Biology subjects

Smit, T.

Publications and source records attributed to Smit, T..

4 recordsLinked to original sources

bioRxiv2025

Therapeutic antisense oligonucleotide mitigates retinal dysfunction in a pig model of CLN3 Batten disease

CLN3 Batten disease is a lethal pediatric autosomal recessive neurodegenerative disease caused by mutations in the CLN3 gene. Typically, the disease manifests as vision loss early in life and progresses to neurological dysfunction and death in young adulthood. Therapeutic development has focused on treating the central nervous system. However, such therapies may not protect against vision loss, which has a significant impact on quality of life. We have shown that a splice-switching antisense oligonucleotide (ASO) delivered to the central nervous system can reduce neurological disease burden in mouse models of CLN3 disease. Here, we report on a similar ASO approach for treating CLN3 Batten disease retinal dysfunction in a pig model of the disease, which is more representative of human vision. A single intravitreal injection of ASO induces robust exon skipping in the retina for up to 12 months. The ASO treatment resulted in higher amplitudes on electroretinograms, suggesting mitigation of retinal dysfunction at early timepoints of disease. One ASO that efficiently induces exon skipping in vivo was well-tolerated and targets a region of CLN3 that is conserved in humans, making it a promising candidate for treating the disease in humans. Our findings demonstrate the potential utility of an ASO-based approach to treat retinal dysfunction in CLN3 Batten disease and generally supports the use of ASOs for treating eye diseases. One Sentence SummarySplice-switching antisense oligonucleotides delivered by intravitreal injection are safe and show efficacy in preventing early retinal dysfunction in a pig model of CLN3 Batten disease.

molecular biology↗

bioRxiv2023

3D-Printed LEGO(R)-inspired Titanium Scaffolds for Patient-Specific Regenerative Medicine

Despite the recent advances in 3D-printing, it is difficult to fabricate implants that optimally fit a defect size/shape. There are some approaches to resolve this issue, such as patient-specific implant based on CT images, however, it is labor-intensive and costly. Especially in developing countries, affordable treatments are required, while still not excluding these patient groups from manufacturing advances. Here, a SLM 3D-printing strategy was used to fabricate a hierarchical, Assemblable Titanium Scaffold(ATS), which can be manually assembled in any shape or size with ease. A surgeon can create a scaffold that would fit to the defect right before the implantation during the surgery. Additionally, the direct inclusion of micro- and macroporous structures via 3D-printing, as well as a double acid-etched surface treatment(ST) in the ATS, ensure improved nutrient flow and cellular activity. Different structures were designed, 3D-printed and then surface treated for the ST groups. Both individual and stacked ATS have sufficient mechanical properties to withstand physiological loading, and the porous groups resulted enhanced cell proliferation, mineralizaton and osteogenesis compared to non-porous group. Furthermore, successful cell attachment and migration between the assembled ATS were observed. Finally, we demonstrate possible medical applications that reveal the potential of the ATS through assembly.

bioengineering↗

bioRxiv2021

Transcriptomic and functional analysis of Aβ1-42 oligomer-stimulated human monocyte-derived microglia-like cells

Dysregulation of microglial function contributes to Alzheimers disease (AD) pathogenesis. Several genetic and transcriptome studies have revealed microglia specific genetic risk factors, and changes in microglia expression profiles in AD pathogenesis, viz. the human-Alzheimers microglia/myeloid (HAM) profile in AD patients and the disease-associated microglia profile (DAM) in AD mouse models. The transcriptional changes involve genes in immune and inflammatory pathways, and in pathways associated with A{beta} clearance. A{beta} oligomers have been suggested to be the initial trigger of microglia activation in AD. To study the direct response to A{beta} oligomers exposure, we assessed changes in gene expression in an in vitro model for microglia, the human monocyte-derived microglial-like (MDMi) cells. We confirmed the initiation of an inflammatory profile following LPS stimulation, based on increased expression of IL1B, IL6, and TNF. In contrast, the A{beta}1-42 oligomers did not induce an inflammatory profile or a classical HAM or DAM profile. Interestingly, we observed a specific increase in the expression of metallothioneins in the A{beta}1-42 oligomer treated MDMi cells. Metallothioneins are involved in metal ion regulation, protection against reactive oxygen species, and have anti-inflammatory properties. In conclusion, our data suggests that A{beta}1-42 oligomers may trigger a protective response both in vitro and in vivo.

neuroscience↗

bioRxiv2020

X-ray Irradiation activates immune response in human T-lymphocytes by eliciting a Ca2+ signaling cascade

Radiation therapy is efficiently employed for eliminating cancer cells and reducing tumor growth. To further improving its therapeutic application it is mandatory to unravel the molecular effects of ionizing irradiation and to understand whether they support or counteract tumor therapy. Here we examine the impact of X-ray irradiation on immune activation of human T cells with single doses typically employed in tumor therapy. We discover that exposing cells to radiation triggers in a population of leukemic Jurkat T cells and in peripheral blood mononuclear cells (PBMCs) a canonical Ca2+ signaling cascade, which elicits immune activation of these cells. An early step in the signaling cascade is the initiation of sustained oscillations of the cytosolic Ca2+ concentration, an event mediated by store operated Ca2+ entry (SOCE) via an X-ray induced clustering of the Calcium Release-Activated Calcium Modulator 1 with the stromal interaction molecule 1 (Oari1/STIM1). A functional consequence of the Ca2+ signaling cascade is the translocation of the transcription factor nuclear factor of activated T cells (NFAT) from the cytosol into the nucleus where it elicits the expression of genes required for immune activation. These data imply that a direct activation of blood immune cells by ionizing irradiation has an impact on toxicity and therapeutic effects of radiation therapy.

biophysics↗