Using single-stranded adeno-associated virus serotype 9 (ssAAV9) vectors containing the neuron-specific synapsin-I promoter, we examined whether different administration routes (direct cerebellar cortical (DC), intrathecal (IT) and intravenous (IV) injections) could elicit specific transduction profiles in the CNS. The DC injection route robustly and exclusively transduced the whole cerebellum, whereas the IT injection route primarily transduced the cerebellar lobules 9 and 10 close to the injection site and the spinal cord. An IV injection in neonatal mice weakly and homogenously transduced broad CNS areas. In the cerebellar cortex, the DC and IT injection routes transduced all neuron types, whereas the IV injection route primarily transduced Purkinje cells. To verify the usefulness of this method, we generated a mouse model of spinocerebellar ataxia type 1 (SCA1). Mice that received a DC injection of the ssAAV9 vector expressing mutant ATXN1, a protein responsible for SCA1, showed the intranuclear aggregation of mutant ATXN1 in Purkinje cells, significant atrophy of the Purkinje cell dendrites and progressive motor deficits, which are characteristics of SCA1. Thus, ssAAV9-mediated transduction areas, levels, and cell types change depending on the route of injection. Moreover, this approach can be used for the generation of different mouse models of CNS/neurodegenerative diseases.
The small GTPase-effector proteins CDC42EP1-5/BORG1–5 interact reciprocally with CDC42 or the septin cytoskeleton. Here we show that, in the cerebellum, CDC42EP4 is exclusively expressed in Bergmann glia and localizes beneath specific membrane domains enwrapping dendritic spines of Purkinje cells. CDC42EP4 forms complexes with septin hetero-oligomers, which interact with a subset of glutamate transporter GLAST/EAAT1. In Cdc42ep4−/− mice, GLAST is dissociated from septins and is delocalized away from the parallel fibre-Purkinje cell synapses. The excitatory postsynaptic current exhibits a protracted decay time constant, reduced sensitivity to a competitive inhibitor of the AMPA-type glutamate receptors (γDGG) and excessive baseline inward current in response to a subthreshold dose of a nonselective inhibitor of the glutamate transporters/EAAT1–5 (DL-TBOA). Insufficient glutamate-buffering/clearance capacity in these mice manifests as motor coordination/learning defects, which are aggravated with subthreshold DL-TBOA. We propose that the CDC42EP4/septin-based glial scaffold facilitates perisynaptic localization of GLAST and optimizes the efficiency of glutamate-buffering and clearance.
Mesenchymal stem cells (MSCs) migrate to damaged tissues, where they participate in tissue repair. Human fetal MSCs (hfMSCs), compared with adult MSCs, have higher proliferation rates, a greater differentiation capacity and longer telomeres with reduced senescence. Therefore, transplantation of quality controlled hfMSCs is a promising therapeutic intervention. Previous studies have shown that intravenous or intracortical injections of MSCs result in the emergence of binucleated cerebellar Purkinje cells (PCs) containing an MSC-derived marker protein in mice, thus suggesting a fusion event. However, transdifferentiation of MSCs into PCs or transfer of a marker protein from an MSC to a PC cannot be ruled out. In this study, we unequivocally demonstrated the fusion of hfMSCs with murine PCs through a tetracycline-regulated (Tet-off) system with or without a Cre-dependent genetic inversion switch (flip-excision; FLEx). In the FLEx-Tet system, we performed intra-cerebellar injection of viral vectors expressing tetracycline transactivator (tTA) and Cre recombinase into either non-symptomatic (4-week-old) or clearly symptomatic (6–8-month-old) spinocerebellar ataxia type 1 (SCA1) mice. Then, the mice received an injection of 50,000 genetically engineered hfMSCs that expressed GFP only in the presence of Cre recombinase and tTA. We observed a significant emergence of GFP-expressing PCs and interneurons in symptomatic, but not non-symptomatic, SCA1 mice 2 weeks after the MSC injection. These results, together with the results obtained using age-matched wild-type mice, led us to conclude that hfMSCs have the potential to preferentially fuse with degenerating PCs and interneurons but not with healthy neurons.
1 November 2025 in Risk Management and Healthcare Policy
Introduction: Stroke is the second leading cause of death worldwide and ranks third as a cause of disability. The American Heart Association/American Stroke Association (AHA/ASA) recommends that treatment begin within three hours of onset with intravenous thrombolysis therapy. This scoping review aimed to identify the factors that influence the delay in intravenous thrombolysis (IVT) management in patients with ischemic stroke. Methods: We searched relevant studies in PubMed, ScienceDirect, and EBSCO and this review includes studies on ischemic stroke patients that analyze the factors contributing to delays in intravenous thrombolysis therapy, and it demonstrates that such delays are present in the management of IVT. Results: A total of 48 studies were included in this study. Among pre-hospital factors, the most frequently reported contributors to delays in IVT for acute ischemic stroke (AIS) patients were the use of Emergency Medical Services (EMS) (12 studies), mode of hospital presentation (12 studies), comorbidities (6 studies), symptom recognition (5 studies), and timing of event (5 studies), with several studies reporting statistically significant associations (p<0.05). Emergency department use shortened hospital admission time by an average of 30 minutes, p<0.05Regarding in-hospital delay factors, the main contributors to delays included long scan times (5 studies), low NIHSS scores (5 studies), and limited implementation of stroke programs (5 studies). Other in-hospital delay variables included delayed activation of stroke codes (3 studies), inefficiency of human resources (3 studies), suboptimal triage processes (2 studies), diagnostic process (1 study), and logistics (1 study). Conclusion: Delayed thrombolysis in ischemic stroke patients is caused by various factors, both pre-hospital and in-hospital. Community education and telemedicine can reduce delays by 30%. Collaboration between the community, stroke units, medical personnel, and the government through comprehensive programs is key in accelerating stroke treatment and improving patient clinical outcomes.
1 January 2018 in International Journal of Pharmacy and Pharmaceutical Sciences
Objective: Despite advanced treatment options available for colorectal cancer, many reported resistance and unresponsiveness to conventional chemotherapeutic agents. Therefore, it is urgent to discover a novel drug for colon cancer. Sarang Semut (Myrmecodia pendans), an Indonesian native plant, has been studied extensively due to its anti-cancer profiles. This study aimed to evaluate the anti-tumour activity of Sarang Semut in colon cancer cells.Methods: We evaluated cytotoxic activity of methanol extract as well as n-hexane and ethyl acetate fraction towards colon cancer cell lines (Caco-2 and HCT-116 cells) utilizing 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. The most potent fraction was evaluated further in inhibiting cell survival using MTT assay and cell proliferation using trypan blue exclusion assay as well as a clonogenic assay.Results: Our data showed that the n-hexane fraction of Sarang Semut induces more cell death than the methanol extract and ethyl acetate fraction. Therefore, we analyzed the n-hexane fraction further and found that the inhibitory concentration 50% (IC50) of the n-hexane fraction was 24 and 30 parts per million (ppm) for Caco-2 and HCT-116 cells, respectively. Moreover, it inhibited cell growth as well as cell colony formation, in particular, shown by the plating efficiency (P<0.05) and colony area per seed (P<0.01) of the control group were different to the treatment group.Conclusion: The n-hexane fraction of Sarang Semut demonstrates a high potential antitumor activity in colon cancer cell line.