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1. Neurofibromin haploinsufficiency results in altered spermatogenesis in a mouse model of neurofibromatosis type 1.

Author

Harleen Chohan, Mitra Esfandiarei, Darian Arman, Catherine D Van Raamsdonk, Cornelis van Breemen, Jan M Friedman, and Kimberly A Jett

Subjects
Medicine, Science
Abstract

The fertility of men with neurofibromatosis 1 (NF1) is reduced. Despite this observation, gonadal function has not been examined in patients with NF1. In order to assess the role of reduced neurofibromin in the testes, we examined testicular morphology and function in an Nf1+/- mouse model. We found that although Nf1+/- male mice are able to reproduce, they have significantly fewer pups per litter than Nf1+/+ control males. Reduced fertility in Nf1+/- male mice is associated with disorganization of the seminiferous epithelium, with exfoliation of germ cells and immature spermatids into the tubule lumen. Morphometric analysis shows that these alterations are associated with decreased Leydig cell numbers and increased spermatid cell numbers. We hypothesized that hyper-activation of Ras in Nf1+/- males affects ectoplasmic specialization, a Sertoli-spermatid adherens junction involved in spermiation. Consistent with this idea, we found increased expression of phosphorylated ERK, a downstream effector of Ras that has been shown to alter ectoplasmic specialization, in Nf1+/- males in comparison to control Nf1+/+ littermates. These data demonstrate that neurofibromin haploinsufficiency impairs spermatogenesis and fertility in a mouse model of NF1.

Published
2018
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2. Neurofibromin haploinsufficiency results in altered spermatogenesis in a mouse model of neurofibromatosis type 1

Author

Catherine D. Van Raamsdonk, Harleen Chohan, Mitra Esfandiarei, Cornelis van Breemen, Jan M. Friedman, Darian Arman, and Kimberly Jett

Subjects
Male, 0301 basic medicine, Physiology, Haploinsufficiency, Epithelium, Mice, Animal Cells, Reproductive Physiology, Medicine and Health Sciences, Cell Cycle and Cell Division, Testes, Extracellular Signal-Regulated MAP Kinases, Neurofibromin 1, Multidisciplinary, biology, Leydig cell, Chromosome Biology, Animal Models, Seminiferous Tubules, Spermatids, Meiosis, Seminiferous Epithelium, medicine.anatomical_structure, Experimental Organism Systems, Cell Processes, Genetic Diseases, Medicine, Cellular Types, Anatomy, Genital Anatomy, Research Article, endocrine system, congenital, hereditary, and neonatal diseases and abnormalities, Neurofibromatosis 1, Science, Mouse Models, Research and Analysis Methods, Andrology, Adherens junction, 03 medical and health sciences, Model Organisms, medicine, Animals, Humans, Neurofibromatosis, Spermatogenesis, neoplasms, Clinical Genetics, Spermatid, Autosomal Dominant Diseases, Reproductive System, Biology and Life Sciences, Cell Biology, medicine.disease, Mice, Mutant Strains, Sperm, eye diseases, nervous system diseases, Disease Models, Animal, Fertility, Germ Cells, Biological Tissue, 030104 developmental biology, ras Proteins, Animal Studies, biology.protein, Neurofibromatosis Type 1
Abstract

The fertility of men with neurofibromatosis 1 (NF1) is reduced. Despite this observation, gonadal function has not been examined in patients with NF1. In order to assess the role of reduced neurofibromin in the testes, we examined testicular morphology and function in an Nf1+/- mouse model. We found that although Nf1+/- male mice are able to reproduce, they have significantly fewer pups per litter than Nf1+/+ control males. Reduced fertility in Nf1+/- male mice is associated with disorganization of the seminiferous epithelium, with exfoliation of germ cells and immature spermatids into the tubule lumen. Morphometric analysis shows that these alterations are associated with decreased Leydig cell numbers and increased spermatid cell numbers. We hypothesized that hyper-activation of Ras in Nf1+/- males affects ectoplasmic specialization, a Sertoli-spermatid adherens junction involved in spermiation. Consistent with this idea, we found increased expression of phosphorylated ERK, a downstream effector of Ras that has been shown to alter ectoplasmic specialization, in Nf1+/- males in comparison to control Nf1+/+ littermates. These data demonstrate that neurofibromin haploinsufficiency impairs spermatogenesis and fertility in a mouse model of NF1.

Published
2018

3. Dysfunctions of the Abdominal Aorta and Renal Arteries in a Mouse Model of Neurofibromatosis Type 1

Author

Harleen Chohan, Mitra Esfandiarei, Jan M. Friedman, Jason Z. Cui, Cornelis van Breemen, and Kimberly Jett

Subjects
congenital, hereditary, and neonatal diseases and abnormalities, business.industry, Abdominal aorta, Ischemia, Nerve sheath, Anatomy, medicine.disease, Biochemistry, medicine.artery, Genetics, medicine, Neurofibromatosis, business, Molecular Biology, Biotechnology
Abstract

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder presented with multiple cafe-au-lait spots, Lisch nodules,multiple nerve sheath tumors, and cardiovascular complications such as ischemia...

Published
2015

4. Impairment of Vascular Function in a Mouse Model of Neurofibromatosis Type 1

Author

Jason Z. Cui, Mitra Esfandiarei, Harleen Chohan, Jan M. Friedman, Cornelis van Breemen, Arash Y. Tehrani, and Kimberly Jett

Subjects
congenital, hereditary, and neonatal diseases and abnormalities, Pathology, medicine.medical_specialty, business.industry, Nerve sheath, medicine.disease, Biochemistry, medicine.anatomical_structure, Genetics, Medicine, Neurofibromatosis, Iris (anatomy), business, Vascular function, Molecular Biology, Biotechnology
Abstract

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder, characterized by multiple cafe-au-lait spots, iris harmartomas, multiple nerve sheath tumors. Patients also present with heart and cereb...

Published
2015

5. Quantitative associations of scalp and body subcutaneous neurofibromas with internal plexiform tumors in neurofibromatosis 1

Author

Lan Kluwe, Rosa Nguyen, Said Farschtschi, Jan M. Friedman, Victor F. Mautner, Patricia Birch, Darian Arman, Harleen Chohan, Kimberly Jett, and Carsten Fuensterer

Subjects
medicine.medical_specialty, Neurofibromatosis 1, Skin Neoplasms, Subcutaneous Tissue, Plexiform neurofibroma, Genetics, medicine, Odds Ratio, Neurofibroma, Humans, In patient, Whole Body Imaging, Neurofibromatosis, Genetics (clinical), Neurofibroma, Plexiform, Scalp, medicine.diagnostic_test, business.industry, Magnetic resonance imaging, Odds ratio, medicine.disease, Tumor Burden, medicine.anatomical_structure, Radiology, business, Subcutaneous neurofibroma
Abstract

Internal plexiform neurofibromas are a major cause of adverse outcomes in patients with neurofibromatosis 1 (NF1). We investigated the relationship of the numbers of subcutaneous neurofibromas of the scalp or body to internal plexiform tumor volume in 120 NF1 patients who had undergone whole body magnetic resonance imaging (MRI). We identified internal plexiform neurofibromas in 55% of patients, subcutaneous neurofibromas of the body in 75%, and subcutaneous neurofibromas of the scalp in 45%. The number of subcutaneous neurofibromas of the body and scalp were associated with each other (Spearman's Rho = 0.36; P

Published
2014

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