ENAM gene polymorphisms associated with dental anomalies in individuals with cleft lip and palate

Aim: This study aimed to investigate the occurrence of enamelin gene (ENAM) single nucleotide polymorphisms (SNP) and ENAM polymorphism association with dental anomalies (DA) in individuals with unilateral or bilateral cleft lip and palate (CLP). Methods: Saliva samples were collected from 147 individuals aged between 6 and 15 years-old, both genders, and divided into 4 groups: Group 1 (G1) - CLP and DA; Group 2 (G2) - CLP without DA; Group 3 (G3) - without CLP with DA; Group 4 (G4) - without CLP and DA. The genomic DNA was extracted from saliva samples and the following ENAM SNPs markers were genotyped: rs3796703, rs3796704, rs3796705, rs7671281, rs2609428, and rs35951442. Fisher exact and Pearson's Chi-square tests statistically analyzed the results (α=5%). Results: Individuals without CLP with DA (Group 3 - 19.2%) showed statistically higher prevalence of SNP rs2609428 heterozygotes (p=0.006) than individuals with CLP and DA (Group 1 - 0%). Individuals without CLP (10%) exhibited statistically higher prevalence of mutated heterozygotes/homozygous (p=0.028) than in individuals with CLP (1.3%). Conclusion: SNP rs2609428 marker of ENAM gene may be associated with dental anomalies in individuals without cleft lip and palate

Kidney stone matrix proteins: Role in stone formation.

Stone formation is induced by an increased level of urine crystallization promoters and reduced levels of its inhibitors. Crystallization inhibitors include citrate, magnesium, zinc, and organic compounds such as glycosaminoglycans. In the urine, there are various proteins, such as uromodulin (Tamm-Horsfall protein), calgranulin, osteopontin, bikunin, and nephrocalcin, that are present in the stone matrix. The presence of several carboxyl groups in these macromolecules reduces calcium oxalate monohydrate crystal adhesion to the urinary epithelium and could potentially protect against lithiasis. Proteins are the most abundant component of kidney stone matrix, and their presence may reflect the process of stone formation. Many recent studies have explored the proteomics of urinary stones. Among the stone matrix proteins, the most frequently identified were uromodulin, S100 proteins (calgranulins A and B), osteopontin, and several other proteins typically engaged in inflammation and immune response. The normal level and structure of these macromolecules may constitute protection against calcium salt formation. Paradoxically, most of them may act as both promoters and inhibitors depending on circumstances. Many of these proteins have other functions in modulating oxidative stress, immune function, and inflammation that could also influence stone formation. Yet, the role of these kidney stone matrix proteins needs to be established through more studies comparing urinary stone proteomics between stone formers and non-stone formers.

Effect of chitosan irrigant solutions on the release of bioactive proteins from root dentin.

OBJECTIVE: To identify the effect of two chitosan solutions on the release of root dentin matrix proteins and to describe the chemical changes observed following conditioning with chelating agents. MATERIALS AND METHODS: The release of dentin sialoprotein (DSP), transforming growth factor-beta 1 (TGF-ß1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor-BB (PDGF-BB) with different chelating agents, including ethylenediaminetetraacetic acid (EDTA), chitosan solution (CS), and nanoparticulate chitosan (CSnp), was investigated. DSP was quantified using an enzyme-linked immunosorbent assay (ELISA). TGF-ß1, VEGF, and PDGF-BB were quantified using a cytokine bead panel (CBA). Raman spectroscopy was performed to identify surface chemical changes. Statistical analysis was performed using Kruskal-Wallis test with Mann-Whitney-Wilcoxon rank-sum test (p < 0.05). RESULTS: TGF-ß1, VEGF, and DSP solubilized in all irrigants tested. CSnp showed the highest concentration of DSP. PDGF-BB did not exceed the detection limits. Raman spectroscopy revealed a decrease in the phosphate and carbonate peaks, representing the chelating effect of EDTA, CS, and CSnp. Additionally, CSnp showed the greatest preservation of the amide I and III content. CONCLUSION: Proteins can be released from dentin via EDTA, CS, and CSnp conditioning. Raman spectroscopic revealed changes in the inorganic content of the root dentin after chelation. Furthermore, use of CSnp facilitated a preservation of the organic content. CLINICAL RELEVANCE: Chelation allows the release of proteins, justifying the use of chelating agents in regenerative endodontics. The chitosan-dentin matrix interaction also promotes the protection of the organic content as an additional benefit to its protein releasing effect.

Alterations of the Extracellular Matrix in Colorectal Carcinoma.

Background: The process of proliferation and invasion of tumor cells depends on changes in the extracellular matrix (ECM) through the activation of enzymes and alterations in the profile of ECM components. Our aims were to investigate the mRNA and protein expression profiles of the ECM components, heparanase-1 (HPSE), heparanase-2 (HPSE2), matrix metalloproteinase-9 (MMP-9), and syndecan-1 (SDC1) in neoplastic and nonneoplastic tissues of 24 patients with colorectal carcinoma (CRC) and to test for associations between the expression patterns of these genes with the presence or absence of lymph node metastases. Materials and Methods: This was a cross-sectional study in which 24 adult patients with CRC were admitted for resectional surgery. We analyzed the mRNA and protein expression patterns of the HPSE, HPSE2, MMP-9, and SDC1 genes by quantitative reverse transcription PCR and immunohistochemistry, respectively. Additionally, we investigated whether variations exist in the expression of the ECM components between the affected tissue and nontumoral tissue collected from the same patient. Tissue samples were collected during the surgical resection. Results and Conclusions: The data showed higher mRNA and protein expression levels of HPSE2 (p = 0.0058), MMP-9 (p = 0.0268), and SDC1 (p = 0.0002) in tumor samples when compared to the adjacent non-neoplastic tissues. There was, however, only an increase in the HPSE protein levels in the tumoral tissues. Increased expression of HPSE2 was observed in patients with lymph node metastasis (p = 0.031). This elevation in HPSE2 mRNA expression in patients with lymph node metastases potentially indicates that it may participate in driving colorectal carcinoma progression.

An acidic protein, Hf15, from Haliotis fulgens involved in biomineralization.

Biomineralization leads to the hardening of mineralized materials, such as the shell of Mollusk, to fulfill a wide range of functions, such as (but not limited to) skeletal support, protection of the soft tissues, navigation, etc. The study of the proteins responsible for this process, shell matrix proteins (SMPs), allows addressing questions related to structure-function relationship and to the mechanism of mineral formation, which is limited in gastropod species. In this study, a low molecular weight protein was isolated from the insoluble fraction after decalcification with acetic acid of the shell of Haliotis fulgens and, named Hf15. The unglycosylated protein has a theoretical molecular weight of 15 kDa, it possesses calcium and chiting binding properties. Hf15 can precipitate calcium carbonate in vitro in presence of different salts. Analysis by LC-MS of the five peptide sequences of Hf15 generated by trypsinization revealed that two peptides displayed homology to an uncharacterized protein 3-like from Haliotis rufescens, Haliotis asinia and H. sorenseni. The results obtained indicated that Hf15 is a novel SMP involved in shell mineralization in Haliotis fulgens.

Decellularized Tissues for Wound Healing: Towards Closing the Gap Between Scaffold Design and Effective Extracellular Matrix Remodeling.

The absence or damage of a tissue is the main cause of most acute or chronic diseases and are one of the appealing challenges that novel therapeutic alternatives have, in order to recover lost functions through tissue regeneration. Chronic cutaneous lesions are the most frequent cause of wounds, being a massive area of regenerative medicine and tissue engineering to have efforts to develop new bioactive medical products that not only allow an appropriate and rapid healing, but also avoid severe complications such as bacterial infections. In tissue repair and regeneration processes, there are several overlapping stages that involve the synergy of cells, the extracellular matrix (ECM) and biomolecules, which coordinate processes of ECM remodeling as well as cell proliferation and differentiation. Although these three components play a crucial role in the wound healing process, the ECM has the function of acting as a biological platform to permit the correct interaction between them. In particular, ECM is a mixture of crosslinked proteins that contain bioactive domains that cells recognize in order to promote migration, proliferation and differentiation. Currently, tissue engineering has employed several synthetic polymers to design bioactive scaffolds to mimic the native ECM, by combining biopolymers with growth factors including collagen and fibrinogen. Among these, decellularized tissues have been proposed as an alternative for reconstructing cutaneous lesions since they maintain the complex protein conformation, providing the required functional domains for cell differentiation. In this review, we present an in-depth discussion of different natural matrixes recently employed for designing novel therapeutic alternatives for treating cutaneous injuries, and overview some future perspectives in this area.

Human Amnion Epithelial Cells: A Potential Cell Source for Pulp Regeneration?

The aim of this study was to analyze the suitability of pluripotent stem cells derived from the amnion (hAECs) as a potential cell source for revitalization in vitro. hAECs were isolated from human placentas, and dental pulp stem cells (hDPSCs) and dentin matrix proteins (eDMPs) were obtained from human teeth. Both hAECs and hDPSCs were cultured with 10% FBS, eDMPs and an osteogenic differentiation medium (StemPro). Viability was assessed by MTT and cell adherence to dentin was evaluated by scanning electron microscopy. Furthermore, the expression of mineralization-, odontogenic differentiation- and epithelial-mesenchymal transition-associated genes was analyzed by quantitative real-time PCR, and mineralization was evaluated through Alizarin Red staining. The viability of hAECs was significantly lower compared with hDPSCs in all groups and at all time points. Both hAECs and hDPSCs adhered to dentin and were homogeneously distributed. The regulation of odontoblast differentiation- and mineralization-associated genes showed the lack of transition of hAECs into an odontoblastic phenotype; however, genes associated with epithelial-mesenchymal transition were significantly upregulated in hAECs. hAECs showed small amounts of calcium deposition after osteogenic differentiation with StemPro. Pluripotent hAECs adhere on dentin and possess the capacity to mineralize. However, they presented an unfavorable proliferation behavior and failed to undergo odontoblastic transition.

The role of osteopontin in oral cancer: A brief review with emphasis on clinical applications.

Osteopontin (OPN) is a calcium-binding glycol-phosphoprotein present in many physiologic and pathological processes. This protein can control bone cell adhesion, osteoclastic activity, and bone matrix mineralization. However, its participation in pathological processes such as atherosclerosis, sarcoidosis, tuberculosis, and cancer have been described. Some studies have shown that OPN may participate in the development and progression of oral cancer. Although the role of OPN in oral cancer is not fully understood, some studies have suggested that this protein may induce malignant phenotype of cells by activation of PI3K/AKT/mTOR pathway, which favors cell proliferation, invasion, metastasis, angiogenesis, and failure of treatment. This review discusses the possible mechanism of involvement of OPN in oral cancer and its potential clinical application in diagnosis and prognosis.

Enamel matrix derivative effects on palatal mucosa wound healing: Randomized clinical trial.

BACKGROUND: This study was conducted to evaluate the clinical, immunologic, and patient-centered outcomes of enamel matrix protein derivative (EMD) on excisional wounds in palatal mucosa. MATERIALS: Forty-four patients in need of ridge preservation were randomly allocated into two groups: control group (n = 22): open palatal wound after free gingival graft (FGG) harvest and EMD group (n = 22): open palatal wound after FGG harvest that received 0.3 ml of EMD. Clinical and patient-centered parameters were analyzed for 3 months post-treatment. Wound fluid levels of inflammatory markers were assessed 3 and 7 days postoperatively. RESULTS: No significant inter-group difference was observed in remaining wound area and re-epithelialization. EMD and control groups achieved wound closure and re-epithelialization 30 days postoperatively (p < .001), without inter-group differences. Similarly, number of analgesics and Oral Health Impact Profile scores did not present significant inter-group differences (p > .05). EMD appeared to selectively modulate wound fluid levels of monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, matrix metallopeptidase 9, and tissue inhibitor of metalloproteinases-2. CONCLUSION: Within the limits of the present study, it can be concluded that EMD application to excisional palatal wounds using the investigated protocol does not provide clinical healing benefits, despite an apparent modulation of selected inflammatory markers.

Fabrication of Adhesive Substrate for Incorporating Hydrogels to Investigate the Influence of Stiffness on Cancer Cell Behavior.

Stiffness control of cell culture platforms provides researchers in cell biology with the ability to study different experimental models in conditions of mimicking physiological or pathological microenvironments. Nevertheless, the signal transduction pathways and drug sensibility of cancer cells have been poorly characterized widely using biomimetic platforms because the limited experience of cancer cell biology groups about handling substrates with specific mechanical properties. The protein cross-linking and stiffening control are crucial checkpoints that could strongly affect cell adhesion and spreading, misrepresenting the data acquired, and also generating inaccurate cellular models. Here, we introduce a simple method to adhere to polyacrylamide (PAA) hydrogels on glass coverslips without any special treatment for mechanics studies in cancer cell biology. By using a commercial photosensitive glue, Loctite 3525, it is possible to polymerize PAA hydrogels directly on glass surfaces. Furthermore, we describe a cross-linking reaction method to attach proteins to PAA as an alternative method to Sulfo-SANPAH cross-linking, which is sometimes difficult to implement and reproduce. In this chapter, we describe a reliable procedure to fabricate ECM protein-cross-linked PAA hydrogels for mechanotransduction studies on cancer cells.

Clinical, radiographic, and patient-centered outcomes after use of enamel matrix proteins for the treatment of intrabony defects in patients with aggressive periodontitis: A 12-month multicenter clinical trial.

BACKGROUND: The aim of this study was to evaluate the clinical, radiographic and patient-centered results of enamel matrix derivative (EMD) therapy in intrabony defects in aggressive periodontitis (AgP) patients and compare them with those in chronic periodontitis (CP) patients. METHODS: Sixty intrabony defects in AgP and CP patients associated with ≥ 6 mm residual probing pocket depth (PPD) were included and randomly assigned to one of three groups: AgP+CS (conservative surgery) (n = 20); AgP+CS/EMD (n = 20); CP+CS/EMD (n  =  20). Clinical parameters were measured at baseline and after 6 and 12 months. Defect resolution (DR) and bone filling (BF) were used for radiographic analysis. The quality of life was recorded at baseline and 6 months using OHIP-14 and VAS scale in the early post-therapy period. RESULTS: PPD and relative clinical attachment level (rCAL) improved for all groups during follow-up (P ≤ 0.05), and AgP+CS/EMD presented a higher rCAL gain (2.4 ± 1.0 mm) when compared to AgP control patients (1.6 ± 1.6 mm, P ≤ 0.05) after 12 months. No difference was observed between AgP+CS/EMD and CP+CS/EMD groups (P > 0.05). No radiographic differences were observed among groups at any time point (P > 0.05). All the groups reported a positive impact on OHIP-14 total score, without differences among them. CONCLUSIONS: EMD therapy of intrabony defects promotes additional benefits in AgP patients, presenting a similar regeneration rate compared to CP patients, and has proven to be a viable therapy for the treatment of individuals with AgP.

Evaluation of the fibulin 5 gene polymorphism as a factor related to the occurrence of pelvic organ prolapse

SUMMARY OBJECTIVE Pelvic organ prolapse (POP) is a very frequent situation in our population that may lead to a significant decrease in patients' quality of life. Currently, we are looking for predictive factors for the development of POPs; thus, this study seeks to evaluate whether the Fibulin 5 polymorphism (FBLN5) is associated with the occurrence of POP. METHODS This is a cohort study with postmenopausal women who were divided into groups by POP stage: POP stages 0 and I (control group) and POP stages III and IV (case group). Subsequently, analyses of genetic polymorphisms of FBLN5 were performed using the Restriction Fragment Length Polymorphism (RFLP) technique. RESULTS A total of 292 women were included in the study. Pregnancy, parity and vaginal delivery in the patients, as well as in data described in the literature, were related to the occurrence of POP in the univariate analysis. However, after binary logistic regression, home birth and age remained independent risk factors for POP. We found no association between the FBLN5 polymorphism and the occurrence of POP (p = 0.371). CONCLUSION There was no association between the FBLN5 polymorphism and the occurrence of POP in Brazilian women.

RESUMO OBJETIVOS O prolapso de órgãos pélvicos (POP) é uma situação muito frequente em nossa população que pode levar a uma diminuição significativa da qualidade de vida dos pacientes. Atualmente, buscam-se fatores preditivos para o desenvolvimento de POPs e, assim, este estudo correlaciona um polimorfismo de Fibulina 5 (FBLN5) com a ocorrência da doença. MÉTODOS Estudo de coorte com mulheres na pós-menopausa, divididas por grupos pelos estádios 0 e I do POP (grupo controle) e POP III e IV (grupo caso). Posteriormente, análises do polimorfismo genético de FBLN5 foram realizadas utilizando a técnica de Polimorfismo de Comprimento de Fragmentos de Restrição (RFLP). RESULTADOS Um total de 292 mulheres foi incluído no estudo. Gestação, paridade e parto vaginal, como bem descritos na literatura, foram relacionados à ocorrência de POPs na análise univariada. No entanto, após a regressão logística binária, o parto domiciliar e a idade permaneceram como fatores de risco independentes para os POPs. Não encontramos associação deste polimorfismo FBLN5 com a ocorrência de POP (p=0,371). CONCLUSÃO Não houve associação deste polimorfismo FBLN5 com a ocorrência de POPs em mulheres brasileiras.

Experimental and clinical studies on regenerative periodontal therapy.

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue-engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice.

Fragile X syndrome and connective tissue dysregulation.

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disabilities and autism spectrum disorders, and it is an X-linked disorder in which there is a deficiency of the fragile X mental retardation 1 protein. This protein is crucial in regulating translation of mRNAs related to dendritic maturation and cognitive development. The phenotype of FXS is characterized by neurobehavioral alterations, social deficits, communication difficulties, and findings which suggest an alteration of connective tissue, especially in the ligaments and muscles, cardiovascular system and genitourinary system. Connective tissue connects and supports all other tissues of the body and is composed of cells and extracellular matrix (ECM). Several proteins have been involved in the connective tissue abnormalities associated with the FXS, such as matrix metalloproteinase 9, which plays an important role in the homeostasis of the ECM, being a potential therapeutic target for certain tetracycline antibiotics that have shown beneficial effects in FXS. Here, we review connective tissue problems described in FXS.

Airway pathology in severe asthma is related to airflow obstruction but not symptom control.

BACKGROUND: Patients with asthma present structural and inflammatory alterations that are believed to play a role in disease severity. However, airway remodeling and inflammation have not been extensively investigated in relation to both symptom control and airflow obstruction in severe asthmatics. We aimed to investigate several inflammatory and structural pathological features in bronchial biopsies of severe asthmatics that could be related to symptom control and airflow obstruction after standardized treatment. METHODS: Fifty severe asthmatics received prednisone 40 mg/d for 2 weeks and maintenance therapy with budesonide/formoterol 400/12 µg twice daily + budesonide/formoterol 200/6 µg as needed for 12 weeks. Endobronchial biopsies were performed at the end of 12 weeks. We performed extensive immunopathological analyses of airway tissue inflammation and remodeling features in patients stratified by asthma symptom control and by airflow obstruction. RESULTS: Airway tissue inflammation and remodeling were not associated with symptom control. Asthmatics with persistent airflow obstruction had greater airway smooth muscle (Asm) area with decreased periostin and transforming growth factor beta-positive cells within Asm bundles, in addition to lower numbers of chymase-positive mast cells in the submucosa compared to patients with nonpersistent obstruction. CONCLUSIONS: Symptom control in severe asthmatics was not associated with airway tissue inflammation and remodeling, although persistent airflow obstruction in these patients was associated with bronchial inflammation and airway structural changes.

Xenogenous Collagen Matrix and/or Enamel Matrix Derivative for Treatment of Localized Gingival Recessions: A Randomized Clinical Trial. Part I: Clinical Outcomes.

BACKGROUND: Considering xenogeneic collagen matrix (CM) and enamel matrix derivative (EMD) characteristics, it is suggested that their combination could promote superior clinical outcomes in root coverage procedures. Thus, the aim of this parallel, double-masked, dual-center, randomized clinical trial is to evaluate clinical outcomes after treatment of localized gingival recession (GR) by a coronally advanced flap (CAF) combined with CM and/or EMD. METHODS: Sixty-eight patients presenting one Miller Class I or II GRs were randomly assigned to receive either CAF (n = 17); CAF + CM (n = 17); CAF + EMD (n = 17), or CAF + CM + EMD (n = 17). Recession height, probing depth, clinical attachment level, and keratinized tissue width and thickness were measured at baseline and 90 days and 6 months after surgery. RESULTS: The obtained root coverage was 68.04% ± 24.11% for CAF; 87.20% ± 15.01% for CAF + CM; 88.77% ± 20.66% for CAF + EMD; and 91.59% ± 11.08% for CAF + CM + EMD after 6 months. Groups that received biomaterials showed greater values (P <0.05). Complete root coverage (CRC) for CAF + EMD was 70.59%, significantly superior to CAF alone (23.53%); CAF + CM (52.94%), and CAF + CM + EMD (51.47%) (P <0.05). Keratinized tissue thickness gain was significant only in CM-treated groups (P <0.05). CONCLUSIONS: The three approaches are superior to CAF alone for root coverage. EMD provides highest levels of CRC; however, the addition of CM increases gingival thickness. The combination approach does not seem justified.

ß-TCP/HA with or without enamel matrix proteins for maxillary sinus floor augmentation: a histomorphometric analysis of human biopsies.

BACKGROUND: It is still unclear whether enamel matrix proteins (EMD) as adjunct to bone grafting enhance bone healing. This study compared histomorphometrically maxillary sinus floor augmentation (MSFA) with ß-TCP/HA in combination with or without EMD in humans. METHODS: In ten systemically healthy patients needing bilateral MSFA, one side was randomly treated using ß-TCP/HA mixed with EMD (BC + EMD) and the other side using only ß-TCP/HA (BC). After 6 months, biopsies were harvested from grafted areas during implant installation, being histologically and histomorphometrically analyzed. Differences between the groups considering new bone formation, soft tissues, and remaining BC were statistically evaluated. RESULTS: All patients showed uneventful healing after MSFA, and dental implant installation was possible in all patients after 6 months. Histological analysis showed newly formed bone that was primarily woven in nature; it was organized in thin trabeculae, and it was occasionally in contact with residual bone substitute particles, which appeared in various forms and sizes and in advanced stage of degradation. Mean bone area was 43.4% (CI95 38.9; 47.8) for the BC group and 43.0% (CI95 36.6; 49.5) for the BC + EMD group. Mean soft tissue area was 21.3% (CI95 16.5; 26.2) for BC group and 21.5% (CI95 17.7; 25.3) for BC + EMD group, while the remaining biomaterial was 35.3% (CI95 36.6; 49.5) and 35.5% (CI95 29.6; 41.3) for BC and BC + EMD group, respectively. CONCLUSIONS: MSFA with BC resulted in adequate amounts of new bone formation allowing successful implant installation; adding EMD did not have a significant effect.

Pneumococcal Predictive Proteins Selected by Microbial Genomic Approach Are Serotype Cross-Reactive and Bind to Host Extracellular Matrix Proteins.

Streptococcus pneumoniae is a colonizer of the human nasopharynx, which accounts for most of the community-acquired pneumonia cases and can cause non-invasive and invasive diseases. Current available vaccines are serotype-specific and the use of recombinant proteins associated with virulence is an alternative to compose vaccines and to overcome these problems. In a previous work, we describe the identification of proteins in S. pneumoniae by reverse vaccinology and the genetic diversity of these proteins in clinical isolates. It was possible to purify a half of 20 selected proteins in soluble form. The expression of these proteins on the pneumococcal cells surface was confirmed by flow cytometry. We demonstrated that some of these proteins were able to bind to extracellular matrix proteins and were recognized by sera from patients with pneumococcal meningitis infection caused by several pneumococcal serotypes. In this context, our results suggest that these proteins may play a role in pneumococcal pathogenesis and might be considered as potential vaccine candidates.

Shell matrix proteins of the clam, Mya truncata: Roles beyond shell formation through proteomic study.

Mya truncata, a soft shell clam, is presented as a new model to study biomineralization through a proteomics approach. In this study, the shell and mantle tissue were analysed in order to retrieve knowledge about the secretion of shell matrix proteins (SMPs). Out of 67 and 127 shell and mantle proteins respectively, 16 were found in both shell and mantle. Bioinformatic analysis of SMP sequences for domain prediction revealed the presence of several new domains such as fucolectin tachylectin-4 pentraxin-1 (FTP), scavenger receptor, alpha-2-macroglobulin (α2 M), lipocalin and myosin tail along with previously reported SMP domains such as chitinase, carbonic anhydrase, tyrosinase, sushi, and chitin binding. Interestingly, these newly predicted domains are attributed with molecular functions other than biomineralization. These findings suggest that shells may not only act as protective armour from predatory action, but could also actively be related to other functions such as immunity. In this context, the roles of SMPs in biomineralization need to be looked in a new perspective.