+publisher:"University of Toledo Health Science Campus" +contributor:("Giovannucci, David")

University of Toledo Health Science Campus

1. Goswamee, Priyodarshan. The Role of Orai-Mediated Ca²⁺ Entry in Migration in a Gastroenteropancreatic Neuroendocrine Tumor Model.

Degree: PhD, Biomedical Sciences (Neurosciences and Neurological Disorders), 2015, University of Toledo Health Science Campus

URL: http://rave.ohiolink.edu/etdc/view?acc_num=mco1438280470

► Gastroenteropancreatic neuroendocrine tumors (GEPNETs) of the midgut are a heterogeneous group of cancers that typically remain asymptomatic until they metastasize to the liver. However, the… (more)

▼ Gastroenteropancreatic neuroendocrine tumors (GEPNETs) of the midgut are a heterogeneous group of cancers that typically remain asymptomatic until they metastasize to the liver. However, the mechanism by which these usually indolent neoplasms establish distal metastasis remains unclear. The results presented in this dissertation support the hypothesis that arachidonic acid-induced Ca²⁺ entry through an Orai3-containing channel enhances GEPNET cell migration and contribute to tumor cell extravasation through the hepatic microvasculature. Using a novel liver slice preparation in combination with ultrastructure analysis, we demonstrated that a subpopulation of BON cells, a well-characterized GEPNET cell line, opportunistically migrated through the discontinuous sinusoidal endothelium and redistributed into the liver parenchyma within 24 hours following their introduction to the sinusoids. In a parallel set of studies, we identified a novel Ca²⁺ entry pathway through an Orai-containing channel that enhanced the migratory capacity of a subpopulation of these tumor cells. Orai-containing channels are known to underlie Ca²⁺ entry in response to both store-depletion and activation by arachidonic acid (AA) or its metabolites. In recent years, the store-operated Ca²⁺ entry (SOCE) has been implicated in the migration of some cancer cell lines. However, the role of AA-induced Ca²⁺ entry in cancer cell migration has not been adequately assessed. We investigated the involvement of AA-induced Ca²⁺ entry in migration in BON cells using live cell fluorescence imaging and standard migration assays in combination with pharmacological and gene knockdown methods. We showed that both SOCE and AA-induced Ca²⁺ entry modes could be selectively activated and inhibited. Administration of AA resulted in Ca²⁺ entry that was pharmacologically distinct from SOCE. Moreover, whereas homomeric Orai1-containing channels appeared to largely underlie SOCE, the AA-activated Ca²⁺ channel required expression of Orai3 as well as, Orai1. Furthermore, we showed that treatment with AA enhanced migration of BON cells and that this enhancement could be abrogated by selective inhibition of the AA-induced Ca²⁺ entry, whereas activation of SOCE did not enhance migration. In addition, the AA-induced Ca²⁺ entry and SOCE appeared to be reciprocally repressive suggesting the possibility that the balance between these two pathways sets the migratory potential of these tumor cells.Taken together, we identified Ca²⁺ entry through the Orai3-containing channel as a novel signal for BON cell migration that may be exploited to develop therapies to limit recurring GEPNET metastasis. Advisors/Committee Members: Giovannucci, David (Committee Chair).

Subjects/Keywords: Biomedical Research; Calcium signaling; Orai1; Orai3; Arachidonate induced Calcium entry; Store operated Calcium entry; Tumor extravasation; Liver metastasis; Carcinoids; Gastroenteropancreatic neuroendocrine tumors

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Goswamee, P. (2015). The Role of Orai-Mediated Ca²⁺ Entry in Migration in a Gastroenteropancreatic Neuroendocrine Tumor Model. (Doctoral Dissertation). University of Toledo Health Science Campus. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=mco1438280470

Chicago Manual of Style (16^th Edition):

Goswamee, Priyodarshan. “The Role of Orai-Mediated Ca²⁺ Entry in Migration in a Gastroenteropancreatic Neuroendocrine Tumor Model.” 2015. Doctoral Dissertation, University of Toledo Health Science Campus. Accessed March 05, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=mco1438280470.

MLA Handbook (7^th Edition):

Goswamee, Priyodarshan. “The Role of Orai-Mediated Ca²⁺ Entry in Migration in a Gastroenteropancreatic Neuroendocrine Tumor Model.” 2015. Web. 05 Mar 2021.

Vancouver:

Goswamee P. The Role of Orai-Mediated Ca²⁺ Entry in Migration in a Gastroenteropancreatic Neuroendocrine Tumor Model. [Internet] [Doctoral dissertation]. University of Toledo Health Science Campus; 2015. [cited 2021 Mar 05]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1438280470.

Council of Science Editors:

Goswamee P. The Role of Orai-Mediated Ca²⁺ Entry in Migration in a Gastroenteropancreatic Neuroendocrine Tumor Model. [Doctoral Dissertation]. University of Toledo Health Science Campus; 2015. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1438280470

2. Bhattacharya, Sumit. Contribution of Purinergic Receptors to Calcium Signaling in Salivary Gland.

Degree: PhD, College of Medicine, 2012, University of Toledo Health Science Campus

URL: http://rave.ohiolink.edu/etdc/view?acc_num=mco1353370433

► There is emerging consensus that P2X4 and P2X7 ionotropic purinoceptors (P2X4R and P2X7R) are critical players in regulating [Ca2+]i dynamics and fluid secretion in the… (more)

▼ There is emerging consensus that P2X4 and P2X7 ionotropic purinoceptors (P2X4R and P2X7R) are critical players in regulating [Ca2+]i dynamics and fluid secretion in the salivary gland. In contrast, details regarding their compartmentalization and selective activation, contributions to the spatiotemporal properties of intracellular signals and roles in regulating protein exocytosis and ion channel activity have remained largely undefined. Moreover, information regarding modulation of P2X class of receptors by cAMP, the major purinergic cell signaling pathway for protein secretion has been limited. To address these gaps in our understanding, we profiled mouse parotid acinar cells using live-cell imaging to follow the spatial and temporal features of ATP-evoked Ca2+ dynamics and exocytotic activity. Selective activation of P2X7Rs revealed an apical-to-basal [Ca2+]i signal that initiated at the sub-luminal border and propagated with a wave speed estimated at 17.3 ± 4.3 μm/s (n = 6). The evoked Ca2+ spike consisted of Ca2+ influx and Ca2+-induced Ca2+ release from intracellular Ca2+ channels. In contrast, selective activation of P2X4Rs induced a Ca2+ signal that initiated basally and propagated toward the lumen with a wave speed of 4.3 ± 0.2 μm/s (n = 8) that was largely independent of intracellular Ca2+ channel blockade. Consistent with these observations, P2X7R expression was enriched in the sub-luminal regions of acinar cells while P2X4R appeared localized to basal areas. We also predict that P2X7R enriching the apical regions of acinar cells are activated by luminal ATP. We also showed that P2X4R and P2X7R activation evokes exocytosis in parotid acinar cells. Our studies also demonstrate that the P2X4R-mediated [Ca2+]i rise and subsequent protein exocytosis was enhanced by ivermectin (IVR) thereby making it a potential target treatment of salivary hypofunction diseases. Additionally, experiments designed to assess crosstalk between purinoceptors (P2X4R and P2X7R) and cAMP signaling pathways showed that [Ca2+]i levels were enhanced upon β-adrenergic receptor stimulation or during rises in intracellular cAMP levels by synthetic cAMP agonists. The current study supports the notion that PKA dependent crosstalk between purinoceptors evoked Ca2+ signals and cAMP pathway might be critical in regulation of both fluid and protein secretion in parotid acinar cells. Thus crosstalk between the two signaling pathways can also be exploited for construction of therapies associated with salivary hypofunction. Advisors/Committee Members: Giovannucci, David (Advisor).

Subjects/Keywords: Biology; Neurobiology; Neurology; Neurosciences; Pharmacology; Physiology; ATP; purinergic; exocytosis; calcium; p2x4; p2x7; saliva; parotid; acinar cells; cAMP

10 more images…

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bhattacharya, S. (2012). Contribution of Purinergic Receptors to Calcium Signaling in Salivary Gland. (Doctoral Dissertation). University of Toledo Health Science Campus. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=mco1353370433

Chicago Manual of Style (16^th Edition):

Bhattacharya, Sumit. “Contribution of Purinergic Receptors to Calcium Signaling in Salivary Gland.” 2012. Doctoral Dissertation, University of Toledo Health Science Campus. Accessed March 05, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=mco1353370433.

MLA Handbook (7^th Edition):

Bhattacharya, Sumit. “Contribution of Purinergic Receptors to Calcium Signaling in Salivary Gland.” 2012. Web. 05 Mar 2021.

Vancouver:

Bhattacharya S. Contribution of Purinergic Receptors to Calcium Signaling in Salivary Gland. [Internet] [Doctoral dissertation]. University of Toledo Health Science Campus; 2012. [cited 2021 Mar 05]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1353370433.

Council of Science Editors:

Bhattacharya S. Contribution of Purinergic Receptors to Calcium Signaling in Salivary Gland. [Doctoral Dissertation]. University of Toledo Health Science Campus; 2012. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1353370433

University of Toledo Health Science Campus

3. Arunachalam, Sasi. The Role of store operated calcium channels in human carcinoid cell lines.

Degree: PhD, College of Medicine, 2010, University of Toledo Health Science Campus

URL: http://rave.ohiolink.edu/etdc/view?acc_num=mco1279216983

► Carcinoid tumors are a heterogeneous set of uncommon slow-growing gastroenteropancreatic neuroendocrine cancers originating primarily from amine or peptide secreting enteroendocrine cells of gastrointestinal tract. Here,… (more)

▼ Carcinoid tumors are a heterogeneous set of uncommon slow-growing gastroenteropancreatic neuroendocrine cancers originating primarily from amine or peptide secreting enteroendocrine cells of gastrointestinal tract. Here, we show that carcinoid cell lines express an array of store operated calcium entry (SOCE) channels. Ca2+ entry following ER Ca2+ depletion and store-operated Ca2+ channel activation can regulate proliferation, migration and apoptosis in some cancer cells including those of neuroendocrine phenotype. Consistent with these observations, SOCE was activated in carcinoid cell lines following depletion of ER Ca2+ stores by artificial or physiological agonist. Moreover, treatment with pharmacological inhibitors of SOCE generally reduced Ca2+ entry. SOCE in carcinoid cell lines evoked by GPCR activation suggested that Ca2+ entry may be important for mediating neural, paracrine or autocrine signals in the gut. Promising molecular candidates artificially or physiologically activated for Ca2+ entry pathways are the recently discovered plasma membrane channel protein Orai and ER calcium sensor protein STIM. Molecular profiling by RT-PCR indicated that STIM 1 and Orai1-Orai3 were robustly expressed in GEPNET cell lines derived from foregut and midgut tumors. Thus to gain insight into the roles of STIM1 and Orai1 in foregut and midgut cancers we used targeted gene silencing and over expression techniques in combination with live cell imaging of Ca2+ entry. These studies demonstrated significant reductions in Ca2+ entry following store depletion in cells where STIM1 was reduced by targeted knocked down compared to controls. Conversely, overexpression of STIM1 and Orai1 or Orai3 dramatically enhanced Ca2+ entry that was largely abolished by coexpression with its corresponding dominant negative/ mutant Orai proteins. This study points to a dominant role for STIM1 and Orai1 in mediating SOCE in foregut and midgut carcinoid cells. Furthermore, STIM1 and Orai1 have been proven critical for breast cancer migration and invasion. Hence to study the role of these proteins in carcinoid tumor genesis we developed a novel ex vivo xenograft organotypic slice culture technique. This provided the model system that resembled the three-dimensional multicellular tumor microenvironment. Using organotypic slice culture, we observed that stable BON cells over expressing shRNA for Orai1 showed altered cell movement characteristics and their ability to form tumorlets were greatly reduced in contrast to control cells. Broadly, this work contributes to the search for strategies to inhibit metastasis of carcinoid tumors. Advisors/Committee Members: Giovannucci, David (Committee Chair).

Subjects/Keywords: Biomedical Research; SOCE; STIM1; Orai1; Carcinoid tumor; organotypic liver slice culture method; tumorgenesis; migration; amoeboid; mesenchymal migration; multiphoton imaging; Fura-2AM; live cell imaging

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Arunachalam, S. (2010). The Role of store operated calcium channels in human carcinoid cell lines. (Doctoral Dissertation). University of Toledo Health Science Campus. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=mco1279216983

Chicago Manual of Style (16^th Edition):

Arunachalam, Sasi. “The Role of store operated calcium channels in human carcinoid cell lines.” 2010. Doctoral Dissertation, University of Toledo Health Science Campus. Accessed March 05, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=mco1279216983.

MLA Handbook (7^th Edition):

Arunachalam, Sasi. “The Role of store operated calcium channels in human carcinoid cell lines.” 2010. Web. 05 Mar 2021.

Vancouver:

Arunachalam S. The Role of store operated calcium channels in human carcinoid cell lines. [Internet] [Doctoral dissertation]. University of Toledo Health Science Campus; 2010. [cited 2021 Mar 05]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1279216983.

Council of Science Editors:

Arunachalam S. The Role of store operated calcium channels in human carcinoid cell lines. [Doctoral Dissertation]. University of Toledo Health Science Campus; 2010. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1279216983

University of Toledo Health Science Campus

4. Zahedi, Shadi. Are Mitochondria a Potential Target for Anti-Cancer Therapy in Carcinoid Tumors?.

Degree: MSBS, College of Medicine, 2010, University of Toledo Health Science Campus

URL: http://rave.ohiolink.edu/etdc/view?acc_num=mco1280427079

► Gastrointestinal (GI) carcinoids are slow growing malignancies of neuroendocrine phenotype that can behave aggressively. To date, there are no effective therapies for metastatic carcinoid cancer.… (more)

Subjects/Keywords: Biomedical Research; Molecular Biology; Scientific Imaging; carcinoid tumors; mitochondrial; calcium signaling; TIRF microscopy; oxidant therapy; vitamin K3; vitamin C

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zahedi, S. (2010). Are Mitochondria a Potential Target for Anti-Cancer Therapy in Carcinoid Tumors?. (Masters Thesis). University of Toledo Health Science Campus. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=mco1280427079

Chicago Manual of Style (16^th Edition):

Zahedi, Shadi. “Are Mitochondria a Potential Target for Anti-Cancer Therapy in Carcinoid Tumors?.” 2010. Masters Thesis, University of Toledo Health Science Campus. Accessed March 05, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=mco1280427079.

MLA Handbook (7^th Edition):

Zahedi, Shadi. “Are Mitochondria a Potential Target for Anti-Cancer Therapy in Carcinoid Tumors?.” 2010. Web. 05 Mar 2021.

Vancouver:

Zahedi S. Are Mitochondria a Potential Target for Anti-Cancer Therapy in Carcinoid Tumors?. [Internet] [Masters thesis]. University of Toledo Health Science Campus; 2010. [cited 2021 Mar 05]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1280427079.

Council of Science Editors:

Zahedi S. Are Mitochondria a Potential Target for Anti-Cancer Therapy in Carcinoid Tumors?. [Masters Thesis]. University of Toledo Health Science Campus; 2010. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1280427079

University of Toledo Health Science Campus

5. Peters, Christian G. SNARE-Mediated Exocytosis of Atrial Natriuretic Peptide from Atrial Cardiac Myocytes.

Degree: PhD, College of Graduate Studies, 2007, University of Toledo Health Science Campus

URL: http://rave.ohiolink.edu/etdc/view?acc_num=mco1179405759

► The heart, often overlooked as an endocrine gland, is responsible for secreting the vasoactive hormone atrial natriuretic peptide (ANP). Physical stretch of the atrial wall… (more)

▼ The heart, often overlooked as an endocrine gland, is responsible for secreting the vasoactive hormone atrial natriuretic peptide (ANP). Physical stretch of the atrial wall is the conical stimulus; however, ouabain has been shown to efficiently evoke exocytosis. Nevertheless, the Ca2+-dependence and molecular mechanisms that mediate ANP exocytosis remain unclear. In the current study, I identified SNARE proteins and determined their association with ANP-containing secretory granules using primary cultures of neonatal and adult rat atrial cardiac myocytes. Myocytes were screened for mRNA transcripts by RT-PCR and further characterized by Western blot analysis. Functional interactions of identified core SNARE proteins were demonstrated using co-immunoprecipitation methods. Localization of core SNARE proteins were completed using cell fractionation and immunocytochemical methods, revealing that VAMP-1, VAMP-2 and synaptotagmin-1 were localized to subpopulations of ANP-containing secretory granules, suggesting an importance for SNARE proteins. To judge whether secretory activity could be evoked by intracellular Ca2+ elevation and the role of ouabain in this process, we used timeresolved membrane capacitance measurements (Cm) in combination with the flash photolysis of caged Ca2+ to follow the exocytotic activity of individual myocytes. Two sequential flashes at room temperature evoked nearly identical Ca2+ changes that induced exponential Cm rises (78 and 66 granules, respectively). The application of 100 nM ouabain to target the á3-subunit of the Na+/K+-ATPase significantly enhanced the average Cm change to the first stimulus and diminished the response to the second stimulus (138 and 58 granules, espectively) with no effect on Ca2+ levels or size of the readily-releasable pool, suggesting ouabain enhanced the Ca+2-sensitivity of exocytosis. Others have shown binding of ouabain to the Na+/K+-ATPase activates Src and subsequent downstream tyrosine phosphorylation. Using coimmunoprecipitation methods, I demonstrated that synaptotagmin-1 associates with an immune complex comprised of Na+/K+-ATPase á3/Src/syntaxin-4. Moreover, treatment with pervanadate (inhibitor of protein tyrosine phosphatases) or ouabain induced tyrosine phosphorylation of synaptotagmin-1 in a dose dependent manner. Based on these findings, I propose SNARE proteins are required for exocytosis and are assembled with Na+/K+-ATPase á3/Src/syntaxin-4 in a signal complex that upon activation by ouabain induces tyrosine phosphorylation of synaptotagmin-1 to enhance the Ca2+-sensitivity of exocytosis. Advisors/Committee Members: Giovannucci, David (Advisor).

Subjects/Keywords: atrial natriuretic peptide; exocytosis; atrial myocytes; Ca2+ imaging; membrane capacitance; SNARE proteins

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Peters, C. G. (2007). SNARE-Mediated Exocytosis of Atrial Natriuretic Peptide from Atrial Cardiac Myocytes. (Doctoral Dissertation). University of Toledo Health Science Campus. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=mco1179405759

Chicago Manual of Style (16^th Edition):

Peters, Christian G. “SNARE-Mediated Exocytosis of Atrial Natriuretic Peptide from Atrial Cardiac Myocytes.” 2007. Doctoral Dissertation, University of Toledo Health Science Campus. Accessed March 05, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=mco1179405759.

MLA Handbook (7^th Edition):

Peters, Christian G. “SNARE-Mediated Exocytosis of Atrial Natriuretic Peptide from Atrial Cardiac Myocytes.” 2007. Web. 05 Mar 2021.

Vancouver:

Peters CG. SNARE-Mediated Exocytosis of Atrial Natriuretic Peptide from Atrial Cardiac Myocytes. [Internet] [Doctoral dissertation]. University of Toledo Health Science Campus; 2007. [cited 2021 Mar 05]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1179405759.

Council of Science Editors:

Peters CG. SNARE-Mediated Exocytosis of Atrial Natriuretic Peptide from Atrial Cardiac Myocytes. [Doctoral Dissertation]. University of Toledo Health Science Campus; 2007. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1179405759

University of Toledo Health Science Campus

6. Brink, Christine. The Role of Calcium and Mitochondria in the Etiology and Treatment of Three Different Disease Paradigms.

Degree: PhD, College of Graduate Studies, 2007, University of Toledo Health Science Campus

URL: http://rave.ohiolink.edu/etdc/view?acc_num=mco1211922352

► Calcium signals are integral steps in pathways for a large variety of important cellular functions ranging from cell growth and proliferation to apoptotic cell death.… (more)

Subjects/Keywords: Biology; Neurology; calcium; mitochondria; cancer; Alzheimers; epilepsy

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Brink, C. (2007). The Role of Calcium and Mitochondria in the Etiology and Treatment of Three Different Disease Paradigms. (Doctoral Dissertation). University of Toledo Health Science Campus. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=mco1211922352

Chicago Manual of Style (16^th Edition):

Brink, Christine. “The Role of Calcium and Mitochondria in the Etiology and Treatment of Three Different Disease Paradigms.” 2007. Doctoral Dissertation, University of Toledo Health Science Campus. Accessed March 05, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=mco1211922352.

MLA Handbook (7^th Edition):

Brink, Christine. “The Role of Calcium and Mitochondria in the Etiology and Treatment of Three Different Disease Paradigms.” 2007. Web. 05 Mar 2021.

Vancouver:

Brink C. The Role of Calcium and Mitochondria in the Etiology and Treatment of Three Different Disease Paradigms. [Internet] [Doctoral dissertation]. University of Toledo Health Science Campus; 2007. [cited 2021 Mar 05]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1211922352.

Council of Science Editors:

Brink C. The Role of Calcium and Mitochondria in the Etiology and Treatment of Three Different Disease Paradigms. [Doctoral Dissertation]. University of Toledo Health Science Campus; 2007. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=mco1211922352

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations