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Immunohistochemical detection of surfactant proteins a SP-A, b SP-B, c SP-C and d SP- D in parotid gland. The serous acinus cells and the lining epithelial cells of the excretory duct system stain positive for all surfactant proteins. Insets in the Wgures show antibody reactivity for the excretory duct system only for each surfactant protein (scale bars 112 m)
Source publication
The oral cavity and the salivary glands are open to the oral environment and are thus exposed to multiple microbiological, chemical and mechanical influences. The existence of an efficient defense system is essential to ensure healthy and physiological function of the oral cavity. Surfactant proteins play an important role in innate immunity and su...
Citations
... Typical salivary protein constituents are enzymes (such as amylases, lysozyme), protease inhibitors, growth factors such epidermal growth factor (EGF), antimicrobial peptides (such as histatins, defensins, cathelicidin), immunoglobulins (mainly secretory IgA and IgG), surfactant proteins, the agglutinin Deleted in Malignant Brain Tumor 1/gp340 (DMBT1 gp340 ), IgG Fc binding protein (FCGBP), and secretory mucins (MUC5B, MUC7, MUC19) [2,5,[10][11][12][13]. Many of these proteins also appear in tears [12]. ...
Human saliva is a complex body fluid with more than 3000 different identified proteins. Besides rheological and lubricating properties, saliva supports wound healing and acts as an antimicrobial barrier. TFF peptides are secreted from the mucous acini of the major and minor salivary glands and are typical constituents of normal saliva; TFF3 being the predominant peptide compared with TFF1 and TFF2. Only TFF3 is easily detectable by Western blotting. It occurs in two forms, a disulfide-linked homodimer (Mr: 13k) and a high-molecular-mass heterodimer with IgG Fc binding protein (FCGBP). TFF peptides are secretory lectins known for their protective effects in mucous epithelia; the TFF3 dimer probably has wound-healing properties due to its weak motogenic effect. There are multiple indications that FCGBP and TFF3-FCGBP play a key role in the innate immune defense of mucous epithelia. In addition, homodimeric TFF3 interacts in vitro with the salivary agglutinin DMBT1gp340. Here, the protective roles of TFF peptides, FCGBP, and DMBT1gp340 in saliva are discussed. TFF peptides are also used to reduce radiotherapy- or chemotherapy-induced oral mucositis. Thus, TFF peptides, FCGBP, and DMBT1gp340 are promising candidates for better formulations of artificial saliva, particularly improving wound healing and antimicrobial effects even in the esophagus.
... Saliva fulfills a key role for the protection of teeth and the oral cavity, and is also part of the first steps of digestion [2][3][4][5]. Saliva contains a huge variety of peptides and proteins, such as enzymes, protease inhibitors, antimicrobial peptides, growth factors, mucins (MUC5B, MUC7, and MUC19), the agglutinin DMBT1, immunoglobulins (mainly secretory IgA and IgG), and surfactant proteins [5][6][7]. Saliva proteomics identified more than 3000 different proteins and their relative abundance spans 14 orders of magnitude [8]. Furthermore, also more than 600 taxa of oral microbiota secrete, e.g., enzymes, into the saliva. ...
The peptide TFF3 is a member of a family of secretory lectins, and is typically synthesized by mucous epithelia together with mucins. It is mainly released from intestinal goblet cells as a high-molecular mass heterodimer with IgG Fc binding protein (FCGBP). Herein, we investigated human saliva by fast protein liquid chromatography (FPLC) and proteomics and identified high- and low-molecular-mass forms of TFF3. Whereas the high-molecular-mass forms represent a heterodimer with FCGBP, the low-molecular-mass forms represent homodimeric TFF3 forms. Proteomic analysis also revealed a C-terminally truncated form of TFF3. We hypothesize that salivary TFF3-FCGBP might play a role in the innate immune defense of the oral cavity and that TFF3 might also bind to microbial glycans. The known interaction of TFF3 with the agglutinin DMBT-1, a typical constituent of human saliva, further supports this protective role.
... [36][37][38] SP-A and SP-D as components of the innate immune system as well as SP-B and SP-C were identified in saliva and in epithelial structures of the parotid and submandibular gland. 21 SPs in various glandular tissues in humans are described in literature so far, but there are no data available on SP-A, SP-B, SP-C, and SP-D expression in infantile labial glands. This study complements information about SPs in glandular tissues. ...
... Antibody reactivity for SP-A, SP-B, SP-C, and SP-D was demonstrated for the excretory duct system and serous acinus cells in parotid and submandibular glands. 21 In a prior analysis by Bräuer et al., 20 acinar epithelial cells of the lacrimal gland and epithelial cells of the conjunctiva and nasolacrimal ducts revealed SP-A and SP-D expression. Gaunsbaek et al. 40 found SP-A, SP-B, SP-C, and SP-D in acini of the submucosal glands in nasal mucosa. ...
... 11 A similar function was attributed to glandular SPs facilitating mucociliary transport, for example, in the Eustachian tube. 46 In a similar way, SP-B and SP-C may help to improve the flow of secretion material through the duct system of glandular tissues as discussed by Bräuer et al. 20 This quality is also helpful in the flow property in human saliva of the parotid gland, submandibular gland, 21 and tear fluid 20 as all four SPs were detected therein. Interestingly, Gaunsbaek et al. 40 revealed that in nasal lavage and mucus, the levels of SP-A, SP-B, SP-C, and SP-D were not detectable although they could be demonstrated immunohistochemically in acinar cells of nasal submucosal glands and in the surface epithelium. ...
Surfactant proteins in different glandular structures of the oral cavity display antimicrobial activity for protection of invading microorganisms. Moreover, they are involved in lowering liquid tension in fluids and facilitate secretion flows. Numerous investigations for studying the occurrence of surfactant proteins in glandular tissues were performed using different methods. In the oral cavity, minor salivary glands secrete saliva continuously for the maintenance of a healthy oral environment. For the first time, we could show that infantile labial glands show expression of the surfactant proteins (SP) SP-A, SP-B, SP-C, and SP-D in acinar cells and the duct system in different intensities. The stratified squamous epithelium of the oral mucosa revealed positive staining for SPs in various cell layers.
... The surfactant system has been subject of scientific attention since 1929 and was first described in the lung (Klaus et al., 1961). Surfactant proteins (SPs) were subsequently detected in a multitude of different organs and tissues (Paananen et al., 2001a(Paananen et al., , 2001bMo et al., 2007;Bräuer et al., 2009;Sati et al., 2010;Schicht et al., 2013;Schob et al., 2013;Beileke et al., 2015). In 2007, the four surfactant proteins SP-A, -B, -C and -D were detected for the first time https://doi.org/10.1016/j.aanat.2017.11.006 0940-9602/© 2017 Elsevier GmbH. ...
... It is involved in the specific and unspecific immune defense (Wright, 1997;Crouch, 1998). With similarity to complement C1q, SP-A opsonizes macrophages and bacterial components (Brodsky-Doyle et al., 1976), enhances chemotaxis (Wright, 1997;Bräuer et al., 2009) and stimulates the release of oxygen radicals (Creuwels et al., 1997). ...
Purpose:
To quantify and compare the amounts of surfactant proteins SP-A, SP-B, SP-C and SP-D in the tear fluid collected from patients with dry eye syndrome and from individuals with a healthy ocular surface.
Methods:
Schirmer strips were used to collect tear fluid from both eyes of 241 volunteers (99 men, 142 women; age range: 18-87 years). Dry eye syndrome was diagnosed by ophthalmologists in 125 patients, whereas the healthy control group comprised 116 individuals. The total protein concentration was determined via Bradford assay. The relative concentration of surfactant proteins SP-A through -D was measured by enzyme-linked immuno-sorbent assay (ELISA).
Results:
The mean relative concentrations of SP-A, SP-C and SP-D were significantly higher in the dry eye group as compared to the healthy controls (p<0.05, one-way ANOVA). SP-B was also detected at a higher concentration in the dry eye group, but the difference to the control group was not statistically significant.
Conclusions:
The upregulation of SP-A and SP-D in the dry eye group is probably related to these proteins' known antimicrobial and immunomodulatory effects at the ocular surface. It may represent a pathophysiological response to the inflammatory condition of the ocular surface in dry eye. The upregulation of SP-B and SP-C may represent an effort of the lacrimal system to reduce surface tension and thus to counteract the increased tendency of the tear film to tear in dry eye.
... The structure of SP-D is comprised of four domains, including N-terminus cysteine-rich domain, triple-helical collagen-like domain, neck region and carbohydrate recognition domain (CRD) [6]. Extrapulmonary tissues/organs SP-D expression has been recognized, such as kidney [7], digestive tract and mesentery [8], nasal epithelium [9], salivary glands and saliva [10], pancreas [11], and prostate and reproductive system [12]. Furthermore, SP-D is expressed in the synovial fluid to vary degrees in rheumatoid arthritis (RA), which reveals a characteristic aspect in the pathogenesis of RA as in lung [13,14]. ...
Innate immune molecule surfactant protein D (SP-D), a member of the C-type lectin protein family, plays an indispensable role in host defense and the regulation of inflammation in the lung and other tissues. Osteoarthritis (OA) is a degenerative disease of cartilage, with inflammation that causes pathologic changes and tissue damage. However, it is unknown whether there exist SP-D expression and its potential role in the pathogenesis of OA. In this study, we examined SP-D expression and explored its biological function in a sodium nitroprusside (SNP)-stimulated rat chondrocytes and surgically-induced rat OA model. We found SP-D expression in both human and rat articular chondrocytes, with higher level in normal chondrocytes compared to in OA chondrocytes. Furthermore, In vivo study demonstrated that recombinant human SP-D (rhSP-D) ameliorated cartilage degeneration in surgically-induced rat OA model. In vitro cell culture study showed that rhSP-D markedly inhibited the expression of caspase-3 as an apoptosis biomarker, and decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK), which resulted in maintaining normal nuclear morphology and increasing mitochondrial membrane potential in SNP-stimulated rat chondrocytes. Collectively, these findings indicate that SP-D expresses in articular chondrocytes and suppresses SNP-stimulated chondrocyte apoptosis and ameliorates cartilage degeneration via suppressing p38 MAPK activity.
... SP-A and SP-D are also expressed in the oral cavity of the upper GIT. They have been detected in the gingiva, saliva, as well as the parotid and submandibular glands, especially in serous acinus cells and epithelial cells lining the ducts [48] . ELISA experiments have shown that SP-A and SP-D expression is upregulated in saliva from pa-tients suffering from periodontal disease as compared to saliva from healthy patients [49] . ...
Surfactant proteins A (SP-A) and D (SP-D) are established as essential components of our innate immune system for protecting the lung from pathogens and allergens. They essentially exert their protective functions by regulating pulmonary homeostasis. Both proteins are however widely expressed throughout the body, including the female reproductive tract, urinary tract, gastrointestinal tract, the eye, ear, nasal compartment, central nervous system, the coronary artery and the skin. The functions of SP-A and SP-D at these sites are a relatively underinvestigated area, but it is emerging that both SP-A and SP-D contribute significantly to the regulation of inflammation and protection from infection at these sites. This review presents our current understanding of the roles of SP-A and SP-D in non-pulmonary sites.
... SP-A, besides its immunological functions, stabilizes the pulmonary surfactant layer and contributes to its surface tension lowering activity [2,[18][19][20][21][22][23][24][25][26][27][28][29]. SP-C strongly interacts with surfactant phospholipids, is responsible for initial surfactant film formation and thus also contributes to the reduction of surface tension [7]. ...
Introduction
Pulmonary Surfactant reduces surface tension in the terminal airways thus facilitating breathing and contributes to host’s innate immunity. Surfactant Proteins (SP) A, B, C and D were recently identified as inherent proteins of the CNS. Aim of the study was to investigate cerebrospinal fluid (CSF) SP levels in hydrocephalus patients compared to normal subjects.
Patients and Methods
CSF SP A-D levels were quantified using commercially available ELISA kits in 126 patients (0–84 years, mean 39 years). 60 patients without CNS pathologies served as a control group. Hydrocephalus patients were separated in aqueductal stenosis (AQS, n = 24), acute hydrocephalus without aqueductal stenosis (acute HC w/o AQS, n = 16) and idiopathic normal pressure hydrocephalus (NPH, n = 20). Furthermore, six patients with pseudotumor cerebri were investigated.
Results
SP A—D are present under physiological conditions in human CSF. SP-A is elevated in diseases accompanied by ventricular enlargement (AQS, acute HC w/o AQS) in a significant manner (0.67, 1.21 vs 0.38 ng/ml in control, p<0.001). SP-C is also elevated in hydrocephalic conditions (AQS, acute HC w/o AQS; 0.87, 1.71 vs. 0.48 ng/ml in controls, p<0.001) and in Pseudotumor cerebri (1.26 vs. 0.48 ng/ml in controls, p<0.01). SP-B and SP-D did not show significant alterations.
Conclusion
The present study confirms the presence of SPs in human CSF. There are significant changes of SP-A and SP-C levels in diseases affecting brain water circulation and elevation of intracranial pressure. Cause of the alterations, underlying regulatory mechanisms, as well as diagnostic and therapeutic consequences of cerebral SP’s requires further thorough investigations.
... SP-A, besides its immunological functions, stabilizes the pulmonary surfactant layer and contributes to its surface tension lowering activity [2,[18][19][20][21][22][23][24][25][26][27][28][29]. SP-C strongly interacts with surfactant phospholipids, is responsible for initial surfactant film formation and thus also contributes to the reduction of surface tension [7]. ...
Introduction
Pulmonary Surfactant reduces surface tension in the terminal airways thus facilitating breath- ing and contributes to host’s innate immunity. Surfactant Proteins (SP) A, B, C and D were recently identified as inherent proteins of the CNS. Aim of the study was to investigate cere- brospinal fluid (CSF) SP levels in hydrocephalus patients compared to normal subjects.
Patients and Methods
CSF SP A-D levels were quantified using commercially available ELISA kits in 126 patients (0–84 years, mean 39 years). 60 patients without CNS pathologies served as a control group. Hydrocephalus patients were separated in aqueductal stenosis (AQS, n = 24), acute hydrocephalus without aqueductal stenosis (acute HC w/o AQS, n = 16) and idiopathic nor- mal pressure hydrocephalus (NPH, n = 20). Furthermore, six patients with pseudotumor cerebri were investigated.
Results
SP A—D are present under physiological conditions in human CSF. SP-A is elevated in dis- eases accompanied by ventricular enlargement (AQS, acute HC w/o AQS) in a significant manner (0.67, 1.21 vs 0.38 ng/ml in control, p<0.001). SP-C is also elevated in hydroce- phalic conditions (AQS, acute HC w/o AQS; 0.87, 1.71 vs. 0.48 ng/ml in controls, p<0.001) and in Pseudotumor cerebri (1.26 vs. 0.48 ng/ml in controls, p<0.01). SP-B and SP-D did not show significant alterations.
Conclusion
The present study confirms the presence of SPs in human CSF. There are significant changes of SP-A and SP-C levels in diseases affecting brain water circulation and elevation of intracranial pressure. Cause of the alterations, underlying regulatory mechanisms, as well as diagnostic and therapeutic consequences of cerebral SP’s requires further thorough investigations.
... This is followed by opsonization and accelerated immune defense reactions to these microorganisms [3][4][5]. SP-A and SP-D were detected in various tissues including human nasal mucosa, digestive tract, tear ducts, salivary glands of the head and gingiva [10][11][12][13][14]. By contrast, SP-B and SP-C feature very low molecular weights and hydrophobic proteins. ...
... All antibodies mentioned were used for Western blot analysis as well as for immunohistochemical investigation as specified by the manufacturer. The antibodies used are highly specific, showing no cross-reactivity with other cellular proteins, and have been used successfully in previous experiments [11,12,16]. ...
... For Western blots, testis and seminoma samples (standardized ratio: 100 mg wet weight/ 400 μm buffer containing 1% SDS and 4% 2-mercaptoethanol) were extracted as previously described in detail by Bräuer et al. [12]. The protein content of these samples, and of the collected seminal fluid samples, was measured with a protein assay based on the Bradford dyebinding procedure (BioRad, Hercules, CA). ...
Background
Surfactant proteins (SPs) have been described in various tissues and fluids including tissues of the nasolacrimal apparatus, airways and digestive tract. Human testis have a glandular function as a part of the reproductive and the endocrine system, but no data are available on SPs in human testis and prostate under healthy and pathologic conditions.
Objective
The aim of the study was the detection and characterization of the surfactant proteins A, B, C and D (SP-A, SP-B, SP-C, SP-D) in human testis. Additionally tissue samples affected by testicular cancer were investigated.
Results
Surfactant proteins A, B, C and D were detected using RT-PCR in healthy testis. By means of Western blot analysis, these SPs were detected at the protein level in normal testis, seminoma and seminal fluid, but not in spermatozoa. Expression of SPs was weaker in seminoma compared to normal testicular tissue. SPs were localized in combination with vimentin immunohistochemically in cells of Sertoli and Leydig.
Conclusion
Surfactant proteins seem to be inherent part of the human testis. By means of physicochemical properties the proteins appear to play a role during immunological and rheological process of the testicular tissue. The presence of SP-B and SP-C in cells of Sertoli correlates with their function of fluid secretion and may support transportation of spermatozoa. In seminoma the expression of all SP's was generally weaker compared to normal germ cells. This could lead to a reduction of immunomodulatory and rheology processes in the germ cell tumor.
... SFTPA1 and SFTPA2 are strongly expressed in the lung and the connective tissues (NCBI UniGene EST Profile). Expression of SFTPA1 and SFTPA2 was also detected in respiratory cells (Wong et al., 1996), the gastrointestinal tract (Rubio et al., 1995), the Eustachian tube epithelium (Paananen et al., 2001), the vagina (MacNeill et al., 2004), the lacrimal system, the parotid glands and the gingiva (Bräuer et al., 2012(Bräuer et al., , 2009(Bräuer et al., , 2007. Chicken SFTPA and LL genes are located on chromosome 6 forming a cluster together with MBL (Hogenkamp et al., 2006). ...
Collectins and ficolins are multimeric proteins present in various tissues and are actively involved in innate immune responses. In chickens, six different collagenous lectins have been characterized so far: mannose-binding lectin (MBL), surfactant protein A (SP-A), collectin 10 (COLEC10), collectin 11 (COLEC11), collectin 12 (COLEC12), lung lectin (LL) and one ficolin (FCN). However, the structural and functional features of the chicken collectins and ficolin are still not fully understood. Therefore, the aims of this study were: (i) to make an overview of the genetic structure and function of chicken collectins and the ficolin, (ii) to investigate the variation in the chicken collectins and the ficolin gene in different chicken populations, and (iii) to assess the presence of MBL gene variants in different chicken populations. We performed comparative genomic analysis using publically available data. The obtained results showed that collectins and ficolins have conserved protein sequences and gene structure across all vertebrate groups and this is especially notable for COLEC10, COLEC11 and COLEC12. For the purpose of studying the genetic variation, 179 animals from 14 populations were genotyped using 31 SNPs covering five genomic regions. The obtained results revealed low level of heterozygosity in the collagenous lectins except for the COLEC12 gene and the LL-SPA-MBL region compared to heterozygosity at neutral microsatellite markers. In addition, the MBL gene variants were assessed in different chicken populations based on the polymorphisms in the promoter region. We observed 10 previously identified MBL variants with A2/A8 and A4 as the most frequent alleles.
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