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- Azim, Kasum, et al.
(författare)
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Persistent Wnt/β‐Catenin Signaling Determines Dorsalization of the Postnatal Subventricular Zone and Neural Stem Cell Specification into Oligodendrocytes and Glutamatergic Neurons
- 2014
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Ingår i: Stem Cells. - Durham, United States : AlphaMed Press, Inc.. - 1066-5099 .- 1549-4918. ; 32:5, s. 1301-1312
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Tidskriftsartikel (refereegranskat)abstract
- In the postnatal and adult central nervous system (CNS), the subventricular zone (SVZ) of the forebrain is the main source of neural stem cells (NSCs) that generate olfactory neurons and oligodendrocytes (OLs), the myelinating cells of the CNS. Here, we provide evidence of a primary role for canonical Wnt/β-catenin signaling in regulating NSC fate along neuronal and oligodendroglial lineages in the postnatal SVZ. Our findings demonstrate that glutamatergic neuronal precursors (NPs) and oligodendrocyte precursors (OPs) are derived strictly from the dorsal SVZ (dSVZ) microdomain under the control of Wnt/β-catenin, whereas GABAergic NPs are derived mainly from the lateral SVZ (lSVZ) microdomain independent of Wnt/β-catenin. Transcript analysis of microdissected SVZ microdomains revealed that canonical Wnt/β-catenin signaling was more pronounced in the dSVZ microdomain. This was confirmed using the β-catenin-activated Wnt-reporter mouse and by pharmacological stimulation of Wnt/β-catenin by infusion of the specific glycogen synthase kinase 3β inhibitor, AR-A014418, which profoundly increased the generation of cycling cells. In vivo genetic/pharmacological stimulation or inhibition of Wnt/β-catenin, respectively, increased and decreased the differentiation of dSVZ-NSCs into glutamatergic NPs, and had a converse effect on GABAergic NPs. Activation of Wnt/β-catenin dramatically stimulated the generation of OPs, but its inhibition had no effect, indicating other factors act in concert with Wnt/β-catenin to fine tune oligodendrogliogenesis in the postnatal dSVZ. These results demonstrate a role for Wnt/β-catenin signaling within the dorsal microdomain of the postnatal SVZ, in regulating the genesis of glutamatergic neurons and OLs.
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| 2. |
- Kumar, Vinay V., et al.
(författare)
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Segmental Mandibular Reconstruction Using Tissue Engineering Strategies : A Systematic Review of Individual Patient Data
- 2020
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Ingår i: Craniomaxillofacial Trauma & Reconstruction. - : SAGE Publications. - 1943-3875 .- 1943-3883. ; 13:4, s. 267-284
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Forskningsöversikt (refereegranskat)abstract
- Objective: The aim of the systematic review was to analyze the current clinical evidence concerning the use of tissue engineering as a treatment strategy for reconstruction of segmental defects of the mandible and their clinical outcomes using individual patient data.Methods: A systematic review of the literature was conducted using PubMed and Cochrane Library on May 21, 2019. The eligibility criteria included patients in whom segmental mandibular reconstruction was carried out using tissue engineering as the primary treatment strategy. After screening and checking for eligibility, individual patient data were extracted to the extent it was available. Data extraction included the type of tissue engineering strategy, demographics, and indication for treatment, and outcomes included clinical and radiographic outcome measures, vitality of engineered bone, dental rehabilitation, and patient-reported outcome measures and complications.Results: Out of a total of 408 articles identified, 44 articles reporting on 285 patients were included, of which 179 patients fulfilled the inclusion criteria. The different tissue engineering treatment strategies could be broadly classified into 5 groups: "prefabrication," "cell culture," "bone morphogenetic protein (BMP) without autografts," "BMP with autografts," and "scaffolds containing autografts." Most included studies were case reports or case series. A wide variety of components were used as scaffolds, cells, and biological substances. There was not a single outcome measure that was both objective and consistently reported, although most studies reported successful outcome.Discussion: A wide variety of tissue engineering strategies were used for segmental mandibular reconstruction that could be classified into 5 groups. Due to the low number of treated patients, lack of standardized and consistent reporting outcomes, lack of comparative studies, and low evidence of reported literature, there is insufficient evidence to recommend any particular tissue engineering strategy.
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