scholarly journals Tooth Enamel and Its Dynamic Protein Matrix

2020 ◽  
Vol 21 (12) ◽  
pp. 4458 ◽  
Author(s):  
Ana Gil-Bona ◽  
Felicitas B. Bidlack

Tooth enamel is the outer covering of tooth crowns, the hardest material in the mammalian body, yet fracture resistant. The extremely high content of 95 wt% calcium phosphate in healthy adult teeth is achieved through mineralization of a proteinaceous matrix that changes in abundance and composition. Enamel-specific proteins and proteases are known to be critical for proper enamel formation. Recent proteomics analyses revealed many other proteins with their roles in enamel formation yet to be unraveled. Although the exact protein composition of healthy tooth enamel is still unknown, it is apparent that compromised enamel deviates in amount and composition of its organic material. Why these differences affect both the mineralization process before tooth eruption and the properties of erupted teeth will become apparent as proteomics protocols are adjusted to the variability between species, tooth size, sample size and ephemeral organic content of forming teeth. This review summarizes the current knowledge and published proteomics data of healthy and diseased tooth enamel, including advancements in forensic applications and disease models in animals. A summary and discussion of the status quo highlights how recent proteomics findings advance our understating of the complexity and temporal changes of extracellular matrix composition during tooth enamel formation.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Lisandra E. de Castro Brás ◽  
Hiroe Toba ◽  
Catalin F. Baicu ◽  
Michael R. Zile ◽  
Susan T. Weintraub ◽  
...  

Secreted protein acidic and rich in cysteine (SPARC), a collagen-binding matricellular protein, has been implicated in procollagen processing and deposition. The aim of this study was to investigate age- and SPARC-dependent changes in protein composition of the cardiac extracellular matrix (ECM). We studied 6 groups of mice (n=4/group): young (4-5 months old), middle-aged (11-12 m.o.), and old (18–29 m.o.) C57BL/6J wild type (WT) and SPARC null. The left ventricle (LV) was decellularized to enrich for ECM proteins. Protein extracts were separated by SDS-PAGE, digested in-gel, and analyzed by HPLC-ESI-MS/MS. Relative quantification was performed by spectral counting, and changes in specific proteins were validated by immunoblotting. We identified 321 proteins, of which 44 proteins were extracellular proteins. Of these proteins, collagen III levels were lower in the old null mice compared to WT, suggestive of a role for SPARC in collagen deposition. Additionally, fibrillin showed a significant increase in the null middle-aged group, suggestive of increased microfibril deposition in the absence of SPARC. Collagen VI increased with age in both genotypes (>3-fold), while collagen IV showed increased age-associated levels only in the WT animals (4-fold,P<0.05). These changes may explain the previously reported age-associated increases in LV stiffness. In summary, our data suggest SPARC is a possible therapeutic target for aging induced LV dysfunction.


2011 ◽  
Vol 43 (13) ◽  
pp. 789-798 ◽  
Author(s):  
Nir Eynon ◽  
María Morán ◽  
Ruth Birk ◽  
Alejandro Lucia

Aerobic ATP generation by the mitochondrial respiratory oxidative phosphorylation system (OXPHOS) is a vital metabolic process for endurance exercise. Notably, mitochondrial DNA (mtDNA) codifies 13 of the 83 polypeptides implied in the respiratory chain. As such, there is a strong rationale for identifying an association between mtDNA variants and “aerobic” (endurance) exercise phenotypes. The aim of this review is to summarize current knowledge on the association between mtDNA, nuclear genes involved in mitochondriogenesis, and elite endurance athletic status. Several studies in nonathletic people have demonstrated an association between certain mtDNA lineages and aerobic performance, characterized by maximal oxygen uptake (V̇o2max). Whether mtDNA haplogroups are also associated with the status of being an elite endurance athlete is more controversial, with differences between studies arising from the different ethnic backgrounds of the athletic cohorts (Caucasian of mixed geographic origin, Asiatic, or East African).


2020 ◽  
Author(s):  
Xuan Chen ◽  
Zuochen Li ◽  
Yanqiu Lv ◽  
Yichao Xu ◽  
Mimi Cheng ◽  
...  

Abstract Background: Sperm capacitation is a process which occurs prior to fertilization, and is essential for producing high-quality living embryos. The main purpose of this study was to explore the difference of proteomics between capacitated and non-capacitated sperm of Yanbian yellow cattle. Bioinformatic analyses of LC-MS/MS data included GO enrichment, KEGG pathway enrichment, and protein-protein interaction (PPI) analysis. Results: The results revealed 23 specific proteins in the capacitated group and 345 in the non-capacitated group. Compared with non-capacitated sperm, capacitated sperm exhibited 89 upregulated proteins and 509 downregulated proteins. Western blotting was used to confirm our proteomics data. The expression level of PSMD1 in the capacitated sperm group was significantly lower than that in the non-capacitated sperm group, and the expression level of HSPA5 was significantly higher than in the non-capacitated sperm group. Conclusions: Our results revealed that many proteins were differentially expressed between capacitated and non-capacitated sperm, particularly those involved in the proteasome signaling and protein transport signaling pathways. This work enhances our understanding of molecular processes involved in sperm viability in Yanbian yellow cattle, and provides a framework for future studies.


2021 ◽  
Author(s):  
Klaas Jan van Wijk ◽  
Eric W Deutsch ◽  
Qi Sun ◽  
Zhi Sun ◽  
Tami Leppert ◽  
...  

We developed a new resource, the Arabidopsis PeptideAtlas (www.peptideatlas.org/builds/arabidopsis/), to solve central questions about the Arabidopsis proteome, such as the significance of protein splice forms, post-translational modifications (PTMs), or simply obtain reliable information about specific proteins. PeptideAtlas is based on published mass spectrometry (MS) analyses collected through ProteomeXchange and reanalyzed through a uniform processing and metadata annotation pipeline. All matched MS-derived peptide data are linked to spectral, technical and biological metadata. Nearly 40 million out of ~143 million MSMS spectra were matched to the reference genome Araport11, identifying ~0.5 million unique peptides and 17858 uniquely identified proteins (only isoform per gene) at the highest confidence level (FDR 0.0004; 2 non-nested peptides ≥ 9 aa each), assigned canonical proteins, and 3543 lower confidence proteins. Physicochemical protein properties were evaluated for targeted identification of unobserved proteins. Additional proteins and isoforms currently not in Araport11 were identified, generated from pseudogenes, alternative start, stops and/or splice variants and sORFs; these features should be considered for updates to the Arabidopsis genome. Phosphorylation can be inspected through a sophisticated PTM viewer. This new PeptideAtlas is integrated with community resources including TAIR, tracks in JBrowse, PPDB and UniProtKB. Subsequent PeptideAtlas builds will incorporate millions more MS data.


2014 ◽  
Vol 10 (3) ◽  
pp. 176-199 ◽  
Author(s):  
Sarah Fotheringham ◽  
Chad Saunders

Purpose – The purpose of this study is to investigate the potential of social enterprise as a strategy for poverty reduction for women. Design/methodology/approach – A literature synthesis on the topic was conducted and patterns, linkages and gaps were examined among key themes to identify how social enterprise can potentially serve as a poverty reduction strategy for women. Findings – The paper presents the findings in terms of specific factors contributing to women’s poverty and hypothesizes mechanisms through which social enterprises can mitigate or address these factors in practice. The paper organizes these findings in an integrative framework that highlights the need to ensure a solid policy foundation is in place before a number of key support mechanisms are enabled, which then facilitate specific types of work that can then grow in a sustainable manner. Research limitations/implications – While the mechanisms and proposed framework are based on the extant literature, additional empirical investigation is required. Practical implications – Women are disproportionately burdened by poverty and the framework presented provides a very practical tool to guide the design of new or diagnosing existing social enterprises targeting poverty reduction for women. Social implications – Without a strategic approach, the risk is either perpetuating the status quo, or worse, placing those women engaged in social enterprises in a worse financial and social position. Originality/value – There is limited research on the poverty reducing role of social enterprise for women and the proposed mechanisms and integrative framework presented provide a means of synthesizing our current knowledge while providing the basis for future investigations.


1957 ◽  
Vol s3-98 (43) ◽  
pp. 349-367
Author(s):  
D.F. G. POOLE

A number of features of enamel formation in the lizard Agama atricollis are described. The behaviour and properties of the ameloblasts indicate that the process of enamel formation is similar to the corresponding process in mammals; the fibrous enamel matrix appears to be formed from outgrowths of the cytoplasm of these cells. Interprismatic material, as it is known in mammals, is not produced, so that reptilian matrix tends to be uniformly fibrous. Nevertheless, the fibres are initially arranged in groups corresponding to the ameloblasts. There is no distinct pre-enamel stage because matrix production is immediately followed by a limited influx of mineral in an elementary state, converting the matrix into an basiphil form. Striae of Retzius may be due to periodic pauses in the normal process of matrix production enabling the ameloblasts to assimilate and secrete mineral. Before the onset of final calcification, the matrix seems to undergo a modification rendering it capable of influencing the size and orientation of mineral crystallites. The organic matrix has a refractive index of 1.57 and has no intrinsic birefringence. However, in suitable liquids the parallel fibres produce a positive form birefringence. If paraffin wax is allowed to crystallize on the matrix, optically negative streaks are formed parallel with the fibres, perhaps as the result of crystal overgrowth. Evidence obtained indicates that this reptilian type of ectodermal enamel is a likely precursor of the mammalian prismatic type. The evolution from one to the other could have been achieved in a comparatively simple step.


1965 ◽  
Vol 2 (03) ◽  
pp. 282-298
Author(s):  
Karl E. Schoenherr

Panel H-10 (Controllability) of The Society of Naval Architects and Marine Engineers Technical and Research Program was requested to undertake an investigation of existing uncertainties in pre-calculating rudder torque and lateral force. In order to become quickly familiar with the subject and prospects therein, the Panel commissioned the author of this paper to survey the status of current knowledge of the subject and prepare a report of the findings. In particular, this report was to identify the most promising approaches for future work leading to an ultimate solution of the problem and to include technical descriptions of proposed programs for an exhaustive investigation, all of which are discussed in this paper.


Stroke ◽  
2020 ◽  
Vol 51 (11) ◽  
pp. 3461-3471
Author(s):  
Johannes Kaesmacher ◽  
Johanna M. Ospel ◽  
Thomas R. Meinel ◽  
Grégoire Boulouis ◽  
Mayank Goyal ◽  
...  

In patients undergoing mechanical thrombectomy, achieving complete (Thrombolysis in Cerebral Infarction 3) rather than incomplete successful reperfusion (Thrombolysis in Cerebral Infarction 2b) is associated with better functional outcome. Despite technical improvements, incomplete reperfusion remains the final angiographic result in 40% of patients according to recent trials. As most incomplete reperfusions are caused by distal vessel occlusions, they are potentially amenable to rescue strategies. While observational data suggest a net benefit of up to 20% in functional independence of incomplete versus complete reperfusions, the net benefit of secondary improvement from Thrombolysis in Cerebral Infarction 2b to 3 reperfusion might differ due to lengthier procedures and delayed reperfusion. Current strategies to tackle distal vessel occlusions consist of distal (microcatheter) aspiration, small adjustable stent retrievers, and administration of intra-arterial thrombolytics. While there are promising reports evaluating those techniques, all available studies show relevant limitations in terms of selection bias, single-center design, or nonconsecutive patient inclusion. Besides an assessment of risks associated with rescue maneuvers, we advocate that the decision-making process should also include a consideration of potential outcomes if complete reperfusion would successfully be achieved. These include (1) a futile angiographic improvement (hypoperfused territory is already infarcted), (2) an unnecessary angiographic improvement (the patient would not have developed infarction if no rescue maneuver was performed), and (3) a successful rescue maneuver with clinical benefit. Currently there is paucity of data on how these scenarios can be predicted and the decision whether to treat or to stop in a patient with incomplete reperfusion involves many unknowns. To advance the status quo, we outline current knowledge gaps and avenues of potential research regarding this clinically important question.


Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2001 ◽  
Author(s):  
Reetu Mukherji ◽  
John Marshall ◽  
Andreas Seeber

The selection of treatment according to genomic alterations is a standard approach in metastatic colorectal cancer but is only starting to have an impact in the earlier stages of the disease. The status of genes like KRAS, BRAF, and MMR has substantial survival implications, and concerted research efforts have revolutionized treatment towards precision oncology. In contrast, a genomic-based approach has not changed the adjuvant setting after curative tumor-resection in the daily routine so far. This review focuses on the current knowledge regarding prognostic and predictive genomic biomarkers in patients with locally advanced nonmetastasized colorectal cancer. Furthermore, we provide an outlook on future challenges for a personalized adjuvant treatment approach in patients with colorectal cancer.


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