scholarly journals Epigenetic Regulation in Mesenchymal Stem Cell Aging and Differentiation and Osteoporosis

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Ruoxi Wang ◽  
Yu Wang ◽  
Lisha Zhu ◽  
Yan Liu ◽  
Weiran Li

Mesenchymal stem cells (MSCs) are a reliable source for cell-based regenerative medicine owing to their multipotency and biological functions. However, aging-induced systemic homeostasis disorders in vivo and cell culture passaging in vitro induce a functional decline of MSCs, switching MSCs to a senescent status with impaired self-renewal capacity and biased differentiation tendency. MSC functional decline accounts for the pathogenesis of many diseases and, more importantly, limits the large-scale applications of MSCs in regenerative medicine. Growing evidence implies that epigenetic mechanisms are a critical regulator of the differentiation programs for cell fate and are subject to changes during aging. Thus, we here review epigenetic dysregulations that contribute to MSC aging and osteoporosis. Comprehending detailed epigenetic mechanisms could provide us with a novel horizon for dissecting MSC-related pathogenesis and further optimizing MSC-mediated regenerative therapies.

2020 ◽  
Vol 10 (4) ◽  
pp. 490-501
Author(s):  
Mozhgan Jahani ◽  
Davood Rezazadeh ◽  
Parisa Mohammadi ◽  
Amir Abdolmaleki ◽  
Amir Norooznezhad ◽  
...  

Blood vessel development is one of the most prominent steps in regenerative medicine due tothe restoration of blood flow to the ischemic tissues and providing the rapid vascularizationin clinical-sized tissue-engineered grafts. However, currently tissue engineering technique isrestricted because of the inadequate in vitro/in vivo tissue vascularization. Some challenges likeas transportation in large scale, distribution of the nutrients and poor oxygen diffusion limit theprogression of vessels in smaller than clinically relevant dimensions as well in vivo integration.In this regard, the scholars attempted to promote the vascularization process relied on the stemcells (SCs), growth factors as well as exosomes and interactions of biomaterials with all of themto enable the emergence of ideal microenvironment which is needed for treatment of unhealthyorgans or tissue regeneration and formation of new blood vessels. Thus, in the present reviewwe aim to describe these approaches, advances, obstacles and opportunities as well as theirapplication in regeneration of heart as a prominent angiogenesis-dependent organ.


2006 ◽  
Vol 33 (7) ◽  
pp. 629 ◽  
Author(s):  
Kim S. Van Beveren ◽  
Antanas V. Spokevicius ◽  
Josquin Tibbits ◽  
Qing Wang ◽  
Gerd Bossinger

Large-scale functional analysis of genes and transgenes suspected to be involved in wood development in trees is hindered by long generation times, low transformation and regeneration efficiencies and difficulties with phenotypic assessment of traits, especially those that appear late in a tree’s development. To avoid such obstacles many researchers have turned to model plants such as Arabidopsis thaliana (L.) Heynh., Zinnia elegans Jacq. and Nicotiana ssp., or have focused their attention on in vitro wood formation systems or in vivo approaches targeting primary meristems for transformation. Complementing such efforts, we report the use of Agrobacterium to introduce transgenes directly into cambial cells of glasshouse-grown trees in order to create transgenic somatic tissue sectors. These sectors are suitable for phenotypic evaluation and analysis of target gene function. In our experiments the wood formation zone containing the cambium of Eucalyptus, Populus and Pinus species of varying age was inoculated with Agrobacterium containing a CaMV 35S::GUS construct. Following an initial wound response, frequent and stable transformation was observed in the form of distinct GUS-staining patterns (sectors) in newly formed secondary tissues. Sector size and extent depended on the cell type transformed, the species and the length of time treated plants were allowed to grow (more than two years in some cases). Induced somatic sector analysis (ISSA) can now be efficiently used to study cell fate and gene function during secondary growth in stems of forest tree species.


2021 ◽  
Vol 320 (1) ◽  
pp. G1-G11
Author(s):  
John D. O’Neill ◽  
Meghan R. Pinezich ◽  
Brandon A. Guenthart ◽  
Gordana Vunjak-Novakovic

Gastrointestinal disease burden continues to rise in the United States and worldwide. The development of bioengineering strategies to model gut injury or disease and to reestablish functional gut tissue could expand therapeutic options and improve clinical outcomes. Current approaches leverage a rapidly evolving gut bioengineering toolkit aimed at 1) de novo generation of gutlike tissues at multiple scales for microtissue models or implantable grafts and 2) regeneration of functional gut in vivo. Although significant progress has been made in intestinal organoid cultures and engineered tissues, development of predictive in vitro models and effective regenerative therapies remains challenging. In this review, we survey emerging bioengineering tools and recent methodological advances to identify current challenges and future opportunities in gut bioengineering for disease modeling and regenerative medicine.


2016 ◽  
Vol 98 ◽  
Author(s):  
PENG LIU ◽  
KE LI ◽  
SHAOHUA XU

SummaryInduced pluripotent stem (iPS) cells have great potential in regenerative medicine, including cell replacement therapies and disease modelling in vitro. However, with this potential comes several challenges, including clinical safety, reprogramming and differentiation efficiency, and compromised functionality of differentiated cell types after transplantation. Many of these issues arise from imprecise control of cell fate. With large-scale sequencing and genome-editing technologies we can now precisely manipulate the genome, which has expanded our knowledge of functional cell types and cell identity. These technologies may improve our efforts in generating iPS-derived therapeutic cells and in development of therapies for human diseases.


1969 ◽  
Vol 22 (03) ◽  
pp. 577-583 ◽  
Author(s):  
M.M.P Paulssen ◽  
A.C.M.G.B Wouterlood ◽  
H.L.M.A Scheffers

SummaryFactor VIII can be isolated from plasma proteins, including fibrinogen by chromatography on agarose. The best results were obtained with Sepharose 6B. Large scale preparation is also possible when cryoprecipitate is separated by chromatography. In most fractions containing factor VIII a turbidity is observed which may be due to the presence of chylomicrons.The purified factor VIII was active in vivo as well as in vitro.


2020 ◽  
Vol 26 ◽  
Author(s):  
Luíza Dantas-Pereira ◽  
Edézio F. Cunha-Junior ◽  
Valter V. Andrade-Neto ◽  
John F. Bower ◽  
Guilherme A. M. Jardim ◽  
...  

: Chagas disease, Sleeping sickness and Leishmaniasis, caused by trypanosomatids Trypanosoma cruzi, Trypanosoma brucei and Leishmania spp., respectively, are considered neglected tropical diseases, and they especially affect impoverished populations in the developing world. The available chemotherapies are very limited and a search for alternatives is still necessary. In folk medicine, natural naphthoquinones have been employed for the treatment of a great variety of illnesses, including parasitic infections. This review is focused on the anti-trypanosomatid activity and mechanistic analysis of naphthoquinones and derivatives. Among all the series of derivatives tested in vitro, naphthoquinone-derived 1,2,3-triazoles were very active on T. cruzi infective forms in blood bank conditions, as well as in amastigotes of Leishmania spp. naphthoquinones containing a CF3 on a phenyl amine ring inhibited T. brucei proliferation in the nanomolar range, and naphthopterocarpanquinones stood out for their activity on a range of Leishmania species. Some of these compounds showed a promising selectivity index (SI) (30 to 1900), supporting further analysis in animal models. Indeed, high toxicity to the host and inactivation by blood components are crucial obstacles to be overcome to use naphthoquinones and/or their derivatives for chemotherapy. Multidisciplinary initiatives embracing medicinal chemistry, bioinformatics, biochemistry, and molecular and cellular biology need to be encouraged to allow the optimization of these compounds. Large scale automated tests are pivotal for the efficiency of the screening step, and subsequent evaluation of both the mechanism of action in vitro and pharmacokinetics in vivo are essential for the development of a novel, specific and safe derivative, minimizing adverse effects.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1288
Author(s):  
Wendy Dong ◽  
Boris Kantor

CRISPR/Cas technology has revolutionized the fields of the genome- and epigenome-editing by supplying unparalleled control over genomic sequences and expression. Lentiviral vector (LV) systems are one of the main delivery vehicles for the CRISPR/Cas systems due to (i) its ability to carry bulky and complex transgenes and (ii) sustain robust and long-term expression in a broad range of dividing and non-dividing cells in vitro and in vivo. It is thus reasonable that substantial effort has been allocated towards the development of the improved and optimized LV systems for effective and accurate gene-to-cell transfer of CRISPR/Cas tools. The main effort on that end has been put towards the improvement and optimization of the vector’s expression, development of integrase-deficient lentiviral vector (IDLV), aiming to minimize the risk of oncogenicity, toxicity, and pathogenicity, and enhancing manufacturing protocols for clinical applications required large-scale production. In this review, we will devote attention to (i) the basic biology of lentiviruses, and (ii) recent advances in the development of safer and more efficient CRISPR/Cas vector systems towards their use in preclinical and clinical applications. In addition, we will discuss in detail the recent progress in the repurposing of CRISPR/Cas systems related to base-editing and prime-editing applications.


Gut ◽  
2021 ◽  
pp. gutjnl-2020-323276
Author(s):  
Jin Zhou ◽  
Zhong Wu ◽  
Zhouwei Zhang ◽  
Louisa Goss ◽  
James McFarland ◽  
...  

ObjectiveOesophageal squamous cell carcinoma (OSCC), like other squamous carcinomas, harbour highly recurrent cell cycle pathway alterations, especially hyperactivation of the CCND1/CDK4/6 axis, raising the potential for use of existing CDK4/6 inhibitors in these cancers. Although CDK4/6 inhibition has shown striking success when combined with endocrine therapy in oestrogen receptor positive breast cancer, CDK4/6 inhibitor palbociclib monotherapy has not revealed evidence of efficacy to date in OSCC clinical studies. Herein, we sought to elucidate the identification of key dependencies in OSCC as a foundation for the selection of targets whose blockade could be combined with CDK4/6 inhibition.DesignWe combined large-scale genomic dependency and pharmaceutical screening datasets with preclinical cell line models, to identified potential combination therapies in squamous cell cancer.ResultsWe identified sensitivity to inhibitors to the ERBB family of receptor kinases, results clearly extending beyond the previously described minority of tumours with EGFR amplification/dependence, specifically finding a subset of OSCCs with dual dependence on ERBB3 and ERBB2. Subsequently. we demonstrated marked efficacy of combined pan-ERBB and CDK4/6 inhibition in vitro and in vivo. Furthermore, we demonstrated that squamous lineage transcription factor KLF5 facilitated activation of ERBBs in OSCC.ConclusionThese results provide clear rationale for development of combined ERBB and CDK4/6 inhibition in these cancers and raises the potential for KLF5 expression as a candidate biomarker to guide the use of these agents. These data suggested that by combining existing Food and Drug Administration (FDA)-approved agents, we have the capacity to improve therapy for OSCC and other squamous cancer.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Edward X. Han ◽  
Hong Qian ◽  
Bo Jiang ◽  
Maria Figetakis ◽  
Natalia Kosyakova ◽  
...  

AbstractA significant barrier to implementation of cell-based therapies is providing adequate vascularization to provide oxygen and nutrients. Here we describe an approach for cell transplantation termed the Therapeutic Vascular Conduit (TVC), which uses an acellular vessel as a scaffold for a hydrogel sheath containing cells designed to secrete a therapeutic protein. The TVC can be directly anastomosed as a vascular graft. Modeling supports the concept that the TVC allows oxygenated blood to flow in close proximity to the transplanted cells to prevent hypoxia. As a proof-of-principle study, we used erythropoietin (EPO) as a model therapeutic protein. If implanted as an arteriovenous vascular graft, such a construct could serve a dual role as an EPO delivery platform and hemodialysis access for patients with end-stage renal disease. When implanted into nude rats, TVCs containing EPO-secreting fibroblasts were able to increase serum EPO and hemoglobin levels for up to 4 weeks. However, constitutive EPO expression resulted in macrophage infiltration and luminal obstruction of the TVC, thus limiting longer-term efficacy. Follow-up in vitro studies support the hypothesis that EPO also functions to recruit macrophages. The TVC is a promising approach to cell-based therapeutic delivery that has the potential to overcome the oxygenation barrier to large-scale cellular implantation and could thus be used for a myriad of clinical disorders. However, a complete understanding of the biological effects of the selected therapeutic is absolutely essential.


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