In recent times, both public and private sectors are ambitious in sending more individuals to space via commercial suborbital space vehicles for various commercial endeavors including mining. Spaceflight, possessing the most life-threatening conditions are very challenging for humans to overcome from their adverse effects. A recent trend of increased space flight participants has resulted in higher heterogeneity in the astronaut’s long-term missions encountered with the exposure of the high radiations beyond low Earth orbit. Thus, vastly varying risk factors in addition to the abnormal unfriendly spacecraft’s conditions and space environments makes the normal humans to acclimatize easily. It has been reported that about 20-25 % of the long-term (>4 months) astronauts sent by the International Space Station (ISS) were reported to have persistent ocular complications soon after they complete their missions (Smith et al. 2012; Zwart et al. 2012). Likewise, some preliminary evidences suggest that astronauts may have altered one carbon metabolic effects due to genetic factors, micronutrients intake and the space flight environment (Schmidt and Goodwin 2013). Thus, it is necessary to consider such factors that may affect individuals and to develop defensive or adaptable environments. In this regard, to help and safeguard the progressively increasing number of astronauts, space researchers, and space visitors, it is necessary to recognize individual risk profiles to counteract such risks individually.
At present, astronauts receive cutting-edge medical attention, however genotypic and molecular assessments are lacked, which are very necessary as a countermeasures. Till date, only short-term cultures have been carried out onboard the ISS. However, long-term studies essentially involving culture-independent methods, such as high-throughput sequencing analyses are needed to examine how biological systems adapt to the space environment (Karouia et al. 2017). Further, to support the crew members, the use of emerging field of personalized medicine is highly advisable.
Astronauts are treated with Earth-based drugs for treating health issues during space missions. However, recent studies have stated the potential adverse effects of drug metabolisms and reactions that are based on an individual’s genotype. A medication given without knowing the genetic makeup of an individual will lead to adverse health outcomes and altered astronaut performance in space. Hence, personalized drug treatments for astronauts are to be considered. For instance, the characterization of individual astronaut’s biotransformation ability could be based on individual cytochrome P450 (CYP450) profiles, i.e., CYP450 gene family is a major subset of drug-metabolizing enzymes (Wu 2011). Likewise, personalized drug regimens is also based on the ethnicity of an individual. As stated by Schmidt et al. (2013), “most western people are characterized by roughly 93 % normal (or efficient) metabolizers, 7 % poor metabolizers, and 1 % ultra-rapid metabolizers of CYP2D6. In contrast, only 1 % of Asians are considered poor metabolizers of CYP2D6. Roughly 20 % of Asians are poor metabolizers via CYP2C19, while only about 4 % of Caucasians are considered poor metabolizers via this isoform”. Therefore, applications of pharmacogenomics could be useful as a personalize drug prescription for improving the safety and efficacy of drugs used in space. Further, assessment of specific genes, proteins, and metabolites that change due to drug administration will help in understanding the effects of drugs in space conditions. Likewise, it has been reported that long-duration crewmembers experience in-flight and post flight visual problems. However, the underlying etiology for these deviations is unfamiliar at the present time. The NASA medical community doubts on the fact that microgravity and radiations induces changes in the human physiology and chromosome instability (Otto 2012; Mader et al. 2012; Gibson et al. 2012; Schmidt et al. 2013). In this regard, metabolomics study could be useful in understanding the reasons for this altered physiological changes during and after space life. Likewise, molecular reasons that influence on the one carbon derangement on bone in the crewmembers in space could be envisaged by omics approaches. In a recent report, a comprehensive Whole Genome Analysis of Differential Epigenetic Effects of Space Travel on Monozygotic Twins (Twins Study – Feinberg) studies suggested the chemical changes in DNA is due to different environmental conditions found in space. They measured DNA methylation and chromatin at a genome-wide level in biological samples obtained from the space traveler before, during, and after flight, as well as from his ground-based twin. The study results suggested that the individual, who spent long-time in space had the predictive prolonged life when compared to ground based individual. This suggested that space conditions significantly influence on the DNA mutations, mainly attributed to radiations. However, detailed assessment is highly warranted to better understand on these observations.
Overall, personalized medicine makes use of a person’s information about genes, proteins and metabolites in response to diet, lifestyle and surrounding environment for diagnosing and preventing/treating diseases. With regard to spaceflight, it can be proposed that an optimized and a defined personalized diet/nutrition, practices, and atmosphere can be achieved for a better safety and performance of a space traveler under space conditions, which is mainly based on considering his/her genes, transcripts, proteins, and metabolites (Schmidt and Goodwin 2013). This will not only allow one to understand the profiles of astronauts individually, but also help in developing countermeasures so as to increase the capabilities of an astronaut to enthusiastically participate and perform to his/her highest competent level. In this regard, advancements in ‘omics’ approaches, such as genomics, transcriptomics, proteomics, and metabolomics are very useful in revealing unique molecular differences existing amongst persons (Karouia et al. 2017). It is necessary to mention that under extreme conditions, including spaceflight, such differences can be higher. Hence, knowing distinct variances in each astronauts will benefit in setting up of personalized countermeasure preparations that suit the best for each astronauts. Overall, high-throughput omics approaches will certainly give information on;
Key Words: Spacetraveler, Spacelife, Spaceflight, Genomics, Health Care, Genetic Variation, ISRO, NASA, Spacestation, ISS, Leucine Rich Bio, Genomic Signature.