Surfactant Pulmonary-Associated Protein D (SP-D) is a 43 kDa member of the collectin family of innate immune modulators. Its principal components consist of a collagen-like region and a C-terminal carbohydrate recognition domain (CRD), a structure that places it in a subset of pattern recognition proteins termed defense collagens. SP-D is constitutively secreted by alveolar lining cells and epithelium associated with tubular structures and induced in cardiac smooth muscle and endothelial cells. It binds both secreted and transmembrane proteins that transduce its function. It binds human neutrophil defensins, modulating influenza anti-viral defense. It binds MD-2/LY96, a secreted protein that cooperates with Toll-like receptors (TLRs) in the response of macrophages to bacterial lipopolysaccharides (LPS) or cell wall components. It also binds macrophage CD14 and TLRs directly, blocking binding of LPS and down-regulating TNF-α secretion. SP-D binding of both SIRPα and the calreticulin/CD91 complex on macrophages allows for a graded response to environmental challenge.

Pulmonary surfactant-associated proteins promote alveolar stability by lowering the surface tension at the air-liquid interface in the peripheral air spaces. SP-B increases the collapse pressure of palmitic acid to nearly 70 millinewtons per meter. SFTPB Protein, Human, Recombinant is expressed in yeast. The predicted molecular weight is 8.7 kDa and the accession number is P07988.

SFTPC Protein, Human, Recombinant (GST) is expressed in E. coli.

In presence of calcium ions, it binds to surfactant phospholipids and contributes to lower the surface tension at the air-liquid interface in the alveoli of the mammalian lung and is essential for normal respiration. Enhances the expression of MYO18A/SP-R210 on alveolar macrophages.; (Microbial infection) Recognition of M.tuberculosis by dendritic cells may occur partially via this molecule. Can recognize, bind, and opsonize pathogens to enhance their elimination by alveolar macrophages. SFTPA1 Protein, Human, Recombinant (B2M & His & Myc) is expressed in E. coli expression system with N-10xHis-B2M and C-Myc tag. The predicted molecular weight is 41.2 kDa and the accession number is Q8IWL2.

SerpinA3, also known as Alpha 1-antichymotrypsin (AACT), is a plasma alpha globulin glycoprotein, and is a member of serpin superfamily of the serine protease inhibitors consisting of at least 35 members. SerpinA3 has been demonstrated to inhibit the activity of certain serine proteases, such as cathepsin G found in neutrophils, and chymases present in mast cells, by inducing a major conformational rearrangement, and thus protects some tissues from damage caused by proteolytic enzymes. This enzyme is produced primarily in the liver, and is identified as an acute-phase inflammatory protein. SerpinA3 deficiency has been associated with liver disease, and mutations of this gene have been observed in patients with Parkinson disease and chronic obstructive pulmonary disease. Besides, ACT gene polymorphism has been implicated with Alzheimer’s disease (AD), cerebral amyloid angiopathy (CAA), as well as stroke, since SerpinA3 is a major constituent of the plaques in AD and an inhibitor of amyloid beta peptide degradation.

Secretory calcium-dependent phospholipase A2 that primarily targets extracellular phospholipids. Hydrolyzes the ester bond of the fatty acyl group attached at sn-2 position of phospholipids with preference for phosphatidylcholines and phosphatidylglycerols over phosphatidylethanolamines. Preferentially releases sn-2 omega-6 and omega-3 polyunsaturated fatty acyl (PUFA) chains over saturated fatty acyls. Contributes to phospholipid remodeling of very low-density lipoprotein (VLDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles. Hydrolyzes LDL phospholipids releasing unsaturated fatty acids that regulate macrophage differentiation toward foam cells. Efficiently hydrolyzes and inactivates PAF, a potent lipid mediator present in oxidized LDL. May act in an autocrine and paracrine manner. Secreted by lung epithelium, targets membrane phospholipids of infiltrating eosinophils, releasing arachidonate and boosting eicosanoid and cysteinyl leukotriene synthesis involved in airway inflammatory response. Secreted by gut epithelium, hydrolyzes dietary and biliary phosphatidylcholines in the gastrointestinal lumen, thereby regulating adipogenesis and body weight. Plays a stem cell regulator role in colon epithelium. Within intracellular compartment, mediates Paneth-like cell differentiation and its stem cell supporting functions by inhibiting Wnt signaling pathway in intestinal stem cell (ISC). Secreted in the intestinal lumen upon inflammation, acts in an autocrine way and promotes prostaglandin E2 synthesis that stimulates the Wnt signaling pathway in ISCs and tissue regeneration. May participate in hair follicle morphogenesis by regulating phosphatidylethanolamines metabolism at the outermost epithelial layer and facilitating melanin synthesis. By generating lysophosphatidylcholines (LPCs) at sperm acrosome controls sperm cell capacitation, acrosome reaction and overall fertility. May promote neurite outgrowth in neuron fibers involved in nociception. Contributes to lipid remodeling of cellular membranes and generation of lipid mediators involved in pathogen clearance. Cleaves sn-2 fatty acyl chains of phosphatidylglycerols and phosphatidylethanolamines, which are major components of membrane phospholipids in bacteria. Displays bactericidal activity against Gram-positive bacteria by directly hydrolyzing phospholipids of the bacterial membrane. In pulmonary epithelium, may contribute to host defense response against adenoviral infection. Prevents adenovirus entry into host cells by hydrolyzing host cell plasma membrane, releasing C16:0 LPCs that inhibit virus-mediated membrane fusion and viral infection. Likely prevents adenoviral entry into the endosomes of host cells. May play a role in maturation and activation of innate immune cells including macrophages, group 2 innate lymphoid cells and mast cells.

Protein with pleiotropic attributes mediated in a cell-compartment- and tissue-specific manner, which include the plasma membrane-associated cell signaling functions, mitochondrial chaperone, and transcriptional co-regulator of transcription factors in the nucleus. Plays a role in adipose tissue and glucose Homeostasis in a sex-specific manner. Contributes to pulmonary vascular remodeling by accelerating proliferation of pulmonary arterial smooth muscle cells.; In the mitochondria, together with PHB2, forms large ring complexes (prohibitin complexes) in the inner mitochondrial membrane (IMM) and functions as chaperone protein that stabilizes mitochondrial respiratory enzymes and maintains mitochondrial integrity in the IMM, which is required for mitochondrial morphogenesis, neuronal survival, and normal lifespan (Probable). The prohibitin complex, with DNAJC19, regulates cardiolipin remodeling and the protein turnover of OMA1 in a cardiolipin-binding manner. Regulates mitochondrial respiration activity playing a role in cellular aging. The prohibitin complex plays a role of mitophagy receptor involved in targeting mitochondria for autophagic degradation. Involved in mitochondrial-mediated antiviral innate immunity, activates DDX58/RIG-I-mediated signal transduction and production of IFNB1 and proinflammatory cytokine IL6.; In the nucleus, acts as a transcription coregulator, enhances promoter binding by TP53, a transcription factor it activates, but reduces the promoter binding by E2F1, a transcription factor it represses. Interacts with STAT3 to affect IL17 secretion in T-helper Th17 cells.; In the plasma membrane, cooperates with CD86 to mediate CD86-signaling in B lymphocytes that regulates the level of IgG1 produced through the activation of distal signaling intermediates. Upon CD40 engagement, required to activate NF-kappa-B signaling pathway via phospholipase C and protein kinase C activation.; (Microbial infection) In neuronal cells, cell surface-expressed PHB is involved in human enterovirus 71/EV-71 entry into neuronal cells specifically, while membrane-bound mitochondrial PHB associates with the virus replication complex and facilitates viral replication. May serve as a receptor for EV71.

72 kDa type IV collagenase also known as matrix metalloproteinase-2 (MMP-2) and gelatinase A is an enzyme that in humans is encoded by the MMP2 gene.It belongs to the matrix metalloproteinase (MMP) family. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade components of the extracellular matrix (ECM) and play essential roles in various physiological processes such as morphogenesis, differentiation, angiogenesis and tissue remodeling, as well as pathological processes including inflammation, arthritis, cardiovascular diseases, pulmonary diseases and tumor invasion. MMP-2 is ubiquitinous metalloproteinase that is involved in diverse functions such as remodeling of the vasculature, angiogenesis, tissue repair, tumor invasion, inflammation, atherosclerotic plaque rupture, as well as degrading extracellular matrix proteins. MMP-2 can also act on several nonmatrix proteins such as big endothelial 1 and beta-type CGRP promoting vasoconstriction. MMP-2 cleaves KISS at a Gly-|-Leu bond and appears to have a role in myocardial cell death pathways.

Galectin-Related Protein (LGALSL) is a 172 amino acid protein that contains one Galectin domain. LGALSL does not appear to bind carbohydrates or lactose as the critical residues required for binding are not conserved. LGALSL may play a significant role in stimulating smooth muscle growth in developing alveolar wall vessels and the development of pulmonary capillaries.

Genetic variation in the cluster on chromosome 15, encoding the nicotinic acetylcholine receptor subunits (CHRNA5-CHRNA3-CHRNB4), has shown strong associations with tobacco consumption and an additional risk increase in smoking-related diseases such as chronic obstructive pulmonary disease (COPD), peripheral artery disease and lung cancer. CHRNA5 may influence susceptibility to lung cancer among Han smokers. Genetic variation in nicotinic receptor alpha 5 (CHRNA5) has been associated with increased risk of addiction-associated phenotypes in humans.

Defects in SOS1 are the cause of gingival fibromatosis 1 (GGF1) [MIM:135300]; also known as GINGF1. Gingival fibromatosis is a rare overgrowth condition. Defects in SOS1 are the cause of Noonan syndrome type 4 (NS4) [MIM:610733]. NS4 is an autosomal dominant disorder characterized by dysmorphic facial features, short stature, hypertelorism, cardiac anomalies, deafness, motor delay, and a bleeding diathesis. It is a genetically heterogeneous and relatively common syndrome, with an estimated incidence of 1 in 1000-2500 live births. Rarely, NS4 is associated with juvenile myelomonocytic leukemia (JMML). SOS1 mutations engender a high prevalence of pulmonary valve disease; atrial septal defects are less common. characterized by a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of maxillary and mandibular keratinized gingiva. GGF1 is usually transmitted as an autosomal dominant trait, although sporadic cases are common.

C-X-C motif chemokine 2 (CXCL2,MIP-2) belongs to the intercrine alpha (chemokine CxC) family. It was originally identified as a heparin-binding protein secreted from a murine macrophage cell line in response to endotoxin stimulation. The expression of mouse MIP-2 is stimulated by endotoxin. The mouse MIP-2 shares approximately 63% aa sequence identity with murine KC, another mouse alpha chemokine, which is induced by PDGF. It has been suggested that mouse KC and MIP-2 are the homologs of the human GROs and rat CINCs. Chemotactic for human polymorphonuclear leukocytes but does not induce chemokinesis or an oxidative burst. The expression of MIP-2 was found to be associated with neutrophil influx in pulmonary inflammation and glomerulonephritis, suggesting that MIP-2 may contribute to the pathogenesis of inflammatory diseases.

CCL18 is a chemotactic cytokine involved in the pathogenesis and progression of various disorders, including cancer. Proof showed high levels of CCL18 in the serum of epithelial ovarian carcinoma patients suggesting its potential as a circulating biomarker. CCL18 chemokine has an important role in chemokine-mediated tumor metastasis, and may serve as a potential predictor for poor survival outcomes for ovarian cancer. (CCL18) is predominantly secreted by M2-tumor associated macrophages (TAMs) and promotes malignant behaviors of various human cancer types. CCL18 has a correlation with cardiac function in patients with AAMI and it might be considered as an indicator of poor LVEF in patients with AAMI. Circulating and WAT-secreted CCL18 correlates with insulin resistance and metabolic risk score. Because CCL18 is macrophage-specific and associates with adipose immune gene expression, it may constitute a marker of WAT inflammation. Macrophages are thought to be the main source of CCL18, and the effect of pirfenidone, an anti-fibrotic agent for idiopathic pulmonary fibrosis, on the expression of CCL18 in macrophages warrants investigation.

Deleted in malignant brain tumors 1 protein, also known as glycoprotein 34, surfactant pulmonary-associated D-binding protein, DMBT1 and GP34, is a secreted protein which belongs to theDMBT1 family. DMBT1 contains 2CUB domains, 14SRCR domains and 1ZP domain. It is highly expressed in alveolar and macrophage tissues. In some macrophages, expression is detected on the membrane, and in other macrophages, it is strongly expressed in the phagosome/phagolysosome compartments. Defects in DMBT1 are involved in the development of glioma (GLM). Gliomas are central nervous system neoplasms derived from glial cells and comprise astrocytomas, glioblastoma multiforme, oligodendrogliomas , and ependymomas. DMBT1 may be considered as a candidate tumor suppressor for brain, lung, esophageal, gastric, and colorectal cancers. It may play roles in mucosal defense system, cellular immune defense and epithelial differentiation. DMBT1 may play a role as an opsonin receptor for SFTPD and SPAR in macrophage tissues throughout the body, including epithelial cells lining the gastrointestinal tract. It may be an important factor in fate decision and differentiation of transit-amplifying ductular (oval) cells within the hepatic lineage. DMBT1 may function as a binding protein in saliva for the regulation of taste sensation. It binds to HIV-1 envelope protein and has been shown to both inhibit and facilitate viral transmission.

Pulmonary surfactant-associated protein B, also known as SFTPB and SP-B, contains one saposin A-type domain and three saposin B-type domains. SP-B is produced primarily by alveolar type II cells (AEC2) but also by nonciliated respiratory epithelial cells lining distal portions of the respiratory tract. Its secretion promotes alveolar homeostasis, stabilizing lipid layers and lowering surface tension at the air-liquid interface in the peripheral air spaces. Alveolar SP-B influences surfactant formation, effector cell functions, and innate host defense. Deficiency is associated with respiratory distress syndrome (RDS), pulmonary surfactant metabolism dysfunction 1 (SMDP1), and other human lung diseases. Gene addition and editing therapies show promise by complementing SP-B expression in AEC2s, restoring the phenotypic defect in vitro and in vivo.

SMAD Family Member 1 (SMAD1) is a member of the dwarfin/SMAD family. SMAD1 has the highest expression in the heart and skeletal muscle, containing one MAD homology 1 domain and one MAD homology 2 domain, As a transcriptional modulator SMAD 1 is activated by bone morphogenetic proteins type 1 receptor kinase. Defects in SMAD1 may cause primary pulmonary hypertension (PPH1), characterized by plexiform lesions of proliferating endothelial cells in pulmonary arterioles. The lesions lead to elevated pulmonary arterial pression, right ventricular failure and death.

Serpin A1 is a prototype member of the Serpin superfamily of the serine protease inhibitors. As one of the most abundant proteinase inhibitors in the circulation, it is synthesized in hepatocytes, and to a lesser extent, in macrophages as well as intestinal epithelial cell lines and secreted as the abundant proteinase inhibitor in the circulation whose targets include elastase, plasmin, thrombin, trypsin, chymotrypsin, and plasminogen activator. Point mutations in the native SerpinA1 variants result in Serpin A1 deficiency, and consequently lead to several clinical complications such as pulmonary emphysema, juvenile hepatitis, cirrhosis, and hepatocellular carcinoma. For example, the Z variants (Glu342 to Lys) forms intracellular inclusion bodies, is not secreted, and leads to a severe SerpinA1 deficiency. Accordingly, Serpin A1 deficiency in circulation is associated with emphysema or liver disease.

Endoglin is a single-pass type I membrane protein which restricted to endothelial cells in all tissues except bone marrow. Endoglin as major glycoprotein of vascular endothelium, it has been found on endothelial cells, activated macrophages, fibroblasts, and smooth muscle cells. Furthermore, Homodimer forms a heteromeric complex with the signaling receptors for transforming growth factor-beta: TGFBR1 and/or TGFBR2. It may have an important role in the binding of endothelial cells to integrins and/or other RGD receptors. Defects in ENG are the cause of hereditary hemorrhagic telangiectasia type 1 (HHT1), which is an autosomal dominant multisystemic vascular dysplasia, characterized by recurrent epistaxis, muco-cutaneous telangiectases, gastro-intestinal hemorrhage, and pulmonary (PAVM), cerebral (CAVM) and hepatic arteriovenous malformations.

Arachidonate 5-Lipoxygenase-Activating Protein (ALOX5AP), also known as FLAP, belongs to the MAPEG family. ALOX5AP/FLAP is an essential partner of 5-LO for this process. The FLAP (ALOX5AP) gene has been linked to risk for myocardial infarction, stroke and restenosis, reigniting pharmaceutical interest in this target. It had been found that ALOX5AP/FLAP is a key enzyme in leukotriene formation, in both human pulmonary microvascular endothelial cells and a transformed human brain endothelial cell line. In addition, the protein FLAP has recently been identified as an emerging target in metabolic disease. In fact, FLAP is overexpressed in the adipose tissue of patients and experimental animals with obesity.

Ceruloplasmin is a blue, copper-binding (6-7 atoms per molecule) glycoprotein. It has ferroxidase activity oxidizing Fe(2+) to Fe(3+) without releasing radical oxygen species. It is involved in iron transport across the cell membrane. Provides Cu(2+) ions for the ascorbate-mediated deaminase degradation of the heparan sulfate chains of GPC1. May also play a role in fetal lung development or pulmonary antioxidant defense. Ceruloplasmin Protein, Human, Recombinant (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 35.4 kDa and the accession number is P00450.

The potent antiangiogenic and proinflammatory protein Endothelial Monocyte Activating Polypeptide II (EMAP II) has been described as a mediator of pulmonary vascular and alveolar formation and its expression is inversely related to the periods of vascularization and alveolarization in the developing lung. Hence the study of EMAP II could play a vital role in studying and devising appropriate therapeutics for diseases of aberrant lung development, such as BPD.

Sulfate conjugation catalyzed by cytosolic sulfotransferase (SULT) enzymes. The SULTs are Phase II drug-metabolizing enzymes that catalyze the addition of a sulfuryl moiety to both endogenous compounds, including steroids and neurotransmitters, and certain xenobiotics, including N-hydroxy-2-acetylaminoflourine and phenolic compounds, like alpha-naphthol. SULTs may be involved in the individual genetic disposition, species differences, and organotropisms for toxicological effects of chemicals. Particularly SULT1A1 (Sulfotransferase family, cytosolic, 1A, phenol-preferring, member 1), a member of the sulfotransferase 1 subfamily, which is a major pathway for drug metabolism in humans. Humans have at least 10 functional SULT genes. There has been an explosion in information on sulfotransferase polymorphisms and their functional consequences. An Arg213His polymorphism in SULT1A1 has a strong influence on the level of enzyme protein and activity in platelets, which have been widely used for phenotyping. Statistically significant associations were observed between the SULT1A1 genotype (Arg213His) and age, obesity and certain neoplasias (mammary, pulmonary, esophageal and urothelial cancer). Furthermore, the polymorphism of the SULT1A1 may be closely associated with breast cancer.

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade components of the extracellular matrix (ECM) and play essential roles in various physiological processes such as morphogenesis, differentiation, angiogenesis, and tissue remodeling, as well as pathological processes including inflammation, arthritis, cardiovascular diseases, pulmonary diseases, and tumor invasion. Macrophage Metalloelastase, also known as Matrix metalloproteinase-12, Macrophage elastase, MMP12, and MMP-12, is a secreted protein that belongs to the peptidase M1A family. MMP12 is a macrophage-secreted elastase that is highly induced in the liver and lung in response to S. mansoni eggs and contains four hemopexin-like domains. MMP12 is a proteolytic enzyme responsible for the cleavage of plasminogen to angiotensin, which has an angiostatic effect. It may be involved in tissue injury and remodeling and has significant elastolytic activity. It may be related to prognosis in breast cancer patients. MMP12 promotes fibrosis by limiting the expression of specific ECM-degrading MMPs. Like MMP12, MMP13 expression is highly dependent on IL-13 and type I I-IL-4 receptor signaling. MMP12 is a potent proinflammatory and oncogenic molecule. MMP12 up-regulation plays a critical role in emphysema to lung cancer transition that is facilitated by inflammation.