Browsing by Author "Zimmers, Teresa"
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Item Aging-associated skeletal muscle defects in HER2/Neu transgenic mammary tumor model(Wiley, 2021) Wang, Ruizhong; Kumar, Brijesh; Bhat-Nakshatri, Poornima; Prasad, Mayuri S.; Jacobsen, Max H.; Ovalle, Gabriela; Maguire, Calli; Sandusky, George; Trivedi, Trupti; Mohammad, Khalid S.; Guise, Theresa; Penthala, Narsimha R.; Crooks, Peter A.; Liu, Jianguo; Zimmers, Teresa; Nakshatri, Harikrishna; Surgery, School of MedicineBackground: Loss of skeletal muscle volume and resulting in functional limitations are poor prognostic markers in breast cancer patients. Several molecular defects in skeletal muscle including reduced MyoD levels and increased protein turn over due to enhanced proteosomal activity have been suggested as causes of skeletal muscle loss in cancer patients. However, it is unknown whether molecular defects in skeletal muscle are dependent on tumor etiology. Methods: We characterized functional and molecular defects of skeletal muscle in MMTV-Neu (Neu+) mice (n= 6-12), an animal model that represents HER2+ human breast cancer, and compared the results with well-characterized luminal B breast cancer model MMTV-PyMT (PyMT+). Functional studies such as grip strength, rotarod performance, and ex vivo muscle contraction were performed to measure the effects of cancer on skeletal muscle. Expression of muscle-enriched genes and microRNAs as well as circulating cytokines/chemokines were measured. Since NF-κB pathway plays a significant role in skeletal muscle defects, the ability of NF-κB inhibitor dimethylaminoparthenolide (DMAPT) to reverse skeletal muscle defects was examined. Results: Neu+ mice showed skeletal muscle defects similar to accelerated aging. Compared to age and sex-matched wild type mice, Neu+ tumor-bearing mice had lower grip strength (202±6.9 vs. 179±6.8 g grip force, p=0.0069) and impaired rotarod performance (108±12.1 vs. 30±3.9 seconds, P<0.0001), which was consistent with reduced muscle contractibility (p<0.0001). Skeletal muscle of Neu+ mice (n=6) contained lower levels of CD82+ (16.2±2.9 vs 9.0±1.6) and CD54+ (3.8±0.5 vs 2.4±0.4) muscle stem and progenitor cells (p<0.05), suggesting impaired capacity of muscle regeneration, which was accompanied by decreased MyoD, p53 and miR-486 expression in muscles (p<0.05). Unlike PyMT+ mice, which showed skeletal muscle mitochondrial defects including reduced mitochondria levels and Pgc1β, Neu+ mice displayed accelerated aging-associated changes including muscle fiber shrinkage and increased extracellular matrix deposition. Circulating "aging factor" and cachexia and fibromyalgia-associated chemokine Ccl11 was elevated in Neu+ mice (1439.56±514 vs. 1950±345 pg/ml, p<0.05). Treatment of Neu+ mice with DMAPT significantly restored grip strength (205±6 g force), rotarod performance (74±8.5 seconds), reversed molecular alterations associated with skeletal muscle aging, reduced circulating Ccl11 (1083.26 ±478 pg/ml), and improved animal survival. Conclusions: These results suggest that breast cancer subtype has a specific impact on the type of molecular and structure changes in skeletal muscle, which needs to be taken into consideration while designing therapies to reduce breast cancer-induced skeletal muscle loss and functional limitations.Item Deep Proteome Profiling in the Progression of Pancreatic Ductal Adenocarcinoma-Associated Cachexia(2021-09) Umberger, Tara; Mosley, Amber L.; Zimmers, Teresa; Goebl, Mark; Doud, EmmaCachexia is a devastating muscle wasting syndrome affecting multiple biochemical pathways and is a comorbidity of many diseases including pancreatic ductal adenocarcinoma (PDAC). PDAC patients with cachexia commonly experience systemic inflammation, progressive loss of lean muscle and adipose tissue, and cardiac dysfunction. The present workflow identifies proteins and their post-translational modifications extracted from both cardiac and skeletal muscle tissue isolated from a murine model of PDAC-associated cachexia. Reported here are differentially occurring post-translational modifications found on the most abundant contractile proteins. Tissue from mouse muscle samples were collected two weeks after either receiving a sham surgery or orthotopically implanted with PDAC tumor cells, with or without a follow-up chemotherapy treatment of the standard of care agent gemcitabine with nab-Paclitaxel. Whole tissue blocks of gastrocnemius or heart were either flash frozen and pulverized or homogenized in denaturing lysis buffer and then sonicated to facilitate protein extraction. After disulfide bond reduction, cysteine alkylation, and trypsin digestion, the resultant peptides were subjected to molecular barcoding using tandem mass tag isobaric labeling reagents to facilitate multiplexing. The first and second dimension of peptide separation in the multiplexed sample is accomplished with an offline, high pH, reverse phase (RP)-LC fractionation followed by an online RP-LC at lower pH. The use of high-field asymmetric-waveform ion mobility spectrometry provided a last dimension of separation before MSn analyses. This novel, proteomic workflow enables deep proteome profiling in the progression of cancer-induced cachexia. The use of multi-dimensional chromatographic separation and differential ion mobility technique have allowed us to identify almost 4,500 proteins groups of gastrocnemius muscle tissue and nearly 7,100 protein groups of myocardium taken from the murine PDAC model of pancreatic cancer. A comprehensive analysis of the data collected from this workflow was used to calculate differential post-translational modifications on major contractile proteins isolated from PDAC model muscle tissue, with or without chemotherapy, when compared to sham surgery controls. Differential post-translational modifications and protein expression changes found to contribute to cancer cachexia may elucidate novel molecular mechanisms and cellular signaling that drive cachexia progression.Item Hormonally Regulated Myogenic miR-486 Influences Sex-specific Differences in Cancer-induced Skeletal Muscle Defects(Endocrine Society, 2022-09-01) Wang, Ruizhong; Bhat-Nakshatri, Poornima; Zhong, Xiaoling; Zimmers, Teresa; Nakshatri, Harikrishna; Surgery, School of MedicineCancer-induced skeletal muscle defects show sex-specific differences in severity with men performing poorly compared to women. Hormones and sex chromosomal differences are suggested to mediate these differences, but the functional skeletal muscle markers to document these differences are unknown. We show that the myogenic microRNA miR-486 is a marker of sex-specific differences in cancer-induced skeletal muscle defects. Cancer-induced loss of circulating miR-486 was more severe in men with bladder, lung, and pancreatic cancers compared to women with the same cancer types. In a syngeneic model of pancreatic cancer, circulating and skeletal muscle loss of miR-486 was more severe in male mice compared to female mice. Estradiol (E2) and the clinically used selective estrogen receptor modulator toremifene increased miR-486 in undifferentiated and differentiated myoblast cell line C2C12 and E2-inducible expression correlated with direct binding of estrogen receptor alpha (ERα) to the regulatory region of the miR-486 gene. E2 and toremifene reduced the actions of cytokines such as myostatin, transforming growth factor β, and tumor necrosis factor α, which mediate cancer-induced skeletal muscle wasting. E2- and toremifene-treated C2C12 myoblast/myotube cells contained elevated levels of active protein kinase B (AKT) with a corresponding decrease in the levels of its negative regulator PTEN, which is a target of miR-486. We propose an ERα:E2-miR-486-AKT signaling axis, which reduces the deleterious effects of cancer-induced cytokines/chemokines on skeletal muscle mass and/or function.Item MiR-10a as a Modulator of Proliferation and Cell Cycle Progression in Ovarian Clear Cell Carcinoma(2024-08) Collins, Kaitlyn Elizabeth; Hawkins, Shannon; Kim, Jaeyeon; Mayo, Lindsey; Nephew, Kenneth; Zhang, Chi; Zimmers, TeresaEndometriosis, a benign inflammatory disease whereby endometrial-like tissue grows outside the uterus, is a significant risk factor for endometriosis-associated ovarian cancers. In particular, ovarian endometriomas, cystic lesions of deeply invasive endometriosis, are a potential precursor lesion for ovarian clear cell carcinoma (OCCC). To explore the transcriptomic landscape, OCCC from women with pathology-proven concurrent endometriosis (n=4) were compared to benign endometriomas (n=4) by bulk RNA and small-RNA sequencing. Analysis of protein-coding genes identified 2449 upregulated and 3131 downregulated protein-coding genes (DESeq2, P<0.05, log2 fold-change>|1|) in OCCC with concurrent endometriosis compared to endometriomas. Gene set enrichment analysis showed upregulation of cell cycle regulation and DNA replication pathways and downregulation in cytokine receptor signaling and matrisome pathways. Analysis of miRNAs revealed 64 upregulated and 61 downregulated mature miRNA molecules (DESeq2, P<0.05, log2 fold-change>|1|). Hsa-miR-10a-5p represented over 21% of the miRNA molecules in OCCC with endometriosis and was significantly upregulated (NGS: log2 fold change=4.37, P=2.43E-18; QPCR: 8.1-fold change, P<0.05). Correlation between miR-10a expression level in OCCC cell lines and IC50 (50% inhibitory concentration) of carboplatin in vitro revealed a positive correlation (R2=0.92). The cellular function of miR-10a was investigated by overexpressing miR-10a in vitro. MiR-10a overexpression revealed a significant decrease in proliferation (n=6; P< 0.05), compared to a non-targeting control. Cell-cycle analysis revealed a significant shift in cells from S and G2 to G1 in (n=6; P<0.0001). MiR-10a overexpression in vitro was correlated with decreased expression of predicted miR-10a target genes critical for proliferation, cell-cycle regulation, and cell survival [SERPINE1 (3.2 downregulated; P<0.05), CDK6 (2.4 downregulated; P<0.05) and, RAP2A (2-3 downregulated; P<0.05)].Item Sonic Hedgehog Signaling in Inner Ear Organoid Development(2019-08) Longworth-Mills, Emma; Hashino, Eri; Jones, Kathryn; Robling, Alexander; Zimmers, Teresa; Chen, JinhuiLoss of the finite cochlear hair cells of the inner ear results in sensorineural deafness. Human cochlear hair cells do not regenerate, and there is no cure for deafness. Our laboratory has established a three-dimensional culture system for deriving functional sensory hair cells from human pluripotent stem cells. A major limitation of this approach is that derived hair cells exhibit a morphological and gene expression phenotype reflective of native vestibular hair cells. Previous studies have shown that establishment of localized domains of gene expression along the dorso-ventral axis of the developing otic vesicle is necessary for proper morphogenesis of both auditory and vestibular inner ear structures. Sonic hedgehog (SHH) signaling has been shown to play a key role in specification of the ventral otic vesicle and subsequent cochlear development. Here, SHH treatment was pursued as a potential strategy for inducing a patterning phenotype permissive to cochlear induction in vitro. Single-cell RNAsequencing analysis revealed that while treatment with the SHH pathway agonist Purmorphamine reduced expression of markers for the vestibular-yielding dorsal otic vesicle, upregulation of ventral otic marker genes was modest. More strikingly, the number of otic progenitors exhibiting a neuroprogenitor phenotype increased in response to Purmorphamine treatment. These results suggest that SHH pathway modulation in early-stage inner ear organoids may bias their differentiation toward a neural lineage at the expense of an epithelial lineage. The present study is the first to evaluate the patterning phenotype of human stem cell derived otic progenitors, and sheds light on the transcriptomic profile at this critical point of inner ear development. This study may also cultivate future efforts to derive cochlear cell types as well as inner ear neural cell types from human pluripotent stem cells, and contribute to the establishment of a more complete in vitro model of inner ear development.