A Bioengineering Strategy to Control ADAM10 Activity in Living Cells

A Disintegrin and Metalloprotease 10, also known as ADAM10, is a cell surface protease ubiquitously expressed in mammalian cells where it cuts several membrane proteins implicated in multiple physiological processes. The dysregulation of ADAM10 expression and function has been implicated in pathological conditions, including Alzheimer’s disease (AD). Although it has been suggested that ADAM10 is expressed as a zymogen and the removal of the prodomain results in its activation, other potential mechanisms for the ADAM10 proteolytic function and activation remain unclear. Another suggested mechanism is post-translational modification of the cytoplasmic domain, which regulates ADAM10-dependent protein ectodomain shedding. Therefore, the precise and temporal activation of ADAM10 is highly desirable to reveal the fine details of ADAM10-mediated cleavage mechanisms and protease-dependent therapeutic applications. Here, we present a strategy to control prodomain and cytosolic tail cleavage to regulate ADAM10 shedding activity without the intervention of small endogenous molecule signaling pathways. We generated a series of engineered ADAM10 analogs containing Tobacco Etch Virus protease (TEV) cleavage site (TEVcs), rendering ADAM10 cleavable by TEV. This strategy revealed that, in the absence of other stimuli, the TEV-mediated removal of the prodomain could not activate ADAM10. However, the TEV-mediated cleavage of the cytosolic domain significantly increased ADAM10 activity. Then, we generated ADAM10 with a minimal constitutively catalytic activity that increased significantly in the presence of TEV or after activating a chemically activatable TEV. Our results revealed a bioengineering strategy for controlling the ADAM10 activity in living cells, paving the way to obtain spatiotemporal control of ADAM10. Finally, we proved that our approach of controlling ADAM10 promoted α-secretase activity and the non-amyloidogenic cleavage of amyloid-β precursor protein (APP), thereby increasing the production of the neuroprotective soluble ectodomain (sAPPα). Our bioengineering strategy has the potential to be exploited as a next-generation gene therapy for AD

High mobility group A1 protein modulates autophagy in cancer cells.

High Mobility Group A1 (HMGA1) is an architectural chromatin protein whose overexpression is a feature of malignant neoplasias with a causal role in cancer initiation and progression. HMGA1 promotes tumor growth by several mechanisms, including increase of cell proliferation and survival, impairment of DNA repair and induction of chromosome instability. Autophagy is a self-degradative process that, by providing energy sources and removing damaged organelles and misfolded proteins, allows cell survival under stress conditions. On the other hand, hyper-activated autophagy can lead to non-apoptotic programmed cell death. Autophagy deregulation is a common feature of cancer cells in which has a complex role, showing either an oncogenic or tumor suppressor activity, depending on cellular context and tumor stage. Here, we report that depletion of HMGA1 perturbs autophagy by different mechanisms. HMGA1-knockdown increases autophagosome formation by constraining the activity of the mTOR pathway, a major regulator of autophagy, and transcriptionally upregulating the autophagy-initiating kinase Unc-51-like kinase 1 (ULK1). Consistently, functional experiments demonstrate that HMGA1 binds ULK1 promoter region and negatively regulates its transcription. On the other hand, the increase in autophagosomes is not associated to a proportionate increase in their maturation. Overall, the effects of HMGA1 depletion on autophagy are associated to a decrease in cell proliferation and ultimately impact on cancer cells viability. Importantly, silencing of ULK1 prevents the effects of HMGA1-knockdown on cellular proliferation, viability and autophagic activity, highlighting how these effects are, at least in part, mediated by ULK1. Interestingly, this phenomenon is not restricted to skin cancer cells, as similar results have been observed also in HeLa cells silenced for HMGA1. Taken together, these results clearly indicate HMGA1 as a key regulator of the autophagic pathway in cancer cells, thus suggesting a novel mechanism through which HMGA1 can contribute to cancer progression

Adherence to antibiotic treatment guidelines and outcomes in the hospitalized elderly with different types of pneumonia

Background: Few studies evaluated the clinical outcomes of Community Acquired Pneumonia (CAP), Hospital-Acquired Pneumonia (HAP) and Health Care-Associated Pneumonia (HCAP) in relation to the adherence of antibiotic treatment to the guidelines of the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS) in hospitalized elderly people (65 years or older). Methods: Data were obtained from REPOSI, a prospective registry held in 87 Italian internal medicine and geriatric wards. Patients with a diagnosis of pneumonia (ICD-9 480-487) or prescribed with an antibiotic for pneumonia as indication were selected. The empirical antibiotic regimen was defined to be adherent to guidelines if concordant with the treatment regimens recommended by IDSA/ATS for CAP, HAP, and HCAP. Outcomes were assessed by logistic regression models. Results: A diagnosis of pneumonia was made in 317 patients. Only 38.8% of them received an empirical antibiotic regimen that was adherent to guidelines. However, no significant association was found between adherence to guidelines and outcomes. Having HAP, older age, and higher CIRS severity index were the main factors associated with in-hospital mortality. Conclusions: The adherence to antibiotic treatment guidelines was poor, particularly for HAP and HCAP, suggesting the need for more adherence to the optimal management of antibiotics in the elderly with pneumonia

Multimorbidity and polypharmacy in the elderly: Lessons from REPOSI

The dramatic demographic changes that are occurring in the third millennium are modifying the mission of generalist professionals such as primary care physicians and internists. Multiple chronic diseases and the related prescription of multiple medications are becoming typical problems and present many challenges. Unfortunately, the available evidence regarding the efficacy of medications has been generated by clinical trials involving patients completely different from those currently admitted to internal medicine: much younger, affected by a single disease and managed in a highly controlled research environment. Because only registries can provide information on drug effectiveness in real-life conditions, REPOSI started in 2008 with the goal of acquiring data on elderly people acutely admitted to medical or geriatric hospital wards in Italy. The main goals of the registry were to evaluate drug prescription appropriateness, the relationship between multimorbidity/polypharmacy and such cogent outcomes as hospital mortality and re-hospitalization, and the identification of disease clusters that most often concomitantly occur in the elderly. The findings of 3-yearly REPOSI runs (2008, 2010, 2012) suggest the following pertinent tasks for the internist in order to optimally handle their elderly patients: the management of multiple medications, the need to become acquainted with geriatric multidimensional tools, the promotion and implementation of a multidisciplinary team approach to patient health and care and the corresponding involvement of patients and their relatives and caregivers. There is also a need for more research, tailored to the peculiar features of the multimorbid elderly patient

Antipsychotic prescription and mortality in hospitalized older persons

Background: Recent scientific reports have shown that older persons treated with antipsychotics for dementia-related behavioural symptoms have increased mortality. However, the impact of these drugs prescribed during hospitalization has rarely been assessed. We aimed to investigate whether antipsychotics are associated with an increased risk of mortality during hospitalization and at 3-month follow-up in elderly inpatients. Methods: We analyzed data gathered during two waves (2010 and 2012) by the REPOSI (Registro Politerapie Società Italiana Medicina Interna). All new prescriptions of antipsychotic drugs during hospitalization, whether maintained or discontinued at discharge, were collected, and logistic regression models were used to analyze their association with in-hospital and 3-month mortality. Covariates were age, sex, the Short Blessed Test (SBT) score, and the Cumulative Illness Rating Scale. Results: Among 2703 patients included in the study, 135 (5%) received new prescriptions for antipsychotic drugs. The most frequently prescribed antipsychotic during hospitalization and eventually maintained at discharge was haloperidol (38% and 36% of cases, respectively). Patients newly prescribed with antipsychotics were older and had a higher Cumulative Illness Rating Scale comorbidity index both at admission and at discharge compared to those who did not receive a prescription. Of those prescribed antipsychotics, 71% had an SBT score ≥10 (indicative of dementia), 12% had an SBT score of 5–9 (indicative of questionable dementia); and 17% had an SBT score <5 (indicative of normal cognition). In-hospital mortality was slightly higher in patients prescribed antipsychotic drugs (14.3% vs 9.4%; P = 0.109), but in multivariate analysis only male sex, older age, and higher SBT scores were significantly related to mortality during hospitalization. At 3-month follow-up, only male sex, older age, and higher SBT scores were associated with mortality. Conclusion: We found that the prescription of antipsychotic drugs during hospitalization was not associated with in-hospital or follow-up mortality. Short-term antipsychotic prescriptions (for acutely ill patients) may have a different effect than long-term, repeated prescriptions

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

Therapeutic Duplicates in a Cohort of Hospitalized Elderly Patients: Results from the REPOSI Study.

BACKGROUND: Explicit criteria for potentially inappropriate prescriptions in the elderly are recommended to avoid prescriptions of duplicate drug classes and to optimize monotherapy within a single drug class before a new agent is considered. Duplicate drug class prescription (or therapeutic duplicates) puts the patient at increased risk of adverse drug reactions with no additional therapeutic benefits. To our knowledge, the prevalence of elderly inpatients receiving therapeutic duplicates has never been studied. OBJECTIVES: Our objective was to assess the prevalence of therapeutic duplicates at admission, discharge, and 3-month follow-up of hospitalized elderly patients. METHODS: This cross-sectional prospective study was conducted in 97 Italian internal medicine and geriatric wards. Therapeutic duplicates were defined as at least two drugs of the same therapeutic class prescribed simultaneously to a patient. A patient's drug therapy at admission relates to prescriptions from general practitioners, whereas prescriptions at discharge are those from hospital internists or geriatricians. RESULTS: The study sample comprised 5821 admitted and 4983 discharged patients. In all, 143 therapeutic duplicates were found at admission and 170 at discharge. The prevalence of patients exposed to at least one therapeutic duplicate rose significantly from hospital admission (2.5 %) to discharge (3.4 %; p = 0.0032). Psychotropic drugs and drugs for peptic ulcer or gastroesophageal reflux disease were the most frequently involved. A total of 86.8 % of patients discharged with at least one therapeutic duplicate were still receiving them at 3-month follow-up. CONCLUSIONS: Hospitalization and drugs prescribed by internists and geriatricians are both factors associated with a small but definite increase in overall therapeutic duplicates in elderly patients admitted to internal medicine and geriatric wards. More attention should be paid to the indications for each drug prescribed, because therapeutic duplicates are not supported by evidence and increase both the risk of adverse drug reactions and costs. Identification of unnecessary therapeutic duplicates is essential for the optimization of polypharmacy