Mixed pathologies in pancreatic ß cells from subjects with neurodegenerative diseases and their interaction with prion protein.

Protein misfolding diseases refer to a variety of disorders that develop as a consequence of the misfolding of proteins in various organs. The etiologies of Parkinson's and Alzheimer's disease remain unclear, but it seems that type two diabetes and other prediabetic states could contribute to the appearance of the sporadic forms of these diseases. In addition to amylin deposition, other amyloidogenic proteins implicated in the pathophysiology of neurodegenerative diseases could have important roles in the pathogenesis of this disease. As we have previously demonstrated the presence of α-synuclein deposits in the pancreas of patients with synucleinopathies, as well as tau and Aß deposits in the pancreatic tissue of Alzheimer's disease patients, we studied the immunoreactivity of amylin, tau and α-synuclein in the pancreas of 138 subjects with neurodegenerative diseases or type two diabetes and assessed whether the pancreatic ß-cells of these subjects present cooccurrence of misfolded proteins. Furthermore, we also assessed the pancreatic expression of prion protein (PrP) in these subjects and its interaction, both in the pancreas and brain, with α-synuclein, tau, Aß and amylin. Our study shows, for the first time, that along with amylin, pancreatic α-synuclein, Aß, PrP and tau may contribute together to the complex pathophysiology of type two diabetes and in the appearance of insulin resistance in Alzheimer's and Parkinson's disease. Furthermore, we show that the same mixed pathologies that are observed in the brains of patients with neurodegenerative diseases are also present outside the nervous system. Finally, we provide the first histological evidence of an interaction between PrP and Aß, α-synuclein, amylin or tau in the pancreas and locus coeruleus. These findings will shed more light on the common pathological pathways shared by neurodegenerative diseases and type two diabetes, benefiting the exploration of common therapeutic strategies to prevent or treat these devastating amyloid diseases.

Nivolumab and Ipilimumab-induced myositis and myocarditis mimicking a myasthenia gravis presentation.

The rapidly growing field of cancer immunotherapy has led to the development of new treatments such as immune checkpoint inhibitors. These agents are monoclonal antibodies that enable tumor-reactive T cells to overcome regulatory mechanisms and produce effective antitumor responses. The use of immune checkpoint inhibitors is expected to progressively increase because they have shown promising therapeutic outcomes in multiple types of cancer and clinicians should be aware of their possible side-effects. We report a case of a man diagnosed with a non-microcytic lung carcinoma who started treatment with a combination of immune checkpoint inhibitors (Nivolumab and Ipilimumab). He subsequently developed binocular diplopia, fatigue, mild dyspnea and upper back pain resembling a myasthenia gravis presentation. Finally, a diagnosis of immune checkpoint inhibitor-related myositis and myocarditis was made. The detection of GFAP antibodies in CSF has unclear clinical and pathogenic significance and they may rather represent an epiphenomenon of the immune inflammation process.

Safinamide in Clinical Practice: A Spanish Multicenter Cohort Study.

Background: Safinamide is an approved drug for the treatment of motor fluctuations of Parkinson's Disease (PD) patients with a potential benefit on non-motor symptoms (NMS). Methods: A retrospective multicenter cohort study was conducted, in which the clinical effect of safinamide on both motor and NMS was assessed by the Clinical Global Impression of Change scale. Furthermore, we assessed the appearance of adverse events (AEs) and its effect on dyskinesia, that were also recorded in non-fluctuating PD patients and in those previously treated with rasagiline. Results: We included 213 PD patients who received safinamide in addition to their regular levodopa therapy. Thirty-five withdrew prematurely from safinamide, mainly because of AEs. Out of 178, clinical improvement on motor and NMS was found in 76.4% and 26.2%, respectively. A total of 44 reported AEs of mild intensity. We did not find a difference concerning the clinical benefit or AEs when comparing either patients who had or had not been taking Monoamine Oxidase B Inhibitor (MAOB-I) previously or between patients with and without motor complications. Conclusions: Safinamide is an effective and safe add-on to levodopa drug for PD patients. Moreover, safinamide could elicit an additional clinical improvement in PD patients previously treated with other MAOB-I and in non- fluctuating patients with suboptimal motor control.

Amylin as a potential link between type 2 diabetes and alzheimer disease.

OBJECTIVE: Alzheimer disease (AD) is the leading cause of dementia, and although its etiology remains unclear, it seems that type 2 diabetes mellitus (T2DM) and other prediabetic states of insulin resistance could contribute to the appearance of sporadic AD. As such, we have assessed whether tau and ß-amyloid (Aß) deposits might be present in pancreatic tissue of subjects with AD, and whether amylin, an amyloidogenic protein deposited in the pancreas of T2DM patients, might accumulate in the brain of AD patients. METHODS: We studied pancreatic and brain tissue from 48 individuals with no neuropathological alterations and from 87 subjects diagnosed with AD. We examined Aß and tau accumulation in the pancreas as well as that of amylin in the brain. Moreover, we performed proximity ligation assays to ascertain whether tau and/or Aß interact with amylin in either the pancreas or brain of these subjects. RESULTS: Cytoplasmic tau and Aß protein deposits were detected in pancreatic ß cells of subjects with AD as well as in subjects with a normal neuropathological examination but with a history of T2DM and in a small cohort of control subjects without T2DM. Furthermore, we found amylin deposits in the brain of these subjects, providing histological evidence that amylin can interact with Aß and tau in both the pancreas and hippocampus. INTERPRETATION: The presence of both tau and Aß inclusions in pancreatic ß cells, and of amylin deposits in the brain, provides new evidence of a potential overlap in the mechanisms underlying the pathogenesis of T2DM and AD. ANN NEUROL 2019;86:539-551.

Interaction of amyloidogenic proteins in pancreatic ß cells from subjects with synucleinopathies.

Parkinson's disease patients experience a wide range of non-motor symptoms that may be provoked by deposits of phosphorylated α-synuclein in the peripheral nervous system. Pre-existing diabetes mellitus might be a risk factor for developing Parkinson's disease, and indeed, nearly 60% of Parkinson's disease patients are insulin resistant. Thus, we have investigated whether phosphorylated α-synuclein is deposited in pancreatic tissue of subjects with synucleinopathies. We studied pancreatic tissue from 39 subjects diagnosed with Parkinson's disease, Lewy body Dementia or incidental Lewy bodies disease, as well as that from 34 subjects with diabetes mellitus and a normal neuropathological examination, and 52 subjects with a normal neuropathological examination. We examined the pancreatic accumulation of phosphorylated α-synuclein and of the islet amyloid polypeptide precursor (IAPP), an amyloidogenic protein that plays an unknown role in diabetes mellitus, but that can promote α-synuclein amyloid deposition in vitro. Moreover, we performed proximity ligation assays to assess whether these two proteins interact in the pancreas of these subjects. Cytoplasmic phosphorylated α-synuclein deposits were found in the pancreatic ß cells of 14 subjects with Parkinson's disease (93%), in 11 subjects with Lewy body Dementia (85%) and in 8 subjects with incidental Lewy body disease (73%). Furthermore, we found similar phosphorylated α-synuclein inclusions in 23 subjects with a normal neuropathological examination but with diabetes mellitus (68%) and in 9 control subjects (17%). In addition, IAPP/α-synuclein interactions appear to occur in patients with pancreatic inclusions of phosphorylated α-synuclein. The presence of phosphorylated α-synuclein inclusions in pancreatic ß cells provides a new evidence of a mechanism that is potentially common to the pathogenesis of diabetes mellitus, PD and DLB. Moreover, the interaction of IAPP and α-synuclein in the pancreatic ß cells of patients may represent a novel target for the development of strategies to treat these diseases.