferential migration of GCT+ PPL to the intraepithelial compartment and the lamina propria. These results suggest that GCT and CD11c can be used as activation markers for gut lymphocytes and CD11c can also be used to differentiate between activated gut and systemic lymphocytes.