Ptpn1, also known as Protein Tyrosine Phosphatase 1B (PTP1B), is a member of the protein tyrosine phosphatase superfamily. It plays a crucial role in regulating protein phosphorylation, thus influencing various signaling pathways such as STAT3, BMPR2, MAPK/ERK, and PI3K/AKT, which are involved in cell differentiation, immune response, and disease development [1,2,3,4]. Genetic models like knockout (KO) or conditional knockout (CKO) mouse models are valuable for studying its functions.

In Duchenne muscular dystrophy (DMD), Ptpn1 phosphatase expression is up-regulated in muscle stem cells (MuSCs), leading to impaired myogenic function. Loss-of-function experiments showed that inhibiting Ptpn1/2 can restore STAT3-mediated myogenic signaling and promote MuSC differentiation, suggesting it as a potential therapeutic strategy [1]. In pulmonary arterial hypertension (PAH), down-regulation of Ptpn1 in blood is linked to endothelial dysfunction, indicating its potential involvement in the disease [2]. In cancer, Ptpn1 is frequently up-regulated and associated with poor prognosis. For example, in glioma, it promotes tumor progression by activating the MAPK/ERK and PI3K/AKT pathways [3,4].

In summary, Ptpn1 is a key regulator in multiple biological processes and disease conditions. Studies using KO/CKO mouse models have revealed its role in DMD, PAH, and cancer, providing insights into disease mechanisms and potential therapeutic targets.

References:

1. Liu, Yiyang, Li, Shulei, Robertson, Rebecca, Tremblay, Michel L, Chang, Natasha C. 2024. PTPN1/2 inhibition promotes muscle stem cell differentiation in Duchenne muscular dystrophy. In Life science alliance, 8, . doi:10.26508/lsa.202402831. https://pubmed.ncbi.nlm.nih.gov/39477543/

2. Ali, Md Khadem, Tian, Xuefei, Zhao, Lan, Nicolls, Mark R, Spiekerkoetter, Edda F. 2023. PTPN1 Deficiency Modulates BMPR2 Signaling and Induces Endothelial Dysfunction in Pulmonary Arterial Hypertension. In Cells, 12, . doi:10.3390/cells12020316. https://pubmed.ncbi.nlm.nih.gov/36672250/

3. Zhao, Ruijun, Chen, Shuanglong, Cui, Weiheng, Yang, Li, Dong, Hongmei. 2023. PTPN1 is a prognostic biomarker related to cancer immunity and drug sensitivity: from pan-cancer analysis to validation in breast cancer. In Frontiers in immunology, 14, 1232047. doi:10.3389/fimmu.2023.1232047. https://pubmed.ncbi.nlm.nih.gov/37936713/

4. Jin, Tao, Li, Dongbo, Yang, Tao, Kong, Juan, Zhou, Yuefei. 2019. PTPN1 promotes the progression of glioma by activating the MAPK/ERK and PI3K/AKT pathways and is associated with poor patient survival. In Oncology reports, 42, 717-725. doi:10.3892/or.2019.7180. https://pubmed.ncbi.nlm.nih.gov/31173266/