Phenotypic characterization of primary non-nodular and nodular lymphangeioleiomyomatosis (LAM) cells
Authors: Lohana Sahil , Tesch Jacob , Kumar Ashish , Balraj Premanand , Sathish Venkatachalem 
Published: May 2023

Background: Lymphangioleiomyomatosis (LAM) is a rare lung disease that predominantly develops in women between the ages of 20–40 years. The main characteristics of LAM are metastatic spread and infiltration of tissues by proliferative, abnormal smooth muscle- like cells (nodular LAM cells); Nodular LAM cells originate from a distal tissue and are phenotypically different than the normal airway smooth muscle-like cells (non-nodular LAM cells). This continued abnormal growth leads to cystic structures that result in progressive dyspnea, increased risk of respiratory infections, and potentially death by respiratory failure. In this context, we aimed to address the phenotypic and functional differences between the patient-derived primary non-nodular and nodular LAM cells using morphological and molecular analysis. We hypothesize that in vitro nodular LAM cells possess diseased phenotype and show differential phenotypic characteristic features compared to non-nodular LAM cells. Methods: LAM lung tissues samples were obtained through National Disease Research Interchange (NDRI) exchange program. Lung samples were collected from LAM patients who underwent surgical dissection to separate cystic excrements and used to isolate LAM cells (papain digestion method). Isolated human nodular and non-nodular LAM cells from the obtained lung tissues were plated onto 100 mm plates grown to 70% confluence in a 5% CO2 humidified incubator. The change in expression pattern of LAM-specific phenotypic marker Glycoprotein 100 (GP-100) was evaluated by standard Western and qRT-PCR analysis. Further, proliferation of nodular and non-nodular LAM cells were evaluated by MTT assay and Lion heart Fx Cell count (LFx) assay. Finally, Western and qRT-PCR analysis were used to evaluate the changes in expression pattern of proliferative markers: PCNA, Cyclin D1 and Cyclin E. Results: We observed significantly higher expression of GP100 in nodular LAM cells compared to non-nodular LAM cells. Further, nodular LAM cells show significantly increased proliferation compared to non-nodular LAM cells. This was supported by both mRNA and protein expression of increased proliferative markers (PCNA, Cyclin D1 and Cyclin E) in nodular LAM cells compared to non-nodular LAM cells. Conclusion: The phenotypic marker proteinGP-100 confirm the identity of LAM phenotype in isolated nodular cells. This was further supported by increased proliferation rate and proliferative markers. Overall, our data suggests differential phenotypic characteristic features of nodular LAM cells compared to non-nodular LAM cells in vitro. This program is supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103442 (Sahil Lohana) and partially funded by NIH Grant R01 HL146705 (Dr. Sathish). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.