Frontotemporal Dementia (FTD) is the second most prevalent form of early-onset dementia, following Alzheimer’s disease (AD). This condition is distinguished by the selective degeneration of the frontal and temporal lobes, resulting in personality and behavioral changes, language impairments, and executive dysfunction. Approximately 40%-50% of FTD cases have a familial component, with known causative genes including MAPT, FUS, and TARDBP. Of these, MAPT is the earliest discovered and most frequently implicated in FTD. Mutations in the MAPT gene are detectable in roughly 30% of familial FTD cases ^[1]. The tau protein, a microtubule-associated protein encoded by MAPT, is primarily localized to neuronal axons and plays a critical role in microtubule stability and assembly. By binding to microtubules, the tau protein helps to maintain neuronal cell shape. Mutations in MAPT can promote tau aggregation, leading to pathological tau protein accumulation and death of glutamatergic cortical neurons ^[2]. Additionally, certain MAPT mutations can affect pre-mRNA exon splicing, altering the ratio of 3R to 4R tau protein isoforms and increasing the relative production of 4R-tau protein, which is more prone to fibril formation ^[3]. Common mutations include P301L, P301S, and Intron10+3 G>A ^[4]. Research indicates that the P301S mutation significantly reduces the ability of recombinant tau protein to promote microtubule assembly. Patients with this mutation exhibit clinical heterogeneity ^[10-12]. Similar to the P301L mutation, the P301S mutation also leads to pathological aggregation of the tau protein, resulting in neurodegenerative diseases. Therapies targeting the MAPT gene primarily consist of small-molecule drugs and monoclonal antibodies, with indications including AD and FTD. Transgenic mice are frequently used in drug development, and the utilization of humanized animal models helps advance potential MAPT-related therapies toward clinical trials ^[5-9]. This strain is a mouse Mapt gene humanized model carrying the P301S mutation and can be used for research on FTD and AD. The homozygous hutau-P301S mice are viable and fertile. In addition, based on the independently developed TurboKnockout fusion BAC recombination technology, Cyagen can also generate other hot mutation models (e.g., B6-htau*P301L mice, Catalog Number: C001835) and provide customized services for specific mutations.

Frontotemporal Dementia (FTD) is the second most prevalent form of early-onset dementia, following Alzheimer’s disease (AD). This condition is distinguished by the selective degeneration of the frontal and temporal lobes, resulting in personality and behavioral changes, language impairments, and executive dysfunction. Approximately 40%-50% of FTD cases have a familial component, with known causative genes including MAPT, FUS, and TARDBP. Of these, MAPT is the earliest discovered and most frequently implicated in FTD. Mutations in the MAPT gene are detectable in roughly 30% of familial FTD cases ^[1]. The tau protein, a microtubule-associated protein encoded by MAPT, is primarily localized to neuronal axons and plays a critical role in microtubule stability and assembly. By binding to microtubules, the tau protein helps to maintain neuronal cell shape. Mutations in MAPT can promote tau aggregation, leading to pathological tau protein accumulation and death of glutamatergic cortical neurons ^[2]. Additionally, certain MAPT mutations can affect pre-mRNA exon splicing, altering the ratio of 3R to 4R tau protein isoforms and increasing the relative production of 4R-tau protein, which is more prone to fibril formation ^[3]. Common mutations include P301L, P301S, and Intron10+3 G>A ^[4]. The P301L mutation affects the 4R-tau isoforms without affecting splicing in exon 10. This mutation accelerates the formation of paired helical filaments in tau proteins, reduces microtubule interactions and stability, and promotes β-sheet folding during the aggregation process. This leads to abnormal tau protein aggregation, resulting in neurofibrillary tangles—a characteristic feature of neurodegenerative diseases ^[10-11]. Therapies targeting the MAPT gene primarily consist of small-molecule drugs and monoclonal antibodies, with indications including AD and FTD. Transgenic mice are frequently used in drug development, and the utilization of humanized animal models helps advance potential MAPT-related therapies toward clinical trials ^[5-9]. This strain is a mouse Mapt gene humanized model carrying the P301L mutation and can be used for research on FTD and AD. The homozygous B6-htau*P301L mice are viable and fertile. In addition, based on the independently developed TurboKnockout fusion BAC recombination technology, Cyagen can also generate other hot mutation models (e.g., B6-htau*P301S mice, Catalog Number: C001836) and provide customized services for specific mutations.

The Transferrin receptor (TFRC) gene encodes Transferrin Receptor 1 (TFR1), a protein that is expressed at low levels in most normal cells but shows increased expression in highly proliferative cells, such as basal epidermal cells, intestinal epithelium, and certain activated immune cells. Brain capillary endothelial cells, which constitute the blood-brain barrier (BBB), also express this receptor at high levels ^[1]. TFR1 plays a critical role in maintaining iron metabolism and homeostasis by facilitating receptor-mediated endocytosis of iron-bound transferrin (Tf) via Tf cycling, thereby promoting iron uptake ^[2]. Cellular iron deficiency can lead to apoptosis, while cellular transformation requires substantial iron to sustain proliferation, with iron overload contributing to tumor progression. The high expression of TFR1 in many tumors makes it a potential tumor marker, offering a target for therapies to inhibit tumor growth and metastasis ^[1]. Moreover, TFR1 is implicated in anemia and iron metabolism disorders. Studies have shown that elevated TFR1 expression in cardiomyocytes is associated with exacerbated inflammation in myocarditis patients ^[3]. The tau protein, a microtubule-associated protein encoded by MAPT, is primarily localized to neuronal axons and plays a critical role in microtubule stability and assembly. By binding to microtubules, the tau protein helps to maintain neuronal cell shape. Mutations in MAPT can promote tau aggregation, leading to pathological tau protein accumulation and death of glutamatergic cortical neurons ^[4]. Additionally, certain MAPT mutations can affect pre-mRNA exon splicing, altering the ratio of 3R to 4R tau protein isoforms and increasing the relative production of 4R-tau protein, which is more prone to fibril formation ^[5]. The B6-hTFRC/htau mice are a model expressing human TFRC protein and tau protein, generated by crossing B6-hTFRC(CDS) mice (Catalog No.: C001584) with B6-htau mice (Catalog No.: C001410). These mice can be used for research on neurodegenerative diseases and iron metabolism disorders, as well as for the development and preclinical evaluation of TFRC/MAPT-targeted therapeutic agents.

The Transferrin receptor (TFRC) gene encodes Transferrin Receptor 1 (TFR1), a protein that is expressed at low levels in most normal cells but shows increased expression in highly proliferative cells, such as basal epidermal cells, intestinal epithelium, and certain activated immune cells. Brain capillary endothelial cells, which constitute the blood-brain barrier (BBB), also express this receptor at high levels ^[1]. TFR1 plays a critical role in maintaining iron metabolism and homeostasis by facilitating receptor-mediated endocytosis of iron-bound transferrin (Tf) via Tf cycling, thereby promoting iron uptake ^[2]. Cellular iron deficiency can lead to apoptosis, while cellular transformation requires substantial iron to sustain proliferation, with iron overload contributing to tumor progression. The high expression of TFR1 in many tumors makes it a potential tumor marker, offering a target for therapies to inhibit tumor growth and metastasis ^[1]. Moreover, TFR1 is implicated in anemia and iron metabolism disorders. Studies have shown that elevated TFR1 expression in cardiomyocytes is associated with exacerbated inflammation in myocarditis patients ^[3]. As a target for antibody-mediated cancer therapy, TFR1 can be leveraged through two approaches: one involves the use of antibodies conjugated to anti-cancer drugs, which are indirectly internalized via receptor-mediated endocytosis; the other employs antibodies that directly disrupt receptor function or induce Fc effector functions such as antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), or complement-dependent cytotoxicity (CDC). Various clinical drugs targeting TFR1 are currently under development, including antisense oligonucleotides (ASOs), antibody-drug conjugates (ADCs), and antibody-oligonucleotide conjugates, applicable to diseases such as cancer, anemia, and neurodegenerative disorders. Research indicates that enhancing antibody transport across the blood-brain barrier via TFR1, by forming specific bispecific antibodies with anti-β-amyloid antibodies, can improve therapeutic outcomes in Alzheimer's patients ^[4-5]. As research progresses, TFR1 is expected to become an effective clinical target for multiple diseases and a synergistic target for drug delivery across the blood-brain barrier (BBB). The tau protein, a microtubule-associated protein encoded by MAPT, is primarily localized to neuronal axons and plays a critical role in microtubule stability and assembly. By binding to microtubules, the tau protein helps to maintain neuronal cell shape. Mutations in MAPT can promote tau aggregation, leading to pathological tau protein accumulation and death of glutamatergic cortical neurons ^[6]. Additionally, certain MAPT mutations can affect pre-mRNA exon splicing, altering the ratio of 3R to 4R tau protein isoforms and increasing the relative production of 4R-tau protein, which is more prone to fibril formation ^[7-8]. The B6-huTFRC/htau mouse is a dual-gene humanized model obtained by mating B6-huTFRC mice (catalog number: C001860) with B6-htau mice (catalog number: C001410). This model can be used for research on neurodegenerative diseases and iron metabolism diseases, as well as pre-clinical studies of TFRC/MAPT-targeted therapeutic drugs.

The hCRBN/hutau-P301S mouse is a dual-gene humanized model obtained by crossing the hCRBN mouse (Catalog No.: C001683) with the hutau-P301S mouse (Catalog No.: C001836). The hCRBN/hutau-P301S mouse is a dual-target humanized model that integrates targeted protein degradation (TPD) technology with research on tau-related neurodegenerative diseases. It can be used to evaluate CRBN-based targeted protein degradation (TPD) therapeutics, including molecular glues and proteolysis-targeting chimeras (PROTACs), for the treatment of tauopathies. This model serves as an ideal preclinical research platform for developing innovative therapies for frontotemporal dementia (FTD), Alzheimer's disease (AD), and other tau-related neurodegenerative diseases.

Frontotemporal Dementia (FTD) is the second most prevalent form of early-onset dementia, following Alzheimer’s disease (AD). This condition is distinguished by the selective degeneration of the frontal and temporal lobes, resulting in personality and behavioral changes, language impairments, and executive dysfunction. Approximately 40%-50% of FTD cases have a familial component, with known causative genes including MAPT, FUS, and TARDBP. Of these, MAPT is the earliest discovered and most frequently implicated in FTD. Mutations in the MAPT gene are detectable in roughly 30% of familial FTD cases ^[1]. The tau protein, a microtubule-associated protein encoded by MAPT, is primarily localized to neuronal axons and plays a critical role in microtubule stability and assembly. By binding to microtubules, the tau protein helps to maintain neuronal cell shape. Mutations in MAPT can promote tau aggregation, leading to pathological tau protein accumulation and death of glutamatergic cortical neurons ^[2]. Additionally, certain MAPT mutations can affect pre-mRNA exon splicing, altering the ratio of 3R to 4R tau protein isoforms and increasing the relative production of 4R-tau protein, which is more prone to fibril formation ^[3-4]. Therapies targeting the MAPT gene primarily consist of small-molecule drugs and monoclonal antibodies, with indications including AD and FTD. Transgenic mice are frequently used in the drug development process, and the utilization of humanized animal models can facilitate the translation of promising treatments into clinical trials ^[5-9]. The tumor necrosis factor-alpha (TNF/TNF-α) gene encodes a pro-inflammatory cytokine belonging to the TNF superfamily. It is primarily produced by macrophages/monocytes during acute inflammation. TNF-α regulates immune cell function by binding to its receptors TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR, participating in normal inflammatory and immune responses. TNF-α is involved in various biological processes, including cell proliferation, differentiation, apoptosis, lipid metabolism, and coagulation. This factor is associated with several diseases, such as autoimmune conditions, insulin resistance, psoriasis, rheumatoid arthritis, ankylosing spondylitis, tuberculosis, autosomal dominant polycystic kidney disease, and cancer. Mutations in the TNF-α gene impact susceptibility to cerebral malaria, septic shock, and Alzheimer’s disease ^[10-11]. In mice, defects in this gene are associated with impaired responses to bacterial infections, defects in the organization of follicular dendritic cell networks and germinal centers, and a lack of primary B cell follicles. The B6;D1-htau/hTNF mouse is a dual-gene humanized model generated by crossing B6-htau mice (Catalog No.: C001410) with DBA/1-hTNF mice (Catalog No.: C001587). This model can be used for the study of neurodegenerative diseases such as frontotemporal lobar dementia (FTD) and Alzheimer's disease (AD) and autoimmune diseases such as rheumatoid arthritis (RA), as well as for the research and development, screening, and pre-clinical evaluation of Tau/TNF-targeted drugs.