Papers by Felix R. Jimenez, Ph.D
The FASEB Journal, 2015
Claudins are tight junctional proteins that are implicated in cell polarity and in establishing a... more Claudins are tight junctional proteins that are implicated in cell polarity and in establishing and maintaining epithelial barrier function. Our published research has also revealed that claudin mi...
The International Journal of Developmental Biology, 2015
Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to ass... more Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to assess the effects of persistent tight junctions involving Cldn6 during lung development, a doxycycline (dox)-inducible conditional transgenic mouse was generated that up-regulates Cldn6 in the distal lung. Pups had unlimited access to dox from conception until sacrifice date at embryonic day (E) 18.5. Quantitative PCR, immunoblotting, and immunohistochemistry revealed significantly elevated Cldn6 expression in transgenic mice compared to non-transgenic controls. There were no differences in terms of lung size, lung weight, or whole body weight at the time of necropsy. Histological evaluations led to the discovery that E18.5 Cldn6 transgenic pups appeared to be in the early canalicular stage of development coincident with fewer, thickened respiratory airspaces. In contrast, controls appeared to have entered the saccular stage characterized by thin airspace walls and spherical architecture. Immunostaining for transcriptional regulators including TTF-1 and FoxA2 was conducted to assess cell differentiation and specific cell types were identified via staining for pro-surfactant protein C (alveolar type II epithelial cells) or Clara Cell Secretory Protein (cub or Clara cells). Lastly, cell turnover was qualitatively measured via staining for cell proliferation or apoptosis. These data suggest that Cldn6 is an important junctional protein potentially involved in the programming of epithelial cells during lung development. Furthermore, genetic down-regulation of Cldn6 as development proceeds may influence differentiation observed in the transition from the canalicular to the saccular lung.
Respiratory Research, 2014
Background: Claudins are transmembrane proteins expressed in tight junctions that prevent paracel... more Background: Claudins are transmembrane proteins expressed in tight junctions that prevent paracellular transport of extracellular fluid and a variety of other substances. However, the expression profile of Claudin-6 (Cldn6) in the developing lung has not been characterized. Methods and results: Cldn6 expression was determined during important periods of lung organogenesis by microarray analysis, qPCR and immunofluorescence. Expression patterns were confirmed to peak at E12.5 and diminish as lung development progressed. Immunofluorescence revealed that Cldn6 was detected in cells that also express TTF-1 and FoxA2, two critical transcriptional regulators of pulmonary branching morphogenesis. Cldn6 was also observed in cells that express Sox2 and Sox9, factors that influence cell differentiation in the proximal and distal lung, respectively. In order to assess transcriptional control of Cldn6, 0.5, 1.0, and 2.0-kb of the proximal murine Cldn6 promoter was ligated into a luciferase reporter and co-transfected with expression vectors for TTF-1 or two of its important transcriptional co-regulators, FoxA2 and Gata-6. In almost every instance, TTF-1, FoxA2, and Gata-6 activated gene transcription in cell lines characteristic of proximal airway epithelium (Beas2B) and distal alveolar epithelium (A-549). Conclusions: These data revealed for the first time that Cldn6 might be an important tight junctional component expressed by pulmonary epithelium during lung organogenesis. Furthermore, Cldn6-mediated aspects of cell differentiation may describe mechanisms of lung perturbation coincident with impaired cell junctions and abnormal membrane permeability.
Respiratory Research, 2014
Background: Receptors for advanced glycation end-products (RAGE) are immunoglobulin-like pattern ... more Background: Receptors for advanced glycation end-products (RAGE) are immunoglobulin-like pattern recognition receptors abundantly localized to lung epithelium. Our research demonstrated that primary tobacco smoke exposure increases RAGE expression and that RAGE partly mediates pro-inflammatory signaling during exposure. However, the degree to which RAGE influences developing lungs when gestating mice are exposed to secondhand smoke (SHS) has not been determined to date. Methods: Timed pregnant RAGE null and wild type control mice were exposed to 4 consecutive days of SHS from embryonic day (E) 14.5 through E18.5 using a state of the art nose-only smoke exposure system (Scireq, Montreal, Canada). RAGE expression was assessed using immunofluorescence, immunoblotting, and quantitative RT-PCR. TUNEL immunostaining and blotting for caspase-3 were performed to evaluate effects on cell turnover. Matrix abnormalities were discerned by quantifying collagen IV and MMP-9, a matrix metalloprotease capable of degrading basement membranes. Lastly, TNF-α and IL-1β levels were assessed in order to determine inflammatory status in the developing lung. Results: Pulmonary RAGE expression was elevated in both dams exposed to SHS and in fetuses gestating within mothers exposed to SHS. Fetal weight, a measure of organismal health, was decreased in SHS-exposed pups, but unchanged in SHS-exposed RAGE null mice. TUNEL assessments suggested a shift toward pulmonary cell apoptosis and matrix in SHS-exposed pups was diminished as revealed by decreased collagen IV and increased MMP-9 expression. Furthermore, SHS-exposed RAGE null mice expressed less TNF-α and IL-1β when compared to SHS-exposed controls. Conclusions: RAGE augmentation in developing pups exposed to maternal SHS weakens matrix deposition and influences lung inflammation.
Amaranth (Amaranthus caudatus L.)
American journal of physiology. Lung cellular and molecular physiology, Jan 15, 2014
The receptor for advanced glycation end-products (RAGE) has increasingly been demonstrated to be ... more The receptor for advanced glycation end-products (RAGE) has increasingly been demonstrated to be an important modulator of inflammation in cases of pulmonary disease. Published reports involving tobacco smoke exposure have demonstrated increased expression of RAGE, its participation in proinflammatory signaling, and its role in irreversible pulmonary remodeling. The current research evaluated the in vivo effects of short-term secondhand smoke (SHS) exposure in RAGE knockout and control mice compared with identical animals exposed to room air only. Quantitative PCR, immunoblotting, and immunohistochemistry revealed elevated RAGE expression in controls after 4 wk of SHS exposure and an anticipated absence of RAGE expression in RAGE knockout mice regardless of smoke exposure. Ras activation, NF-κB activity, and cytokine elaboration were assessed to characterize the molecular basis of SHS-induced inflammation in the mouse lung. Furthermore, bronchoalveolar lavage fluid was procured from...
Experimental lung research, Feb 1, 2018
Claudins are tight junctional proteins implicated in cell polarity and epithelial barrier mainten... more Claudins are tight junctional proteins implicated in cell polarity and epithelial barrier maintenance. Claudin misregulation adversely impacts developmental aspects of cell differentiation and proliferation. The current research evaluated transcriptional expression for Claudins 1-11 and 18 in the developing murine lung at embryonic days (E) 14.5, 16.5, and 18.5 and at post-natal day (PN) 3 and PN15. Mouse lungs were also assessed by immunohistochemical analysis to qualitatively evaluate Claudin protein expression. Pregnant dams were further exposed to secondhand smoke (SHS) from embryonic day (E)15.5 to 18.5 and Claudin mRNA was immediately screened in pup lungs. Other than Claudin-6, mRNA expression patterns for Claudin family members tended to decrease at E16.5, increase at E18.5, and decrease again at PN3 before reaching a peak of expression at PN15. Claudin-6 mRNA expression decreased through gestation and into post-natal periods. Immunohistochemical profiling implicated a subse...
Applications in Plant Sciences, 2014
The American Cross Timbers forest ecosystem runs from southeastern Kansas to Central Texas and is... more The American Cross Timbers forest ecosystem runs from southeastern Kansas to Central Texas and is primarily composed of post oak (Quercus stellata). This old-growth forest currently occupies only about 2% of its ancestral range. To facilitate genetic research on this species, we developed microsatellite primers specifi c to post oak from reduced genomic libraries. • Methods and Results: Two Q. stellata individuals, sampled from the northern and southern range of the post oak forest, were subject to genomic reduction and 454 pyrosequencing. Bioinformatic analysis identifi ed putative microsatellites from which 12 polymorphic primer sets were screened on three populations. The number of alleles observed ranged from fi ve to 20 across all populations, while observed and expected heterozygosity values ranged from 0.05 to 0.833 and 0.236 to 0.893, respectively, within individual populations. • Conclusions: We report the development of microsatellite markers, specifi c to post oak, to aid the study of genetic diversity and population structure of extant forest remnants.
Respiratory Research, 2014
Background: Receptors for advanced glycation end-products (RAGE) are multiligand cell-surface rec... more Background: Receptors for advanced glycation end-products (RAGE) are multiligand cell-surface receptors expressed abundantly by distal pulmonary epithelium. Our lab has discovered RAGE-mediated effects in the orchestration of lung inflammation induced by tobacco smoke and environmental pollutants; however, the specific contribution of RAGE to the progression of proximal airway inflammation is still inadequately characterized. Methods and results: We generated a Tet-inducible transgenic mouse that conditionally overexpressed RAGE using the club cell (Clara) secretory protein (CCSP) promoter expressed by club (Clara) cells localized to the proximal airway. RAGE was induced for 40 days from weaning (20 days of age) until sacrifice date at 60 days. Immunohistochemistry, immunoblotting, and qPCR revealed significant RAGE up-regulation when compared to non-transgenic controls; however, H&E staining revealed no detectible morphological abnormalities and apoptosis was not enhanced during the 40 days of augmentation. Freshly procured bronchoalveolar lavage fluid (BALF) from CCSP-RAGE TG mice had significantly more total leukocytes and PMNs compared to age-matched control littermates. Furthermore, CCSP-RAGE TG mice expressed significantly more tumor necrosis factor alpha (TNF-α), interleukin 7 (IL-7), and interleukin 14 (IL-14) in whole lung homogenates compared to controls. Conclusions: These data support the concept that RAGE up-regulation specifically in lung airways may function in the progression of proximal airway inflammation.
Experimental lung research, Jan 16, 2016
Chronic obstructive pulmonary disease is a condition involving perturbed barrier integrity coinci... more Chronic obstructive pulmonary disease is a condition involving perturbed barrier integrity coincident with both emphysema and inflammation of the airways, and smoking is considered a major risk factor. Claudins (Cldns) stabilize barriers and contribute to tight junctions by preventing paracellular transport of extracellular fluid constituents. To determine Cldn6 was differentially influenced by tobacco smoke, Cldn6 was evaluated in cells and tissues by q-PCR, immunoblotting, and immunohistochemistry following exposure. Cldn6 transcriptional regulation was also assessed using luciferase reporter constructs. Q-PCR and immunoblotting revealed that Cldn6 was decreased in alveolar type II-like epithelial cells (A549) and primary small airway epithelial cells when exposed to cigarette smoke extract (CSE). Cldn6 was also markedly decreased in the lungs of mice exposed to acute tobacco smoke delivered by a nose-only automated smoke machine compared to controls. Luciferase reporter assays in...
Purpose: Chronic obstructive pulmonary disease is a condition involving perturbed barrier integri... more Purpose: Chronic obstructive pulmonary disease is a condition involving perturbed barrier integrity coincident with both emphysema and inflammation of the airways, and smoking is considered a major risk factor. Claudins (Cldns) stabilize barriers and contribute to tight junctions by preventing paracellular transport of extracellular fluid constituents. Methods: To determine Cldn6 was differentially influenced by tobacco smoke, Cldn6 was evaluated in cells and tissues by q-PCR, immunoblotting, and immunohistochemistry following exposure. Cldn6 transcriptional regulation was also assessed using luciferase reporter constructs. Results: Q-PCR and immunoblotting revealed that Cldn6 was decreased in alveolar type II-like epithelial cells (A549) and primary small airway epithelial cells when exposed to cigarette smoke extract (CSE). Cldn6 was also markedly decreased in the lungs of mice exposed to acute tobacco smoke delivered by a nose-only automated smoke machine compared to controls. Luciferase reporter assays incorporating 0.5-kb, 1.0-kb, or 2.0-kb of the Cldn6 promoter revealed decreased transcription of Cldn6 following exposure to CSE. Cldn6 transcriptional regulation was also assessed in hypoxic conditions due to low oxygen tension observed during smoking. Hypoxia and hypoxia inducible factor-1 alpha caused decreased transcription of the Cldn6 gene via interactions with putative response elements in the proximal promoter sequence. Conclusions: These data reveal that tight junctional proteins such as Cldn6 are differentially regulated by tobacco-smoke exposure and that Cldns are potentially targeted when epithelial cells respond to tobacco smoke. Further research may show that Cldns expressed in tight junctions between parenchymal cells contribute to impaired structural integrity of the lung coincident with smoking.
Physiological genomics, Jan 7, 2015
Chronic treatment with the β-blocker carvedilol has been shown to reduce established maladaptive ... more Chronic treatment with the β-blocker carvedilol has been shown to reduce established maladaptive left ventricle (LV) hypertrophy and to improve LV function in experimental heart failure. However, the detailed mechanisms by which carvedilol improves LV failure are incompletely understood. We previously showed that carvedilol is a β-arrestin-biased β1-adrenergic receptor ligand, which activates cellular pathways in the heart independent of G protein-mediated second messenger signaling. More recently, we have demonstrated by microRNA (miR) microarray analysis that carvedilol upregulates a subset of mature and pre-mature miRs, but not their primary miR transcripts in mouse hearts. Here, we next sought to identify the effects of carvedilol on LV gene expression on a genome-wide basis. Adult mice were treated with carvedilol or vehicle for 1 week. RNA was isolated from LV tissue and hybridized for microarray analysis. Gene expression profiling analysis revealed a small group of genes diff...
ABSTRACT Genome reduction followed by 454 DNA sequencing was previously described in three orphan... more ABSTRACT Genome reduction followed by 454 DNA sequencing was previously described in three orphaned Andean crops: grain amaranth or kiwicha (Amaranthus caudatus, 2n=2x=32); papalisa (Ullucus tuberosus, 2n=2x=24); and oca (Oxalis tuberosa, 2n=8x=). Kiwicha is an ideal subsistence crop for intermediate-altitude tropical and subtropical environments due to its superb nutritional characteristics and culinary versatility. Papalisa and oca are starchy tuber crops that fill a vital agronomic niche in highland potato production systems. These sequences were mined for potentially useful SNP and SSR markers. We herein discuss the use of these markers for diversity studies in Peruvian collections of kiwicha and oca. Most notably, Fluidigm-based SNP assays in kiwicha identified that a cryptic vitreous-seeded type of kiwicha derived from unintentional hybridization with black-seeded wild amaranths has been under selection in multiple areas of the central Andes.
Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to ass... more Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to assess the effects of persistent tight junctions involving Cldn6 during lung development, a doxycycline (dox)-inducible conditional transgenic mouse was generated that up-‐regulates Cldn6 in the distal lung. Pups had unlimited access to dox from conception until sacrifice date at embryonic day (E) 18.5. Quantitative PCR, immunoblotting, and immunohistochemistry revealed significantly elevated Cldn6 expression in transgenic mice compared to non-‐transgenic controls. There were no differences in terms of lung size, lung weight, or whole body weight at the time of necropsy. Histological evaluations led to the discovery that E18.5 Cldn6 transgenic pups appeared to be in the early canalicular stage of development coincident with fewer, thickened respiratory airspaces. In contrast, controls appeared to have entered the saccular stage characterized by thin airspace walls and spherical architecture. Immunostaining for transcriptional regulators including TTF‐1 and FoxA2 was conducted to assess cell differentiation and specific cell types were identified via staining for pro‐surfactant protein C (alveolar type II epithelial cells) or Clara Cell Secretory Protein (cub or Clara cells). Lastly, cell turnover was qualitatively measured via staining for cell proliferation or apoptosis. These data suggest that Cldn6 is an important junctional protein potentially involved in the programming of epithelial cells during lung development. Furthermore, genetic down‐regulation of Cldn6 as development proceeds may influence differentiation observed in the transition from the canalicular to the saccular lung.
Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to ass... more Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to assess the effects of persistent tight junctions involving Cldn6 during lung development, a doxycycline (dox)-inducible conditional transgenic mouse was generated that up-regulates Cldn6 in the distal lung. Pups had unlimited access to dox from conception until sacrifice date at embryonic day (E) 18.5. Quantitative PCR, immunoblotting, and immunohistochemistry revealed significantly elevated Cldn6 expression in transgenic mice compared to non-transgenic controls. There were no differences in terms of lung size, lung weight, or whole body weight at the time of necropsy. Histological evaluations led to the discovery that E18.5 Cldn6 transgenic pups appeared to be in the early canalicular stage of development coincident with fewer, thickened respiratory airspaces. In contrast, controls appeared to have entered the saccular stage characterized by thin airspace walls and spherical architecture. Immunostaining for transcriptional regulators including TTF-1 and FoxA2 was conducted to assess cell differentiation and specific cell types were identified via staining for pro-surfactant protein C (alveolar type II epithelial cells) or Clara Cell Secretory Protein (cub or Clara cells). Lastly, cell turnover was qualitatively measured via staining for cell proliferation or apoptosis. These data suggest that Cldn6 is an important junctional protein potentially involved in the programming of epithelial cells during lung development. Furthermore, genetic down-regulation of Cldn6 as development proceeds may influence differentiation observed in the transition from the canalicular to the saccular lung.
Background
Claudins are transmembrane proteins expressed in tight junctions that prevent paracel... more Background
Claudins are transmembrane proteins expressed in tight junctions that prevent paracellular transport of extracellular fluid and a variety of other substances. However, the expression profile of Claudin-6 (Cldn6) in the developing lung has not been characterized.
Methods and results
Cldn6 expression was determined during important periods of lung organogenesis by microarray analysis, qPCR and immunofluorescence. Expression patterns were confirmed to peak at E12.5 and diminish as lung development progressed. Immunofluorescence revealed that Cldn6 was detected in cells that also express TTF-1 and FoxA2, two critical transcriptional regulators of pulmonary branching morphogenesis. Cldn6 was also observed in cells that express Sox2 and Sox9, factors that influence cell differentiation in the proximal and distal lung, respectively. In order to assess transcriptional control of Cldn6, 0.5, 1.0, and 2.0-kb of the proximal murine Cldn6 promoter was ligated into a luciferase reporter and co-transfected with expression vectors for TTF-1 or two of its important transcriptional co-regulators, FoxA2 and Gata-6. In almost every instance, TTF-1, FoxA2, and Gata-6 activated gene transcription in cell lines characteristic of proximal airway epithelium (Beas2B) and distal alveolar epithelium (A-549).
Conclusions
These data revealed for the first time that Cldn6 might be an important tight junctional component expressed by pulmonary epithelium during lung organogenesis. Furthermore, Cldn6-mediated aspects of cell differentiation may describe mechanisms of lung perturbation coincident with impaired cell junctions and abnormal membrane permeability.
Background: Receptors for advanced glycation end-products (RAGE) are multiligand cell-surface rec... more Background: Receptors for advanced glycation end-products (RAGE) are multiligand cell-surface receptors expressed
abundantly by distal pulmonary epithelium. Our lab has discovered RAGE-mediated effects in the orchestration of lung
inflammation induced by tobacco smoke and environmental pollutants; however, the specific contribution of RAGE to
the progression of proximal airway inflammation is still inadequately characterized.
Methods and results: We generated a Tet-inducible transgenic mouse that conditionally overexpressed RAGE using
the club cell (Clara) secretory protein (CCSP) promoter expressed by club (Clara) cells localized to the proximal airway.
RAGE was induced for 40 days from weaning (20 days of age) until sacrifice date at 60 days. Immunohistochemistry,
immunoblotting, and qPCR revealed significant RAGE up-regulation when compared to non-transgenic controls; however,
H&E staining revealed no detectible morphological abnormalities and apoptosis was not enhanced during the 40 days
of augmentation. Freshly procured bronchoalveolar lavage fluid (BALF) from CCSP-RAGE TG mice had significantly more
total leukocytes and PMNs compared to age-matched control littermates. Furthermore, CCSP-RAGE TG mice expressed
significantly more tumor necrosis factor alpha (TNF-α), interleukin 7 (IL-7), and interleukin 14 (IL-14) in whole lung
homogenates compared to controls.
Conclusions: These data support the concept that RAGE up-regulation specifically in lung airways may function in the
progression of proximal airway inflammation.
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Papers by Felix R. Jimenez, Ph.D
Claudins are transmembrane proteins expressed in tight junctions that prevent paracellular transport of extracellular fluid and a variety of other substances. However, the expression profile of Claudin-6 (Cldn6) in the developing lung has not been characterized.
Methods and results
Cldn6 expression was determined during important periods of lung organogenesis by microarray analysis, qPCR and immunofluorescence. Expression patterns were confirmed to peak at E12.5 and diminish as lung development progressed. Immunofluorescence revealed that Cldn6 was detected in cells that also express TTF-1 and FoxA2, two critical transcriptional regulators of pulmonary branching morphogenesis. Cldn6 was also observed in cells that express Sox2 and Sox9, factors that influence cell differentiation in the proximal and distal lung, respectively. In order to assess transcriptional control of Cldn6, 0.5, 1.0, and 2.0-kb of the proximal murine Cldn6 promoter was ligated into a luciferase reporter and co-transfected with expression vectors for TTF-1 or two of its important transcriptional co-regulators, FoxA2 and Gata-6. In almost every instance, TTF-1, FoxA2, and Gata-6 activated gene transcription in cell lines characteristic of proximal airway epithelium (Beas2B) and distal alveolar epithelium (A-549).
Conclusions
These data revealed for the first time that Cldn6 might be an important tight junctional component expressed by pulmonary epithelium during lung organogenesis. Furthermore, Cldn6-mediated aspects of cell differentiation may describe mechanisms of lung perturbation coincident with impaired cell junctions and abnormal membrane permeability.
abundantly by distal pulmonary epithelium. Our lab has discovered RAGE-mediated effects in the orchestration of lung
inflammation induced by tobacco smoke and environmental pollutants; however, the specific contribution of RAGE to
the progression of proximal airway inflammation is still inadequately characterized.
Methods and results: We generated a Tet-inducible transgenic mouse that conditionally overexpressed RAGE using
the club cell (Clara) secretory protein (CCSP) promoter expressed by club (Clara) cells localized to the proximal airway.
RAGE was induced for 40 days from weaning (20 days of age) until sacrifice date at 60 days. Immunohistochemistry,
immunoblotting, and qPCR revealed significant RAGE up-regulation when compared to non-transgenic controls; however,
H&E staining revealed no detectible morphological abnormalities and apoptosis was not enhanced during the 40 days
of augmentation. Freshly procured bronchoalveolar lavage fluid (BALF) from CCSP-RAGE TG mice had significantly more
total leukocytes and PMNs compared to age-matched control littermates. Furthermore, CCSP-RAGE TG mice expressed
significantly more tumor necrosis factor alpha (TNF-α), interleukin 7 (IL-7), and interleukin 14 (IL-14) in whole lung
homogenates compared to controls.
Conclusions: These data support the concept that RAGE up-regulation specifically in lung airways may function in the
progression of proximal airway inflammation.
Claudins are transmembrane proteins expressed in tight junctions that prevent paracellular transport of extracellular fluid and a variety of other substances. However, the expression profile of Claudin-6 (Cldn6) in the developing lung has not been characterized.
Methods and results
Cldn6 expression was determined during important periods of lung organogenesis by microarray analysis, qPCR and immunofluorescence. Expression patterns were confirmed to peak at E12.5 and diminish as lung development progressed. Immunofluorescence revealed that Cldn6 was detected in cells that also express TTF-1 and FoxA2, two critical transcriptional regulators of pulmonary branching morphogenesis. Cldn6 was also observed in cells that express Sox2 and Sox9, factors that influence cell differentiation in the proximal and distal lung, respectively. In order to assess transcriptional control of Cldn6, 0.5, 1.0, and 2.0-kb of the proximal murine Cldn6 promoter was ligated into a luciferase reporter and co-transfected with expression vectors for TTF-1 or two of its important transcriptional co-regulators, FoxA2 and Gata-6. In almost every instance, TTF-1, FoxA2, and Gata-6 activated gene transcription in cell lines characteristic of proximal airway epithelium (Beas2B) and distal alveolar epithelium (A-549).
Conclusions
These data revealed for the first time that Cldn6 might be an important tight junctional component expressed by pulmonary epithelium during lung organogenesis. Furthermore, Cldn6-mediated aspects of cell differentiation may describe mechanisms of lung perturbation coincident with impaired cell junctions and abnormal membrane permeability.
abundantly by distal pulmonary epithelium. Our lab has discovered RAGE-mediated effects in the orchestration of lung
inflammation induced by tobacco smoke and environmental pollutants; however, the specific contribution of RAGE to
the progression of proximal airway inflammation is still inadequately characterized.
Methods and results: We generated a Tet-inducible transgenic mouse that conditionally overexpressed RAGE using
the club cell (Clara) secretory protein (CCSP) promoter expressed by club (Clara) cells localized to the proximal airway.
RAGE was induced for 40 days from weaning (20 days of age) until sacrifice date at 60 days. Immunohistochemistry,
immunoblotting, and qPCR revealed significant RAGE up-regulation when compared to non-transgenic controls; however,
H&E staining revealed no detectible morphological abnormalities and apoptosis was not enhanced during the 40 days
of augmentation. Freshly procured bronchoalveolar lavage fluid (BALF) from CCSP-RAGE TG mice had significantly more
total leukocytes and PMNs compared to age-matched control littermates. Furthermore, CCSP-RAGE TG mice expressed
significantly more tumor necrosis factor alpha (TNF-α), interleukin 7 (IL-7), and interleukin 14 (IL-14) in whole lung
homogenates compared to controls.
Conclusions: These data support the concept that RAGE up-regulation specifically in lung airways may function in the
progression of proximal airway inflammation.