Browsing by Author "Li Calzi, Sergio"

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    Bone Marrow–Derived Cell Recruitment to the Neurosensory Retina and Retinal Pigment Epithelial Cell Layer Following Subthreshold Retinal Phototherapy
    (ARVO, 2017-10) Caballero, Sergio; Kent, David L.; Sengupta, Nilanjana; Li Calzi, Sergio; Shaw, Lynn; Beli, Eleni; Moldovan, Leni; Dominguez, James M.; Moorthy, Ramana S.; Grant, Maria B.; Medicine, School of Medicine
    Purpose We investigated whether subthreshold retinal phototherapy (SRPT) was associated with recruitment of bone marrow (BM)–derived cells to the neurosensory retina (NSR) and RPE layer. Methods GFP chimeric mice and wild-type (WT) mice were subjected to SRPT using a slit-lamp infrared laser. Duty cycles of 5%, 10%, 15%, and 20% (0.1 seconds, 250 mW, spot size 50 μm) with 30 applications were placed 50 to 100 μm from the optic disc. In adoptive transfer studies, GFP+ cells were given intravenously immediately after WT mice received SRPT. Immunohistochemistry was done for ionized calcium-binding adapter molecule-1 (IBA-1+), CD45, Griffonia simplicifolia lectin isolectin B4, GFP or cytokeratin). Expression of Ccl2, Il1b, Il6, Hspa1a, Hsp90aa1, Cryab, Hif1a, Cxcl12, and Cxcr4 mRNA and flow cytometry of the NSR and RPE-choroid were performed. Results Within 12 to 24 hours of SRPT, monocytes were detected in the NSR and RPE-choroid. Detection of reparative progenitors in the RPE occurred at 2 weeks using flow cytometry. Recruitment of GFP+ cells to the RPE layer occurred in a duty cycle–dependent manner in chimeric mice and in mice undergoing adoptive transfer. Hspa1a, Hsp90aa1, and Cryab mRNAs increased in the NSR at 2 hours post laser; Hif1a, Cxcl12, Hspa1a increased at 4 hours in the RPE-choroid; and Ccl2, Il1b, Ifng, and Il6 increased at 12 to 24 hours in the RPE-choroid. Conclusions SRPT induces monocyte recruitment to the RPE followed by hematopoietic progenitor cell homing at 2 weeks. Recruitment occurs in a duty cycle–dependent manner and potentially could contribute to the therapeutic efficacy of SRPT.
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    Complementary Embryonic and Adult Cell Populations Enhance Myocardial Repair in Rat Myocardial Injury Model
    (Hindawi, 2019-11-03) Li Calzi, Sergio; Cook, Todd; Della Rocca, Domenico G.; Zhang, Juan; Shenoy, Vinayak; Yan, Yuanqing; Espejo, Andrew; Rathinasabapathy, Anandharajan; Jacobsen, Max H.; Salazar, Tatiana; Sandusky, George E.; Shaw, Lynn C.; March, Keith; Raizada, Mohan K.; Pepine, Carl J.; Katovich, Michael J.; Grant, Maria B.; Medicine, School of Medicine
    We compared the functional outcome of Isl-1+ cardiac progenitors, CD90+ bone marrow-derived progenitor cells, and the combination of the two in a rat myocardial infarction (MI) model. Isl-1+ cells were isolated from embryonic day 12.5 (E12.5) rat hearts and expanded in vitro. Thy-1+/CD90+ cells were isolated from the bone marrow of adult Sprague-Dawley rats by immunomagnetic cell sorting. Six-week-old female Sprague-Dawley rats underwent permanent left anterior descending (LAD) coronary artery ligation and received intramyocardial injection of either saline, Isl-1+ cells, CD90+ cells, or a combination of Isl-1+ and CD90+ cells, at the time of infarction. Cells were delivered transepicardially to the peri-infarct zone. Left ventricular function was assessed by transthoracic echocardiography at 1- and 4-week post-MI and by Millar catheterization (-dP/dt and +dP/dt) at 4-week post-MI. Fluorescence in situ hybridization (Isl-1+cells) and monochrystalline iron oxide nanoparticles labeling (MION; CD90+ cells) were performed to assess biodistribution of transplanted cells. Only the combination of cells demonstrated a significant improvement of cardiac function as assessed by anterior wall contractility, dP/dt (max), and dP/dt (min), compared to Isl-1+ or CD90+ cell monotherapies. In the combination cell group, viable cells were detected at week 4 when anterior wall motion was completely restored. In conclusion, the combination of Isl-1+ cardiac progenitors and adult bone marrow-derived CD90+ cells shows prolonged and robust myocardial tissue repair and provides support for the use of complementary cell populations to enhance myocardial repair.
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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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    Rap1B promotes VEGF-induced endothelial permeability and is required for dynamic regulation of the endothelial barrier
    (The Company of Biologists, 2018-01-10) Lakshmikanthan, Sribalaji; Sobczak, Magdalena; Li Calzi, Sergio; Shaw, Lynn; Grant, Maria B.; Chrzanowska-Wodnicka, Magdalena; Ophthalmology, School of Medicine
    Vascular endothelial growth factor (VEGF), a key angiogenic and permeability factor, plays an important role in new blood vessel formation. However, abnormal VEGF-induced VEGFR2 signaling leads to hyperpermeability. We have shown previously that Rap1, best known for promoting cell adhesion and vessel stability, is a critical regulator of VEGFR2-mediated angiogenic and shear-stress EC responses. To determine the role of Rap1 role in endothelial barrier dynamics, we examined vascular permeability in EC-specific Rap1A- and Rap1B-knockout mice, cell-cell junction remodeling and EC monolayer resistivity in Rap1-deficient ECs under basal, inflammatory or elevated VEGF conditions. Deletion of either Rap1 isoform impaired de novo adherens junction (AJ) formation and recovery from LPS-induced barrier disruption in vivo However, only Rap1A deficiency increased permeability in ECs and lung vessels. Interestingly, Rap1B deficiency attenuated VEGF-induced permeability in vivo and AJ remodeling in vitro Therefore, only Rap1A is required for the maintenance of normal vascular integrity. Importantly, Rap1B is the primary isoform essential for normal VEGF-induced EC barrier dissolution. Deletion of either Rap1 isoform protected against hyper permeability in the STZ-induced diabetes model, suggesting clinical implications for targeting Rap1 in pathologies with VEGF-induced hyperpermeability.
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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.