Pandemic Responsiveness in an Acute Care Setting: A Community Hospital's Utilization of Operational Resources During COVID-19.

Background: To ensure continuity of services while mitigating patient surge and nosocomial infections during the coronavirus disease 2019 (COVID-19) pandemic, acute care hospitals have been required to make significant operational adjustments. Here, we identify and discuss key administrative priorities and strategies utilized by a large community hospital located in Ontario, Canada. Methods: Guided by a qualitative descriptive approach, we performed a thematic analysis of all COVID-19-related documentation discussed by the hospital's emergency operation centre (EOC) during the pandemic's first wave. We then solicited operational strategies from a multidisciplinary group of hospital leaders to construct a narrative for each theme. Results: Seven recurrent themes critical to the hospital's pandemic response emerged: 1) Organizational structure: a modified EOC structure was adopted to increase departmental interoperability and situational awareness; 2) Capacity planning: Design Thinking guided rapid infrastructure decisions to meet surge requirements; 3) Occupational health and workplace safety: a multidisciplinary team provided respirator fit-testing, critical absence adjudication, and wellness needs; 4) Human resources/workforce planning: new workforce planning, recruitment, and redeployment strategies addressed staffing shortages; 5) Personal protective equipment (PPE): PPE conservation required proactive sourcing from traditional and non-traditional suppliers; 6) Community response: local partnerships were activated to divert patients through a non-referral-based assessment and treatment centre, support long-term care and retirement homes, and establish a 70-bed field hospital; and 7) Corporate communication: a robust communication strategy provided timely and transparent access to rapidly evolving information. Conclusion: A community hospital's operational preparedness for COVID-19 was supported by inter-operability, leveraging internal and external expertise and partnerships, creative problem solving, and developing novel tools to support occupational health and community initiatives.

Effects of the COVID-19 Pandemic on Healthcare Providers: Policy Implications for Pandemic Recovery.

BACKGROUND: Notably higher rates of mental health issues have been reported among healthcare providers (HCPs) during the COVID-19 pandemic. Concerns over the impact of policy decisions on the well-being of HCPs is growing, yet it remains underexplored in the literature. METHOD: HCPs from a 301-bed mental health hospital and a 408-bed acute care community hospital, both located in central Ontario, participated in interviews (N = 30) and answered open-ended questionnaires (N = 88) to provide their experiences with the COVID-19 pandemic. RESULTS: Using interpretive description methods, we found that public health policies and other strategies intended to mitigate COVID-19 transmission variably impacted HCP well-being and professional practice. DISCUSSION: Pandemic-related policies contributed to HCP stress by changing the healthcare environment and clinical practice. Understanding HCP experiences is key for leaders, policy makers and health system planners to deal with the current state, recovery and preparation for future pandemics. Direct input into policy development, implementation and evaluation from HCPs may support their well-being.

Implications of Oncoplastic Breast Surgery on Radiation Boost Delivery in Localized Breast Cancer.

Background Oncoplastic partial mastectomy (OPM) is a technique utilized to improve aesthetic and survivorship outcomes in patients with localized breast cancer. This technique leads to breast tissue rearrangement, which can have an impact on target definition for boost radiotherapy (BRT). The aim of this study was to determine if the choice of surgical technique independently affected the decision to deliver a radiation boost. Materials and methods This was a retrospective study of patients treated between January 2017 and December 2018. We selected consecutive patients based on surgical procedure: 50 undergoing standard breast-conserving surgery and 50 having had an OPM. The primary outcome was average treatment effect (ATE) of surgery type on reception of BRT. Secondary outcomes included ATE of surgery type on the time to reception of radiotherapy and incidence of ipsilateral breast tumor recurrence (IBTR). The ratio of boost clinical target volume (CTV) to pathologic tumor size was also compared between the two groups. Treatment effects regression adjustment and inverse-probability weighted analysis was used to estimate ATEs for both primary and secondary outcomes. Results For the entire cohort, the median age was 64 years (range: 37-88 years). The median tumor size was 1.5 cm (range: 0.1-6.5 cm). The majority of patients were with ≤ stage IIA (78%), invasive ductal subtype (80%), negative lymphovascular space invasion (78%), negative margin (90%), and positive ER/PR (estrogen receptor/progesterone receptor) (69%). Overall, surgical technique was not associated with differences in the proportion of patients receiving BRT (ATE: 6.0% [95% CI: -4.5 to 16.0]). There were no differences in delays to radiation treatment between the two groups (ATE: 32.8 days [95% CI: -22.1 to 87.7]). With a median follow-up time of 419 days (range: 30-793 days), there were only five recurrences, with one case of IBTR in each group. There was no difference in the ratio of CTV volume to tumor size between the two groups (p=0.38). Conclusions OPM did not affect the decision to offer localized BRT following standard whole breast radiotherapy or significantly affect treatment times or radiation volumes. The decision to offer OPM should include a multi-disciplinary approach.

Effects of the COVID-19 Pandemic on the Mental Health of Healthcare Providers: A Comparison of a Psychiatric Hospital and a General Hospital.

BACKGROUND: Before the COVID-19 pandemic, healthcare providers (HCPs) were already experiencing a higher prevalence of mental health disorders compared with non-healthcare professionals. Here, we report on the psychosocial functioning and stress resilience of HCPs who worked during the COVID-19 pandemic in a large-sized psychiatric facility and a large acute care hospital, both located in central Ontario, Canada. METHODS: Participants completed five validated psychometric instruments assessing depression, anxiety, and stress (The Depression, Anxiety, and Stress Scale-21, DASS-21); work-related quality of life (Work-Related Quality of Life Scale, WRQoL); resilience (Connor-Davidson Resilience Scale, CD-RISC); anxiety about the novel coronavirus (Coronavirus Anxiety Scale, CAS); and loneliness (UCLA Loneliness Scale, ULS). Participants from the psychiatric hospital (n = 94) were sampled during the easing of restrictions after the first wave in Ontario, and participants from the acute care hospital (n = 146) were sampled during the height of the second wave in Ontario. RESULTS: Data showed that HCPs from the acute care hospital and psychiatric hospital reported similar scores on the psychometric scales. There were also no significant differences in psychometric scale scores between medical disciplines at the acute care hospital. Among all HCPs, being a nurse predicted better quality of life (p = 0.01) and greater stress resilience (p = 0.031). CONCLUSION: These results suggest that HCPs' psychological symptoms are similar across the hospital settings sampled. Compared to other HCPs, nurses may show a unique resiliency to the pandemic. We suggest that emergencies such as the COVID-19 pandemic have a pervasive effect on HCPs. It is important to address HCPs' mental health needs in terms of crisis management and improve resilience among all HCPs during the inter-crisis period before a new challenge arrives.

Premedication with montelukast and rupatadine decreased rituximab infusion time, rate, severity of reactions and use of rescue medications.

Rituximab-associated infusion reactions (IRs) are significant burdens on oncology patients, caregivers and healthcare providers. We evaluated whether montelukast and rupatadine improve rituximab delivery, decrease frequency/severity of IRs and the number of medications used to control IRs. Using a nonrandomized clinical study design, we assessed adult rituximab naïve patients with B-cell lymphoid malignancies from January 2017 to July 2019. Prior to the first rituximab infusion patients received one of the premedication regimens: (i) standard premedications, diphenhydramine hydrochloride and acetaminophen ("SP" group); (ii) SP + montelukast ("M" group); (iii) SP + rupatadine ("R" group); (iv) SP + rupatadine + montelukast Schedule 1 ("M + R Schedule 1" group); (v) SP + rupatadine + montelukast Schedule 2 ("M + R Schedule 2" group). A total of 223 patients with a median age of 69 years were assessed. Demographics and treatment groups were comparable among all five groups. Mean rituximab infusion time was 290 min in the SP group versus 273, 261, 243 and 236 min in the M, R, M + R Schedule 1 and M + R Schedule 2 groups, respectively. The incidence of rituximab IRs was 75% in the SP group versus 44, 41, 22 and 22% in the M, R, M + R Schedule 1 and M + R Schedule 2 groups, respectively. The median reaction grade was 2 in the SP group and 0 in all other groups. The median number of rescue medications was 3 in the SP group and 0 in all other groups. In conclusion, montelukast and rupatadine significantly improved rituximab delivery, decreased the rate and severity of IRs and reduced the need for rescue medications.

An alternative to standard lumpectomy: a 5-year case series review of oncoplastic breast surgery outcomes in a Canadian setting

Background: Oncoplastic surgery (OPS) is becoming the new standard of care for breast-conserving surgery (BCS). It has become increasingly popular in Europe; however, it has not yet been widely accepted in North America. This study aims to describe the experience with OPS at a Canadian tertiary care centre. Methods: This study is a retrospective case series consisting of consecutive OPS cases at a single Canadian centre, the Royal Victoria Regional Health Centre in Barrie, Ontario, between 2009 and 2015. Results: A total of 275 women who consecutively underwent OPS were included. The average size of the tumour was 17 mm (standard deviation [SD] 13 mm; range 0­110 mm). The average specimen weight was 155 g (SD 146 g; range 15­1132 g). Invasive ductal carcinoma was the most common diagnosis (237 patients, 86.2%), followed by ductal carcinoma in situ (18 patients, 6.6%) and then invasive lobular carcinoma (15 patients, 5.5%). A positive margin was recorded in 37 (13.5%) patients. Immediate postoperative complications included seroma and edema (32.7%), wound infection (13.1%), hematoma (8.7%) and delayed wound healing (6.5%). A delay to adjuvant therapy due to postoperative complications occurred in 7 of 217 (3.2%) patients. The median follow-up was 18 months. There were local and distant recurrences in 9 (3.3%) and 2 (0.7%) patients, respectively. Overall survival was 99.3%. Conclusion: The findings of this study are comparable to results in the literature on OPS and demonstrate that OPS is an attractive alternative to standard lumpectomy for Canadian general surgeons who treat breast cancer.

Contexte: La chirurgie oncoplastique (COP) est en passe de devenir la nouvelle norme pour la chirurgie conservatrice du sein (CCS). Elle est de plus en plus populaire en Europe, mais elle n'a pas encore été largement adoptée en Amérique du Nord. Cette étude vise à décrire l'expérience d'un établissement de soins tertiaires au Canada en matière de COP. Méthodes: Cette étude repose sur une série rétrospective de cas de COP dans un établissement canadien, le Centre régional de santé Royal Victoria de Barrie, en Ontario, entre 2009 et 2015. Résultats: En tout, 275 cas consécutifs de COP ont été inclus. La taille moyenne des tumeurs était de 17 mm (écart-type [É.-T.] 13 mm; éventail 0­110 mm). Le poids moyen des spécimens était de 155 g (É.-T. 146 g; éventail 15­1132 g). Le diagnostic le plus fréquent était le carcinome canalaire invasif (237 patientes, 86,2 %), suivi du carcinome canalaire in situ (18 patientes, 6,6 %), puis du carcinome lobulaire invasif (15 patientes, 5,5 %). Une marge positive a été enregistrée chez 37 patientes (13,5 %). Parmi les complications postopératoires immédiates, mentionnons sérome et oedème (32,7 %), infection de plaie (13,1 %), hématome (8,7 %) et retard de cicatrisation de la plaie (6,5 %). Un retard du traitement adjuvant dû à des complications postopératoires est survenu chez 7 patientes sur 217 (3,2 %). Le suivi médian a été de 18 mois. On a noté des récurrences locales et à distance chez 9 (3,3 %) et 2 (0,7 %) patientes, respectivement. La survie globale a été de 99,3 %. Conclusion: Les conclusions de cette étude se comparent aux résultats recensés dans la littérature au sujet de la COP et démontrent que cette dernière est une solution de rechange attrayante à la tumorectomie standard pour les chirurgiens généraux qui soignent le cancer du sein au Canada.

Synchronous dual hematological malignancies: new or underreported entity?

BACKGROUND: Patients with a single hematological malignancy may be unexpectedly diagnosed with a clonally unrelated synchronous dual hematological malignancy (SDHM). The presence of a secondary hematological malignancy may be overlooked and only identified in situations presenting with discordant clinical or laboratory findings. Clinical management of these patients can be challenging, in part due to the relatively unknown etiopathology of SDHM and the impact of therapy on the secondary malignancy. OBJECTIVES: To assess, characterize patients with synchronous double hematological malignancies and share our experience with this challenging group of patients. METHODS: We performed a retrospective chart review of 3036 patients with hematological malignancy at our cancer center between February 2013 and July 2017. RESULTS AND DISCUSSION: We identified 46 patients with SDHM, a prevalence of 1.51% among patients diagnosed with any hematological malignancy. We identify several heterogeneous combinations of SDHM comprised of myeloid and/or lymphoid lineages and provide our experience with managing patients with these underreported conditions. CONCLUSION: SDHMs are not uncommon and should be suspected in situations presenting with unusual or unexpected findings.

C9orf72 isoforms in Amyotrophic Lateral Sclerosis and Frontotemporal Lobar Degeneration.

A hexanucleotide (G4C2) repeat expansion in the 5' non-coding region C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Three modes of toxicity have been proposed: gain of function through formation of RNA foci and sequestration of RNA binding proteins; expression of dipeptide repeat proteins generated by repeat-associated non-ATG translation; and loss of function due to C9orf72 haploinsufficiency. Much is known about the proposed gain of function mechanisms, but there is little knowledge of the normal function of C9orf72 and the cellular consequences if its activity is perturbed. Here we will review what is known of C9orf72 at the transcript and protein levels and how changes in C9orf72 expression could contribute to disease pathogenesis. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.

Glucocerebrosidase gene therapy prevents α-synucleinopathy of midbrain dopamine neurons.

Diminished lysosomal function can lead to abnormal cellular accumulation of specific proteins, including α-synuclein, contributing to disease pathogenesis of vulnerable neurons in Parkinson's disease (PD) and related α-synucleinopathies. GBA1 encodes for the lysosomal hydrolase glucocerebrosidase (GCase), and mutations in GBA1 are a prominent genetic risk factor for PD. Previous studies showed that in sporadic PD, and in normal aging, GCase brain activity is reduced and levels of corresponding glycolipid substrates are increased. The present study tested whether increasing GCase through AAV-GBA1 intra-cerebral gene delivery in two PD rodent models would reduce the accumulation of α-synuclein and protect midbrain dopamine neurons from α-synuclein-mediated neuronal damage. In the first model, transgenic mice overexpressing wildtype α-synuclein throughout the brain (ASO mice) were used, and in the second model, a rat model of selective dopamine neuron degeneration was induced by AAV-A53T mutant α-synuclein. In ASO mice, intra-cerebral AAV-GBA1 injections into several brain regions increased GCase activity and reduced the accumulation of α-synuclein in the substantia nigra and striatum. In rats, co-injection of AAV-GBA1 with AAV-A53T α-synuclein into the substantia nigra prevented α-synuclein-mediated degeneration of nigrostriatal dopamine neurons by 6 months. These neuroprotective effects were associated with altered protein expression of markers of autophagy. These experiments demonstrate, for the first time, the neuroprotective effects of increasing GCase against dopaminergic neuron degeneration, and support the development of therapeutics targeting GCase or other lysosomal genes to improve neuronal handling of α-synuclein.

Isoform-specific antibodies reveal distinct subcellular localizations of C9orf72 in amyotrophic lateral sclerosis.

OBJECTIVE: A noncoding hexanucleotide repeat expansion in C9orf72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). It has been reported that the repeat expansion causes a downregulation of C9orf72 transcripts, suggesting that haploinsufficiency may contribute to disease pathogenesis. Two protein isoforms are generated from three alternatively spliced transcripts of C9orf72; a long form (C9-L) and a short form (C9-S), and their function(s) are largely unknown owing to lack of specific antibodies. METHODS: To investigate C9orf72 protein properties, we developed novel antibodies that recognize either C9-L or C9-S. Multiple techniques, including Western blot, immunohistochemistry, and coimmunoprecipitation, were used to determine the expression levels and subcellular localizations of C9-L and C9-S. RESULTS: Investigation of expression of C9-L and C9-S demonstrated distinct biochemical profiles, region-specific changes, and distinct subcellular localizations in ALS tissues. In particular, C9-L antibody exhibited a diffuse cytoplasmic staining in neurons and labeled large speckles in cerebellar Purkinje cells. In contrast, C9-S antibody gave very specific labeling of the nuclear membrane in healthy neurons, with apparent relocalization to the plasma membrane of diseased motor neurons in ALS. Coimmunoprecipitation experiments revealed an interaction of the C9-isoforms with both Importin ß1 and Ran-GTPase, components of the nuclear pore complex. INTERPRETATION: Using these antibodies, we have shown that C9orf72 may be involved in nucleocytoplasmic shuttling and this may have relevance to pathophysiology of ALS/FTLD. Our antibodies have provided improved detection of C9orf72 protein isoforms, which will help elucidate its physiological function and role in ALS/FTLD.

Sustained Systemic Glucocerebrosidase Inhibition Induces Brain α-Synuclein Aggregation, Microglia and Complement C1q Activation in Mice.

AIMS: Loss-of-function mutations in GBA1, which cause the autosomal recessive lysosomal storage disease, Gaucher disease (GD), are also a key genetic risk factor for the α-synucleinopathies, including Parkinson's disease (PD) and dementia with Lewy bodies. GBA1 encodes for the lysosomal hydrolase glucocerebrosidase and reductions in this enzyme result in the accumulation of the glycolipid substrates glucosylceramide and glucosylsphingosine. Deficits in autophagy and lysosomal degradation pathways likely contribute to the pathological accumulation of α-synuclein in PD. In this report we used conduritol-ß-epoxide (CBE), a potent selective irreversible competitive inhibitor of glucocerebrosidase, to model reduced glucocerebrosidase activity in vivo, and tested whether sustained glucocerebrosidase inhibition in mice could induce neuropathological abnormalities including α-synucleinopathy, and neurodegeneration. RESULTS: Our data demonstrate that daily systemic CBE treatment over 28 days caused accumulation of insoluble α-synuclein aggregates in the substantia nigra, and altered levels of proteins involved in the autophagy lysosomal system. These neuropathological changes were paralleled by widespread neuroinflammation, upregulation of complement C1q, abnormalities in synaptic, axonal transport and cytoskeletal proteins, and neurodegeneration. INNOVATION: A reduction in brain GCase activity has been linked to sporadic PD and normal aging, and may contribute to the susceptibility of vulnerable neurons to degeneration. This report demonstrates that systemic reduction of GCase activity using chemical inhibition, leads to neuropathological changes in the brain reminiscent of α-synucleinopathy. CONCLUSIONS: These data reveal a link between reduced glucocerebrosidase and the development of α-synucleinopathy and pathophysiological abnormalities in mice, and support the development of GCase therapeutics to reduce α-synucleinopathy in PD and related disorders.

Jump from pre-mutation to pathologic expansion in C9orf72.

An expanded G4C2 repeat in C9orf72 represents the most common known genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). However, the lower limit for pathological expansions is unknown (the suggested cutoff is 30 repeats). It has been proposed that the expansion might have occurred only once in human history and subsequently spread throughout the population. However, our present findings support a hypothesis of multiple origins for the expansion. We report a British-Canadian family in whom a ∼70-repeat allele from the father (unaffected by ALS or FTLD at age 89 years) expanded during parent-offspring transmission and started the first generation affected by ALS (four children carry an ∼1,750-repeat allele). Epigenetic and RNA-expression analyses further discriminated the offspring's large expansions (which were methylated and associated with reduced C9orf72 expression) from the ∼70-repeat allele (which was unmethylated and associated with upregulation of C9orf72). Moreover, RNA foci were only detected in fibroblasts from offspring with large expansions, but not in the father, who has the ∼70-repeat allele. All family members with expansions were found to have an ancient known risk haplotype, although it was inherited on a unique 5-Mb genetic backbone. We conclude that small expansions (e.g., 70 repeats) might be considered "pre-mutations" to reflect their propensity to expand in the next generation. Follow-up studies might help explain the high frequency of ALS- or FTLD-affected individuals with an expansion but without a familial history (e.g., 21% among Finnish ALS subjects).

A Nurr1 agonist causes neuroprotection in a Parkinson's disease lesion model primed with the toll-like receptor 3 dsRNA inflammatory stimulant poly(I:C).

Dopaminergic neurons in the substantia nigra pars compacta (SNpc) are characterized by the expression of genes required for dopamine synthesis, handling and reuptake and the expression of these genes is largely controlled by nuclear receptor related 1 (Nurr1). Nurr1 is also expressed in astrocytes and microglia where it functions to mitigate the release of proinflammatory cytokines and neurotoxic factors. Given that Parkinson's disease (PD) pathogenesis has been linked to both loss of Nurr1 expression in the SNpc and inflammation, increasing levels of Nurr1 maybe a promising therapeutic strategy. In this study a novel Nurr1 agonist, SA00025, was tested for both its efficiency to induce the transcription of dopaminergic target genes in vivo and prevent dopaminergic neuron degeneration in an inflammation exacerbated 6-OHDA-lesion model of PD. SA00025 (30mg/kg p.o.) entered the brain and modulated the expression of the dopaminergic phenotype genes TH, VMAT, DAT, AADC and the GDNF receptor gene c-Ret in the SN of naive rats. Daily gavage treatment with SA00025 (30mg/kg) for 32 days also induced partial neuroprotection of dopaminergic neurons and fibers in rats administered a priming injection of polyinosinic-polycytidylic acid (poly(I:C) and subsequent injection of 6-OHDA. The neuroprotective effects of SA00025 in this dopamine neuron degeneration model were associated with changes in microglial morphology indicative of a resting state and a decrease in microglial specific IBA-1 staining intensity in the SNpc. Astrocyte specific GFAP staining intensity and IL-6 levels were also reduced. We conclude that Nurr1 agonist treatment causes neuroprotective and anti-inflammatory effects in an inflammation exacerbated 6-OHDA lesion model of PD.

A two-hybrid screen identifies an unconventional role for the intermediate filament peripherin in regulating the subcellular distribution of the SNAP25-interacting protein, SIP30.

Peripherin is a type III intermediate filament protein, the expression of which is associated with the acquisition and maintenance of a terminally differentiated neuronal phenotype. Peripherin up-regulation occurs during acute neuronal injury and in degenerating motor neurons of amyotrophic lateral sclerosis. The functional role(s) of peripherin during normal, injurious, and disease conditions remains unknown, but may be related to differential expression of spliced isoforms. To better understand peripherin function, we performed a yeast two-hybrid screen on a mouse brain cDNA library using an assembly incompetent peripherin isoform, Per-61, as bait. We identified new peripherin interactors with roles in vesicular trafficking, signal transduction, DNA/RNA processing, protein folding, and mitochondrial metabolism. We focused on the interaction of Per-61 and the constitutive isoform, Per-58, with SNAP25 interacting protein 30 (SIP30), a neuronal protein involved in SNAP receptor-dependent exocytosis. We found that peripherin and SIP30 interacted through coiled-coil domains and colocalized in cytoplasmic aggregates in SW13vim(-) cells. Interestingly, Per-61 and Per-58 differentially altered the subcellular distribution of SIP30 and SNAP25 in primary motor neurons. Our findings suggest a novel role of peripherin in vesicle trafficking.

ALS-associated peripherin spliced transcripts form distinct protein inclusions that are neuroprotective against oxidative stress.

Intracellular proteinaceous inclusions are well-documented hallmarks of the fatal motor neuron disorder amyotrophic lateral sclerosis (ALS). The pathological significance of these inclusions remains unknown. Peripherin, a type III intermediate filament protein, is upregulated in ALS and identified as a component within different types of ALS inclusions. The formation of these inclusions may be associated with abnormal peripherin splicing, whereby an increase in mRNA retaining introns 3 and 4 (Per-3,4) leads to the generation of an aggregation-prone isoform, Per-28. During the course of evaluating peripherin filament assembly in SW-13 cells, we identified that expression of both Per-3,4 and Per-28 transcripts formed inclusions with categorically distinct morphology: Per-3,4 was associated with cytoplasmic condensed/bundled filaments, small inclusions (<10µM), or large inclusions (≥10µM); while Per-28 was associated with punctate inclusions in the nucleus and/or cytoplasm. We found temporal and spatial changes in inclusion morphology between 12 and 48h post-transfected cells, which were accompanied by unique immunofluorescent and biochemical changes of other ALS-relevant proteins, including TDP-43 and ubiquitin. Despite mild cytotoxicity associated with peripherin transfection, Per-3,4 and Per-28 expression increased cell viability during H2O2-mediated oxidative stress in BE(2)-M17 neuroblastoma cells. Taken together, this study shows that ALS-associated peripherin isoforms form dynamic cytoplasmic and intranuclear inclusions, effect changes in local endogenous protein expression, and afford cytoprotection against oxidative stress. These findings may have important relevance to understanding the pathophysiological role of inclusions in ALS.

Widespread neuron-specific transgene expression in brain and spinal cord following synapsin promoter-driven AAV9 neonatal intracerebroventricular injection.

Adeno-associated viral (AAV) gene transfer holds great promise for treating a wide-range of neurodegenerative disorders. The AAV9 serotype crosses the blood-brain barrier and shows enhanced transduction efficiency compared to other serotypes, thus offering advantageous targeting when global transgene expression is required. Neonatal intravenous or intracerebroventricular (i.c.v.) delivery of recombinant AAV9 (rAAV9) have recently proven effective for modeling and treating several rodent models of neurodegenerative disease, however, the technique is associated with variable cellular tropism, making tailored gene transfer a challenge. In the current study, we employ the human synapsin 1 (hSYN1) gene promoter to drive neuron-specific expression of green fluorescent protein (GFP) after neonatal i.c.v. injection of rAAV9 in mice. We observed widespread GFP expression in neurons throughout the brain, spinal cord, and peripheral nerves and ganglia at 6 weeks-of-age. Region-specific quantification of GFP expression showed high neuronal transduction rates in substantia nigra pars reticulata (43.9±5.4%), motor cortex (43.5±3.3%), hippocampus (43.1±2.7%), cerebellum (29.6±2.3%), cervical spinal cord (24.9±3.9%), and ventromedial striatum (16.9±4.3%), among others. We found that 14.6±2.2% of neuromuscular junctions innervating the gastrocnemius muscle displayed GFP immunoreactivity. GFP expression was identified in several neuronal sub-types, including nigral tyrosine hydroxylase (TH)-positive dopaminergic cells, striatal dopamine- and cAMP-regulated neuronal phosphoprotein (DARPP-32)-positive neurons, and choline acetyltransferase (ChAT)-positive motor neurons. These results build on contemporary gene transfer techniques, demonstrating that the hSYN1 promoter can be used with rAAV9 to drive robust neuron-specific transgene expression throughout the nervous system.

Progressive axonal transport and synaptic protein changes correlate with behavioral and neuropathological abnormalities in the heterozygous Q175 KI mouse model of Huntington's disease.

A long-term goal of modeling Huntington's disease (HD) is to recapitulate the cardinal features of the disease in mice that express both mutant and wild-type (WT) huntingtin (Htt), as HD commonly manifests as a heterozygous condition in humans, and loss of WT Htt is associated with loss-of-function. In a new heterozygous Q175 knock-in (KI) mouse model, we performed an extensive evaluation of motor and cognitive functional deficits, neuropathological and biochemical changes and levels of proteins involved in synaptic function, the cytoskeleton and axonal transport, at 1-16 months of age. Motor deficits were apparent at 6 months of age in Q175 KI mice and at that time, postmortem striatal gamma-aminobutyric acid (GABA) levels were elevated and mutant Htt inclusions were present throughout the brain. From 6 months of age, levels of proteins associated with synaptic function, including SNAP-25, Rab3A and PSD-95, and with axonal transport and microtubules, including KIF3A, dynein and dynactin, were altered in the striatum, motor cortex, prefrontal cortex and hippocampus of Q175 KI mice, compared with WT levels. At 12-16 months of age, Q175 KI mice displayed motor and cognitive deficits, which were paralleled at postmortem by striatal atrophy, cortical thinning, degeneration of medium spiny neurons, dense mutant Htt inclusion formation, decreased striatal dopamine levels and loss of striatal brain-derived neurotrophic factor (BDNF). Data from this study indicate that the heterozygous Q175 KI mouse represents a realistic model for HD and also provides new insights into the specific and progressive synaptic, cytoskeletal and axonal transport protein abnormalities that may accompany the disease.

Pharmacological rescue of mitochondrial deficits in iPSC-derived neural cells from patients with familial Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder caused by genetic and environmental factors that results in degeneration of the nigrostriatal dopaminergic pathway in the brain. We analyzed neural cells generated from induced pluripotent stem cells (iPSCs) derived from PD patients and presymptomatic individuals carrying mutations in the PINK1 (PTEN-induced putative kinase 1) and LRRK2 (leucine-rich repeat kinase 2) genes, and compared them to those of healthy control subjects. We measured several aspects of mitochondrial responses in the iPSC-derived neural cells including production of reactive oxygen species, mitochondrial respiration, proton leakage, and intraneuronal movement of mitochondria. Cellular vulnerability associated with mitochondrial dysfunction in iPSC-derived neural cells from familial PD patients and at-risk individuals could be rescued with coenzyme Q(10), rapamycin, or the LRRK2 kinase inhibitor GW5074. Analysis of mitochondrial responses in iPSC-derived neural cells from PD patients carrying different mutations provides insight into convergence of cellular disease mechanisms between different familial forms of PD and highlights the importance of oxidative stress and mitochondrial dysfunction in this neurodegenerative disease.

α-Synuclein overexpressing transgenic mice show internal organ pathology and autonomic deficits.

While studying transgenic mice that overexpress human wildtype alpha-synuclein (Thy1-ASO, ASO) for typical brain alpha-synucleinopathy and central nervous system neuropathology, we observed progressive functional changes in the gastrointestinal and other peripheral organs. A more systematic study revealed that the gastrointestinal tract in ASO mice showed severe distension and blockage of the large intestine by 9-12 months of age. Functional assessments demonstrated a reduction in fecal water content and fecal pellet output, and increased whole gut transit time, in ASO mice compared to wildtype littermates, indicative of constipation, a symptom commonly reported by Parkinson's disease (PD) patients. Food intake was increased and body weight was decreased in 12 month old ASO mice, suggestive of metabolic abnormalities. Post-mortem histological analyses showed that human alpha-synuclein protein was robustly expressed in axonal fibers and in occasional cell bodies of the enteric nervous system, and in the heart of ASO mice. Accumulation of proteinase-K insoluble alpha-synuclein, reminiscent of neurodegenerative processes in PD was also observed. The functional and pathological changes we document here in ASO mice could relate to the autonomic deficits also seen in idiopathic and alpha-synuclein-mediated genetic forms of PD. These experimental data provide a foundation for therapeutic modeling of autonomic changes in PD and related alpha-synucleinopathies.

Transcript expression levels of full-length alpha-synuclein and its three alternatively spliced variants in Parkinson's disease brain regions and in a transgenic mouse model of alpha-synuclein overexpression.

Alternative splicing is a complex post-transcriptional process that can be regulated by cis-acting elements located within genomic non-coding regions. Recent studies have identified that polymorphic variations in non-coding regions of the α-synuclein gene (SNCA) locus are associated with an increased risk for developing Parkinson's disease (PD). The underlying mechanism(s) for this susceptibility may involve changes in α-synuclein mRNA expression and alternative splicing. As a first step towards understanding the biology of α-synuclein splice variants in PD, we characterized the levels of the full-length SNCA-140 mRNA transcript and SNCA-126, -112, and -98 alternatively spliced variants in different neuronal regions from PD patients or transgenic mice overexpressing human α-synuclein (ASO). In human post-mortem tissue, α-synuclein spliced transcripts were expressed in a region-specific manner in the cortex, substantia nigra, and cerebellum. We observed increased nigral SNCA-140 and SNCA-126 transcript levels in PD patients when compared to neurologically unaffected cases. Human α-synuclein splicing changes were also found to occur in a region-specific manner in ASO mice. Here, SNCA-126, -112, and -98 transcript levels did not increase proportionally with SNCA-140 levels, or parallel the region-specific mouse transcript ratios seen in wild-type (WT) littermates. While most transcripts were elevated in ASO mice when compared to WT mice, the most prominent increase was found in the ventral midbrain of 15-month-old ASO mice. These results demonstrate region-specific human α-synuclein transcript level abnormalities in PD patients and in a transgenic mouse model of α-synucleinopathy. This study is relevant to understanding the normal, adaptive, or pathological role(s) of α-synuclein splice variants.