Sex-specific up-regulation of p50-associated COX-2 extragenic RNA (PACER) lncRNA in periodontitis.

A number of recent studies have shown dysregulation of some long non-coding RNAs (lncRNAs) in affected tissues or peripheral blood of patients with periodontitis. In the current study, we investigated the role of TNF and HNRNPL related immunoregulatory (THRIL) and p50-associated COX-2 extragenic RNA (PACER) lncRNAs in periodontitis. We assessed expression of these lncRNAs in 30 affected tissue, 30 control tissue samples, 23 blood samples from patients and 18 blood samples from healthy controls. Expression of PACER was higher in total blood samples of patients compared with controls (Posterior beta of RE = 5.143, P value = 0.001). However, when assessing its expression in a gender-based manner, the difference in the expression of this lncRNA was significant only among male subgroups (Posterior beta of RE = 7.16, P value < 0.0001). Moreover, expression of PACER was significantly higher in female subjects compared with male subjects (Posterior beta of RE = 3.098, P value < 0.0001). There was no significant difference in tissue expression of PACER between study subgroups. Expression of THRIL was not significantly different between blood/tissue samples of cases and controls. However, expression of this lncRNA was higher in blood of female subjects compared with male subjects (Posterior beta of RE = 4.353, P value = 0.002). Tissue expression of THRIL was correlated with blood levels of this lncRNA (r = 0.33, P < 0.0001) and with the tissue levels of PACER (r = 0.3, P < 0.0001). Moreover, blood levels of these lncRNAs were correlated with each other (r = 0.34, P < 0.0001). However, there was no significant correlation between blood and tissue levels of PACER. Expression of these lncRNAs were not correlated with age either in males or in females. Taken together, we demonstrated a sex-based up-regulation of PACER in blood samples of patients with periodontitis which implies possible participation of this lncRNA in the pathobiology of periodontitis.

Blood and tissue levels of lncRNAs in periodontitis.

Periodontitis is a complex disorder that affects a large number of human beings from different ethnic groups. This condition has been associated with dysregulation of a number of genes, among them are long noncoding RNAs (lncRNAs). In the current study, we assessed the expression of four lncRNAs (BDNF-AS, MIAT, MIR137HG, and PNKY) as well as BDNF in the peripheral blood and gingival tissues obtained from patients with periodontitis and healthy subjects. The expression of BDNF was significantly lower in blood samples of male patients with periodontitis compared with male controls (posterior ß of RE = -4.754, p = .048). However, there was no significant difference in the expression of BDNF in tissue samples from the cases and controls. The expression of BDNF-AS was significantly lower in the tissue samples of patients compared with control tissue samples (posterior ß of RE = -2.151, p = .019). Such an expression difference was detected between male subgroups as well (posterior ß of RE = -3.679, p = .009). However, expression of this lncRNA was not different in blood samples obtained from patients compared with healthy subjects. The expression of PNKY was significantly higher in tissue samples obtained from female patients compared with sex-matched controls (posterior ß of RE = 6.23, p = .037). Blood levels of this lncRNA were not different between cases and controls. There was no significant difference either in the tissue expression or in blood expression of MIR137HG or MIAT between cases and controls. The current study indicates the putative role of BDNF, BDNF-AS, and PNKY in the pathophysiology of periodontitis and potentiates these genes as candidates for functional studies.

The lncRNA ANRIL is down-regulated in peripheral blood of patients with periodontitis.

Long non-coding RNAs (lncRNAs) have crucial roles in lncRNAs in periodontal development and disorders of this tissue. A number of lncRNAs especially those regulating immune responses contribute in the pathophysiology of periodontitis. In the current case-control study, we assessed expression levels of two immune response-related lncRNAs namely the antisense non-coding RNA in the INK4 locus (ANRIL) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in gingival tissues and blood samples of patients with periodontitis and healthy subjects. Expression of ANRIL was significantly lower in peripheral blood of patients compared with controls (Posterior Beta RE = -1.734, P value = 0.035). However, when diving study participants based on their gender, no significant difference was found between patients and sex-matched controls. Expression of this lncRNA was not different between periodontitis tissues and normal tissues. Expression of MALAT1 was not different between samples obtained from cases and controls. Tissue or blood expressions of ANRIL or MALAT1 were not correlated with age of either patients or controls. There were significant correlations between expression levels of ANRIL and MALAT1 in gingival tissues both in cases (r = 0.62, P < 0.0001) and in controls (r = 0.37, P < 0.0001). However, blood levels of these lncRNAs were not correlated with each other either in cases or in controls. Most notably, there was no significant correlation between expression levels of these lncRNAs in gingival tissues and in the blood of study participants. The current study indicates dysregulation of ANRIL in the peripheral blood of patients with periodontitis in spite of its normal levels in gingival tissues which might reflect disturbance in systemic immune responses in these patients.

Evaluation of Resistin Levels in Saliva of Patients with Chronic Periodontitis and Healthy Subjects.

OBJECTIVE: To evaluate resistin levels in the saliva of patients with chronic periodontitis, and healthy subjects. METHODS: Thirty-four subjects aged between 25 and 50 years were included and divided into healthy group (n = 19) and chronic periodontitis group (n = 15). The saliva levels of resistin were assessed by enzyme-linked immunosorbent assay. Comparisons of resistin levels between the two groups were made with the Mann-Whitney Test. RESULTS: The chronic periodontitis group showed significantly higher resistin levels than the control group (P = 0.001). CONCLUSION: The level of resistin in saliva might help to determine the inflammatory status of periodontal diseases.