B6-hTARDBP Mice

Figure 1. Diagram of the gene editing strategy of B6-hTARDBP mice. The sequences from the ATG start codon to the TAG stop codon of the endogenous mouse Tardbp gene were replaced with the sequences from the ATG start codon to the TAG stop codon of the human TARDBP gene by TurboKnockout targeting technology.

● Research on amyotrophic lateral sclerosis (ALS);

● Research on frontotemporal dementia (FTD);

● Research on other neurodegenerative diseases.

1. Detection of human TARDBP gene and murine Tardbp gene expression

Figure 2. Expression of human TARDBP and mouse Tardbp genes in the brain and thymus of wild-type (WT) and B6-hTARDBP (hTARDBP) mice (n=5). Specific primers were designed to detect the expression of human TARDBP and mouse Tardbp genes in wild-type and B6-hTARDBP mice using RT-qPCR. The results showed that the expression of the human TARDBP gene was significantly detected in the brain and thymus of B6-hTARDBP mice, but the expression of the mouse Tardbp gene was not detected. On the contrary, the expression of the human TARDBP gene was not detected in wild-type mice, and only the expression of the mouse Tardbp gene was detected.
ND: Not detected

2. Western Blot detection of human TARDBP protein expression in the brain

Figure 3. Expression of human TARDBP protein in the brain tissue of 6-week-old male wild-type mice (WT), Prp-TARDBP A315T transgenic mice*, and B6-hTARDBP mice (n=3). Western blot was used to detect the expression of human TARDBP protein. The results showed that B6-hTARDBP mice showed significant expression of human TARDBP protein in the brain, with expression levels comparable to those of Prp-TARDBP A315T mice.
*Prp-TARDBP A315T mice (Catalog Number: C001380) are transgenic models that express human TARDBP protein carrying the A315T mutation. For more information on this model, please refer to the product manual.

3. IHC detection of human TARDBP protein expression in the spinal cord

Figure 4. Expression and distribution of human TARDBP protein in the spinal cord of 12-week-old male wild-type mice (WT), Prp-TARDBP A315T transgenic mice, and B6-hTARDBP mice (n=3). Immunohistochemistry (IHC) was used to detect the expression and distribution of human TARDBP protein in the spinal cord. The results showed that both Prp-TARDBP A315T transgenic mice and B6-hTARDBP mice had significant expression of human TARDBP protein in the spinal cord, while no expression of human TARDBP protein was detected in the spinal cord of wild-type mice.

1.Basic information about the TARDBP gene

https://rddc.tsinghua-gd.org/en/gene/23435

2. TARDBP clinical variants

https://rddc.tsinghua-gd.org/en/ai/pathogenicity/result?id=da7590ae-b264-4e25-a000-a52827f0b00e

3. Disease introduction

The majority of ALS is sporadic ALS (sALS) with no family history of ALS, accounting for about 90%. A small proportion of ALS is familial ALS (fALS), which means that there is more than one ALS patient in the family, accounting for about 10%. There are approximately 50 pathogenic genes that cause ALS. Mutations in the following genes have been studied more frequently: Superoxide dismutase 1 (SOD1) gene, Chromosome 9 open reading frame 72 (C9orf72) gene, Fused in sarcoma (FUS) gene, and TARDBP gene.

4. TARDBP gene and mutations

The human TARDBP gene is located on chromosome 1. TDP-43 is a DNA and RNA binding protein expressed mainly in the nucleus and performs several important functions under normal physiological conditions, such as transcription, translation, mRNA transport, mRNA stabilization, microRNA (miRNA) and long non-coding RNA (lncRNA) processing, etc. Under normal physiological conditions, TDP-43 can shuttle in the nucleus and cytoplasm. However, TDP-43 will function preferentially in the nucleus. In contrast, under pathological conditions, TDP-43 aggregates toward the cytoplasm and shows high phosphorylation or ubiquitination, resulting in greatly reduced solubility^[2]. Abnormal localization of TDP-43 to the cytoplasm can lead to the development of cytotoxicity or, as TDP-43 continues to bind RNA in the cytoplasm, which causes functional abnormalities, resulting in degenerative neuronal lesions. The majority of ALS-related mutations in the TARDBP gene occur in exon 6, which encodes the C-terminal glycine-rich region of TDP-43. The most common missense mutations are A382T, M337V, A315T, etc.

5. Function of non-coding DNA sequences

According to published reports, mutations in the C-terminal region of TDP-43 enhance its propensity for intrinsic aggregation. TARDBP has pathogenic mutations in both the intron and UTR regions^[3].

6. TARDBP-targeted gene therapy

Drugs targeting TARDBP are dominated by monoclonal antibodies. Among the drug pipelines for ALS, those targeting SOD1 are the most numerous, followed by TARDBP. The current pipeline focused on targeting TARDBP is primarily in the preclinical stage, which signifies the significant interest in preclinical research on drugs that target TARDBP. The application of fully humanized models can help drive the translation of relevant potential TARDBP-targeted therapies to clinical trials.

In summary, the TARDBP gene is an important pathogenic gene in amyotrophic lateral sclerosis with a complex pathogenic mechanism. This clinical drug development is based on monoclonal antibodies. Using humanized models can facilitate the preclinical development of the drug. Cyagen's TARDBP fully humanized mice can be used in preclinical research for ALS and FTD gene therapy. Custom modeling services are available for different point mutations.