Differences in the physiological proteome of men of different racial origin is poorly researched, albeit hair is mostly composed of keratins and keratin-associated proteins. Hence, we have carried out label-free, shotgun proteomics analysis on hair samples collected from black African, Caucasian, Asian, and Mixed-Ancestry donors within a heterogeneous population of the Western Cape of South Africa. Further, the same hair was also classified using geometrical measurements. Using both qualitative and quantitative proteomics bioinformatics pipelines, we identified over 450 protein groups (FDR = 0.01). Identified protein classes included keratins, keratin-associated proteins, histone proteins and desmosomes, inter alia. No protein by quantitative proteomic analyses significantly differentiated racial or geometric groups in our cohort. Functional pathway analysis of top-ranking proteins showed enrichment for skin, epidermal and tissue development, as well as intermediate-filament organization. Racial classification is a social construct, and attributing differences in a biologic endpoint to it is both imprecise and valueless in the era of precision medicine. Nonetheless, clarity on the physiological hair proteome could serve as a foundation for using hair proteomics for disease biomarker and targeted therapy identification for precision medicine. For the first time, we established the physiological hair proteome of individuals in a culturally diverse cohort from Africa.

Significance

For the first time we have been able to characterize the physiological human hair proteome in a culturally diverse South African cohort. We have also identified that proteomics differences were not observed in individual hair samples using our quantitative proteomics bioinformatics pipeline. This outcome supports a widely known notion that DNA sequence comparison often shows that people on each continent are not more genetically similar to one another than to people who come from other continents and that there is more genetic variation in Africa. Hence, adaptive traits such as hair and skin phenotype are not scientifically valid distinctions. Racial classification is believed to be a social construct, and attributing differences in a biologic endpoint to it is both imprecise and valueless in the era of precision medicine. Our preliminary finding would serve as a much-needed foundation for establishing a well-annotated, customized hair proteomics repository for Africans.

中文翻译：

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南非人群中按种族和几何分类的头皮头发样品的蛋白质组没有差异：初步发现。

尽管种族的头发主要由角蛋白和与角蛋白相关的蛋白质组成，但对不同种族男性的生理蛋白质组差异的研究很少。因此，我们对从南非西开普省异种种群中的非洲黑人，高加索人，亚洲人和混合祖先供体收集的头发样本进行了无标签，shot弹枪蛋白质组学分析。此外，还使用几何测量对同一根头发进行了分类。使用定性和定量蛋白质组学生物信息学流水线，我们确定了450多个蛋白质组（FDR = 0.01）。鉴定出的蛋白质类别包括角蛋白，与角蛋白相关的蛋白质，组蛋白和桥粒，尤其是。通过定量蛋白质组学分析，没有蛋白质能显着区分我们队列中的种族或几何群体。排名靠前的蛋白质的功能途径分析显示，其丰富了皮肤，表皮和组织的发育以及中间丝的组织。种族分类是一种社会建构，在生物学终点上将差异归因于种族分类在精确医学时代既不精确又毫无价值。尽管如此，在生理上蛋白质组学上的清晰度仍可作为将蛋白质组学用于疾病生物标志物和针对精准医学进行靶向治疗鉴定的基础。我们首次在非洲不同文化背景的人群中建立了个体的生理生发蛋白质组。

意义

我们首次能够在一个文化多元的南非人群中表征人的生理性蛋白质组。我们还确定了使用定量蛋白质组学生物信息学流水线在单个头发样本中未观察到蛋白质组学差异。这一结果支持了一个广为人知的观念，即DNA序列比较通常表明，与来自其他大洲的人相比，每个大洲的人在遗传上并不更相似，并且非洲存在更多的遗传变异。因此，诸如头发和皮肤表型的适应性特征不是科学上有效的区别。种族分类被认为是一种社会建构，在生物学终点上将差异归因于种族分类在精确医学时代既不精确也没有价值。