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Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder that caused by NF1 mutations. NF1 gene encodes neurofibromin (a GTPase‐activating protein) and plays a regulatory role in many signalling pathway such as the Ras/MAPK pathway, which is important for regulating cell growth, proliferation and neural development. Therefore, NF1 gene mutations causes the excessive activation of signalling pathways and uncontrolled cell growth. NF1 exhibits complete genetic penetrance and clinical heterogeneity. Glomerular disease has rarely been reported in patients with NF1, especially in children. Currently, the relationship between NF1 and nephrotic syndrome is unclear. Here, we present a case of NF1 with nephrotic syndrome and further explore the association between NF1 and glomerular diseases. It also reminds clinicians that NF1 has complex and highly variable clinical manifestations and that a comprehensive workup is essential for patients. [ABSTRACT FROM AUTHOR]

Lung cancer remains the leading cause of cancer-associated mortality worldwide, and non-small-cell lung cancer (NSCLC) contributes to ~80% of these deaths. However, both primary and acquired cisplatin resistance frequently occurs within the disease and represents a huge clinical treatment problem. The underlying molecular mechanisms are not yet completely understood, but in recent years, microRNAs (miR) have been reported to play vital roles in the development of lung cancer and chemoresistance. In the present study, it was revealed that there were increased expression levels of miR-103a-3p in both NSCLC cell lines and human NSCLC samples that exhibited resistance to cisplatin. The results also revealed that the inhibition of miR-103a-3p in A549/cisplatin cells significantly sensitized these cells to cisplatin, while inhibition of miR-103a-3p expression inhibited tumor growth and enhanced the function of cisplatin in a xenograft animal model. Furthermore, the present study demonstrated that miR-103a-3p regulates cisplatin resistance by targeting neurofibromatosis 1 (NF1) via activating ERK signaling in vitro and in vivo. In conclusion, NF1 was identified as a special miR-103a-3p target in the present study, and it was revealed that targeting NF1 via miR-103a-3p may help reverse chemoresistance and provide a biomarker to cisplatin responsiveness in NSCLC. [ABSTRACT FROM AUTHOR]

Forkhead box A1 (FOXA1), a member of the forkhead family of transcription factors, plays a crucial role in the development of various organ systems and exhibits neuroprotective properties. This study aims to investigate the effect of FOXA1 on Parkinson's disease (PD) and unravel the underlying mechanism. Transcriptome analysis of PD was conducted using three GEO datasets to identify aberrantly expressed genes. A mouse model of PD was generated by injecting neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP), resulting in reduced FOXA1 expression. FOXA1 decline was also observed in 1-methyl-4-phenylpyridinium-treated SH-SY5Y cells. Artificial upregulation of FOXA1 improved motor abilities of mice according to rotarod and pole tests, and it mitigated tissue damage, cell loss, and neuronal damage in the mouse substantia nigra or in vitro. FOXA1 was found to bind to the neurofibromin 1 (NF1) promoter, thereby inducing its transcription and inactivating the mitogen-activated protein kinase (MAPK) signaling pathway. Further experimentation revealed that silencing NF1 in mice or SH-SY5Y cells counteracted the neuroprotective effects of FOXA1. In conclusion, this research suggests that FOXA1 activates NF1 transcription and inactivates the MAPK signaling pathway, ultimately ameliorating neuronal damage and motor disability in PD. The findings may offer novel ideas in the field of PD management. • FOXA1 is poorly expressed in the substantia nigra of PD mice and in cell models. • FOXA1 upregulation improves motor function and neuron loss in PD mice. • FOXA1 upregulation alleviates oxidative stress and neuronal damage in SH-SY5Y cells. • FOXA1 activates NF1 transcription to inactivate the MAPK signaling pathway. • Knockdown of NF1 restores PD-like symptoms in mice and neuronal damage in vitro. [ABSTRACT FROM AUTHOR]

The neuromuscular junction (NMJ) consists of three components, namely presynaptic motor neurons, postsynaptic muscle fibers and perisynaptic Schwann cells (PSCs). The role of Schwann cells (SCs) in regulating NMJ structural and functional development remains unclear. In this study, mice with conditional inactivation of neurofibromin 1 (Nf1) and phosphatase and tensin homolog (Pten), specifically in SCs, resulted in delayed NMJ maturation that led to delayed muscle growth, recapitulating the muscular dystrophy condition observed in human neurofibromatosis type I syndrome (NF1) patients. Expression levels of NMJ development related molecules such as cholinergic receptor, nicotinic, alpha polypeptide 1 (Chrna1), agrin (Agrn), dystrophin, muscular dystrophy (Dmd), laminin, beta 2 (Lamb2) and dystroglycan 1 (Dag1) were also downregulated. To further explore the molecular alterations in these SCs, NF1- and PTEN-related pathways were analyzed in mutant sciatic nerves. As expected, hyperactive RAS/PI3K/AKT/ mTOR signaling pathways were identified, suggesting the importance of these pathways for NMJ development, and subsequent muscle maturation. [ABSTRACT FROM AUTHOR]

Neurofibromatosis type 1 (NF-1) is an autosomal dominant neurocutaneous syndrome caused by mutations in the neurofibromin gene. NF-1 patients have a high risk of tumors, and optic glioma is the most commonly observed central nervous system tumor in these patients. However, glioblastoma is extremely rare in pediatric NF-1 patients. Here we report the discovery of a novel heterozygous c.6766_6767insAA (p.Ser2256Lysfs*4), pathogenic mutation in the neurofibromin gene in a 17-year-old boy with NF-1-associated glioblastoma. [ABSTRACT FROM AUTHOR]

The epicardium is the primary source of coronary vascular smooth muscle cells (cVSMCs) and fibroblasts that reside in the compact myocardium. To form these epicardial-derived cells (EPDCs), the epicardium undergoes the process of epithelial to mesenchymal transition (EMT). Although several signaling pathways have been identified that disrupt EMT, no pathway has been reported that restricts this developmental process. Here, we identify neurofibromin 1 (Nf1) as a key mediator of epicardial EMT. To determine the function of Nf1 during epicardial EMT and the formation of epicardial derivatives, cardiac fibroblasts and cVSMCs, we generated mice with a tissue-specific deletion of Nf1 in the epicardium. We found that mutant epicardial cells transitioned more readily to mesenchymal cells in vitro and in vivo. The mesothelial epicardium lost epithelial gene expression and became more invasive. Using lineage tracing of EPDCs, we found that the process of EMT occurred earlier in Nf1 mutant hearts, with an increase in epicardial cells entering the compact myocardium. Moreover, loss of Nf1 caused increased EPDC proliferation and resulted in more cardiac fibroblasts and cVSMCs. Finally, we were able to partially reverse the excessive EMT caused by loss of Nf1 by disrupting Pdgfr? expression in the epicardium. Conversely, Nf1 activation was able to inhibit PDGF-induced epicardial EMT. Our results demonstrate a regulatory role for Nf1 during epicardial EMT and provide insights into the susceptibility of patients with disrupted NF1 signaling to cardiovascular disease. [ABSTRACT FROM AUTHOR]

Neurofibromatosis Type 1 (NF1) is a common genetic disorder and cancer predisposition syndrome (1:3000 births) caused by mutations in the tumor suppressor gene NF1. NF1 encodes neurofibromin, a negative regulator of the Ras signaling pathway. Individuals with NF1 often develop benign tumors of the peripheral nervous system (neurofibromas), originating from the Schwann cell linage, some of which progress further to malignant peripheral nerve sheath tumors (MPNSTs). Treatment options for neurofibromas and MPNSTs are extremely limited, relying largely on surgical resection and cytotoxic chemotherapy. Identification of novel therapeutic targets in both benign neurofibromas and MPNSTs is critical for improved patient outcomes and quality of life. Recent clinical trials conducted in patients with NF1 for the treatment of symptomatic plexiform neurofibromas using inhibitors of the mitogen-activated protein kinase (MEK) have shown very promising results. However, MEK inhibitors do not work in all patients and have significant side effects. In addition, preliminary evidence suggests single agent use of MEK inhibitors for MPNST treatment will fail. Here, we describe the preclinical efforts that led to the identification of MEK inhibitors as promising therapeutics for the treatment of NF1-related neoplasia and possible reasons they lack single agent efficacy in the treatment of MPNSTs. In addition, we describe work to find targets other than MEK for treatment of MPNST. These have come from studies of RAS biochemistry, in vitro drug screening, forward genetic screens for Schwann cell tumors, and synthetic lethal screens in cells with oncogenic RAS gene mutations. Lastly, we discuss new approaches to exploit drug screening and synthetic lethality with NF1 loss of function mutations in human Schwann cells using CRISPR/Cas9 technology. [ABSTRACT FROM AUTHOR]