Transfected Stable Cell Lines
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Precision reporter, kinase, immune receptor, biosimilar, Cas9, and knockout stable cell lines for diverse applications.
| Cat.No. | Product Name | Price |
|---|---|---|
| CSC-DC011133 | Panoply™ Human ORMDL3 Knockdown Stable Cell Line | Inquiry |
| CSC-SC011133 | Panoply™ Human ORMDL3 Over-expressing Stable Cell Line | Inquiry |
| Cat.No. | Product Name | Price |
|---|---|---|
| AD11635Z | Human ORMDL3 adenoviral particles | Inquiry |
| LV20699L | human ORMDL3 (NM_139280) lentivirus particles | Inquiry |
| Cat.No. | Product Name | Price |
|---|---|---|
| SHW007480 | shRNA set against Danio rerio ORMDL3 (NM_001006087) | Inquiry |
| SHH368548 | shRNA set against Human ORMDL3 (NM_139280.2) | Inquiry |
| SHH368552 | shRNA set against Mouse ORMDL3 (NM_025661.4) | Inquiry |
| SHH368556 | shRNA set against Rat ORMDL3 (NM_001047897.1) | Inquiry |
| SHR081182 | shRNA set against Mouse Ormdl3(NM_025661.4) | Inquiry |
| Cat.No. | Product Name | Price |
|---|---|---|
| CDCS416866 | Human ORMDL3 ORF Clone (BC017087) | Inquiry |
| CDFR004891 | Rat Ormdl3 cDNA Clone(NM_001047897.1) | Inquiry |
| MiUTR1M-08755 | ORMDL3 miRNA 3'UTR clone | Inquiry |
| MiUTR1R-03200 | ORMDL3 miRNA 3'UTR clone | Inquiry |
| MiUTR3H-11013 | ORMDL3 miRNA 3'UTR clone | Inquiry |
| CDCB168955 | Danio rerio ORMDL3 ORF Clone (NM_001006087) | Inquiry |
| CDCB184090 | Rabbit ORMDL3 ORF clone (XM_008271421.1) | Inquiry |
| CDCR257078 | Mouse Ormdl3 ORF Clone(NM_025661.4) | Inquiry |
| CDCR371975 | Rat Ormdl3 ORF Clone(NM_001047897.1) | Inquiry |
| CDCS416865 | Human ORMDL3 ORF Clone (BC000638) | Inquiry |
The ER-resident transmembrane protein orosomucoid like 3 (ORMDL3) belongs to a novel evolutionarily conserved gene family which encodes transmembrane proteins located at the endoplasmic reticulum (ER) membrane. Breslow et al. found Orm proteins as negative regulators of sphingolipid synthesis and suggested that sphingolipid misregulation could contribute to the development of asthma. ORMDL3 has been found to alter ER Ca2+ concentration and facilitate the unfolded protein response (UPR), a process considered as an endogenous inducer of inflammation (Figure 1). ORMDL3 shows a wide distribution in different human tissues, being particularly high expression in cells that participate in the inflammatory response. Genetic variants on chromosome 17q21 locus were strongly associated with transcript levels of ORMDL3 in EBV-transformed lymphoblastoid cell lines from asthmatic children.
Figure 1. ORMDL3 facilitates the unfolded protein response (UPR).
ORMDL3 and sphingolipids
A role of orm proteins in the regulation of sphingolipid synthesis has been established in yeast for many years and recently has been demonstrated in human cells. ORMDL proteins act as negative regulators of sphingolipid synthesis by interacting with serine palmitoyl-coenzyme A transferase (SPT). SPT catalyzes the condensation of serine and palmitoyl-coenzyme A, the rate-limiting step of the de novo sphingolipid synthesis. The asthma-associated ORMDL3 SNPs are associated with higher expression of ORMDL. Knock-down of ORMDL1, 2, and 3 in mammalian cells increases ceramides, products of sphingolipid synthesis. Thus, asthma-associated SNPs are expected to negatively regulate SPT resulting in inhibited de novo sphingolipid synthesis.
ORMDL3 and asthma
None of the genes in the asthma-associated 17q21 region would have been associated with asthma without the unbiased GWAS approach. This approach is an opportunity to discover novel targets and pathomechanisms but has often been both a challenge and a curse for complex diseases. This is particularly true for ORMDL3. Up to date, little was known about its overall cellular function in mammalian cells, as most of its function had been studied in yeast. There, ORMDL functions as the regulator of sphingolipid synthesis. Since the asthma-associated SNPs result in increased cellular ORMDL3 protein expression, it would suggest that an asthma phenotype related to ORMDL3 should be associated with a gain-of-protein function. So far, the following mechanisms of how increased ORMDL3 could be related to asthma have been proposed (Figure 2): (i) ORMDL3 is involved in ER-mediated Ca2+ signaling and activation of the UPR, leading to epithelial cell remodeling via its effect on the sarco/endoplasmic reticulum CaATPase (SERCA) and (ii) ORDML3 influences sphingolipid metabolism to directly affect bronchial reactivity.
Figure 2. Proposed mechanisms for the role of ORMDL3 in asthma pathogenesis in an airway epithelial cell.
ORMDL3 is widely expressed in both fetal and adult mammalian tissues including lung epithelial cells. In mouse lungs, expression can be increased by various stimuli, such as allergens, lipopolysaccharides, and tobacco smoke. In lung epithelial cells, in vitro expression can be increased by interleukin-4 (IL-4) and interleukin-13 (IL-13) but not tumor necrosis factor-α. Interestingly, overexpression of ORMDL3 in airway epithelial cells activates activating transcription factor 6 (ATF6), one of the three signaling branches of the UPR in response to ER stress. This appears to be accompanied by increases in metalloproteases (ADAM-8, MMP-9), CC chemokines (CCL-20), CXC chemokines (CXCL-10, CXCL-11, IL-8), and oligoadenylate synthetase (OAS). These findings suggest that ORMDL3 is an allergen- and cytokine-inducible gene that could regulate the expression of chemokines, metalloproteinases, and OAS through activation of the UPR and thus may be linked to inflammatory and remodeling responses in asthma. Activation of the UPR has been implicated in other inflammatory and immune-related diseases other than asthma, such as inflammatory bowel disease, diabetes, and chronic obstructive pulmonary disease, as well as environmental stressors such as tobacco smoke, an important trigger for asthma exacerbations.
None of the current medications for asthma are disease modifying or curative. Despite tremendous efforts to find an underlying cause for asthma that can be targeted therapeutically, none of these have yet been successful. Remarkably though is the consistency with which the 17q21 locus and within it ORMDL3 has been associated with asthma. Without this approach, it is impossible that the genes in this region would have been primarily identified to be associated with asthma. It is becoming increasingly clear that this locus is associated with early-onset asthma and bronchial hyperreactivity, independent of allergic sensitization and wheezing phenotypes. Although the functional connection of altered ORMDL3 expression has not been made in humans, recent experimental data linking this protein’s effect on asthma to altered calcium homeostasis, airway remodeling, UPR, and sphingolipid synthesis opens new therapeutic targets for asthma at its basic mechanisms.
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