UNASSIGNED: The salivary microbiome may interact with chemoradiotherapy through dynamic changes in microbial composition and systemic immunity. We aimed to explore the association between the salivary microbiome and response to chemoradiotherapy in initially inoperable patients with local advanced esophageal squamous cell carcinoma (LAESCC).
UNASSIGNED: Salivary and peripheral blood samples were collected before and after chemoradiotherapy. The microbiome and metabolic pathways were analyzed by 16S ribosomal RNA sequencing and liquid chromatography tandem mass spectrometry/Mass spectrometry analyses.
UNASSIGNED: The salivary microbiome exhibited characteristic variations between patients and healthy controls. A significant correlation was found between Prevotella_salivae, Saccharibacteria_TM7_G3_bacterium_HMT_351, and Veillonellaceae_G1_bacterium_HMT_129 and pathological complete response (pCR) in initially inoperable patients who underwent surgery. The PICRUSt suggested that immune diseases and cell motility were different in tumor compared to normal groups. KEGG enrichment analysis showed enriched lipid metabolism, signal transduction, and membrane transport in the tumor group. CD3+CD8 T cells, IL6, IL10, and IFNγ exhibited an increasing trend during the treatment process of chemoradiotherapy.
UNASSIGNED: Our study demonstrated that variations in specific saliva taxa associated with host immunomodulatory cells and cytokines could be promising for early efficacy prediction of chemoradiotherapy in initially inoperable patients with LAESCC.

BACKGROUND: Drug-induced liver injury (DILI) is one of the most common adverse events of medication use, and its incidence is increasing. However, early detection of DILI is a crucial challenge due to a lack of biomarkers and noninvasive tests.
OBJECTIVE: To identify salivary metabolic biomarkers of DILI for the future development of noninvasive diagnostic tools.
METHODS: Saliva samples from 31 DILI patients and 35 healthy controls (HCs) were subjected to untargeted metabolomics using ultrahigh-pressure liquid chromatography coupled with tandem mass spectrometry. Subsequent analyses, including partial least squares-discriminant analysis modeling, t tests and weighted metabolite coexpression network analysis (WMCNA), were conducted to identify key differentially expressed metabolites (DEMs) and metabolite sets. Furthermore, we utilized least absolute shrinkage and selection operato and random fores analyses for biomarker prediction. The use of each metabolite and metabolite set to detect DILI was evaluated with area under the receiver operating characteristic curves.
RESULTS: We found 247 differentially expressed salivary metabolites between the DILI group and the HC group. Using WMCNA, we identified a set of 8 DEMs closely related to liver injury for further prediction testing. Interestingly, the distinct separation of DILI patients and HCs was achieved with five metabolites, namely, 12-hydroxydodecanoic acid, 3-hydroxydecanoic acid, tetradecanedioic acid, hypoxanthine, and inosine (area under the curve: 0.733-1).
CONCLUSIONS: Salivary metabolomics revealed previously unreported metabolic alterations and diagnostic biomarkers in the saliva of DILI patients. Our study may provide a potentially feasible and noninvasive diagnostic method for DILI, but further validation is needed.

UNASSIGNED: Nitrate, a key component of saliva, has been shown widely physiological functions in the human body. But its function on bone metabolism remains unclear. The aim of this study was to investigate the function and mechanism of saliva nitrate on osteoporosis and the function of bone marrow mesenchymal stem cells (BMSCs).
UNASSIGNED: Saliva nitrate removal or supplemental interventions were performed for 1 month in ovariectomized (OVX) osteopenia mice. The nitrate levels in saliva and serum were detected. The bone formation and bone microarchitecture in the OVX mouse model were investigated by quantitative Micro--computed tomography imaging, histological staining and serum bone biomarker analysis. The effects of nitrate on the functional homeostasis of BMSCs in OVX mice were explored by Ki67 immunofluorescence staining, Ki67 flow staining, alizarin red staining, qPCR and western blotting. Finally, downstream signaling pathways were screened by proteomics and verified by western blotting.
UNASSIGNED: The results showed that nitrate deficiency exacerbated osteoporosis, while nitrate administration prevent osteoporosis in OVX mice. Nitrate increased the expression of PINP, a biomarker of bone formation, in OVX mice. Besides, nitrate enhanced the proliferative capacity and osteogenic function of BMSCs in OVX mice in vitro and in vivo. In addition, nitrate upregulated the expression levels of osteogenesis-related genes ALP, Run2 and OPN of BMSCs. EGFR and mTOR signaling were screened as the key downstream of nitrate, and phosphorylated protein levels of its subfamily members AKT, ERK and S6K were significantly upregulated by nitrate.
UNASSIGNED: The present results showed saliva nitrate preventively protects against osteoporosis through enhances the proliferation and osteogenic differentiation potential of BMSCs. The effects of nitrate on bone homeostasis are closely related to the EGFR/AKT/ERK and mTOR/S6K signaling axes.
UNASSIGNED: Our study provides experimental evidence for the use of saliva nitrate as an effective candidate for the prevention of osteoporosis and maintenance of bone homeostasis.

BACKGROUND: Salivary carcinoma ex pleomorphic adenoma (CXPA) is defined as a carcinoma that develops from benign pleomorphic adenoma (PA). Abnormally activated Androgen signaling pathway and amplification of HER-2/neu(ERBB-2) gene are known to be involved in CXPA tumorigenesis. Recent progress in tumour microenvironment research has led to identification that extracellular matrix (ECM) remodelling and increased stiffness act as critical contributing role in tumour carcinogenesis. This study examined ECM modifications to elucidate the mechanism underlying CXPA tumorigenesis.
RESULTS: PA and CXPA organoids were successfully established. Histological observation, immunohistochemistry (IHC), and whole-exome sequencing demonstrated that organoids recapitulated phenotypic and molecular characteristics of their parental tumours. RNA-sequencing and bioinformatic analysis of organoids showed that differentially expressed genes are highly enriched in ECM-associated terms, implying that ECM alternations may be involved in carcinogenesis. Microscopical examination for surgical samples revealed that excessive hyalinized tissues were deposited in tumour during CXPA tumorigenesis. Transmission electron microscopy confirmed that these hyalinized tissues were tumour ECM in nature. Subsequently, examination by picrosirius red staining, liquid chromatography with tandem mass spectrometry, and cross-linking analysis indicated that tumour ECM was predominantly composed of type I collagen fibers, with dense collagen alignment and an increased level of collagen cross-linking. IHC revealed the overexpression of COL1A1 protein and collagen-synthesis-related genes, DCN and IGFBP5 (p < 0.05). Higher stiffness of CXPA than PA was demonstrated by atomic force microscopy and elastic imaging analysis. We utilized hydrogels to mimic ECM with varying stiffness degrees in vitro. Compared with softer matrices (5Kpa), CXPA cell line and PA primary cells exhibited more proliferative and invasive phenotypes in stiffer matrices (50Kpa, p < 0.01). Protein-protein interaction (PPI) analysis of RNA-sequencing data revealed that AR and ERBB-2 expression was associated with TWIST1. Moreover, surgical specimens demonstrated a higher TWIST1 expression in CXPA over PA. After knocking down TWIST1 in CXPA cells, cell proliferation, migration, and invasiveness were significantly inhibited (p < 0.01).
CONCLUSIONS: Developing CXPA organoids provides a useful model for cancer biology research and drug screening. ECM remodelling, attributed to overproduction of collagen, alternation of collagen alignment, and increased cross-linking, leads to increased ECM stiffness. ECM modification is an important contributor in CXPA tumorigenesis.

OBJECTIVE: To determine the levels of s-IgA in saliva of caries patients and healthy controls, and to evaluate whether there is a correlation between it and caries by systematic review and meta-analysis.
METHODS:  Eight databases were searched initially in April 2020 and repeated in August 2020. Two independent evaluators screened the literature and extracted the data according to the inclusion and exclusion criteria. I2 test was commonly reflected the heterogeneity. Subgroup analysis and meta-regression analysis explore the sources of heterogeneity. Sensitivity analysis, funnel diagram, Begg\'s rank correlation and Egger\'s linear regression were used to determine the possibility of publication bias.
RESULTS: A total of 30 case-control studies were included, with a total sample size of 1545 patients, including 918 caries patients and 627 healthy controls. Salivary s-IgA levels in caries patients were significantly lower than those in healthy controls. In addition, the results of subgroup analysis showed that the significant decrease of salivary s-IgA level was correlated with children patients, mixed dentition and Asian people. The funnel diagram included in the study was symmetrically distributed, and the sensitivity analysis confirmed the robustness of the results.  Conclusion: Salivary s-IgA levels in caries patients were significantly lower than in healthy controls. It has also been demonstrated that salivary s-IgA may be used as an alternative measure to identify subjects at risk of caries susceptibility, suggesting that salivary s-IgA may be a protective factor for dental caries.

Promoting cell spreading is crucial to enhance bone healing and implant osteointegration. In this study, we investigated the stimulatory effect of human salivary histatin-1 (Hst-1) on the spreading of osteogenic cells in vitro as well as the potential signaling pathways involved. Osteogenic cells were seeded on bio-inert glass slides with or without the presence of Hst1 in dose-dependent or time-course assays. 1 scrambled and 6 truncated Hst1 variants were also evaluated. Cell spreading was analyzed using a well-established point-counting method. Fluorescent microscopy was adopted to examine the cellular uptake of fluorescently labeled Hst1 (F-Hst1) and also the cell spreading on sandblasted and acid etched titanium surfaces. Signaling inhibitors, such as U0126, SB203580, and pertussis toxin (PTx) were used to identify the potential role of extracellular-signal-regulated kinase, p38 and G protein-coupled receptor pathways, respectively. After 60 min incubation, Hst1 significantly promoted the spreading of osteogenic cells with an optimal concentration of 10 μM, while truncated and scrambled Hst1 did not. F-Hst1 was taken up and localized in the vicinity of the nuclei. U0126 and SB2030580, but not PTx, inhibited the effect of Hst1. 10 μM Hst1 significantly promoted the spreading of osteogenic cells on both bio-inert substrates and titanium SLA surfaces, which involved ERK and p38 signaling. Human salivary histatin-1 might be a promising peptide to enhance bone healing and implant osteointegration in clinic.

Lipases play essential roles in digestion, transport, and processing of dietary lipids in insects. For parasitoid wasps with a unique life cycle, lipase functions could be multitudinous in particular. Pteromalus puparum is a pupal endoparasitoid of butterflies. The female adult deposits eggs into its host, along with multifunctional venom, and the developing larvae consume host as its main nutrition source. Parasitoid lipases are known to participate in the food digestion process, but the mechanism remains unclear. P. puparum genome and transcriptome data were interrogated. Multiple alignments and phylogenetic trees were constructed. We annotated a total of 64 predicted lipase genes belonging to five lipase families and suggested that eight venom and four salivary lipases could determine host nutrition environment post-parasitization. Many putative venom lipases were found with incomplete catalytic triads, relatively long β9 loops, and short lids. Data analysis reveals the loss of catalytic activities and weak triacylglycerol (TAG) hydrolytic activities of lipases in venom. Phylogenetic trees indicate various predicted functions of lipases in P. puparum. Our information enriches the database of parasitoid lipases and the knowledge of their functional diversification, providing novel insight into how parasitoid wasps manipulate host lipid storage by using venom lipases.

We investigated the relationship between salivary cortisol level and the prevalence of depression 585 police officers working at the Police Departments of Beijing.
Cross-sectional data were obtained from 585 Chinese police officers recruited from Beijing, China. Salivary cortisol was assayed using the chemiluminescence immunoassay. A multiple logistic regression analysis adjusted for potential confounders was used to assess independent associations between salivary cortisol level and depression.
The median age of the included was 38 years (IQR, 29-45), 20.9% were female (n = 122). Finally, 15.6% (91/585; 95% CI: 12.6-18.5%) were considered to have depression. The median salivary cortisol level was significantly higher in police with depression than those police without depression [14.5(IQR, 11.9-15.9) nmol/l vs. 11.8(IQR, 9.4-14.2) nmol/l; P < 0.001]. The depression distribution across the salivary cortisol quartiles ranged between 5.4% (first quartile) and 26.9% (fourth quartile), P for trend <0.001. In multivariate models comparing the second (Q2), third and fourth quartiles against the first quartile of the salivary cortisol, cortisol in Q3 and Q4 were associated with depression, and increased prevalence of depression by 148% (OR: 2.48; 95% CI: 1.55-3.86) and 277% (3.77; 2.12-5.36). Based on ROC curves, the optimal cutoff value of salivary cortisol level to diagnose the depression was 13.8 nmol/l, which yielded the highest sensitivity and specificity [63.8% and 71.7%, respectively; area under the curve (AUC) = 0.695, 95% CI: 0.639-0.751; P < 0.0001].
The data showed that elevated levels of salivary cortisol were associated with increased prevalence of depression.

We aimed to assess the association between salivary alpha-amylase and salivary cortisol, and obstructive sleep apnea (OSA) severity.
Fifty-eight adults with suspected OSA were divided into the following 4 groups based on the apnea hypopnea index (AHI): control (AHI <5 events/hour), mild OSA (5 events/hour < AHI ≤15 events/hour), moderate OSA (15 events/hour < AHI ≤30 events/hour) and severe OSA (AHI >30 events/hour) groups. Salivary samples were collected after overnight polysomnography. Correlations between the salivary biomarkers and polysomnography parameters were analyzed.
Salivary alpha-amylase levels of the moderate and severe OSA groups were significantly higher than those of the control and mild OSA groups, and no association was found between salivary cortisol and OSA severity. The salivary alpha-amylase levels were positively correlated with the AHI (r = 0.538; P < 0.01) and microarousal index (r = 0.541, P < 0.01), and negatively correlated with the lowest pulse oxygen saturation (r = -0.375, P < 0.01). Salivary cortisol levels were significantly higher in patients with hypertension than in those without hypertension (10.01 ± 2.77 ng/mL vs. 5.52 ± 1.90 ng/mL, P < 0.05), and the salivary alpha-amylase levels were highest in the OSA concomitant hypertension group (32.81 ± 11.85 U/mL). Areas under the receiver operator characteristic analysis revealed that the cutoff values of salivary alpha-amylase for identifying moderate-severe OSA and OSA concomitant hypertension were 17.64 U/mL (sensitivity 85%, specificity 91%) and 25.35 U/mL (sensitivity 70%, specificity 94%), respectively.
Salivary alpha-amylase is positively associated with the severity of OSA and OSA concomitant hypertension.

OBJECTIVE: Peptest is a new non-invasive reflux diagnostic test based on lateral flow technology that containing two highly specific human pepsin monoclonal antibodies for detecting pepsin, a biomarker for reflux disease. The primary aim of this multicenter clinical study was to validate the efficacy of Peptest in patients diagnosed with gastroesophageal reflux and healthy controls in China.
METHODS: Patients with suspected gastroesophageal reflux underwent an endoscopy and were classified into non-erosive reflux disease and erosive esophagitis subgroups. A healthy control group was also recruited. All participants were given a reflux disease questionnaire-patients scoring greater than 12 and controls scoring zero. All participants provided a postprandial saliva sample and most patients gave an additional post-symptom sample for pepsin analysis.
RESULTS: Altogether 1032 participants aged between 19 and 78 years were recruited. They consisted of 488 patients with non-erosive reflux disease, 221 with erosive esophagitis and 323 healthy controls. The number of postprandial and post-symptom samples analyzed totaled 1031 and 692, respectively. The results across all centers showed an overall pepsin-positive sensitivity of 85%, a specificity of 60%, a positive predictive value of 82%, a negative predictive value of 65% and a positive likelihood ratio of 2.12.
CONCLUSIONS: The sensitivity of Peptest was high, but the specificity achieved in some centers was low, resulting overall in only a moderate specificity. Further diagnostic investigative studies are warranted.