Effects of local reduction of endogenous α-synuclein using antisense oligonucleotides on the fibril-induced propagation of pathology through the neural network in wild-type mice.

In Parkinson's disease and other synucleinopathies, fibrillar forms of α-synuclein (aSyn) are hypothesized to structurally convert and pathologize endogenous aSyn, which then propagates through the neural connections, forming Lewy pathologies and ultimately causing neurodegeneration. Inoculation of mouse-derived aSyn preformed fibrils (PFFs) into the unilateral striatum of wild-type mice causes widespread aSyn pathologies in the brain through the neural network. Here, we used the local injection of antisense oligonucleotides (ASOs) against Snca mRNA to confine the area of endogenous aSyn protein reduction and not to affect the PFFs properties in this model. We then varied the timing and location of ASOs injection to examine their impact on the initiation and propagation of aSyn pathologies in the whole brain and the therapeutic effect using abnormally-phosphorylated aSyn (pSyn) as an indicator. By injecting ASOs before or 0-14 days after the PFFs were inoculated into the same site in the left striatum, the reduction in endogenous aSyn in the striatum leads to the prevention and inhibition of the regional spread of pSyn pathologies to the whole brain including the contralateral right hemisphere. ASO post-injection inhibited extension from neuritic pathologies to somatic ones. Moreover, injection of ASOs into the right striatum prevented the remote regional spread of pSyn pathologies from the left striatum where PFFs were inoculated and no ASO treatment was conducted. This indicated that the reduction in endogenous aSyn protein levels at the propagation destination site can attenuate pSyn pathologies, even if those at the propagation initiation site are not inhibited, which is consistent with the original concept of prion-like propagation that endogenous aSyn is indispensable for this regional spread. Our results demonstrate the importance of recruiting endogenous aSyn in this neural network propagation model and indicate a possible potential for ASO treatment in synucleinopathies.

Non-human primate model of amyotrophic lateral sclerosis with cytoplasmic mislocalization of TDP-43.

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by progressive motoneuron loss. Redistribution of transactive response deoxyribonucleic acid-binding protein 43 from the nucleus to the cytoplasm and the presence of cystatin C-positive Bunina bodies are considered pathological hallmarks of amyotrophic lateral sclerosis, but their significance has not been fully elucidated. Since all reported rodent transgenic models using wild-type transactive response deoxyribonucleic acid-binding protein 43 failed to recapitulate these features, we expected a species difference and aimed to make a non-human primate model of amyotrophic lateral sclerosis. We overexpressed wild-type human transactive response deoxyribonucleic acid-binding protein 43 in spinal cords of cynomolgus monkeys and rats by injecting adeno-associated virus vector into the cervical cord, and examined the phenotype using behavioural, electrophysiological, neuropathological and biochemical analyses. These monkeys developed progressive motor weakness and muscle atrophy with fasciculation in distal hand muscles first. They also showed regional cytoplasmic transactive response deoxyribonucleic acid-binding protein 43 mislocalization with loss of nuclear transactive response deoxyribonucleic acid-binding protein 43 staining in the lateral nuclear group of spinal cord innervating distal hand muscles and cystatin C-positive cytoplasmic aggregates, reminiscent of the spinal cord pathology of patients with amyotrophic lateral sclerosis. Transactive response deoxyribonucleic acid-binding protein 43 mislocalization was an early or presymptomatic event and was later associated with neuron loss. These findings suggest that the transactive response deoxyribonucleic acid-binding protein 43 mislocalization leads to α-motoneuron degeneration. Furthermore, truncation of transactive response deoxyribonucleic acid-binding protein 43 was not a prerequisite for motoneuronal degeneration, and phosphorylation of transactive response deoxyribonucleic acid-binding protein 43 occurred after degeneration had begun. In contrast, similarly prepared rat models expressed transactive response deoxyribonucleic acid-binding protein 43 only in the nucleus of motoneurons. There is thus a species difference in transactive response deoxyribonucleic acid-binding protein 43 pathology, and our monkey model recapitulates amyotrophic lateral sclerosis pathology to a greater extent than rodent models, providing a valuable tool for studying the pathogenesis of sporadic amyotrophic lateral sclerosis.

Pandemic-Induced Occupational Disruption and Association With Health in Japanese Community-Dwelling Older Adults.

The COVID-19 pandemic caused occupational disruption and adverse health outcomes in community-dwelling older adults. This study aimed to investigate the extent of occupational disruption in older adults and its relationship to health-related quality of life (QOL), depression, and frailty. In this cross-sectional study, retention rates in four activity domains and relationships with health outcomes were examined in Japanese older adults aged ≥65 years (n=163) using canonical correlation analysis (CCA) and mixed linear models. More than 25% of activities were restricted compared with the pre-pandemic period. CCA demonstrated correlations between four retention rates and health outcomes (canonical correlation = .42, p = .0003). Retention in instrumental and social activities independently predicted QOL and depression (p < .05). This study highlights that different activities may have different effects on health outcomes and can provide community occupational therapy practitioners with a perspective to assess occupational disruption and identify activities for intervention.

Pandemic-Induced Changes of Daily Routine and Its Association with Health for Japanese Older AdultsWe investigated the changes in daily activity due to the COVID-19 pandemic among community-dwelling older adults in Japan and examined their association with health outcomes. The results showed that more than 25% of activity was reduced due to the pandemic. There was a moderate association between changes in activity and physical, mental, and subjective health. Especially, instrumental and social activities were strongly associated with mental and subjective health. This study highlights the possibility that different types of activities may have different effects on health. Our study can provide occupational therapy practitioners supporting community-dwelling older adults with a perspective to assess changes in daily activities due to the pandemic and identify activities to target for future intervention. As this study was conducted at a single point in time, future studies should be conducted at multiple points in time.

Retrobulbar optic neuropathy associated with sphenoid sinus mucormycosis.

Because fungi usually spread from the paranasal sinuses to the orbital apex in invasive fungal sinusitis (IFS), IFS often presents as an orbital apex syndrome (OAS) characterized by dysfunction of cranial nerves II, III, IV, V1, and VI. We report a case of sphenoid sinus mucormycosis that presented as isolated retrobulbar optic neuropathy. A 94-year-old woman presented with acute blindness in the right eye. Examination revealed the absence of light perception and pupillary reflex in the right eye. Head MRI showed a mass in the right sphenoid sinus, which was contiguous with the right optic nerve. She underwent endoscopic surgery, and a histopathological diagnosis of mucormycosis was established. Treatment with intravenous liposomal amphotericin B reduced the size of the mass. She has survived for more than 1 year without recurrence. Clinicians should consider that IFS can present as isolated retrobulbar optic neuropathy.