Prakash, Y. S.

Intracellular Ca 2+ ([Ca 2+ ] i ) levels are increased in inflamed airway smooth muscle (ASM). Sarcoplasmic reticulum (SR) Ca 2+ release and reuptake are key components of ASM [Ca 2+ ] i regulation. Ca 2+ reuptake occurs via the ATPase SERCA. We hypothesized that inflammation disrupts SERCA function, contributing to increased [Ca 2+ ] i . We examined SERCA expression and regulation in human ASM exposed to pro‐inflammatory cytokines TNFα and IL‐13. Western blot analysis showed significantly decreased SERCA expression following overnight cytokine exposure. In other tissues, SERCA is regulated by the inhibitory protein phospholamban (PLB). We found that human ASM does not express PLB protein (although mRNA is detectable). Cytokine exposure did not induce PLB expression, raising the issue of how SERCA is regulated. We then found that direct SERCA phosphorylation (potentially via CaMKII) occurs in human ASM. In fura‐2 loaded human ASM cells, we examined [Ca 2+ ] i responses to ACh or bradykinin (zero extracellular Ca 2+ ) and found significant reduction in rates of fall of [Ca 2+ ] i transients in cells exposed to TNF‐α or IL‐13. We further found that CaMKII antagonist KN‐93 significantly slowed the fall of [Ca 2+ ] i transients in both controls and cytokine‐exposed human ASM cells. These data suggest that a) SERCA in human ASM is regulated by mechanisms such as CaMKII; and b) airway inflammation decreases SR refilling by blunting SERCA expression and function. Supported by NIH grants HL74309, the Flight Attendants Medical Research Institute (FAMRI), and the Department of Anesthesiology, Mayo Clinic.

Background Uterine leiomyomas, also known as fibroids (UF), are benign neoplasms of the uterus. UF consist of smooth muscle cells and fibroblasts, and display enriched extracellular matrix (ECM). Reports estimate a cumulative incidence of 70% in premenopausal women, with annual total health care costs attributed to UF exceeding 34 billion dollars in the United States alone. In spite of their prevalence, the underlying processes that drive UF development and growth are still poorly understood. Accumulating evidence implicates the canonical Hippo signaling pathway effectors Yes‐associated protein (YAP)/transcriptional coactivator with PDZ‐binding domain (TAZ) as key drivers of fibroblast biology. Thus, we seek to assess the differences in YAP/TAZ localization, ECM deposition, and gene expression between UF and normal myometrium (Myo). Methods Matched samples of UF and Myo were obtained from premenopausal women with IRB approval. Immunohistochemistry (N=5) was performed on OCT embedded tissue with YAP/TAZ antibody. For cell culture, UF and Myo were minced and digested with collagenase type 4. Cells (passages 1–4) were plated on plastic at confluence (N=4 for both). Immunostaining for YAP/TAZ, Fibronectin (FN), Collagen Type I (COL1), and Collagen Type III (COL3) were performed (N=4–5). Transcript levels were analyzed by treating cells with control or YAP/TAZ siRNA, and performing subsequent cDNA synthesis and qPCR reactions (N=4). Kruskall‐Wallis and Mann Whitney tests were used as appropriate. Results YAP/TAZ nuclear localization was upregulated in UF when compared to Myo tissue by immunofluorescence imaging. In freshly isolated cells cultured at confluence on tissue culture plastic, baseline YAP/TAZ nuclear localization was increased in UF when compared to Myo (p=0.03). UFs also exhibited a trend toward increased FN, COL1, and COL3 deposition when compared to Myo. UF displayed increased transcript levels for several matrix and pro‐fibrotic signaling genes (COL1A1, COL3A1, CTGF, EDN1, FN1) compared to the matched Myo. Following siRNA treatment for YAP/TAZ gene expression was reduced 40% and 50% for EDN1 (encoding endothelin‐1), as well as 70% and 65% for CTGF (encoding connective tissue growth factor), in UF and Myo respectively. Conclusions UF nuclear YAP/TAZ is increased at baseline in vivo as well as in vitro . UF also display upregulated deposition of the ECM proteins. Additionally, there are increased transcript levels of profibrotic genes in UF compared to Myo. Moreover, the observed decreases in gene expression following siRNA knockdown of YAP/TAZ suggests a role for the Hippo signaling pathway in regulation of certain profibrotic genes in UF. Together these results suggest that enhanced baseline YAP/TAZ localization in UF may drive upregulated expression of pro‐fibrotic genes promoting UF progression. Support or Funding Information Center for Biomedical Discovery‐Department of Obstetrics and Gynecology Team Science Pilot Award Program This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Introduction: Children with low Vitamin D levels are at increased risk of developing asthma. In the present study, we tested the hypothesis that the Vitamin D receptor (VDR) agonist, calcitriol, will reduce tumor necrosis factor‐α (TNF‐α)‐induced expression of chemokines in human fetal airway smooth muscle cells (fASM). Methods and Results Human fASM cells were dissociated from canalicular stage (18‐22 weeks gestation) lung tissue (de‐identified samples, in vitro use only and considered exempt by Mayo Institutional Review Board). Fetal ASM cells were pre‐treated with vehicle (0.001% DMSO) or 100 nM calcitriol for 1 h, and then exposed to 10 ng/mL TNFα for 6 or 24 h. Expression of CCL5 and CCL11 were measured by quantitative real time PCR and ELISA. Cells were transfected with VDR siRNA. Treatment with TNFα for 6 h increased mRNA expression and secretion of CCL5 and CCL11. While pre‐treatment with calcitriol reduced CCL5 and CCL11 expression in the presence of TNFα. Knockdown of the VDR expression demonstrated that calcitriol's effects are mediated through VDR. Conclusions These novel data demonstrate that calcitriol modulates cytokine enhancement of chemokines in developing ASM. Vitamin D may be a new therapeutic target in reducing inflammation in the immature airway. Supported by NIH F32 HL123075 (Britt), T32 HL105355 (Vogel), and R01s HL088029 and HL056470 (Prakash), and the Mayo Clinic Department of Anesthesiology (Pabelick, Prakash).

Background Uterine leiomyomas (fibroids; UF) are benign myometrial neoplasms that produce clinically‐relevant symptoms in >25% of all women including excessive menstrual bleeding and infertility, and represent the leading cause of hysterectomy (~600,000/year in the US). Despite their importance, the mechanisms that promote UF growth are still not well‐understood. UFs are comprised of smooth muscle cells and fibroblasts with substantial extracellular matrix (ECM). While cells within UFs produce ECM, the role of ECM per se in modulating cell properties towards overall tumor growth is not known. This study tests the hypothesis that UF cells are mechanically sensitive, and that the ECM provides a positive feedback mechanism which further promotes UF growth. Methods Cells were enzymatically isolated from UFs of patients undergoing myomectomy at Mayo Clinic Rochester (IRB approved). Fibroid cells were plated onto soft (0.2kPa) vs. stiff (64kPa) polydimethylsiloxane (PDMS) elastomer substrates or standard tissue culture plastic substrates (~100GPa) for 24 h in DMEM containing 10% FBS prior to RNA isolation and qPCR analysis. Transcript levels for known ECM and profibrotic genes were determined. Nuclear localization of YAP and TAZ was visualized using immunofluorescence and quantified using a Cytation5 imaging system. Separately, 2‐color fluorescence immunohistochemistry for YAP and TAZ was performed on formalin fixed; paraffin embedded normal myometrium and fibroid tissue sections. Transciption level and nuclear localization calculations were performed with Kruskall‐Wallis and Wilcoxon Sign‐Rank tests, respectively. Results Significant increases in transcripts for ECM gene Collagen 1 ( COL1A1 ) were noted for UF cells plated on stiff PDMS and standard plastic compared to soft PDMS. The pro‐fibrotic genes Connective Tissue Growth Factor ( CTGF ), alpha smooth muscle actin ( ACTA2 ), Endothelin 1 ( EDN1 ), and plasminogen activator inhibitor 1 ( SERPINE1 ) were progressively increased in expression going from soft PDMS substrate to plastic. The anti‐fibrotic gene, cyclooxygenase 2 ( PTGS2 ) was decreased on stiff PDMS and plastic compared to soft PDMS. In cells plated on plastic, there was a significant decrease in YAP/TAZ nuclear localization in cells treated with the Rho‐kinase inhibitor Y‐27632, consistent with a mechanobiologic feedback. Immunohistochemistry showed a two‐fold increase in YAP/TAZ nuclear localization for fibroid tissue compared to normal myometrium. Conclusions Based on the growing appreciation that ECM mechanical properties contribute to UF pathobiology and fibrotic matrix deposition, we show enhanced ECM and profibrotic gene expression by fibroid cells as a function of substrate stiffness. These results demonstrate a feedback mechanism by which UFs progress through matrix stiffness‐mediated ECM deposition. Here, the mechanosensitive pathways of YAP and TAZ may be involved in transducing ECM signals to UF growth. Support or Funding Information None This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Purpose Bronchial asthma is a chronic inflammation of the airways that is characterized by airway remodeling, hyperactive responsiveness and acute bronchoconstriction of airway smooth muscle (ASM) cells. Clinical findings suggest that there is a higher incidence of asthma in pre‐menopausal women and aging men, strongly indicating the role of sex steroids in modulating the airway tone. A major sex steroid, estrogen mediates its role through estrogen receptors (ER) ‐ ERα and ERβ. Our recent study demonstrated that these receptors are expressed in both male and female ASM cells and their expression is upregulated in the presence of inflammation/asthma. However, the role of ER signaling in asthma or genomic mechanisms in intracellular Ca 2+ ([Ca 2+ ] i ) regulation in human ASM are unknown. In this study, we evaluated the genomic effect of specific ERα and ERβ modulators on the [Ca 2+ ] i in human ASM cells. Methods Human ASM cells were enzymatically dissociated from tissue obtained incidental to lung surgery from Mayo Clinic (IRB approved). Cells were plated onto 8‐well Lab‐Tek plates and grown to 70% confluence in a 5% CO 2 humidified incubator. Cells were exposed to pro‐inflammatory cytokines TNFα (20ng/ml) or IL‐13 (50ng/ml) in the presence and absence of 1nM 17β‐estradiol (E 2 ), 10nM PPT (ERα agonist) or WAY (ERβ agonist) for 24h. Cells were washed with HBSS and incubated with 3 μm Fluo‐3 for 1h for calcium imaging. The [Ca 2+ ] i levels are measured from the intensity change observed following exposure to 10μM histamine under both physiological (2 mM) and zero extracellular calcium using Biotek LFX Fluorescence Imager. Results In fluo‐3 loaded ASM cells, 24h exposure to WAY (and to a lesser extent PPT and E 2 ) was effective in reducing [Ca 2+ ] i levels. TNFα and IL‐13 significantly increased [Ca 2+ ] i compared to vehicle. In the presence of TNFα or IL‐13, WAY significantly reduced [Ca 2+ ] i in ASM cells, while PPT did not draw out any notable changes compared to TNFα or IL‐13 treatment alone. Addition of nifedipine (1μM, L‐type calcium channel blocker) resulted in a ~40% decrease in [Ca 2+ ] i compared to control. This nifedipine blunting effect was similar in PPT treated group and to a higher extend to the WAY on [Ca 2+ ] i responses to histamine, suggesting that ER effects were mediated via L‐type calcium channels. To verify the ER effect on sarcoplasmic reticulum (SR) Ca 2+ reuptake, extracellular Ca 2+ was removed by perfusion with zero Ca 2+ HBSS, and Ca 2+ influx was non‐specifically blocked with 1 mM LaCl 3. Under these conditions, the [Ca 2+ ] i responses were significantly reduced in the presence of WAY. Further, we examined effects of ER signaling on [Ca 2+ ] i sequestration to SR (SERCA activity). In both control ASM cells as well as in those exposed to cytokines, WAY increased the rate of fall of [Ca 2+ ] i responses to histamine, suggesting greater sequestration of [Ca 2+ ] i. Conclusions Overall, our data highlights that both ERα and ERβ specific agonist were able to reduce [Ca 2+ ] i in the inflamed ASM via receptor‐mediated genomic action. Specifically, ERβ activation is more effective in the presence of inflammation. Support or Funding Information Supported by NIH grants R01 HL123494 and R01 HL123494‐02S1 (Venkatachalem) This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background Uterine leiomyomas (fibroids) are benign smooth muscle cell tumors of the uterus that affect a large percentage of reproductive aged women, contribute to infertility, excessive menstrual bleeding, and represent the leading cause of hysterectomy (~70%). Despite their importance, the mechanisms that promote fibroid growth are still not well‐understood. Fibroids are comprised of smooth muscle cells (SMCs) and fibroblasts and their growth is modulated by hormones including estrogen and progesterone. Intracellular calcium [Ca 2+ ] i signaling is a key aspect of SMC physiology in promoting contractility, cell proliferation, and fibrosis: aspects relevant to fibroid biology. While [Ca 2+ ] i regulation in normal myometrium is well characterized, this has not been explored in fibroids. The goal of this study was to explore [Ca 2+ ] i regulation in fibroid SMCs and the effect of sex steroids towards obtaining insights into tumor progression. Methods Cells were enzymatically isolated from normal myometrium and select fibroids of different sizes from patients undergoing myomectomy at Mayo Clinic, Rochester, MN (IRB approved). [Ca 2+ ] i was measured using fura‐2/AM and real‐time fluorescence microscopy. The contribution of Ca 2+ influx vs. intracellular pathways in the responses to 1uM oxytocin were assessed using pharmacological inhibitors/activators. Cells were pretreated with vehicle, 1nM estrogen, or 1nM progesterone to assess the effect of sex steroids. Results Fibroid‐derived cells showed a greater contribution of Ca 2+ influx pathways in their responses to oxytocin than normal myometrium. Here, the Ca 2+ ‐activated chloride channel TMEM16A (Ano1) was found to be contributory, with Western analysis showing higher levels of Ano1 in fibroids. Exposure to estrogen resulted in significantly higher [Ca 2+ ] i responses compared to cells treated with vehicle or progesterone, although progesterone did enhance [Ca 2+ ] i responses as well. Estrogen increased Ano1 expression. Cell proliferation was also increased in fibroid cells. Conclusions Exposure to estrogen and progesterone enhances oxytocin induced [Ca 2+ ] i responses of fibroid‐derived cells, potentially via increased TMEM16A (Ano1). Such increases may further contribute to the observed hormone‐induced enhancement of fibroid cell proliferation. Menstrual cycle fluctuations in reproductive aged women may thus contribute to the progression of fibroids. Greater understanding of calcium signaling pathways such as Ano1 in fibroid tissue may allow for novel therapeutic targets in uterine leiomyomas. Support or Funding Information Supported by NIH grants R25 GMO75148 (JLR), R01 HL088029 (YSP), and R01 HL56470 (YSP). This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Intracellular Ca 2+ regulation in human airway smooth muscle (hASM) involves plasma membrane (PM) Ca 2+ influx, including that triggered by sarcoplasmic reticulum (SR) Ca 2+ depletion, i.e. store‐operated Ca 2+ entry (SOCE). While transient receptor potential channels (e.g. TRPC3, TRPC4) are thought to mediate SOCE, the mechanisms triggering or regulating SOCE are being actively investigated. Recent studies suggest that stromal interaction molecule 1 (STIM1) acts as a signaling mediator between PM and SR, potentially regulating Ca 2+ entry via SOCE. In hASM, fluorescence microscopy and western blot analyses were used to verify the presence of STIM1. SR Ca 2+ depletion with 10μM cyclopiazonic acid (CPA) resulted in increased STIM1 expression in the PM fraction, compared to controls. Transfection with 50nM STIM1 siRNA for 48h significantly decreased STIM1 levels. In cells where [Ca 2+ ] i was measured using fura 2‐AM, SOCE was significantly reduced in cells transfected with STIM1 siRNA. Green‐fluorescent protein (GFP)‐tagged STIM1 transfection showed intracellular localization in non‐stimulated cells, with increased PM staining following CPA exposure. Subsequent immunostaining revealed co‐localization of STIM1 with TRPC3 and TRPC4. These results indicate that STIM1 is present in hASM and suggest a role for this protein in regulating SOCE. This work has been supported by NIH grants UL1RR024150‐01(CR to CMP, CR20 and Early Career Development Award to YSP), HL74309 (GCS), and the Department of Anesthesiology (CMP, YSP), Mayo Clinic College of Medicine, Rochester, MN

Acute administration of estrogen induces vasodilation in several vascular beds including coronary artery smooth muscle (CSM). We tested the hypothesis that the response of CSM to estrogen is mediated via the binding of estrogen to estrogen receptors (ER) and that the response will be influenced by hormonal status. Coronary smooth muscle was prepared from gonadally intact (INT) and. ovariectomized (OVX) female pigs. Immunocytochemistry and receptor binding assays were performed to confirm presence vs. absence of ER. In INT CSM cells, but not OVX CSM, acute administration of 17β‐estradiol resulted in a concentration‐dependent decrease in [Ca 2+ ] i responses to endothelin‐1. [Ca 2+ ] i responses to 17β‐estradiol were comparable between groups. The effect of 17β‐estradiol was inhibited by the ER antagonist ICI 182,780. 17β‐estradiol decreased [Ca 2+ ] i in INT (but not OVX) CSM cells when sarcoplasmic reticulum (SR) Ca 2+ reuptake was inhibited, but to a lesser extent than when extracellular Ca 2+ was present. This effect was abolished by extracellular lanthanum. These data suggest that 17β‐estradiol modulates [Ca 2+ ] i in CSM via a likely non‐genomic and necessary ER signaling cascade that mediates both plasma membrane Ca 2+ influx and efflux, but does not involve SR Ca 2+ release. Supported by NIH grants UL1RR024150‐01(Mayo Clinic CTSA awards to YSP & CMP) and HL74309 (GCS)

Neurotrophins (NTs), which play an integral role in directing proper neuronal development and function, have been found in non‐neuronal tissue (including lung), but their role is still under investigation. We previously found NTs such as brain‐derived neurotrophic factor (BDNF) and neurotrophin‐3 (NT3) and their receptors to be expressed in human airway smooth muscle (ASM). In this study, we hypothesized that NTs contribute to regulation of ASM function via regulation of mechanisms that control intracellular Ca 2+ ([Ca 2+ ] i ). Human ASM cells isolated from lung samples incidental to patient surgery were incubated for 24 or 48 h in medium (control), 10 nM BDNF or NT3 in the presence or absence of inhibitors of signaling pathways such as MAP kinases (PD98059), PI3/Akt (Wortmannin) and NFκB (SN50). In fluo‐4 loaded cells, [Ca 2+ ] i responses to ACh and histamine were significantly higher following BDNF and NT3 exposure: effects that were blunted by SN50 and PD98059, but not Wortmannin. Western analysis of cell lysates showed higher expressions of Ca 2+ regulatory proteins such as Orai1, TRPC3, and SERCA with 1 or 10nM BDNF exposure, but decreased expression by NT3. These data show that NTs activate signaling pathways in human ASM that lead to enhanced [Ca 2+ ] i responses, and could thus contribute to airway hyperresponsiveness. Supported by NIH grants HL088029, HL090595 and FAMRI.