The role of the heat shock protein B8 (HSPB8) in motoneuron diseases

Amyotrophic lateral sclerosis (ALS) and spinal and bulbar muscular atrophy (SBMA) are two motoneuron diseases (MNDs) characterized by aberrant protein behavior in affected cells. In familial ALS (fALS) and in SBMA specific gene mutations lead to the production of neurotoxic proteins or peptides prone to misfold, which then accumulate in form of aggregates. Notably, some of these proteins accumulate into aggregates also in sporadic ALS (sALS) even if not mutated. To prevent proteotoxic stresses detrimental to cells, misfolded and/or aggregated proteins must be rapidly removed by the protein quality control (PQC) system. The small heat shock protein B8 (HSPB8) is a chaperone induced by harmful events, like proteasome inhibition. HSPB8 is expressed both in motoneuron and muscle cells, which are both targets of misfolded protein toxicity in MNDs. In ALS mice models, in presence of the mutant proteins, HSPB8 is upregulated both in spinal cord and muscle. HSPB8 interacts with the HSP70 co-chaperone BAG3 and enhances the degradation of misfolded proteins linked to sALS, or causative of fALS and of SBMA. HSPB8 acts by facilitating autophagy, thereby preventing misfolded protein accumulation in affected cells. BAG3 and BAG1 compete for HSP70-bound clients and target them for disposal to the autophagy or proteasome, respectively. Enhancing the selective targeting of misfolded proteins by HSPB8-BAG3-HSP70 to autophagy may also decrease their delivery to the proteasome by the BAG1-HSP70 complex, thereby limiting possible proteasome overwhelming. Thus, approaches aimed at potentiating HSPB8-BAG3 may contribute to the maintenance of proteostasis and may delay MNDs progression

Transcriptional induction of the heat shock protein B8 mediates the clearance of misfolded proteins responsible for motor neuron diseases

Neurodegenerative diseases (NDs) are often associated with the presence of misfolded protein inclusions. The chaperone HSPB8 is upregulated in mice, the human brain and muscle structures affected during NDs progression. HSPB8 exerts a potent pro-degradative activity on several misfolded proteins responsible for familial NDs forms. Here, we demonstrated that HSPB8 also counteracts accumulation of aberrantly localized misfolded forms of TDP-43 and its 25 KDa fragment involved in most sporadic cases of Amyotrophic Lateral Sclerosis (sALS) and of Fronto Lateral Temporal Dementia (FLTD). HSPB8 acts with BAG3 and the HSP70/HSC70-CHIP complex enhancing the autophagic removal of misfolded proteins. We performed a high-through put screening (HTS) to find small molecules capable of inducing HSPB8 in neurons for therapeutic purposes. We identified two compounds, colchicine and doxorubicin, that robustly up-regulated HSPB8 expression. Both colchicine and doxorubicin increased the expression of the master regulator of autophagy TFEB, the autophagy linker p62/SQSTM1 and the autophagosome component LC3. In line, both drugs counteracted the accumulation of TDP-43 and TDP-25 misfolded species responsible for motoneuronal death in sALS. Thus, analogs of colchicine and doxorubicin able to induce HSPB8 and with better safety and tolerability may result beneficial in NDs models

Pathogenic variants of Valosin Containing Protein induce lysosomal damage and transcriptional activation of autophagy regulators in neuronal cells

Aim: Mutations in the Valosin-containing protein (VCP) gene cause various lethal proteinopathies that mainly include inclusion body myopathy with Paget's disease of bone frontotemporal dementia (IBMPFD) and amyotrophic lateral sclerosis (ALS). Different pathological mechanisms have been proposed. Here, we define the impact of VCP mutants on lysosomes and how cellular homeostasis is restored by inducing autophagy in the presence of lysosomal damage. Methods: By electron microscopy, we studied lysosomal morphology in VCP animal and motoneuronal models. Using western blotting, RT-qPCR, immunofluorescence, and filter trap assay, we evaluated the effect of selected VCP mutants in neuronal cells on lysosome size and activity, lysosomal membrane permeabilization, and their impact on autophagy. Results: We found that VCP mutants induced aberrant multilamellar organelles in VCP animal and cell models similar to those found in patients with VCP mutations or with lysosomal storage disorders. In neuronal cells, we found altered lysosomal activity characterized by membrane permeabilization with galectin-3 redistribution and activation of PPP3CB. This selectively activated the autophagy/lysosomal transcriptional regulator TFE3, but not TFEB, and enhanced both SQSTM1/p62 and lipidated MAP 1LC3B levels inducing autophagy. Moreover, we found that WT VCP, but not the mutants, counteracted lysosomal damage induced either by trehalose or by a mutant form of SOD1 (G93A), also blocking the formation of its insoluble intracellular aggregates. Thus, chronic activation of autophagy might fuel the formation of multilamellar bodies. Conclusion: Together, our findings provide insights into the pathogenesis of VCP-related diseases, by proposing a novel mechanism of multilamellar body formation induced by VCP mutants that involves lysosomal damage and induction of lysophagy

Gender-differences in disease distribution and outcome in hospitalized elderly: Data from the REPOSI study

Background and purpose Women live longer and outnumber men. On the other hand, older women develop more chronic diseases and conditions such as arthritis, osteoporosis and depression, leading to a greater number of years of living with disabilities. The aim of this study was to describe whether or not there are gender differences in the demographic profile, disease distribution and outcome in a population of hospitalized elderly people. Methods Retrospective observational study including all patients recruited for the REPOSI study in the year 2010. Analyses are referred to the whole group and gender categorization was applied. Results A total of 1380 hospitalized elderly subjects, 50.5% women and 49.5% men, were considered. Women were older than men, more often widow and living alone or in nursing homes. Disease distribution showed that malignancy, diabetes, coronary artery disease, chronic kidney disease and chronic obstructive pulmonary disease were more frequent in men, but hypertension, osteoarthritis, anemia and depression were more frequent in women. Severity and comorbidity indexes according to the Cumulative Illness Rating Scale (CIRS-s and CIRS-c) were higher in men, while cognitive impairment evaluated by the Short Blessed Test (SBT), mood disorders by the Geriatric Depression Scale (GDS) and disability in daily life measured by Barthel Index (BI) were worse in women. In-hospital and 3-month mortality rates were higher in men. Conclusions Our study showed a gender dimorphism in the demographic and morbidity profiles of hospitalized elderly people, emphasizing once more the need for a personalized process of healthcare

Heart failure and chronic kidney disease in a registry of internal medicine wards

Background: The aim of the present study was to evaluate the association between heart failure (HF) and chronic kidney disease (CKD) in tertiary care centers using the clinical records of patients enrolled in internal medicine departments.Patients and methods: We used the clinical records of 1380 elderly patients to identify patients with a history of HF and CKD using admission ICD codes and glomerular filtration rate (GFR) formulas. Magnitude and strength of such associations were investigated by univariable and multivariable analysis.Results: Of the 1380 patients enrolled, 27.9% had HF (age 80 \ub1 7, BMI 27 \ub1 6 kg/m2) and 17.4% CKD (age 81 \ub1 7, BMI 26.8 \ub1 6 kg/m2). Both groups were significantly older (P <' 0.0001) with BMI higher than the patients without those diagnosis (P < 0.02). Patients with a history of CKD showed higher non-fasting glycaemia (140 \ub1 86 vs. 125 \ub1 63 mg/dL, P < 0.001). CKD was significantly associated with HF (P < 0.0001). Patients with HF had an estimated GFR lower than patients without HF (P < 0.0001). Comorbidity and severity indices were significantly higher in subjects with HF (P < 0.0001) and CKD (P < 0.0001) than in those without. Multivariable analysis showed a significant association between HF and age (for five years increase OR 1.13, P < 0.009), BMI (for each 3 kg/m2 increase OR 1.15, P < 0.001), GFR (for each decrease of 10 mL/min increase OR 0.92, P < 0.002) and severity index (IS) (for each 0.25 units increase OR 1.43, P < 0.001).Conclusion: HF on admission is strongly associated with CKD, older age, BMI, and SI. These data focus the value of epidemiological studies such REPOSI in identifying and monitoring multimorbidity in elderly