Shunbin Xu - Academia.edu (original) (raw)

Papers by Shunbin Xu

The Journal of Immunology

MicroRNAs (miRNAs), a class of non-coding small RNAs. Invariant Natural Killer T (iNKT) cells are... more MicroRNAs (miRNAs), a class of non-coding small RNAs. Invariant Natural Killer T (iNKT) cells are potent regulators of diverse immune responses. Our previous study indicated that lack of miRNAs following the deletion of Dicer, a miRNAs-processing enzyme, affect iNKT cell development and function (PNAS, 2009). However, the roles of specific miRNA in iNKT cell development and function remain unclear. The miR-183/96/182 cluster, composed of 3 miRNA genes, is significantly upregulated upon T cell activation. In this study, we investigate the role of miR-183/96/182 cluster on development and function of iNKT cells, using miR-183/96/182 knockout (KO) mice. We found that the frequency of immature iNKT cells significantly increased, while mature iNKT cells significantly decreased in thymus of KO mice compared to littermate control (P<0.05), indicating the blockage of iNKT cell development in thymus. Furthermore, lack of miR-183/96/182 resulted in a substantial reduction of iNKT cell numb...

Scientific Reports, Jan 15, 2020

improved in situ hybridization methods for mRnA detection in tissues have been developed based on... more improved in situ hybridization methods for mRnA detection in tissues have been developed based on the hybridization chain reaction (HCR). We show that in situ HCR methods can be used for the detection of microRNAs in tissue sections from mouse retinas. In situ HCR can be used for the detection of two microRNAs simultaneously or for the combined detection of microRNA and mRNA. In addition, miRNA in situ HCR can be combined with immunodetection of proteins. We use these methods to characterize cells expressing specific microRNAs in the mouse retina. We find that miR-181a is expressed in amacrine cells during development and in adult retinas, and it is present in both GABAergic and glycinergic amacrine cells. The detection of microRNAs with in situ HCR should facilitate studies of microRNA function and gene regulation in the retina and other tissues.

Investigative Opthalmology & Visual Science

Purpose Previously, we demonstrated that miR-183/96/182 cluster (miR-183C) knockout mice exhibit ... more Purpose Previously, we demonstrated that miR-183/96/182 cluster (miR-183C) knockout mice exhibit decreased severity of Pseudomonas aeruginosa (PA)-induced keratitis. This study tests the hypothesis that prophylactic knockdown of miR-183C ameliorates PA keratitis indicative of a therapeutic potential. Methods Eight-week-old miR-183C wild-type and C57BL/6J inbred mice were used. Locked nucleic acid–modified anti-miR-183C or negative control oligoribonucleotides with scrambled sequences (NC ORNs) were injected subconjunctivally 1 day before and then topically applied once daily for 5 days post-infection (dpi) (strain 19660). Corneal disease was graded at 1, 3, and 5 dpi. Corneas were harvested for RT-PCR, ELISA, immunofluorescence (IF), myeloperoxidase and plate count assays, and flow cytometry. Corneal nerve density was evaluated in flatmounted corneas by IF staining with anti-β-III tubulin antibody. Results Anti-miR-183C downregulated miR-183C in the cornea. It resulted in an increase in IL-1β at 1 dpi, which was decreased at 5 dpi; fewer polymorphonuclear leukocytes (PMNs) at 5 dpi; lower viable bacterial plate count at both 1 and 5 dpi; increased percentages of MHCII+ macrophages (Mϕ) and dendritic cells (DCs), consistent with enhanced activation/maturation; and decreased severity of PA keratitis. Anti-miR-183C treatment in the cornea of naïve mice resulted in a transient reduction of corneal nerve density, which was fully recovered one week after the last anti-miR application. miR-183C targets repulsive axon-guidance receptor molecule Neuropilin 1, which may mediate the effect of anti-miR-183C on corneal nerve regression. Conclusions Prophylactic miR-183C knockdown is protective against PA keratitis through its regulation of innate immunity, corneal innervation, and neuroimmune interactions.

Investigative Ophthalmology & Visual Science, 2008

Investigative Ophthalmology & Visual Science, 2012

Investigative Ophthalmology & Visual Science, 2018

Investigative Ophthalmology & Visual Science, 2006

Investigative Ophthalmology & Visual Science, 2012

The Ocular Surface, 2021

Corneal infections result through interaction between microbes and host innate immune receptors. ... more Corneal infections result through interaction between microbes and host innate immune receptors. Damage to the cornea occurs as a result of microbial virulence factors and is often exacerbated by lack of a controlled host immune response; the latter contributing to bystander damage to corneal structure. Understanding mechanisms involved in host microbial interactions is critical to development of novel therapeutic targets, ultimate control of microbial pathogenesis, and restoration of tissue homeostasis. Studies on these interactions continue to provide exciting findings directly related to this ultimate goal.

Scientific Reports, 2020

Improved in situ hybridization methods for mRNA detection in tissues have been developed based on... more Improved in situ hybridization methods for mRNA detection in tissues have been developed based on the hybridization chain reaction (HCR). We show that in situ HCR methods can be used for the detection of microRNAs in tissue sections from mouse retinas. In situ HCR can be used for the detection of two microRNAs simultaneously or for the combined detection of microRNA and mRNA. In addition, miRNA in situ HCR can be combined with immunodetection of proteins. We use these methods to characterize cells expressing specific microRNAs in the mouse retina. We find that miR-181a is expressed in amacrine cells during development and in adult retinas, and it is present in both GABAergic and glycinergic amacrine cells. The detection of microRNAs with in situ HCR should facilitate studies of microRNA function and gene regulation in the retina and other tissues.

The Journal of Immunology, 2019

Although primary humoral responses are vital to durable immunity, fine-tuning is critical to prev... more Although primary humoral responses are vital to durable immunity, fine-tuning is critical to preventing catastrophes such as autoimmunity, chronic inflammation, and lymphomagenesis. MicroRNA (miRNA)-mediated regulation is particularly well suited for fine-tuning roles in physiology. Expression of clustered paralogous miR-182, miR-96, and miR-183 (collectively, 183c) is robustly induced upon B cell activation, entry into the germinal center, and plasmablast differentiation. 183cGT/GT mice lacking 183c miRNA expression exhibit largely normal primary humoral responses, encompassing class switch recombination, affinity maturation, and germinal center reaction, as well as plasmablast differentiation. Our rigorous analysis included ex vivo class switch recombination and plasmablast differentiation models as well as in vivo immunization with thymus-dependent and thymus-independent Ags. Our work sways the debate concerning the role of miR-182 in plasmablast differentiation, strongly suggest...

Journal of Innate Immunity, 2019

Macrophages (Mϕ) are an important component of the innate immune system; they play critical roles... more Macrophages (Mϕ) are an important component of the innate immune system; they play critical roles in the first line of defense to pathogen invasion and modulate adaptive immunity. MicroRNAs (miRNAs) are a newly recognized, important level of gene expression regulation. However, their roles in the regulation of Mϕ and the immune system are still not fully understood. In this report, we provide evidence that the conserved miR-183/96/182 cluster (miR-183/96/182) modulates Mϕ function in their production of reactive nitrogen (RNS) and oxygen species (ROS) and their inflammatory response to Pseudomonas aeruginosa (PA) infection and/or lipopolysaccharide (LPS) treatment. We show that knockdown of miR-183/96/182 results in decreased production of multiple proinflammatory cytokines in response to PA or LPS treatment in Mϕ-like Raw264.7 cells. Consistently, peritoneal Mϕ from miR-183/96/182-knockout versus wild-type mice are less responsive to PA or LPS, although their basal levels of proinf...

Genome Research, 1997

Identification of genes expressed preferentially or exclusively in photoreceptors will facilitate... more Identification of genes expressed preferentially or exclusively in photoreceptors will facilitate the understanding of photoreceptor biology as well as provide candidate genes for inherited retinal degenerations. To achieve this goal we performed a differential hybridization screen of 3717 well-isolated phage clones from a human retinal cDNA library. Clones were selected for further study if they hybridized exclusively or strongly preferentially to a probe derived from RNA isolated from the cone-predominant retina of 13-line ground squirrels as compared to a probe derived from human fibroblast RNA. Twenty percent of clones (9/45) identified by this screen were derived from photoreceptor-specific genes and an additional 24.4% (11/45) were from neural-specific genes, demonstrating the utility of this strategy in identifying genes important for retinal biology.[The sequence tags of cDNAs identified in this screen have been deposited in GenBank under accession nos. U89715, U89878–U89888...

Investigative ophthalmology & visual science, 2017

Previously, we showed that microRNA-146 (miR-146) is a pivotal negative feedback regulator of mul... more Previously, we showed that microRNA-146 (miR-146) is a pivotal negative feedback regulator of multiple nuclear factor kappa-B (NF-κB) activation pathways in retinal endothelial cells (RECs). We hypothesized that miR-146 plays an important role in diabetic retinopathy (DR) by inhibiting diabetes-induced inflammatory response in the retina. The purpose of the current study is to test this hypothesis in vivo. Lentiviruses expressing rno-miR-146a, lenti-miR-146a, and negative control oligonucleotide with scrambled sequence, lenti-miR-neg ctl, were produced. Young male Sprague-Dawley rats were injected with a single dose of streptozotocin ([STZ] 65 mg/kg) to induce diabetes. One week after diabetes, animals were injected with lentivirus intravitreally (4 μl, ∼106 CFU/mL). Three months after diabetes, retinal microvascular leakage was tested by Evans blue assay; retinal function by electroretinogram (ERG). Total RNA and protein lysate were isolated from the retina for quantitative (q)RT-P...

Progress in retinal and eye research, 2009

microRNAs (miRNAs) are endogenous, small, non-coding, regulatory RNAs, approximately 22 nucleotid... more microRNAs (miRNAs) are endogenous, small, non-coding, regulatory RNAs, approximately 22 nucleotides (nts) in size. Since the first discovery of miRNAs in 1993 in Caenorhabditis elegans, miRNAs have been shown to be widely expressed in metazoans and plants in tissue-specific and developmental stage-specific manners. miRNAs target their downstream messenger RNAs (mRNAs) by base pairing to their target sites with sequence complementarity, mainly in the 3' untranslated region (UTR), and induce the breakdown of the targeted mRNAs and/or inhibition of translation from the mRNAs. Approximately 30% of the protein-coding genes are estimated to be regulated by miRNAs. One miRNA can target hundreds of downstream target mRNAs, while one mRNA can be targeted by multiple miRNAs. miRNAs have been recognized as a major level of post-transcriptional regulation of the fine-tuning of gene expression, playing important roles in cellular proliferation, differentiation, and cell death and are involve...

Investigative ophthalmology & visual science, 2014

Nuclear factor-κB (NF-κB), a key regulator of immune and inflammatory responses, plays important ... more Nuclear factor-κB (NF-κB), a key regulator of immune and inflammatory responses, plays important roles in diabetes-induced microvascular complications including diabetic retinopathy (DR). Thrombin activates NF-κB through protease-activated receptor (PAR)-1, a member of the G-protein-coupled receptor (GPCR) superfamily, and contributes to DR. The current study is to uncover the roles of microRNA (miRNA) in thrombin-induced NF-κB activation and retinal endothelial functions. Target prediction was performed using the TargetScan algorithm. Predicted target was experimentally validated by luciferase reporter assays. Human retinal endothelial cells (HRECs) were transfected with miRNA mimics or antimiRs and treated with thrombin. Expression levels of miR-146 and related protein-coding genes were analyzed by quantitative (q)RT-PCR. Functional changes of HRECs were analyzed by leukocyte adhesion assays. We identified that caspase-recruitment domain (CARD)-containing protein 10 (CARD10), an e...

Alzheimer's & Dementia, 2015

Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Al... more Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Alzheimer's disease (AD) by several years and may signify increased risk of developing AD. Traditionally, sensory and motor dysfunctions in aging and AD have been studied separately. To ascertain the evidence supporting the relationship between age‐related changes in sensory and motor systems and the development of AD and to facilitate communication between several disciplines, the National Institute on Aging held an exploratory workshop titled “Sensory and Motor Dysfunctions in Aging and AD.” The scientific sessions of the workshop focused on age‐related and neuropathologic changes in the olfactory, visual, auditory, and motor systems, followed by extensive discussion and hypothesis generation related to the possible links among sensory, cognitive, and motor domains in aging and AD. Based on the data presented and discussed at this workshop, it is clear that sensory and motor regions ...

The Laryngoscope, 2010

Objectives/Hypothesis.To characterize the role of Phr1, a gene highly expressed in primary sensor... more Objectives/Hypothesis.To characterize the role of Phr1, a gene highly expressed in primary sensory neurons where it encodes an integral membrane protein with an N‐terminal pleckstrin homology domain and a C‐terminal transmembrane domain, in the olfactory system.Methods.We studied the immunelocalization of the PHR1 protein in mouse olfactory epithelium both at steady state and during regeneration following methyl bromide (MeBr) exposure using scanning confocal microscopy. Additionally, we examined the electrophysiologic role of Phr1 in olfaction and short‐term olfactory adaptation.Results.We found that PHR1 is abundantly and specifically expressed in olfactory neurons. It is widely distributed in punctate, vesiculated organelles throughout the cell bodies, axons, and glomeruli of primary olfactory neurons but is specifically excluded from the olfactory cilia. In the regenerating olfactory epithelium, PHR1 expression appears at 14 days following MeBr ablation coinciding with the onset...

The Journal of Cell Biology, 2006

The mechanisms governing the emergence of the earliest mammalian neural cells during development ... more The mechanisms governing the emergence of the earliest mammalian neural cells during development remain incompletely characterized. A default mechanism has been suggested to underlie neural fate acquisition; however, an instructive process has also been proposed. We used mouse embryonic stem (ES) cells to explore the fundamental issue of how an uncommitted, pluripotent mammalian cell will self-organize in the absence of extrinsic signals and what cellular fate will result. To assess this default state, ES cells were placed in conditions that minimize external influences. Individual ES cells were found to rapidly transition directly into neural cells, a process shown to be independent of suggested instructive factors (e.g., fibroblast growth factors). Further, we provide evidence that the default neural identity is that of a primitive neural stem cell (NSC). The exiguous conditions used to reveal the default state were found to present primitive NSCs with a survival challenge (limiti...

Surgical Neurology International, 2014

Background: Os odontoideum is a well identified anomaly of the craniovertebral junction. Since it... more Background: Os odontoideum is a well identified anomaly of the craniovertebral junction. Since its initial description, there has been a continuous debate regarding the nature of its etiology: Whether congenital or traumatic. We sought to compare the gene expression profiles in patients with congenital os odontoideum, those with traumatic os odontoideum and controls. Methods: We have evaluated a pair of identical twins both with os odontoideum. We identified two additional patients with and four subjects without os odontoideum. We analyzed the gene expression profiles in these patients using a custom TaqMan microarray and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The relative gene expression profiles in the two identical twins, the two nontwin patients with os odontoideum and the controls were assessed. Results: A total of 213 genes with significantly different expression between the twin os odontoideum patients and the subjects without os odontoideum were detected. CACNG6, PHEX, CACNAD3, IL2, FAS, TUFT1, KIT, TGFBR2, and IGF2 were expressed at levels greater than 100-fold more in the twins. There were six genes with significantly different expression profiles in the twins as compared with the nontwin os odontoideum patients: CMK4, ATF1, PLCG1, TAB1, E2F3, and ATF4. There were no statistically significant differences in gene expression in the four patients with os odontoideum and the subjects without. Trends, however, were noted in MMP8, KIT,

The Journal of Immunology

MicroRNAs (miRNAs), a class of non-coding small RNAs. Invariant Natural Killer T (iNKT) cells are... more MicroRNAs (miRNAs), a class of non-coding small RNAs. Invariant Natural Killer T (iNKT) cells are potent regulators of diverse immune responses. Our previous study indicated that lack of miRNAs following the deletion of Dicer, a miRNAs-processing enzyme, affect iNKT cell development and function (PNAS, 2009). However, the roles of specific miRNA in iNKT cell development and function remain unclear. The miR-183/96/182 cluster, composed of 3 miRNA genes, is significantly upregulated upon T cell activation. In this study, we investigate the role of miR-183/96/182 cluster on development and function of iNKT cells, using miR-183/96/182 knockout (KO) mice. We found that the frequency of immature iNKT cells significantly increased, while mature iNKT cells significantly decreased in thymus of KO mice compared to littermate control (P<0.05), indicating the blockage of iNKT cell development in thymus. Furthermore, lack of miR-183/96/182 resulted in a substantial reduction of iNKT cell numb...

Scientific Reports, Jan 15, 2020

improved in situ hybridization methods for mRnA detection in tissues have been developed based on... more improved in situ hybridization methods for mRnA detection in tissues have been developed based on the hybridization chain reaction (HCR). We show that in situ HCR methods can be used for the detection of microRNAs in tissue sections from mouse retinas. In situ HCR can be used for the detection of two microRNAs simultaneously or for the combined detection of microRNA and mRNA. In addition, miRNA in situ HCR can be combined with immunodetection of proteins. We use these methods to characterize cells expressing specific microRNAs in the mouse retina. We find that miR-181a is expressed in amacrine cells during development and in adult retinas, and it is present in both GABAergic and glycinergic amacrine cells. The detection of microRNAs with in situ HCR should facilitate studies of microRNA function and gene regulation in the retina and other tissues.

Investigative Opthalmology & Visual Science

Purpose Previously, we demonstrated that miR-183/96/182 cluster (miR-183C) knockout mice exhibit ... more Purpose Previously, we demonstrated that miR-183/96/182 cluster (miR-183C) knockout mice exhibit decreased severity of Pseudomonas aeruginosa (PA)-induced keratitis. This study tests the hypothesis that prophylactic knockdown of miR-183C ameliorates PA keratitis indicative of a therapeutic potential. Methods Eight-week-old miR-183C wild-type and C57BL/6J inbred mice were used. Locked nucleic acid–modified anti-miR-183C or negative control oligoribonucleotides with scrambled sequences (NC ORNs) were injected subconjunctivally 1 day before and then topically applied once daily for 5 days post-infection (dpi) (strain 19660). Corneal disease was graded at 1, 3, and 5 dpi. Corneas were harvested for RT-PCR, ELISA, immunofluorescence (IF), myeloperoxidase and plate count assays, and flow cytometry. Corneal nerve density was evaluated in flatmounted corneas by IF staining with anti-β-III tubulin antibody. Results Anti-miR-183C downregulated miR-183C in the cornea. It resulted in an increase in IL-1β at 1 dpi, which was decreased at 5 dpi; fewer polymorphonuclear leukocytes (PMNs) at 5 dpi; lower viable bacterial plate count at both 1 and 5 dpi; increased percentages of MHCII+ macrophages (Mϕ) and dendritic cells (DCs), consistent with enhanced activation/maturation; and decreased severity of PA keratitis. Anti-miR-183C treatment in the cornea of naïve mice resulted in a transient reduction of corneal nerve density, which was fully recovered one week after the last anti-miR application. miR-183C targets repulsive axon-guidance receptor molecule Neuropilin 1, which may mediate the effect of anti-miR-183C on corneal nerve regression. Conclusions Prophylactic miR-183C knockdown is protective against PA keratitis through its regulation of innate immunity, corneal innervation, and neuroimmune interactions.

Investigative Ophthalmology & Visual Science, 2008

Investigative Ophthalmology & Visual Science, 2012

Investigative Ophthalmology & Visual Science, 2018

Investigative Ophthalmology & Visual Science, 2006

Investigative Ophthalmology & Visual Science, 2012

The Ocular Surface, 2021

Corneal infections result through interaction between microbes and host innate immune receptors. ... more Corneal infections result through interaction between microbes and host innate immune receptors. Damage to the cornea occurs as a result of microbial virulence factors and is often exacerbated by lack of a controlled host immune response; the latter contributing to bystander damage to corneal structure. Understanding mechanisms involved in host microbial interactions is critical to development of novel therapeutic targets, ultimate control of microbial pathogenesis, and restoration of tissue homeostasis. Studies on these interactions continue to provide exciting findings directly related to this ultimate goal.

Scientific Reports, 2020

Improved in situ hybridization methods for mRNA detection in tissues have been developed based on... more Improved in situ hybridization methods for mRNA detection in tissues have been developed based on the hybridization chain reaction (HCR). We show that in situ HCR methods can be used for the detection of microRNAs in tissue sections from mouse retinas. In situ HCR can be used for the detection of two microRNAs simultaneously or for the combined detection of microRNA and mRNA. In addition, miRNA in situ HCR can be combined with immunodetection of proteins. We use these methods to characterize cells expressing specific microRNAs in the mouse retina. We find that miR-181a is expressed in amacrine cells during development and in adult retinas, and it is present in both GABAergic and glycinergic amacrine cells. The detection of microRNAs with in situ HCR should facilitate studies of microRNA function and gene regulation in the retina and other tissues.

The Journal of Immunology, 2019

Although primary humoral responses are vital to durable immunity, fine-tuning is critical to prev... more Although primary humoral responses are vital to durable immunity, fine-tuning is critical to preventing catastrophes such as autoimmunity, chronic inflammation, and lymphomagenesis. MicroRNA (miRNA)-mediated regulation is particularly well suited for fine-tuning roles in physiology. Expression of clustered paralogous miR-182, miR-96, and miR-183 (collectively, 183c) is robustly induced upon B cell activation, entry into the germinal center, and plasmablast differentiation. 183cGT/GT mice lacking 183c miRNA expression exhibit largely normal primary humoral responses, encompassing class switch recombination, affinity maturation, and germinal center reaction, as well as plasmablast differentiation. Our rigorous analysis included ex vivo class switch recombination and plasmablast differentiation models as well as in vivo immunization with thymus-dependent and thymus-independent Ags. Our work sways the debate concerning the role of miR-182 in plasmablast differentiation, strongly suggest...

Journal of Innate Immunity, 2019

Macrophages (Mϕ) are an important component of the innate immune system; they play critical roles... more Macrophages (Mϕ) are an important component of the innate immune system; they play critical roles in the first line of defense to pathogen invasion and modulate adaptive immunity. MicroRNAs (miRNAs) are a newly recognized, important level of gene expression regulation. However, their roles in the regulation of Mϕ and the immune system are still not fully understood. In this report, we provide evidence that the conserved miR-183/96/182 cluster (miR-183/96/182) modulates Mϕ function in their production of reactive nitrogen (RNS) and oxygen species (ROS) and their inflammatory response to Pseudomonas aeruginosa (PA) infection and/or lipopolysaccharide (LPS) treatment. We show that knockdown of miR-183/96/182 results in decreased production of multiple proinflammatory cytokines in response to PA or LPS treatment in Mϕ-like Raw264.7 cells. Consistently, peritoneal Mϕ from miR-183/96/182-knockout versus wild-type mice are less responsive to PA or LPS, although their basal levels of proinf...

Genome Research, 1997

Identification of genes expressed preferentially or exclusively in photoreceptors will facilitate... more Identification of genes expressed preferentially or exclusively in photoreceptors will facilitate the understanding of photoreceptor biology as well as provide candidate genes for inherited retinal degenerations. To achieve this goal we performed a differential hybridization screen of 3717 well-isolated phage clones from a human retinal cDNA library. Clones were selected for further study if they hybridized exclusively or strongly preferentially to a probe derived from RNA isolated from the cone-predominant retina of 13-line ground squirrels as compared to a probe derived from human fibroblast RNA. Twenty percent of clones (9/45) identified by this screen were derived from photoreceptor-specific genes and an additional 24.4% (11/45) were from neural-specific genes, demonstrating the utility of this strategy in identifying genes important for retinal biology.[The sequence tags of cDNAs identified in this screen have been deposited in GenBank under accession nos. U89715, U89878–U89888...

Investigative ophthalmology & visual science, 2017

Previously, we showed that microRNA-146 (miR-146) is a pivotal negative feedback regulator of mul... more Previously, we showed that microRNA-146 (miR-146) is a pivotal negative feedback regulator of multiple nuclear factor kappa-B (NF-κB) activation pathways in retinal endothelial cells (RECs). We hypothesized that miR-146 plays an important role in diabetic retinopathy (DR) by inhibiting diabetes-induced inflammatory response in the retina. The purpose of the current study is to test this hypothesis in vivo. Lentiviruses expressing rno-miR-146a, lenti-miR-146a, and negative control oligonucleotide with scrambled sequence, lenti-miR-neg ctl, were produced. Young male Sprague-Dawley rats were injected with a single dose of streptozotocin ([STZ] 65 mg/kg) to induce diabetes. One week after diabetes, animals were injected with lentivirus intravitreally (4 μl, ∼106 CFU/mL). Three months after diabetes, retinal microvascular leakage was tested by Evans blue assay; retinal function by electroretinogram (ERG). Total RNA and protein lysate were isolated from the retina for quantitative (q)RT-P...

Progress in retinal and eye research, 2009

microRNAs (miRNAs) are endogenous, small, non-coding, regulatory RNAs, approximately 22 nucleotid... more microRNAs (miRNAs) are endogenous, small, non-coding, regulatory RNAs, approximately 22 nucleotides (nts) in size. Since the first discovery of miRNAs in 1993 in Caenorhabditis elegans, miRNAs have been shown to be widely expressed in metazoans and plants in tissue-specific and developmental stage-specific manners. miRNAs target their downstream messenger RNAs (mRNAs) by base pairing to their target sites with sequence complementarity, mainly in the 3' untranslated region (UTR), and induce the breakdown of the targeted mRNAs and/or inhibition of translation from the mRNAs. Approximately 30% of the protein-coding genes are estimated to be regulated by miRNAs. One miRNA can target hundreds of downstream target mRNAs, while one mRNA can be targeted by multiple miRNAs. miRNAs have been recognized as a major level of post-transcriptional regulation of the fine-tuning of gene expression, playing important roles in cellular proliferation, differentiation, and cell death and are involve...

Investigative ophthalmology & visual science, 2014

Nuclear factor-κB (NF-κB), a key regulator of immune and inflammatory responses, plays important ... more Nuclear factor-κB (NF-κB), a key regulator of immune and inflammatory responses, plays important roles in diabetes-induced microvascular complications including diabetic retinopathy (DR). Thrombin activates NF-κB through protease-activated receptor (PAR)-1, a member of the G-protein-coupled receptor (GPCR) superfamily, and contributes to DR. The current study is to uncover the roles of microRNA (miRNA) in thrombin-induced NF-κB activation and retinal endothelial functions. Target prediction was performed using the TargetScan algorithm. Predicted target was experimentally validated by luciferase reporter assays. Human retinal endothelial cells (HRECs) were transfected with miRNA mimics or antimiRs and treated with thrombin. Expression levels of miR-146 and related protein-coding genes were analyzed by quantitative (q)RT-PCR. Functional changes of HRECs were analyzed by leukocyte adhesion assays. We identified that caspase-recruitment domain (CARD)-containing protein 10 (CARD10), an e...

Alzheimer's & Dementia, 2015

Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Al... more Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Alzheimer's disease (AD) by several years and may signify increased risk of developing AD. Traditionally, sensory and motor dysfunctions in aging and AD have been studied separately. To ascertain the evidence supporting the relationship between age‐related changes in sensory and motor systems and the development of AD and to facilitate communication between several disciplines, the National Institute on Aging held an exploratory workshop titled “Sensory and Motor Dysfunctions in Aging and AD.” The scientific sessions of the workshop focused on age‐related and neuropathologic changes in the olfactory, visual, auditory, and motor systems, followed by extensive discussion and hypothesis generation related to the possible links among sensory, cognitive, and motor domains in aging and AD. Based on the data presented and discussed at this workshop, it is clear that sensory and motor regions ...

The Laryngoscope, 2010

Objectives/Hypothesis.To characterize the role of Phr1, a gene highly expressed in primary sensor... more Objectives/Hypothesis.To characterize the role of Phr1, a gene highly expressed in primary sensory neurons where it encodes an integral membrane protein with an N‐terminal pleckstrin homology domain and a C‐terminal transmembrane domain, in the olfactory system.Methods.We studied the immunelocalization of the PHR1 protein in mouse olfactory epithelium both at steady state and during regeneration following methyl bromide (MeBr) exposure using scanning confocal microscopy. Additionally, we examined the electrophysiologic role of Phr1 in olfaction and short‐term olfactory adaptation.Results.We found that PHR1 is abundantly and specifically expressed in olfactory neurons. It is widely distributed in punctate, vesiculated organelles throughout the cell bodies, axons, and glomeruli of primary olfactory neurons but is specifically excluded from the olfactory cilia. In the regenerating olfactory epithelium, PHR1 expression appears at 14 days following MeBr ablation coinciding with the onset...

The Journal of Cell Biology, 2006

The mechanisms governing the emergence of the earliest mammalian neural cells during development ... more The mechanisms governing the emergence of the earliest mammalian neural cells during development remain incompletely characterized. A default mechanism has been suggested to underlie neural fate acquisition; however, an instructive process has also been proposed. We used mouse embryonic stem (ES) cells to explore the fundamental issue of how an uncommitted, pluripotent mammalian cell will self-organize in the absence of extrinsic signals and what cellular fate will result. To assess this default state, ES cells were placed in conditions that minimize external influences. Individual ES cells were found to rapidly transition directly into neural cells, a process shown to be independent of suggested instructive factors (e.g., fibroblast growth factors). Further, we provide evidence that the default neural identity is that of a primitive neural stem cell (NSC). The exiguous conditions used to reveal the default state were found to present primitive NSCs with a survival challenge (limiti...

Surgical Neurology International, 2014

Background: Os odontoideum is a well identified anomaly of the craniovertebral junction. Since it... more Background: Os odontoideum is a well identified anomaly of the craniovertebral junction. Since its initial description, there has been a continuous debate regarding the nature of its etiology: Whether congenital or traumatic. We sought to compare the gene expression profiles in patients with congenital os odontoideum, those with traumatic os odontoideum and controls. Methods: We have evaluated a pair of identical twins both with os odontoideum. We identified two additional patients with and four subjects without os odontoideum. We analyzed the gene expression profiles in these patients using a custom TaqMan microarray and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The relative gene expression profiles in the two identical twins, the two nontwin patients with os odontoideum and the controls were assessed. Results: A total of 213 genes with significantly different expression between the twin os odontoideum patients and the subjects without os odontoideum were detected. CACNG6, PHEX, CACNAD3, IL2, FAS, TUFT1, KIT, TGFBR2, and IGF2 were expressed at levels greater than 100-fold more in the twins. There were six genes with significantly different expression profiles in the twins as compared with the nontwin os odontoideum patients: CMK4, ATF1, PLCG1, TAB1, E2F3, and ATF4. There were no statistically significant differences in gene expression in the four patients with os odontoideum and the subjects without. Trends, however, were noted in MMP8, KIT,