Unique Organization of actin cytoskeleton in magnocellular vasopressin neurons in normal conditions and in response to salt-loading.

Pattern analysis of the salivary metabolic profile has been proven accurate in discriminating between generalized periodontitis (GP) patients and healthy individuals (HI), as this disease modifies the salivary concentrations of specific metabolites. Due to the scarcity of data from previous studies, this study aimed to evaluate if non-surgical periodontal therapy (NST) could affect the metabolomic profile in GP patients’ saliva and if it compares to that of HI. Unstimulated salivary samples were collected from 11 HI and 12 GP patients before and 3 months after NST. Nuclear Magnetic Resonance (NMR) spectroscopy, followed by a supervised multivariate statistical approach on entire saliva spectra and partial least square (PLS) discriminant analysis, were performed to obtain metabolic profiles. In the GP group, periodontal treatment improved all clinical parameters, but not all the diseased sites were eradicated. PLS revealed an accuracy of 100% in distinguishing between metabolic profiles of GP patients before and after NST. Orthogonal projection to latent structure was able to discriminate between the three groups of subjects with an accuracy of 85.6%. However, the post-NST metabolic profile of GP patients could not be completely assimilated to that of HI. Although NST may produce significant changes in the metabolic profile, GP patients maintained a distinctive fingerprint compared to HI.

Magnocellular vasopressin (VP) neurones are activated by increases in blood osmolality, leading to the secretion of VP into the circulation to promote water retention in the kidney, thus constituting a key mechanism for the regulation of body fluid homeostasis. However, chronic high salt intake can lead to excessive activation of VP neurones and increased circulating levels of VP, contributing to an elevation in blood pressure. Multiple extrinsic factors, such as synaptic inputs and glial cells, modulate the activity of VP neurones. Moreover, magnocellular neurones are intrinsically osmosensitive, and are activated by hypertonicity in the absence of neighbouring cells or synaptic contacts. Hypertonicity triggers cell shrinking, leading to the activation of VP neurones. This cell‐autonomous activation is mediated by a scaffold of dense somatic microtubules, uniquely present in VP magnocellular neurones. Treating isolated magnocellular neurones with drugs modulating microtubule stability modifies the sensitivity of neuronal activation in response to acute hypertonic stimuli. However, whether the microtubule network is altered in conditions associated with enhanced neuronal activation and increased VP release, such as chronic high salt intake, remains unknown. We examined the organisation of microtubules in VP neurones of the supraoptic and paraventricular hypothalamic nuclei (SON and PVN, respectively) of rats subjected to salt‐loading (drinking 2% NaCl for 7 days). Using super‐resolution imaging, we found that the density of microtubules in magnocellular VP neurones from the SON and PVN was significantly increased, whereas the density and organisation of microtubules remain unchanged in other hypothalamic neurones, as well as in neurones from other brain areas (e.g., hippocampus, cortex). We propose that the increase in microtubule density in magnocellular VP neurones in salt‐loading promotes their enhanced activation, possibly contributing to elevated blood pressure in this condition.

Pattern analysis of salivary metabolic profile has been proven accurate to discriminate generalized periodontitis (GP) patients from healthy individuals (HI) as disease modifies the salivary concentrations of specific metabolites. Due to the scarcity of data in the literature, the aim of this study was to determine whether non-surgical periodontal therapy (NST) could change salivary metabolomic profile in GP to one more similar to HI. Unstimulated whole saliva of 11 HI and 12 GP patients were obtained prior to and 3 months after NST. Metabolic profiling was performed using Nuclear Magnetic Resonance (NMR) spectroscopy, followed by supervised multivariate statistical approach on entire saliva spectra and partial least square (PLS) discriminant analysis. In GP group, periodontal treatment improved all clinical parameters, but not all the diseased sites were eradicated. PLS revealed an accuracy of 100% in discriminating the metabolomic profile of each GP patient before and after NST. OPLS was able to discriminate the 3 groups of subjects with an accuracy of 85.6%. However the post-NST metabolic profile of GP patients could not be completely assimilated to that of HS. Although NST may produce significant changes in the metabolic profile, GP patients maintained a distinctive fingerprint compared to HI.