One of the advantages of human adipose-derived stem cells (ASCs) in regenerative medicine is that they can be harvested in abundance. However, the stemness biomarkers, which marked the safety and efficacy of ASCs in accordance with the good manufacturing practice guidelines, is not yet well established. This study was designed to investigate the effect of long-term culture on the stemness properties of ASCs using quantitative real-time polymerase chain reaction and flow cytometry. Results showed the growth rate of ASCs was at its peak when they reached P10 (population doubling; PD = 26) but started to decrease when they were expanded to P15 (PD = 36) and P20 (PD = 46). The ASCs can be culture expanded with minimal alteration in the stemness genes and cluster of differentiation (CD) markers expression up to P10. Expression level of Sox2, Nestin, and Nanog3 was significantly decreased at later passage. CD31, CD45, CD117, and human leukocyte antigen DR, DQ, and DP were lowly expressed at P5 and P10 but their expressions increased significantly at P15 or P20. The differentiation ability of ASCs (adipogenesis, osteogenesis, and neurogenesis) also decreased in long-term culture. Our findings suggested that P10 (PD = 26) should be the "cutoff point" for clinical usage because ASCs at passage 15 onward showed significant changes in the stemness genes, CD markers expression, and differentiation capability.
Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the hallmark pathologies of amyloid-beta plaques and neurofibrillary tangles. Symptoms of this devastating disease include behavioral changes and deterioration of higher cognitive functions. Impairment of neurogenesis has also been shown to occur in AD, which adversely impacts new neuronal cell growth, differentiation, and survival. This impairment possibly results from the cumulative effects of the various pathologies of AD. Preclinical studies have suggested that the administration of melatonin-the pineal hormone primarily responsible for the regulation of the circadian rhythm-targets the effects of AD pathologies and improves cognitive impairment. It is postulated that by mitigating the effect of these pathologies, melatonin can also rescue neurogenesis impairment. This review aims to explore the effect of AD pathologies on neurogenesis, as well as the mechanisms by which melatonin is able to ameliorate AD pathologies to potentially promote neurogenesis.
The molecular basis of the earliest neuronal changes that lead to Alzheimer's disease (AD) is unclear. Here, we analyze neural cells derived from sporadic AD (SAD), APOE4 gene-edited and control induced pluripotent stem cells (iPSCs). We observe major differences in iPSC-derived neural progenitor (NP) cells and neurons in gene networks related to neuronal differentiation, neurogenesis, and synaptic transmission. The iPSC-derived neural cells from SAD patients exhibit accelerated neural differentiation and reduced progenitor cell renewal. Moreover, a similar phenotype appears in NP cells and cerebral organoids derived from APOE4 iPSCs. Impaired function of the transcriptional repressor REST is strongly implicated in the altered transcriptome and differentiation state. SAD and APOE4 expression result in reduced REST nuclear translocation and chromatin binding, and disruption of the nuclear lamina. Thus, dysregulation of neural gene networks may set in motion the pathologic cascade that leads to AD.
Ankrd11 is a potential chromatin regulator implicated in neural development and autism spectrum disorder (ASD) with no known function in the brain. Here, we show that knockdown of Ankrd11 in developing murine or human cortical neural precursors caused decreased proliferation, reduced neurogenesis, and aberrant neuronal positioning. Similar cellular phenotypes and aberrant ASD-like behaviors were observed in Yoda mice carrying a point mutation in the Ankrd11 HDAC-binding domain. Consistent with a role for Ankrd11 in histone acetylation, Ankrd11 was associated with chromatin and colocalized with HDAC3, and expression and histone acetylation of Ankrd11 target genes were altered in Yoda neural precursors. Moreover, the Ankrd11 knockdown-mediated decrease in precursor proliferation was rescued by inhibiting histone acetyltransferase activity or expressing HDAC3. Thus, Ankrd11 is a crucial chromatin regulator that controls histone acetylation and gene expression during neural development, thereby providing a likely explanation for its association with cognitive dysfunction and ASD.
Ruxolitinib is the first janus kinase 1 (JAK1) and JAK2 inhibitor that was approved by the United States Food and Drug Administration (FDA) agency for the treatment of myeloproliferative neoplasms. The drug targets the JAK/STAT signalling pathway, which is critical in regulating the gliogenesis process during nervous system development. In the study, we assessed the effect of non-maternal toxic dosages of ruxolitinib (0-30 mg/kg/day between E7.5-E20.5) on the brain of the developing mouse embryos. While the pregnant mice did not show any apparent adverse effects, the Gfap protein marker for glial cells and S100β mRNA marker for astrocytes were reduced in the postnatal day (P) 1.5 pups' brains. Gfap expression and Gfap+ cells were also suppressed in the differentiating neurospheres culture treated with ruxolitinib. Compared to the control group, adult mice treated with ruxolitinib prenatally showed no changes in motor coordination, locomotor function, and recognition memory. However, increased explorative behaviour within an open field and improved spatial learning and long-term memory retention were observed in the treated group. We demonstrated transplacental effects of ruxolitinib on astrogenesis, suggesting the potential use of ruxolitinib to revert pathological conditions caused by gliogenic-shift in early brain development such as Down and Noonan syndromes.