Project description:Parkinson's disease (PD) is a challenging neurodegenerative disorder. Recently, therapy of neural stem cells (NSCs) derived from human induced pluripotent stem cells (hiPSCs) has emerged as a significant advancement in regenerative medicine. Melatonin (MT), acting as a mitochondrial targeting hormone, exhibits neuroprotective properties in neurodegenerative diseases and modulates stem cell differentiation through mitochondrial dynamics. However, the precise mechanism by which MT influences dopaminergic (DA) neuronal differentiation in hiPSCs through regulating mitochondrial dynamics remains unclear. In this study, we developed and optimized a technical protocol for the in vitro functional neuronal differentiation of hiPSCs. Our findings demonstrate that MT enhances the differentiation potential of hiPSCs toward neuroectoderm and significantly improves the efficiency of NSCs differentiation into DA neurons within hiPSCs. Using the specific MT receptor inhibitor, Luzindole, we confirmed its inhibitory effect on MT-mediated promotion of neural differentiation. Mechanistically, we propose that MT enhances functional DA neuron differentiation from hiPSCs by activating mitochondrial dynamics-mediated WNT/β-catenin signaling pathways. Additionally, we elucidated the critical role of mitofusin2 (MFN2) in enhancing the directed differentiation of DA neurons from hiPSCs. In vivo studies validated the efficacy of MT-treated hiPSC-derived DA progenitor cells in regenerating tyrosine hydroxylase (TH)-positive DA neurons and improving motor function in PD mouse models. In conclusion, this study highlights the potential clinical relevance of MT-enhanced differentiation of hiPSCs into DA neurons, offering promising implications for the treatment of PD.
Project description:Dopaminergic (DA) neurons marked by the dopamine transporter (DAT) have multiple physiological functions and are involved in the regulation of mental and neurological diseases, prompting in-depth studies into their development and functions. This research explores the spatiotemporal proteomic and transcriptomic changes in DAT+ DA neurons within key brain regions involved in DA signaling—the nucleus accumbens (NAc), substantia nigra (SNc), and ventral tegmental area (VTA). Utilizing cutting-edge multi-omics techniques, such as ultrasensitive trace sample proteomics and SMART_x0002_seq2 for transcriptomics, we examine the DA neuronal system at critical postnatal milestones: postnatal day 7 (P7), postnatal day 30 (P30), and postnatal day 60 (P60). The study reveals unique molecular profiles within DA neuron populations, showcasing their varied functional roles and developmental progression. Immunofluorescence mapping illustrates these molecular distributions, validating the quantitative data and highlighting the dynamic molecular structure of DA neurons. Our findings notably highlight a marked increase over time in Aldh1a1 expression, an essential enzyme for retinoic acid production, suggesting its evolving role in neuronal development and specific functions. This comprehensive analysis offers a profound molecular perspective on DAT+ DA neuron development, enhancing our understanding of their functional diversity and potential relevance in DA-related diseases.
Project description:Because of severe abiotic limitations, Antarctic soils represent simplified ecosystems, where microorganisms are the principle drivers of nutrient cycling. This relative simplicity makes these ecosystems particularly vulnerable to perturbations, like global warming, and the Antarctic Peninsula is among the most rapidly warming regions on the planet. However, the consequences of the ongoing warming of Antarctica on microorganisms and the processes they mediate are unknown. Here, using 16S rRNA gene pyrosequencing and qPCR, we report a number of highly consistent changes in microbial community structure and abundance across very disparate sub-Antarctic and Antarctic environments following three years of experimental field warming (+ 0.5-2°C). Specifically, we found significant increases in the abundance of fungi and bacteria and in the Alphaproteobacteria-to-Acidobacteria ratio. These alterations were linked to a significant increase in soil respiration. Furthermore, the shifts toward generalist or opportunistic bacterial communities following warming weakened the linkage between bacterial diversity and functional diversity. Warming also increased the abundance of some organisms related to the N-cycle, detected as an increase in the relative abundance of nitrogenase genes via GeoChip microarray analyses. Our results demonstrate that soil microorganisms across a range of sub-Antarctic and Antarctic environments can respond consistently and rapidly to increasing temperatures, thereby potentially disrupting soil functioning.