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Giuseppe Nicolardi
Ruolo
Professore Associato
Organizzazione
Università del Salento
Dipartimento
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali
Area Scientifica
Area 05 - Scienze biologiche
Settore Scientifico Disciplinare
BIO/16 - Anatomia Umana
Settore ERC 1° livello
LS - Life sciences
Settore ERC 2° livello
LS5 Neurosciences and Neural Disorders: Neurobiology, neuroanatomy, neurophysiology, neurochemistry, neuropharmacology, neuroimaging, systems neuroscience, neurological and psychiatric disorders
Settore ERC 3° livello
LS5_1 Neuroanatomy and neurophysiology
The endoplasmic reticulum (ER) is a complex and multifunctional organelle. It is the intracellular compartment of protein folding, a complex task, both facilitated and monitored by ER folding enzymes and molecular chaperones. The ER is also a stress-sensing organelle. It senses stress caused by disequilibrium between ER load and folding capacity and responds by activating signal transduction pathways, known as unfolded protein response (UPR). Three major classes of transducer are known, inositol-requiring protein-1 (IRE1), activating transcription factor-6 (ATF6), and protein kinase RNA (PKR)-like endoplasmic reticulum kinase (PERK), which sense with their endoluminal domain the state of protein folding, although the exact mechanism(s) involved is not entirely clear. Depending on whether the homeostatic response of the UPR is successful in restoring an equilibrium between ER load and protein folding or not, the two possible outcomes of the UPR so far considered have been life or death. Indeed, recent efforts have been devoted to understand the life/death switch mechanisms. However, recent data suggest that what appears to be a pure binary decision may in fact be more complex, and survival may be achieved at the expenses of luxury cell functions, such as expression of differentiation genes.
Obstructive sleep apnea syndrome (OSAS) is an independent and modifiable risk factor for cardiovascular diseases; however, the pathophysiological mechanisms underlying this association are not yet fully understood. Intermittent hypoxemia, one of the physiological markers of OSAS, is characterized by transient periods of oxygen desaturation followed by reoxygenation. The hypoxia-reoxygenation cycles are associated with oxidative stress that, in turn, triggers the activation of pathways that lead to cardiovascular damage. The results of several studies show that OSAS causes oxidative stress and that nasal continuous positive airway pressure therapy normalizes these biological abnormalities. In conclusion, treatment of OSAS with continuous positive airway pressure may lower cardiovascular risk by reducing sympathetic nerve activity, ambulatory blood pressure and arterial stiffness, and by increasing sensitivity of the arterial baroreflex. Newer modalities such as C-Flex and A-Flex also show promise as treatment options in the future. However, the evidence supporting the use of these alternative modalities remains scant, in particular with regards to long-term cardiovascular outcomes.
Purpose The aim of this study was to investigate the time course of body weight, daytime sleepiness, and functional cardiorespiratory parameters in patients with both chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome (OSA), after institution of domiciliary nasal continuous positive airway pressure (nCPAP). Methods Twelve consecutive obese outpatients (mean age= 61±11 years; four women) were evaluated before (baseline) and after 3, 12, and 24 months of nocturnal nCPAP (4 h per night). Results At baseline, all patients were hypercapnic and hypoxemic, suffering from night desaturation (T90 is the percentage of total recording time (TRT) spent with SaO2≤ 90%=38±2%) and sleepy (Epworth sleepiness scale [ESS]=16.58±0.86). Three months after the implementation of nCPAP, daytime PaCO2 and PaO2 improved up to 45.1±0.9 and 69.0±1 mmHg, respectively; mean pulmonary artery pressure (MPAP) decreased from 24.7±1.1 to 19.2±04 mmHg. All other variables showed progressive improvements up to 12 months. At 3 and 12 months, mean body mass index was slightly decreased (to 31.6±0.2 and 30.7±0.1 kg/m2, respectively); daytime sleepiness, nocturnal O2 desaturation, and maximal inspiratory pressure were also improved and thereafter remained stable. Conclusions In conclusion, in our patients with both severe OSA and mild-to-moderate COPD, arterial blood gasses and MPAP improved and stabilized after 3 months of nCPAP therapy, with the greatest improvements being in ESS score, T90, and maximal inspiratory force from 3 up to 12 months; these parameters remained stable over the following 12 months. Finally, our data support early treatment with nCPAP in such patients.
Activated microglia secrete an array of pro-inflammatory factors, such as prostaglandins, whose accumulation contributes to neuronal damages. Prostaglandin endoperoxide synthases or cyclooxygenases (COX-1 and COX-2), which play a critical role in the inflammation, are the pharmacological targets of non-steroidal anti-inflammatory drugs, used to treat pain and inflammation. Since it was reported that COX-1 is the major player in mediating the brain inflammatory response, the aim of this study was to evaluate the effects of highly selective COX-1 inhibitors, such as P6 and mofezolac, in neuroinflammation models. Lipopolysaccharide (LPS)-activated mouse BV-2 microglial cells and LPS intracerebroventricular-injected mice as in vitro and in vivo neuroinflammation models, respectively, were used to probe the antiinflammatory efficacy of P6 and mofezolac. Both P6 and mofezolac reduce COX-1 expression in LPS-activated BV-2 cells. This reduction was accompanied with PGE2 release reduction and NF-kB activation downregulation. Coextensively, in the in vivo model, both glial fibrillary acidic protein and ionized calcium-binding adapter molecule-1 expression, two markers of inflammation, were reduced by mofezolac to a rank depending on the encephalon area analyzed. The increase of COX-1 expression observed in all the brain sections of LPS-treated mice was selectively downregulated by the in vivo treatment with mofezolac as well as PGE2 release and Ikβα phosphorylation amount assayed in the brain areas tested. These results indicate the capability of P6 and mofezolac to modulate the NF-kB signaling pathway, emphasizing the neuroprotective effect and therapeutic potential of COX-1 inhibitors in the control of neuroinflammatory diseases.
Astrocytes have a key role in the pathogenesis of several diseases, including multiple sclerosis, and are proposed as a possible target for immunotherapy. Our earlier study reported that astrocytes treated with IFN-β modified their biomechanical properties possibly due to changes in the expression of the proteins involved in cytoskeleton organization and other important physiological processes. To gain insight into the mechanism underlying IFN-β action during inflammation, we stimulated astrocytes with LPS, a bacterial wall component used as a model for both in vitro and in vivo immunological stimulation of microglia and astrocytes. We showed that IFN-β reverses the effects of LPS on the proteome of astrocytes. To better examine this result, we performed a proteomic analysis of astrocytes treated with LPS or LPS plus IFN-β. Treatment with LPS caused increases both in a series of proteins mainly involved in cytoskeletal changes and in protein degradation, as well as protective enzymes like superoxide dismutase. IFN-β reverses LPS effects on astrocyte proteome, supporting its protective role during inflammatory insults.
AIMS/HYPOTHESIS: Beta cell failure is caused by loss of cell mass, mostly by apoptosis, but also by simple dysfunction (decline of glucose-stimulated insulin secretion, downregulation of specific gene expression). Apoptosis and dysfunction are caused, at least in part, by lipoglucotoxicity. The mechanisms implicated are oxidative stress, increase in the hexosamine biosynthetic pathway (HBP) flux and endoplasmic reticulum (ER) stress. Oxidative stress plays a role in glucotoxicity-induced beta cell dedifferentiation, while glucotoxicity-induced ER stress has been mostly linked to beta cell apoptosis. We sought to clarify whether ER stress caused by increased HBP flux participates in a dedifferentiating response of beta cells, in the absence of relevant apoptosis. METHODS: We used INS-1E cells and murine islets. We analysed the unfolded protein response and the expression profile of beta cells by real-time RT-PCR and western blot. The signal transmission pathway elicited by ER stress was investigated by real-time RT-PCR and immunofluorescence. RESULTS: Glucosamine and high glucose induced ER stress, but did not decrease cell viability in INS-1E cells. ER stress caused dedifferentiation of beta cells, as shown by downregulation of beta cell markers and of the transcription factor, pancreatic and duodenal homeobox 1. Glucose-stimulated insulin secretion was inhibited. These effects were prevented by the chemical chaperone, 4-phenyl butyric acid. The extracellular signal-regulated kinase (ERK) signal transmission pathway was implicated, since its inhibition prevented the effects induced by glucosamine and high glucose. CONCLUSIONS/INTERPRETATION: Glucotoxic ER stress dedifferentiates beta cells, in the absence of apoptosis, through a transcriptional response. These effects are mediated by the activation of ERK1/2.
Researches concerning the psychological and behavioral alterations following exposure to Intimate Partner Violence, associated with post-traumatic stress disorder (PTSD) as well, represent an interesting area of analyses. The aim of this work was to study the variations of event related brain potentials (ERPs), specifically N200 and P300, related to the establishment of visual emotional stimuli in women with Post-Traumatic Stress Disorder due to IPV. We administered the Beck Depression Inventory II (BDI II), Beck Anxiety Inventory (BAI) and a PTSD questionnaire to select a group of women recruited in a Center against Family Violence. Two categories of visual stimuli, emotional pictures with negative valence (EP) and positive and neutral pictures (NP), were presented during a decisional task, utilizing an oddball paradigm. The task was to press a button when the subject saw an emotional image. The IPV group was composed of 14 women (mean age: 39). The Control Group was composed of 14 women (mean age: 33) without PTDS or IPV nor depressive/anxiety symptomatology (measured with BDI II and BAI). Univariate ANOVAs were computed separately for each ERP component in amplitude and latency for electrode and for Lateralization. Both N200 and P300 had shown significant differences in amplitude (p<,05) and only N2 in latency as well (p<,05). IPV Group had shown a decrement in Amplitude and Latency in P300 waves. The IPV group displayed an increase in latency of N200 (p<,05) in Occipital single channels and in Left (p<,05) and Right (p<,05) position for Lateralization analysis as well. The Behavioral Result confirms an increase of Latency in RT for IPV group. The possible interpretations for these findings is that IPV Group exhibits a lower sensitivity threshold when the stimuli in question relate to negative emotional valence to stimuli, that could be an habituation in elicitation of emotional arousal.
Parkinson's disease (PD) is a common neurodegenerative disease characterised by a slow and progressive degeneration of dopaminergic neurons in the substantia nigra (SN). Despite intensive research, the cause of neuronal loss in PD is poorly understood. Inflammatory mechanisms have been implicated in the pathophysiology of PD. In this study, conducted on an experimental 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model, we investigated the expression of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6 and their receptors (IL-1RI, TNF-αRI, IL-6Rα) at the SN and caudate-putamen (CP) levels. In MPTP-treated animals we observed a significant increase in IL-1β, TNF-α and IL-6 mRNA expression levels both in the SN and CP in comparison with untreated mice. In addition, both mRNA and protein levels of IL-1RI, TNF-αRI and IL-6Rα were significantly enhanced in the SN of MPTP-treated mice in comparison to controls, whereas no significant differences were observed in the CP between treated and untreated mice. Overall, these results indicate a role of both pro-inflammatory cytokines and their receptors in the pathogenesis of PD.
In the present study we used a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson’s disease (PD) mouse model to analyze resveratrol neuroprotective effects. The MPTP-induced PD model is characterized by chronic inflammation, oxidative stress and loss of the dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). We observed that resveratrol treatment significantly reduced glial activation, decreasing the levels of IL-1b, IL-6 and TNF-a, as well as their respective receptors in the SNpc of MPTP-treated mice, as demonstrated by Western blotting, RT-PCR and quantitative PCR analysis. This reduction is related to possible neuroprotection as we also observed that resveratrol administration limited the decline of tyrosine hydroxylase-immunoreactivity induced in the striatum and SNpc by MPTP injection. Consistent with these data, resveratrol treatment up-regulated the expression of the suppressor of cytokine signaling-1 (SOCS-1), supporting the hypothesis that resveratrol protects DA neurons of the SNpc against MPTP-induced cell loss by regulating inflammatory reactions, possibly through SOCS-1 induction
The uterine myoma pseudocapsule is a neurovascular bundle surrounding fibroid, containing neuropeptides, probably involved in uterine scar healing. We studied neurotensin (NT), neuropeptide tyrosine (NPY), and protein gene product 9.5 (PGP 9.5) nerve fibres in the pseudocapsule neurovascular bundle of intramural uterine fibroids on 67 no pregnant women by intracapsular myomectomy sparing the neurovascular bundle, sampling full thickness specimens of the pseudocapsule of uterine fibroids (PUF) and normal myometrium (NM) obtained from the fundus uteri (FU) and the uterine body (UB). The samples were sent for histological and immunofluorescent analyses and compared by morphometrical quantification. The Conventional Unit (C.U.) difference of NT, NPY, and PGP 9.5 nerve fibres was statistically analyzed. Our results showed that NT, NPY, and PGP 9.5 neurofibers are almost equally present in PUF as in NM of a no pregnant uterus. As all of these neuropeptides are present in the uterine muscle and can affect muscle contractility, uterine peristalsis and muscular healing. A myomectomy respecting the pseudocapsule neurofibers should facilitate smooth muscle scarring and promote restoration of normal uterine peristalsis with a possible positive influence on fertility.
In this study, the effects of Radio Electric Asymmetric Conveyer (REAC), a non-invasive physical treatment, on neuroinflammatory responses in a mouse model of parkinsonism induced by intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), were investigated in vivo. We found that the REAC tissue optimization treatment specific for neuro-regenerative purposes (REAC TO-RGN-N) attenuated the inflammatory picture evoked by MPTP-induced nigro-striatal damage in mice, decreasing the levels of pro-inflammatory molecules and increasing anti-inflammatory mediators. Besides, there was a significant reduction of both astrocyte and microglial activation in MPTP-treated mice exposed to REAC TO-RGN-N. These results indicated that REAC TO-RGN-N treatment modulates the pro-inflammatory responses and reduces neuronal damage in MPTP-induced parkinsonism.
Background: Secretory proteins acquire their native three-dimensional conformation through repeated brief interactions with ER chaperones and oxidoreductases. Results: We have captured and defined previously-unidentified disulfide adducts of newly-synthesized thyroglobulin with ERp72 and CaBP1/P5. Conclusion: Multiple oxidoreductases simultaneously engage thyroglobulin during its early folding in the ER. Significance: Distinct chaperone/oxidoreductase partners coordinately engage this multi-domain secretory protein to promote its advancement to the native state.
STUDY QUESTION Can uterine scar healing after laparoscopic intracapsular myomectomy (LIM) be adequately monitored by traditional two-dimensional (2D) ultrasound (US) and Doppler velocimetry? SUMMARY ANSWER The myometrial area of the scar after LIM can be followed by 2D US and Doppler velocimetry. WHAT IS KNOWN ALREADY Apart from post-surgical adhesions, the main concern linked to laparoscopic myomectomy is the quality of healing of the myometrial incision: it has been suggested that US could be useful for assessing uterine scars after myomectomy. However, no diagnostic method has yet been widely accepted to assess the healing process. STUDY DESIGN, SIZE, DURATION A cohort prospective study (level of evidence II-2), run in University-affiliated hospitals: 149 women with symptomatic uterine fibroids (UFs) underwent LIM, between January 2007 and October 2011. During follow up 13 patients withdrew from the study. PARTICIPANTS/MATERIALS, SETTING, METHODS After LIM, all patients were followed by traditional 2D US scanning and Doppler velocimetry on Days: 0, 1, 7, 30 and 45. Authors evaluated: number, size and location of UFs, scar diameter and Doppler velocimetry and resistance index (RI) of the uterine arteries, at their ascending branch. MAIN RESULTS AND THE ROLE OF CHANCE The uterine examination showed a significant (P < 0.05) progressive reduction of uterine scar area from 78% of the previous UF location on the first day, to 19% on 30th day, and <4% on the 45th day. There was no correlation with the size of the fibroid or the relative reduction in the size of the scar, on both Days 1 and 45. There was a significant (P < 0.05) increase in the RI of the ipsilateral uterine arteries from 0.65 on the first post-operative day to 0.83 after 7 days followed by a decrease to 0.71 on the 30th and 0.61 on the 45th post-operative day. LIMITATIONS, REASONS FOR CAUTION This is a cohort investigation on a limited number of patients and it does not surgically compare LIM and ‘classic’ myomectomy in the scar US follow up. WIDER IMPLICATIONS OF THE FINDINGS LIM avoided intraoperative bleeding and excessive tissue damage, as post-operative US follow up showed, with just two intra-myometrial hematomas (1.5%). The 2D US and Doppler velocimetry, a non-invasive safe method to check the myometrium after LIM, can detect post-operative hematoma and disechogenic, heterogeneous or ill-defined scar area, all unfavorable signs for myometrial scarring. Moreover, Doppler transvaginal monitoring, evaluating the pulsatility index (PI) and RI of the uterine arteries at their ascending branch, could identify patients with altered PI and RI parameters, possible markers of impaired wound healing.
OBJECTIVE: The fibroid pseudocapsule is a structure which surrounds the uterine fibroid, separates it from the uterine tissue and contains a vascular network rich in neurotransmitters like a neurovascular bundle. The authors examined the composition of the fibroid pseudocapsule using electron microscopy. STUDY DESIGN: Twenty non-pregnant patients were submitted to laparoscopic myomectomy by the intracapsular method and samples of the removed pseudocapsules were analyzed using transmission electron microscopy. RESULTS: At the ultrastructural level the pseudocapsule cells have the features of smooth muscle cells similar to the myometrium. So, the pseudocapsules are part of the myometrium which compresses the leiomyoma. CONCLUSION: This ultrastructural feature suggests that when removing fibroids their pseudocapsules should be preserved. This study confirms preliminary evidence that pseudocapsules contain neuropeptides together with their related fibers, as a neurovascular bundle. The surgeon's behavior should be directed to carefully control and spare this muscular surrounding tissue during fibroid excision, in order to preserve the myometrium as much as possible.
Microglia-mediated neuroinflammation has been described as a common hallmark of Parkinson's disease (PD) and is believed to further exacerbate the progressive degeneration of dopaminergic neurons. Current therapies are unable to prevent the disease progression. A significant association has been demonstrated between PD and low levels of vitamin D in patients serum, and vitamin D supplement appears to have a beneficial clinical effect. Herein, we investigated whether vitamin D administered orally in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced preclinical animal model of PD protects against glia-mediated inflammation and nigrostriatal neurodegeneration. Vitamin D significantly attenuated the MPTP-induced loss of tyrosine hydrlase (TH)-positive neuronal cells, microglial cell activation (Iba1-immunoreactive), inducible nitric oxide synthase (iNOS) and TLR-4 expression, typical hallmarks of the pro-inflammatory (M1) activation of microglia. Additionally, Vitamin D was able to decrease pro-inflammatory cytokines mRNA expression in distinct brain areas of the MPTP mouse. Importantly, we also assessed the anti-inflammatory property of vitamin D in the MPTP mouse, in which it upregulated the anti-inflammatory cytokines (IL-10, IL-4 and TGF-β) mRNA expression as well as increasing the expression of CD163, CD206 and CD204, typical hallmarks of alternative activation of microglia for anti-inflammatory signalling (M2). Collectively, these results demonstrate that vitamin D exhibits substantial neuroprotective effects in this PD animal model, by attenuating pro-inflammatory and up-regulating anti-inflammatory processes.
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