Nutritional rehabilitation of mitochondrial aberrations in aplastic anaemia

eDNA Metabarcoding Reveals the Species-Area Relationship of Amphibians on the Zhoushan Archipelago

The species-area relationship is important for understanding species diversity patterns at spatial scales, but few studies have examined the relationship using environmental DNA (eDNA) techniques. We investigated amphibian diversity on 21 islands of the Zhoushan Archipelago and nearby mainland areas in China using the combination of eDNA metabarcoding and the traditional line transect method (TLTM) and identified the species-area relationship for amphibians on the islands. The mean detection probability of eDNA is 0.54, while the mean detection probability of TLTM is 0.24. The eDNA metabarcoding detected eight amphibian species on the islands and nine species in the mainland areas, compared with seven species on the islands and nine species in the mainland areas that were identified by TLTM. Amphibian richness on the islands increased with island area and habitat diversity. The species-area relationship for amphibians in the archipelago was formulated as the power function (S = 0.47A0.21) or exponential function (S = 2.59 + 2.41 (logA)). Our results suggested that eDNA metabarcoding is more sensitive for the detection of amphibian species. The combined use of eDNA metabarcoding and the traditional line transect method may optimize the survey results for amphibians.

Validating eDNA measurements of the richness and abundance of anurans at a large scale

In some situations, environmental DNA (eDNA) metabarcoding is a more accurate tool for measuring species richness of a taxon than conventional methods. Whether this tool can reliably estimate the abundance of a taxon remains unresolved. We examined the reliability of metabarcoding for measuring anuran diversity compared to a commonly used traditional line transect method (TLTM) through the replicate sampling of three visits across 71 waterbodies (ponds or reservoirs) in Liuheng, China. We also investigated the relative contributions of species-specific characteristics and the physiochemical properties of a waterbody on the relative read count across species and waterbodies. We found that eDNA metabarcoding had a higher detection probability for each of seven anuran species found in the sampling region than TLTM. Furthermore, the relative read count estimated by metabarcoding was positively correlated with the density or relative density of individuals identified with the TLTM across waterbodies for every species. Species-specific characteristics of anurans, such as density, relative density, body mass, biomass and relative biomass, accounted for substantial variations in the read count across species and waterbodies, while physiochemical factors, including pH, temperature, water volume, vegetation and elevation, had little effect on the read count. Our results based on robust sampling suggest that metabarcoding enables more reliable and efficient measurements of anuran occurrence at a large scale during a short-term survey (within 15 days) than that obtained by the TLTM, and offers an alternative tool for quantifications of anuran abundance. Density or biomass is better and more reliable indicator of anuran abundance associated with read count than relative density or relative biomass.

Mitochondrial metabolism and the maintenance of hematopoietic stem cell quiescence

PURPOSE OF REVIEW

Hematopoietic stem cells (HSCs) are characterized by a potent multilineage regenerative capability that is dependent on their quiescence property. In the past few decades, researchers have found many intrinsic and niche-derived factors that can regulate HSCs, whereas how to precisely control HSC behaviors remains elusive. Recently, mitochondrial metabolism has been shown to be involved in the regulation of HSC biology. The purpose of this review is to overview recent advances in the relationship between mitochondrial metabolism and maintenance of HSC quiescence.

RECENT FINDINGS

On the basis of fact that HSCs are heterogeneous populations that have their unique metabolic characteristics, increasing studies have demonstrated that the quiescence and function of HSCs are closely correlated with the mitochondrial mass and activity, as well as the levels of mitochondria-derived reactive oxygen species and metabolites. Apart from that, mitochondria have been reported to undergo internal protective programs, including mitochondrial unfolded protein response, autophagy and mitochondrial dynamics, which are beneficial to maintaining HSC homeostasis.

SUMMARY

The maintenance of HSC quiescence needs a metabolic balance in mitochondria, and unraveling the metabolic complexity may provide deep understanding of the functional heterogeneity of HSCs.

Effect of nutritional supplement on bone marrow-derived mesenchymal stem cells from aplastic anaemia

Aplastic anaemia (AA) is characterised by pancytopenia resulting from a marked reduction in haemopoietic stem cells (HSC). The regulation of haemopoiesis depends on the interaction between HSC and various cells of the bone marrow (BM) microenvironment, including BM-derived mesenchymal stromal cells (BMSC). The purpose of this study was to analyse the biological effect of nutritional supplement (NS), a dietary supplement consisting of thirty-six compounds: amino acids, nucleotides, vitamins and micronutrients on the BMSC of AA rats. The AA rat model was established by irradiating X-ray (2·5 Gy) and intraperitoneal injections of cyclophosphamide (35 mg/kg; Sigma) and chloramphenicol (35 mg/kg; Sigma). Then AA rats were fed with NS in a dose-dependent manner (2266·95, 1511·3, 1057·91 mg/kg d) by intragastric administration. The effect of NS on the BMSC of AA rats was analysed. As compared with AA rats, NS treatment significantly improved these peripheral blood parameters and stimulated the proliferation of total femoral nucleated cells. NS treatment affected proliferative behaviour of BMSC and suppressed BMSC differentiation to adipocytes. Furthermore, NS treatment of AA rats accelerated osteogenic differentiation of BMSC and enhanced bone mineral density. Co-incubation of HSC with mesenchymal stromal cells and serum from AA rats subjected to high-dose NS markedly improved the yield of CD34+cells. Protein microarray analysis revealed that there were eleven differentially expressed proteins in the NS group compared with the AA rat group. The identified specific NS might be implicated in rehabilitation of BMSC in AA rats, suggesting their potential of nutritional support in AA treatment.

The positive effect of chick embryo and nutrient mixture on bone marrow- derived mesenchymal stem cells from aging rats

The aging of many mammalian tissues is associated with loss of functional adult stem cells, especially bone marrow-derived mesenchymal stem cells (BMSCs). This study was aimed to analyze the biological effect of chick embryo (CE) and nutrient mixture (NM) on the BMSCs of aging rats. The aging rat model was established to be induced by D-galactose (500 mg/kg/d) for 90 days. Meanwhile, aging rats were fed with CE and NM in different dose manner by intragastric administration. At the end of the experimental period, serum was collected from rats and used for BMSCs culture. Flow cytometric analysis was used to investigate the BMSCs surface markers. Alizarin Red and oil red O staining were performed to evaluate the multi-lineage differentiation of BMSCs. The results showed that CE plus NM increased the telomere length of BMSCs and promoted BMSCs proliferation. Moreover, CE plus NM administration promoted BMSCs differentiation into osteoblasts and suppressed differentiation into adipocytes. High-throughput sequencing analysis revealed that there were 326 genes were up-regulated and 59 genes were down-regulated in BMSCs of aging rats treated with CE plus NM. In conclusion, CE plus NM supplement had potential to delay aging through the recovery of BMSCs senescence and could be used as a safe effective approach for nutritional therapy of anti-aging.