Browsing by Author "Salazar, Tatiana E."

Now showing 1 - 5 of 5
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    Conditional Deletion of Bmal1 Accentuates Microvascular and Macrovascular Injury
    (Elsevier, 2017-06) Bhatwadekar, Ashay D.; Beli, Eleni; Diao, Yanpeng; Chen, Jonathan; Luo, Qianyi; Alex, Alpha; Caballero, Sergio; Dominguez, James M., II; Salazar, Tatiana E.; Busik, Julia V.; Segal, Mark S.; Grant, Maria B.; Ophthalmology, School of Medicine
    The brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein (BMAL)-1 constitutes a major transcriptional regulator of the circadian clock. Here, we explored the impact of conditional deletion of Bmal1 in endothelium and hematopoietic cells in murine models of microvascular and macrovascular injury. We used two models of Bmal1fx/fx;Tek-Cre mice, a retinal ischemia/reperfusion model and a neointimal hyperplasia model of the femoral artery. Eyes were enumerated for acellular capillaries and were stained for oxidative damage markers using nitrotyrosine immunohistochemistry. LSK (lineage-negative, stem cell antigen-1-positive, c-Kit-positive) cells were quantified and proliferation assessed. Hematopoiesis is influenced by innervation to the bone marrow, which we assessed using IHC analysis. The number of acellular capillaries increased threefold, and nitrotyrosine staining increased 1.5-fold, in the retinas of Bmal1fx/fx;Tek-Cre mice. The number of LSK cells from the Bmal1fx/fx;Tek-Cre mice decreased by 1.5-fold and was accompanied by a profound decrease in proliferative potential. Bmal1fx/fx;Tek-Cre mice also exhibited evidence of bone marrow denervation, demonstrating a loss of neurofilament-200 staining. Injured femoral arteries showed a 20% increase in neointimal hyperplasia compared with similarly injured wild-type controls. Our study highlights the importance of the circadian clock in maintaining vascular homeostasis and demonstrates that specific deletion of BMAL1 in endothelial and hematopoietic cells results in phenotypic features similar to those of diabetes.
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    Electroacupuncture Promotes Central Nervous System-Dependent Release of Mesenchymal Stem Cells
    (Wiley, 2017-05) Salazar, Tatiana E.; Richardson, Matthew R.; Beli, Eleni; Ripsch, Matthew S.; George, John; Kim, Youngsook; Duan, Yaqian; Moldovan, Leni; Yan, Yuanqing; Bhatwadekar, Ashay; Jadhav, Vaishnavi; Smith, Jared A.; McGorray, Susan; Bertone, Alicia L.; Traktuev, Dmitri O.; March, Keith L.; Colon-Perez, Luis M.; Avin, Keith; Sims, Emily; Mund, Julie A.; Case, Jamie; Deng, Shaolin; Kim, Min Su; McDavitt, Bruce; Boulton, Michael E.; Thinschmidt, Jeffrey; Calzi, Sergio Li; Fitz, Stephanie D.; Fuchs, Robyn K.; Warden, Stuart J.; McKinley, Todd; Shekhar, Anantha; Febo, Marcelo; Johnson, Phillip L.; Chang, Lung Ji; Gao, Zhanguo; Kolonin, Mikhail G.; Lai, Song; Ma, Jinfeng; Dong, Xinzhong; White, Fletcher A.; Xie, Huisheng; Yoder, Mervin C.; Grant, Maria B.; Ophthalmology, School of Medicine
    Electroacupuncture (EA) performed in rats and humans using limb acupuncture sites, LI-4 and LI-11, and GV-14 and GV-20 (humans) and Bai-hui (rats) increased functional connectivity between the anterior hypothalamus and the amygdala and mobilized mesenchymal stem cells (MSCs) into the systemic circulation. In human subjects, the source of the MSC was found to be primarily adipose tissue, whereas in rodents the tissue sources were considered more heterogeneous. Pharmacological disinhibition of rat hypothalamus enhanced sympathetic nervous system (SNS) activation and similarly resulted in a release of MSC into the circulation. EA-mediated SNS activation was further supported by browning of white adipose tissue in rats. EA treatment of rats undergoing partial rupture of the Achilles tendon resulted in reduced mechanical hyperalgesia, increased serum interleukin-10 levels and tendon remodeling, effects blocked in propranolol-treated rodents. To distinguish the afferent role of the peripheral nervous system, phosphoinositide-interacting regulator of transient receptor potential channels (Pirt)-GCaMP3 (genetically encoded calcium sensor) mice were treated with EA acupuncture points, ST-36 and LIV-3, and GV-14 and Bai-hui and resulted in a rapid activation of primary sensory neurons. EA activated sensory ganglia and SNS centers to mediate the release of MSC that can enhance tissue repair, increase anti-inflammatory cytokine production and provide pronounced analgesic relief.
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    Loss of Angiotensin-Converting Enzyme 2 Exacerbates Diabetic Retinopathy by Promoting Bone Marrow Dysfunction
    (Wiley, 2018-09) Duan, Yaqian; Beli, Eleni; Calzi, Sergio Li; Quigley, Judith L.; Miller, Rehae C.; Moldovan, Leni; Feng, Dongni; Salazar, Tatiana E.; Hazra, Sugata; Al-Sabah, Jude; Chalam, Kakarla V.; Trinh, Thao Le Phuong; Meroueh, Marya; Markel, Troy A.; Murray, Matthew C.; Vyas, Ruchi J.; Boulton, Michael E.; Parsons-Wingerter, Patricia; Oudit, Gavin Y.; Obukhov, Alexander G.; Grant, Maria B.; Cellular and Integrative Physiology, School of Medicine
    Angiotensin-converting enzyme 2 (ACE2) is the primary enzyme of the vasoprotective axis of the renin angiotensin system (RAS). We tested the hypothesis that loss of ACE2 would exacerbate diabetic retinopathy by promoting bone marrow dysfunction. ACE2-/y were crossed with Akita mice, a model of type 1 diabetes. When comparing the bone marrow of the ACE2-/y-Akita mice to that of Akita mice, we observed a reduction of both short-term and long-term repopulating hematopoietic stem cells, a shift of hematopoiesis towards myelopoiesis, and an impairment of lineage-c-kit+ hematopoietic stem/progenitor cell (HS/PC) migration and proliferation. Migratory and proliferative dysfunction of these cells was corrected by exposure to angiotensin-1–7 (Ang-1–7), the protective peptide generated by ACE2. Over the duration of diabetes examined, ACE2 deficiency led to progressive reduction in electrical responses assessed by electroretinography and to increases in neural infarcts observed by fundus photography. Compared to Akita mice, ACE2-/y-Akita at 9-months of diabetes showed an increased number of acellular capillaries indicative of more severe diabetic retinopathy. In diabetic and control human subjects, CD34+ cells, a key bone marrow HS/PC population, were assessed for changes in mRNA levels for MAS, the receptor for Ang-1–7. Levels were highest in CD34+ cells from diabetics without retinopathy. Higher serum Ang-1–7 levels predicted protection from development of retinopathy in diabetics. Treatment with Ang-1–7 or alamandine restored the impaired migration function of CD34+ cells from subjects with retinopathy. These data support that activation of the protective RAS within HS/PCs may represent a therapeutic strategy for prevention of diabetic retinopathy.
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    Peripheral blood-derived mesenchymal stem cells demonstrate immunomodulatory potential for therapeutic use in horses
    (PLOS, 2019-03-14) Longhini, Ana Leda F.; Salazar, Tatiana E.; Vieira, Cristiano; Trinh, Thao; Duan, Yaqian; Pay, Louise M.; Li Calzi, Sergio; Losh, Megan; Johnston, Nancy A.; Xie, Huisheng; Kim, Minsu; Hunt, Robert J.; Yoder, Mervin C.; Santoro, Domenico; McCarrel, Taralyn M.; Grant, Maria B.; Ophthalmology, School of Medicine
    Previously, we showed that mesenchymal stem cells (MSC) can be mobilized into peripheral blood using electroacupuncture (EA) at acupoints, LI-4, LI-11, GV-14, and GV-20. The purpose of this study was to determine whether EA-mobilized MSC could be harvested and expanded in vitro to be used as an autologous cell therapy in horses. Peripheral blood mononuclear cells (PBMC) isolated from young and aged lame horses (n = 29) showed a marked enrichment for MSCs. MSC were expanded in vitro (n = 25) and administered intravenously at a dose of 50 x 106 (n = 24). Treatment resulted in significant improvement in lameness as assessed by the American Association of Equine Practitioners (AAEP) lameness scale (n = 23). MSCs exhibited immunomodulatory function by inhibition of lymphocyte proliferation and induction of IL-10. Intradermal testing showed no immediate or delayed immune reactions to MSC (1 x 106 to 1 x 104). In this study, we demonstrated an efficient, safe and reproducible method to mobilize and expand, in vitro, MSCs in sufficiently high concentrations for therapeutic administration. We confirm the immunomodulatory function of these cells in vitro. This non-pharmacological and non-surgical strategy for stem cell harvest has a broad range of biomedical applications and represents an improved clinically translatable and economical cell source for humans.
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    Reshaping lipid metabolism with long-term alternate day feeding in type 2 diabetes mice
    (Springer Nature, 2025) Beli, Eleni; Yan, Yuanqing; Moldovan, Leni; Lydic, Todd A.; Krishman, Preethi; Tersey, Sarah A.; Duan, Yaqian; Salazar, Tatiana E.; Dominguez, James M., II; Nguyen, Dung V.; Cox, Abigail; Li Calzi, Sergio; Beam, Craig; Mirmira, Raghavendra G.; Evans-Molina, Carmella; Busik, Julia V.; Grant, Maria B.; Ophthalmology, School of Medicine
    Strategies to improve metabolic health include calorie restriction, time restricted eating and fasting several days per week or month. These approaches have demonstrated benefits for individuals experiencing obesity, metabolic syndrome, and prediabetes. However, their impact on established diabetes remains incompletely studied. The chronicity of type 2 diabetes (T2D) requires that interventions must be undertaken for extended periods of time, typically the entire lifetime of the individual. In this study, we examined the impact of intermittent fasting (IF), with an every-other-day protocol for a duration of 6 months in a murine model of T2D, the db/db (D) mouse on metabolism and liver steatosis. We compared D-IF mice with diabetic ad-libitum (AL; D-AL), control-IF (C-IF) and control-AL (C-AL) cohorts. We demonstrated using lipidomic, microbiome, metabolomic and liver transcriptomic studies that chronic IF improved carbohydrate utilization and glucose homeostasis without weight loss and reduced white adipose tissue inflammation and significantly impacted lipid metabolism in the liver. Microbiome studies and predicted functional analysis of gut microbiota showed that IF increased beneficial bacteria involved in sphingolipid (SL) metabolism. The metabolomic studies showed that oxidation of lipid species and ceramide levels were reduced in D-IF compared to D-AL. The liver lipidomic analysis and liver microarray confirmed a reduction in overall lipid content in D-IF mice compared to D-AL mice, especially in the feeding state as well as an overall reduction in oxidized lipids and ceramides. These studies support that long-term IF can improve glucose homeostasis and dramatically altered lipid metabolism in the absence of weight loss.