Luis Ortiz - Academia.edu (original) (raw)

Papers by Luis Ortiz

American Journal of Respiratory Cell and Molecular Biology, Apr 1, 2014

Idiopathic pulmonary fibrosis (IPF) is a relentless, fibrotic parenchymal lung disease in which a... more Idiopathic pulmonary fibrosis (IPF) is a relentless, fibrotic parenchymal lung disease in which alternatively programmed macrophages produce profibrotic molecules that promote myofibroblast survival and collagen synthesis. Effective therapies to treat patients with IPF are lacking, and conventional therapy may be harmful. We tested the hypothesis that therapeutic lung delivery of the proinflammatory cytokine tumor necrosis factor (TNF)-a into wild-type fibrotic mice would reduce the profibrotic milieu and accelerate the resolution of established pulmonary fibrosis. Fibrosis was assessed in bleomycin-instilled wild-type and TNF-a 2/2 mice by measuring hydroxyproline levels, static compliance, and Masson's trichrome staining. Macrophage infiltration and programming status was assessed by flow cytometry of enzymatically digested lung and in situ immunostaining. Pulmonary delivery of TNF-a to wild-type mice with established pulmonary fibrosis was found to reduce their fibrotic burden, to improve lung function and architecture, and to reduce the number and programming status of profibrotic alternatively programmed macrophages. In contrast, fibrosis and alternative macrophage programming were prolonged in bleomycin-instilled TNF-a 2/2 mice. To address the role of the reduced numbers of alternatively programmed macrophages in the TNF-a-induced resolution of established pulmonary fibrosis, we conditionally depleted macrophages in MAFIA (MAcrophage Fas-Induced Apoptosis) mice. Conditional macrophage depletion phenocopied the resolution of established pulmonary fibrosis observed after therapeutic TNF-a delivery. Taken together, our results show for the first time that TNF-a is involved in the resolution of established pulmonary fibrosis via a mechanism involving reduced numbers and programming status of profibrotic macrophages. We speculate that pulmonary delivery of TNF-a or augmenting its signaling pathway represent a novel therapeutic strategy to resolve established pulmonary fibrosis.

Frontiers in Immunology

In the lungs, macrophages constitute the first line of defense against pathogens and foreign bodi... more In the lungs, macrophages constitute the first line of defense against pathogens and foreign bodies and play a fundamental role in maintaining tissue homeostasis. Activated macrophages show altered immunometabolism and metabolic changes governing immune effector mechanisms, such as cytokine secretion characterizing their classic (M1) or alternative (M2) activation. Lipopolysaccharide (LPS)-stimulated macrophages demonstrate enhanced glycolysis, blocked succinate dehydrogenase (SDH), and increased secretion of interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). Glycolysis suppression using 2 deoxyglucose in LPS-stimulated macrophages inhibits IL-1β secretion, but not TNF-α, indicating metabolic pathway specificity that determines cytokine production. In contrast to LPS, the nature of the immunometabolic responses induced by non-organic particles, such as silica, in macrophages, its contribution to cytokine specification, and disease pathogenesis are not well understoo...

Cytotherapy, 2020

Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on ... more Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

International Journal of Molecular Sciences, Mar 18, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Journal of Extracellular Vesicles, 2019

ABSTRACTSmall extracellular vesicles (sEVs) from mesenchymal stromal/stem cells (MSCs) are transi... more ABSTRACTSmall extracellular vesicles (sEVs) from mesenchymal stromal/stem cells (MSCs) are transiting rapidly towards clinical applications. However, discrepancies and controversies about the biology, functions, and potency of MSC‐sEVs have arisen due to several factors: the diversity of MSCs and their preparation; various methods of sEV production and separation; a lack of standardized quality assurance assays; and limited reproducibility of in vitro and in vivo functional assays. To address these issues, members of four societies (SOCRATES, ISEV, ISCT and ISBT) propose specific harmonization criteria for MSC‐sEVs to facilitate data sharing and comparison, which should help to advance the field towards clinical applications. Specifically, MSC‐sEVs should be defined by quantifiable metrics to identify the cellular origin of the sEVs in a preparation, presence of lipid‐membrane vesicles, and the degree of physical and biochemical integrity of the vesicles. For practical purposes, new...

Journal of Extracellular Vesicles, 2018

Respiratory Medicine Case Reports, 2018

Introduction: Hard metal pneumoconiosis is a rare but serious disease of the lungs associated wit... more Introduction: Hard metal pneumoconiosis is a rare but serious disease of the lungs associated with inhalational exposure to tungsten or cobalt dust. Little is known about the radiologic and pathologic characteristics of this disease and the efficacy of treating with immunosuppression. Objective: We describe the largest cohort of patients with hard metal pneumoconiosis in the literature, including radiographic and pathologic patterns as well as treatment options. Methods: We retrospectively identified patients from the University of Pittsburgh pathology registry between the years of 1985 and 2016. Experts in chest radiology and pulmonary pathology reviewed the cases for radiologic and pathologic patterns. Results: We identified 23 patients with a pathologic pattern of hard metal pneumoconiosis. The most common radiographic findings were ground glass opacities (93%) and small nodules (64%). Of 20 surgical biopsies, 17 (85%) showed features of giant cell interstitial pneumonia. Most patients received systemic corticosteroids and/ or steroid-sparing immunosuppression. Conclusions: Hard metal pneumoconiosis is characterized predominately by radiographic ground glass opacities and giant cell interstitial pneumonia on histopathology. Systemic corticosteroids and steroid-sparing immunosuppression are common treatment options.

American journal of respiratory and critical care medicine, Jan 4, 2018

Idiopathic pulmonary fibrosis (IPF) is a progressive, fibrotic interstitial lung disease characte... more Idiopathic pulmonary fibrosis (IPF) is a progressive, fibrotic interstitial lung disease characterized by (myo)fibroblast accumulation and collagen deposition. Resistance to Fas-induced apoptosis is thought to facilitate (myo)fibroblast persistence in fibrotic lung tissues, by poorly understood mechanisms. We tested the hypothesis that protein tyrosine phosphatase PTPN13 is expressed by IPF lung (myo)fibroblasts, promotes their resistance to Fas-induced apoptosis and contributes to the development of pulmonary fibrosis. PTPN13 was localized in lung tissues from IPF patients and control subjects by immunohistochemical staining. Inhibition of PTPN13 function in primary IPF and normal lung (myo)fibroblasts was accomplished by: (i) down-regulation with TNF-α/IFN-γ, (ii) siRNA knockdown, or (iii) a cell permeable Fas:PTPN13 interaction inhibitory peptide. The role of PTPN13 in the development of pulmonary fibrosis was assessed in mice with genetic deficiency of PTP-BL, the murine ortholo...

European Respiratory Journal, Sep 1, 2013

Stem cells (Dayton, Ohio), 2012

Large scale expansion of human mesenchymal stem cells (MSCs) is routinely performed for clinical ... more Large scale expansion of human mesenchymal stem cells (MSCs) is routinely performed for clinical therapy. In contrast, developing protocols for large scale expansion of primary mouse MSCs has been more difficult due to unique aspects of rodent biology. Currently, established methods to isolate mouse MSCs select for rapidly dividing subpopulations that emerge from bone marrow cultures following long-term (months) expansion in atmospheric oxygen. Herein, we demonstrate that exposure to atmospheric oxygen rapidly induced p53, TOP2A, and BCL2-associated X protein (BAX) expression and mitochondrial reactive oxygen species (ROS) generation in primary mouse MSCs resulting in oxidative stress, reduced cell viability, and inhibition of cell proliferation. Alternatively, procurement and culture in 5% oxygen supported more prolific expansion of the CD45(-ve) /CD44(+ve) cell fraction in marrow, produced increased MSC yields following immunodepletion, and supported sustained MSC growth resulting...

European Respiratory Journal, 2001

It has recently been suggested that proteinase inhibitors modulate the fibrotic response in the l... more It has recently been suggested that proteinase inhibitors modulate the fibrotic response in the lung. This study investigated the development of bleomycin-induced pulmonary changes in pallid mice, deficient in serum α1‐proteinase inhibitor, and with a lower elastase inhibitory capacity, and in congenic C57Bl/6J mice.Male pallid and C57Bl/6J mice received a single intratracheal instillation of either saline or bleomycin. The investigation was carried out by means of biochemical, morphological and morphometrical methods.In both strains, 21 and 72 h after bleomycin, the lungs showed foci of inflammatory cell infiltration associated with emphysema. Fibrosis developed with time after bleomycin. At 14 days fibrosis affected 23.46±9.48% (mean± sd) and 40.62±13.34% (p<0.01) of the lungs of C57Bl/6J and pallid mice, respectively. Emphysema affected 3.68±3.11% and 12.57±4.13% (p<0.01) of lung in C57Bl/6J and pallid mice, respectively. In C57Bl/6J mice bleomycin increased lung hydroxypro...

Cell Death & Differentiation, 2005

Bone, 2003

Connective tissue growth factor (CTGF) has been identified as a secretory protein encoded by an i... more Connective tissue growth factor (CTGF) has been identified as a secretory protein encoded by an immediate early gene and is a member of the CCN family. In vitro CTGF directly regulates the proliferation and differentiation of chondrocytes; however, a previous study showed that it was localized only in the hypertrophic chondrocytes in the costal cartilages of E 18 mouse embryos. We described the expression of CTGF mRNA and protein in chondrocytes of different types of cartilages, including femoral growth plate cartilage, costal cartilage, femoral articular cartilage, mandibular condylar cartilage, and cartilage formed during the healing of mandibular ramus fractures revealed by in situ hybridization and immunohistochemistry. To characterize the CTGF-expressing cells, we also analyzed the distribution of the type I, type II, and type X collagen mRNA expression. Among these different types of cartilages we found distinct patterns of CTGF mRNA and protein expression. Growth plate cartilage and the costal cartilage showed localization of CTGF mRNA and protein in the hypertrophic chondrocytes that expressed type X collagen mRNA with less expression in proliferating chondrocytes that expressed type II collagen mRNA, whereas it was also expressed in the proliferating chondrocytes that expressed type I collagen mRNA in the condylar cartilage, the articular cartilage, and the cartilage appearing during fracture healing. In contrast, the growth plate cartilages or the costal cartilages were negative for type I collagen and showed sparse expression of CTGF mRNA in the proliferating chondrocytes. We found for the first time that CTGF mRNA could be differentially expressed in five different types of cartilage associated with those expressing type I collagen. Moreover, the spatial distribution of CTGF mRNA in the cartilages with type I collagen mRNA suggested its roles in the early differentiation, as well as in the proliferation and the terminal differentiation, of those cartilages.

American Journal of Respiratory Cell and Molecular Biology, 2013

In the mouse lung, Escherichia coli LPS can decrease surfactant protein-B (SFTPB) mRNA and protei... more In the mouse lung, Escherichia coli LPS can decrease surfactant protein-B (SFTPB) mRNA and protein concentrations. LPS also regulates the expression, synthesis, and concentrations of a variety of gene and metabolic products that inhibit SFTPB gene expression. The purpose of the present study was to determine whether LPS acts directly or indirectly on pulmonary epithelial cells to trigger signaling pathways that inhibit SFTPB expression, and whether the transcription factor CCAAT/enhancer binding protein (C/EBP)-b (CEBPB) is a downstream inhibitory effector. To investigate the mechanism of SFTPB repression, the human pulmonary epithelial cell lines NCI-H441 (H441) and NCI-H820 (H820) and the mouse macrophage-like cell line RAW264.7 were treated with LPS. Whereas LPS did not decrease SFTPB transcripts in H441 or H820 cells, the conditioned medium of LPS-treated RAW264.7 cells decreased SFTPB transcripts in H441 and H820 cells, and inhibited SFTPB promoter activity in H441 cells. In the presence of neutralizing anti-tumor necrosis factor (TNF) antibodies, the conditioned medium of LPS-treated RAW264.7 cells did not inhibit SFTPB promoter activity. In H441 cells treated with recombinant TNF protein, SFTPB transcripts decreased, whereas CEBPB transcripts increased and the transient coexpression of CEBPB decreased SFTPB promoter activity. Further, CEBPB short, interfering RNA increased basal SFTPB transcripts and countered the decrease of SFTPB transcripts by TNF. Together, these findings suggest that macrophages participate in the repression of SFTPB expression by LPS, and that macrophage-released cytokines (including TNF) regulate the transcription factor CEBPB, which can function as a downstream transcriptional repressor of SFTPB gene expression in pulmonary epithelial cells.

American Journal of Respiratory and Critical Care Medicine, 2001

The role of strain difference in the response to cigarette smoke was investigated in mice. Mice o... more The role of strain difference in the response to cigarette smoke was investigated in mice. Mice of the strains DBA/2 and C57BL/6J responded to acute cigarette smoke with a decrease of the antioxidant defenses of their bronchoalveolar lavage (BAL) fluids. On the other hand, under these conditions ICR mice increased their BAL antioxidant defenses. Mice of these three strains were then exposed to cigarette smoke (three cigarettes/d, 5 d/wk) for 7 mo. Lung elastin content was significantly decreased in C57BL/6J and DBA/2 but not in ICR mice. Also, emphysema, assessed morphometrically using three methods, was present in C57BL/6J and DBA/2 but not in ICR mice. In an additional study pallid mice, with a severe serum ␣ 1-proteinase inhibitor (␣ 1-PI) deficiency and that develop spontaneous emphysema, were exposed to cigarette smoke for 4 mo. This resulted in an acceleration of the development of the spontaneous emphysema assessed with morphometrical and biochemical (lung elastin content) methods. All these results indicate that sensitivity to the effects of cigarette smoke is strain-dependent and cigarette smoke accelerates the effects of ␣ 1-PI deficiency.

American Journal of Respiratory and Critical Care Medicine, 2006

This document has been developed by an international committee and has been endorsed by both the ... more This document has been developed by an international committee and has been endorsed by both the ATS and the ERS. It places pulmonary rehabilitation within the concept of integrated care. The World Health Organization has defined integrated care as "a concept bringing together inputs, delivery, management and organization of services related to diagnosis, treatment, care, rehabilitation and health promotion" (1). Integration of services improves access, quality, user satisfaction, and efficiency of medical care. As such, pulmonary rehabilitation provides an opportunity to coordinate care and focus on the entire clinical course of an individual's disease. Building on previous statements (2, 3), this document presents recent scientific advances in our understanding of the multisystemic effects of chronic respiratory disease and how pulmonary rehabilitation addresses the resultant functional limitations. It was created as a comprehensive statement, using both a firm evidence-based approach and the clinical expertise of the writing committee. As such, it is complementary to two current documents on pulmonary rehabilitation: the American College of Chest Physicians and American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) evidence-based guidelines (4), which formally grade the level of scientific evidence, and the AACVPR Guidelines for Pulmonary Rehabilitation Programs (5), which give practical recommendations. SECTION 2: EXERCISE PERFORMANCE: LIMITATIONS AND INTERVENTIONS Practice guideline: Pulmonary rehabilitation programs should address body composition abnormalities, which are frequently present and underrecognized in chronic lung disease. Intervention may be in the form of caloric, physiologic, pharmacologic, or combination therapy.

American Journal of Respiratory and Critical Care Medicine, 2002

The chemotherapeutic drug bleomycin causes DNA damage and transcription factor. Wild-type p53 for... more The chemotherapeutic drug bleomycin causes DNA damage and transcription factor. Wild-type p53 forms a tetramer and apoptosis in the lungs of mice within hours of endotracheal instillabinds DNA in a sequence-specific manner to activate trantion followed by inflammation and fibrosis weeks later. The p53 scription of numerous target genes. Among the targets actitumor suppressor protein mediates cellular responses to DNA damvated by wild-type p53: p21/WAF1 promotes cell cycle arrest age, including induction of apoptosis, but the effects of p53 activa-(12, 13); bax (14), p53 apoptosis-inducing protein 1 (15), and/ tion in the various cell types of the lung during bleomycin-induced or redox regulatory proteins (16); and induce apoptosis and pulmonary fibrosis remain unclear. We show here that a transgene ribonucleotide reductase (17), GADD45 (18, 19), and prolifwith a dominant-negative mutant form of human p53 expressed erating cell nuclear antigen (20) potentiate DNA repair. from the surfactant protein C promoter sensitizes mice to bleomy-Many oncogenic mutant forms of p53 lack the ability to bind cin-induced lung injury. The bleomycin-exposed transgenic animals DNA and activate transcription of these target genes. In display more severe lung pathology with associated collagen depoaddition to this loss of activity, some mutant p53 proteins sition and more pronounced lung eosinophilia than simultaneously can interact with the wild-type protein (21) and thereby inexposed nontransgenic littermates. These observations suggest hibit p53 function in a dominant-negative manner (22, 23). that compromising p53 function in the alveolar epithelium impairs Endotracheal instillation of bleomycin activates p53 exrecovery of the lung from bleomycin-induced injury.

American Journal of Respiratory and Critical Care Medicine, 2013

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health conven... more The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health convened the Cell Therapy for Lung Disease Working Group on November 13-14, 2012, to review and formulate recommendations for future research directions. The workshop brought together investigators studying basic mechanisms and the roles of cell therapy in preclinical models of lung injury and pulmonary vascular disease, with clinical trial experts in cell therapy for cardiovascular diseases and experts from the NHLBI Production Assistance for Cell Therapy program. The purpose of the workshop was to discuss the current status of basic investigations in lung cell therapy, to identify some of the scientific gaps in current knowledge regarding the potential roles and mechanisms of cell therapy in the treatment of lung diseases, and to develop recommendations to the NHLBI and the research community on scientific priorities and practical steps that would lead to first-inhuman trials of lung cell therapy.