Adipose-Derived Stem Cells Stimulate Regeneration of Peripheral Nerves: BDNF Secreted by These Cells Promotes Nerve Healing and Axon Growth De Novo

Transplantation of adipose-derived mesenchymal stem cells (ASCs) induces tissue regeneration by accelerating the growth of blood vessels and nerve. However, mechanisms by which they accelerate the growth of nerve fibers are only partially understood. We used transplantation of ASCs with subcutaneous matrigel implants (well-known in vivo model of angiogenesis) and model of mice limb reinnervation to check the influence of ASC on nerve growth. Here we show that ASCs stimulate the regeneration of nerves in innervated mice's limbs and induce axon growth in subcutaneous matrigel implants. To investigate the mechanism of this action we analyzed different properties of these cells and showed that they express numerous genes of neurotrophins and extracellular matrix proteins required for the nerve growth and myelination. Induction of neural differentiation of ASCs enhances production of brain-derived neurotrophic factor (BDNF) as well as ability of these cells to induce nerve fiber growth. BDNF neutralizing antibodies abrogated the stimulatory effects of ASCs on the growth of nerve sprouts. These data suggest that ASCs induce nerve repair and growth via BDNF production. This stimulatory effect can be further enhanced by culturing the cells in neural differentiation medium prior to transplantation

Grey wolf genomic history reveals a dual ancestry of dogs

The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived1,2,3,4,5,6,7,8. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located

Genomes of Pleistocene Siberian wolves uncover multiple extinct wolf lineages

Extant Canis lupus genetic diversity can be grouped into three phylogenetically distinct clades: Eurasian and American wolves and domestic dogs.1 Genetic studies have suggested these groups trace their origins to a wolf population that expanded during the last glacial maximum (LGM)1, 2, 3 and replaced local wolf populations.4 Moreover, ancient genomes from the Yana basin and the Taimyr peninsula provided evidence of at least one extinct wolf lineage that dwelled in Siberia during the Pleistocene.35 Previous studies have suggested that Pleistocene Siberian canids can be classified into two groups based on cranial morphology. Wolves in the first group are most similar to present-day populations, although those in the second group possess intermediate features between dogs and wolves.67 However, whether this morphological classification represents distinct genetic groups remains unknown. To investigate this question and the relationships between Pleistocene canids, present-day wolves, and dogs, we resequenced the genomes of four Pleistocene canids from Northeast Siberia dated between >50 and 14 ka old, including samples from the two morphological categories. We found these specimens cluster with the two previously sequenced Pleistocene wolves, which are genetically more similar to Eurasian wolves. Our results show that, though the four specimens represent extinct wolf lineages, they do not form a monophyletic group. Instead, each Pleistocene Siberian canid branched off the lineage that gave rise to present-day wolves and dogs. Finally, our results suggest the two previously described morphological groups could represent independent lineages similarly related to present-day wolves and dogs

Arctic-adapted dogs emerged at the Pleistocene-Holocene transitiond

Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an ~9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an ~33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog–specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago

Grey wolf genomic history reveals a dual ancestry of dogs

The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived1–8. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located. © 2022, The Author(s).8028-00005B; IP DKRVO 2019-2023, MK000094862; 220457/Z/20/Z, ERC-2013-StG-337574-UNDEAD, ERC-2019-StG-853272-PALAEOFARM; 075-15-2021-1069; European Molecular Biology Organization, EMBO: 217223/Z/19/Z; Vallee Foundation; Velux Fonden; Wellcome Trust, WT; Francis Crick Institute, FCI: FC001595; Horizon 2020 Framework Programme, H2020: 796877; Medical Research Council, MRC; Natural Environment Research Council, NERC: 210119/Z/18/Z, NE/K003259/1, NE/K005243/1, NE/S00078X/1, NE/S007067/1; Cancer Research UK, CRUK; European Research Council, ERC: 852558; Grantová Agentura České Republiky, GA ČR: 15-06446S; Svenska Forskningsrådet Formas: 2018-01640; Knut och Alice Wallenbergs Stiftelse; Vetenskapsrådet, VR: 681396, BELSPO B2/191/P2/ICHIE; Russian Science Foundation, RSF: 16-18-10265-RNF, 20-17-00033, 21-18-00457-RNF, 310763; Science for Life Laboratory, SciLifeLab; Narodowa Agencja Wymiany Akademickiej, NAWA: PPN/PPO/2018/1/00037This work was supported by grants to P. Skoglund from the European Research Council (grant no. 852558), the Erik Philip Sörensen Foundation and the Science for Life Laboratory, Swedish Biodiversity Program, made available by support from the Knut and Alice Wallenberg Foundation. A.B., L.S., P. Swali and P. Skoglund were supported by Francis Crick Institute core funding (FC001595) from Cancer Research UK, the UK Medical Research Council and the Wellcome Trust. P. Skoglund was also supported by the Vallee Foundation, the European Molecular Biology Organisation and the Wellcome Trust (217223/Z/19/Z). Computations were supported by SNIC-UPPMAX. We also acknowledge support from Science for Life Laboratory, the Knut and Alice Wallenberg Foundation, the National Genomics Infrastructure funded by the Swedish Research Council and the Uppsala Multidisciplinary Center for Advanced Computational Science for assistance with massively parallel sequencing and access to the UPPMAX computational infrastructure. We thank the Yukon gold mining community and First Nations, including the Tr’ondëk Hwëch’in, for continued support of our palaeontology research in the Yukon Territories, Canada. We thank the Danish National High-Throughput Sequencing Centre and BGI-Europe for assistance in sequencing data generation and the Danish National Supercomputer for Life Sciences–Computerome ( https://computerome.dtu.dk ) for computational resources. We thank National Museum Wales for continued sampling support. M. Germonpré acknowledges support from the Brain.be 2.0 ICHIE project (BELSPO B2/191/P2/ICHIE). M.T.P.G. was supported by the European Research Council (grant no. 681396). M.-H.S.S. was supported by the Velux Foundations through the Qimmeq Project, the Aage og Johanne Louis-Hansens Fond and the Independent Research Fund Denmark (8028-00005B). L.D. acknowledges support from FORMAS (2018-01640). D.W.G.S. received funding for this project from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement no. 796877. M.P. was supported by the Polish National Agency for Academic Exchange–NAWA (grant no. PPN/PPO/2018/1/00037). V.J.S. was supported by the University of Zurich’s University Research Priority Program ‘Evolution in Action: From Genomes to Ecosystems’. This research was done with the participation of ZIN RAS (grant no. 075-15-2021-1069). We are grateful to the museum of the Institute of Plant and Animal Ecology UB RAS (Ekaterinburg, Russia) for provision of samples. R.P.J. and C.O’D. were supported by the Standing Committee for Archaeology of the Royal Irish Academy through the Archaeological Excavation Research Grant Scheme. E.Y.P., P.N. and V.V.P. are supported by the Russian Science Foundation (grant no. 16-18-10265-RNF and 21-18-00457-RNF). Y.V.K. was supported by the Russian Science Foundation (grant no. 20-17-00033). M.H. was supported by the European Research Council (consolidator grant GeneFlow no. 310763). M.L.-G. was supported by the Czech Science Foundation GAČR (grant no. 15-06446S) and institutional financing of the Moravian Museum from the Czech Ministry of Culture (IP DKRVO 2019-2023, MK000094862). L.S. is supported by the Sir Henry Wellcome fellowship (220457/Z/20/Z). We thank Staatliches Museum für Naturkunde Stuttgart for sample access. L.F. and G.L. were supported by European Research Council grants (ERC-2013-StG-337574-UNDEAD and ERC-2019-StG-853272-PALAEOFARM) and Natural Environmental Research Council grants (NE/K005243/1, NE/K003259/1, NE/S007067/1 and NE/S00078X/1). L.F. was also supported by the Wellcome Trust (210119/Z/18/Z). This research was funded in whole, or in part, by the Wellcome Trust (FC001595). For the purpose of open access, the author has applied a CC-BY public copyright licence to any author accepted manuscript version arising from this submission