| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Bhat, Goutam, et al.
(författare)
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NTIRE 2022 Burst Super-Resolution Challenge
- 2022
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Ingår i: 2022 IEEE/CVF CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION WORKSHOPS (CVPRW 2022). - : IEEE. - 9781665487399 - 9781665487405 ; , s. 1040-1060
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Konferensbidrag (refereegranskat)abstract
- Burst super-resolution has received increased attention in recent years due to its applications in mobile photography. By merging information from multiple shifted images of a scene, burst super-resolution aims to recover details which otherwise cannot be obtained using a simple input image. This paper reviews the NTIRE 2022 challenge on burst super-resolution. In the challenge, the participants were tasked with generating a clean RGB image with 4x higher resolution, given a RAW noisy burst as input. That is, the methods need to perform joint denoising, demosaicking, and super-resolution. The challenge consisted of 2 tracks. Track 1 employed synthetic data, where pixel-accurate high-resolution ground truths are available. Track 2 on the other hand used real-world bursts captured from a handheld camera, along with approximately aligned reference images captured using a DSLR. 14 teams participated in the final testing phase. The top performing methods establish a new state-of-the-art on the burst super-resolution task.
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| 3. |
- Zhang, Wei, et al.
(författare)
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Sustained Release of TPCA-1 from Silk Fibroin Hydrogels Preserves Keratocyte Phenotype and Promotes Corneal Regeneration by Inhibiting Interleukin-1β Signaling
- 2020
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Ingår i: Advanced Healthcare Materials. - : Wiley-VCH Verlagsgesellschaft. - 2192-2640 .- 2192-2659. ; 9:17
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Tidskriftsartikel (refereegranskat)abstract
- Corneal injury due to ocular trauma or infection is one of the most challenging vision impairing pathologies that exists. Many studies focus on the pro-inflammatory and pro-angiogenic effects of interleukin-1 beta(IL-1 beta) on corneal wound healing. However, the effect of IL-1 beta on keratocyte phenotype and corneal repair, as well as the underlying mechanisms, is not clear. This study reports, for the first time, that IL-1 beta induces phenotype changes of keratocytes in vitro, by significantly down-regulating the gene and protein expression levels of keratocyte markers (Keratocan, Lumican, Aldh3a1 and CD34). Furthermore, it is found that the NF-kappa B pathway is involved in the IL-1 beta-induced changes of keratocyte phenotype, and that the selective IKK beta inhibitor TPCA-1, which inhibits NF-kappa B, can preserve keratocyte phenotype under IL-1 beta simulated pathological conditions in vitro. By using a murine model of corneal injury, it is shown that sustained release of TPCA-1 from degradable silk fibroin hydrogels accelerates corneal wound healing, improves corneal transparency, enhances the expression of keratocyte markers, and supports the regeneration of well-organized epithelium and stroma. These findings provide insights not only into the pathophysiological mechanisms of corneal wound healing, but also into the potential development of new treatments for patients with corneal injuries.
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| 4. |
- Chen, Jialin, et al.
(författare)
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Fos Promotes Early Stage Teno-Lineage Differentiation of Tendon Stem/Progenitor Cells in Tendon
- 2017
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Ingår i: Stem Cells Translational Medicine. - : John Wiley & Sons. - 2157-6564 .- 2157-6580. ; 6:11, s. 2009-2019
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Tidskriftsartikel (refereegranskat)abstract
- Stem cells have been widely used in tendon tissue engineering. The lack of refined and controlled differentiation strategy hampers the tendon repair and regeneration. This study aimed to find new effective differentiation factors for stepwise tenogenic differentiation. By microarray screening, the transcript factor Fos was found to be expressed in significantly higher amounts in postnatal Achilles tendon tissue derived from 1 day as compared with 7-days-old rats. It was further confirmed that expression of Fos decreased with time in postnatal rat Achilles tendon, which was accompanied with the decreased expression of multiply tendon markers. The expression of Fos also declined during regular in vitro cell culture, which corresponded to the loss of tendon phenotype. In a cell-sheet and a three-dimensional cell culture model, the expression of Fos was upregulated as compared with in regular cell culture, together with the recovery of tendon phenotype. In addition, significant higher expression of tendon markers was found in Fos-overexpressed tendon stem/progenitor cells (TSPCs), and Fos knock-down gave opposite results. In situ rat tendon repair experiments found more normal tendon-like tissue formed and higher tendon markers expression at 4 weeks postimplantation of Fos-overexpressed TSPCs derived nonscaffold engineering tendon (cell-sheet), as compared with the control group. This study identifies Fos as a new marker and functional driver in the early stage teno-lineage differentiation of tendon, which paves the way for effective stepwise tendon differentiation and future tendon regeneration.
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| 5. |
- Chen, Jialin, et al.
(författare)
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Hydroxycamptothecin and substratum stiffness synergistically regulate fibrosis of human corneal fibroblasts
- 2023
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Ingår i: ACS Biomaterials Science & Engineering. - : American Chemical Society (ACS). - 2373-9878. ; 9:2, s. 959-967
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Tidskriftsartikel (refereegranskat)abstract
- Corneal fibrosis is a common outcome of inappropriate repair associated with trauma or ocular infection. Altered biomechanical properties with increased corneal stiffness is a feature of fibrosis that cause corneal opacities, resulting in severe visual impairment and even blindness. The present study aims to determine the effect of hydroxycamptothecin (HCPT) and matrix stiffness on transforming growth factor-β1 (TGF-β1)-induced fibrotic processes in human corneal fibroblasts (HTK cells). HTK cells were cultured on substrates with different stiffnesses ("soft", ∼261 kPa; "stiff", ∼2.5 × 103 kPa) and on tissue culture plastic (TCP, ∼106 kPa) and simultaneously treated with or without 1 μg/mL HCPT and 10 ng/mL TGF-β1. We found that HCPT induced decreased cell viability and antiproliferative effects on HTK cells. TGF-β1-induced expression of fibrosis-related genes (FN1, ACTA2) was reduced if the cells were simultaneously treated with HCPT. Substrate stiffness did not affect the expression of fibrosis-related genes. The TGF-β1 induced expression of FN1 on both soft and stiff substrates was reduced if cells were simultaneously treated with HCPT. However, this trend was not seen for ACTA2, i.e., the TGF-β1 induced expression of ACTA2 was not reduced by simultaneous treatment of HCPT in either soft or stiff substrate. Instead, HCPT treatment in the presence of TGF-β1 resulted in increased gene expression of keratocyte phenotype makers (LUM, KERA, AQP1, CHTS6) on both substrate stiffnesses. In addition, the protein expression of keratocyte phenotype makers LUM and ALDH3 was increased in HTK cells simultaneously treated with TGF-β1 and HCPT on stiff substrate as compared to control, i.e., without HCPT. In conclusion, we found that HCPT can reduce TGF-β1-induced fibrosis and promote the keratocyte phenotype in a substrate stiffness dependent manner. Thus, HCPT stimulation might be an approach to stimulate keratocytes in the appropriate healing stage to avoid or reverse fibrosis and achieve more optimal corneal wound healing.
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| 6. |
- Sheng, Renwang, et al.
(författare)
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Material stiffness in cooperation with macrophage paracrine signals determines the tenogenic differentiation of mesenchymal stem cells
- 2023
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Ingår i: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 10:17
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Tidskriftsartikel (refereegranskat)abstract
- Stiffness is an important physical property of biomaterials that determines stem cell fate. Guiding stem cell differentiation via stiffness modulation has been considered in tissue engineering. However, the mechanism by which material stiffness regulates stem cell differentiation into the tendon lineage remains controversial. Increasing evidence demonstrates that immune cells interact with implanted biomaterials and regulate stem cell behaviors via paracrine signaling; however, the role of this mechanism in tendon differentiation is not clear. In this study, polydimethylsiloxane (PDMS) substrates with different stiffnesses are developed, and the tenogenic differentiation of mesenchymal stem cells (MSCs) exposed to different stiffnesses and macrophage paracrine signals is investigated. The results reveal that lower stiffnesses facilitates tenogenic differentiation of MSCs, while macrophage paracrine signals at these stiffnesses suppress the differentiation. When exposed to these two stimuli, MSCs still exhibit enhanced tendon differentiation, which is further elucidated by global proteomic analysis. Following subcutaneous implantation in rats for 2 weeks, soft biomaterial induces only low inflammation and promotes tendon-like tissue formation. In conclusion, the study demonstrates that soft, rather than stiff, material has a greater potential to guide tenogenic differentiation of stem cells, which provides comprehensive evidence for optimized bioactive scaffold design in tendon tissue engineering.
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| 7. |
- Zhang, Aini, et al.
(författare)
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Advances in Regulatory Strategies of Differentiating Stem Cells towards Keratocytes
- 2022
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Ingår i: Stem Cells International. - : Hindawi Publishing Corporation. - 1687-9678 .- 1687-966X. ; 2022
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Forskningsöversikt (refereegranskat)abstract
- Corneal injury is a commonly encountered clinical problem which led to vision loss and impairment that affects millions of people worldwide. Currently, the available treatment in clinical practice is corneal transplantation, which is limited by the accessibility of donors. Corneal tissue engineering appears to be a promising alternative for corneal repair. However, current experimental strategies of corneal tissue engineering are insufficient due to inadequate differentiation of stem cell into keratocytes and thus cannot be applied in clinical practice. In this review, we aim to clarify the role and effectiveness of both biochemical factors, physical regulation, and the combination of both to induce stem cells to differentiate into keratocytes. We will also propose novel perspectives of differentiation strategy that may help to improve the efficiency of corneal tissue engineering.
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| 8. |
- Zhang, Jialin, et al.
(författare)
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FS-GBDT : identification multicancer-risk module via a feature selection algorithm by integrating Fisher score and GBDT
- 2021
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Ingår i: Briefings in Bioinformatics. - : Oxford University Press (OUP). - 1477-4054 .- 1467-5463. ; 22:3
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Tidskriftsartikel (refereegranskat)abstract
- Cancer is a highly heterogeneous disease caused by dysregulation in different cell types and tissues. However, different cancers may share common mechanisms. It is critical to identify decisive genes involved in the development and progression of cancer, and joint analysis of multiple cancers may help to discover overlapping mechanisms among different cancers. In this study, we proposed a fusion feature selection framework attributed to ensemble method named Fisher score and Gradient Boosting Decision Tree (FS-GBDT) to select robust and decisive feature genes in high-dimensional gene expression datasets. Joint analysis of 11 human cancers types was conducted to explore the key feature genes subset of cancer. To verify the efficacy of FS-GBDT, we compared it with four other common feature selection algorithms by Support Vector Machine (SVM) classifier. The algorithm achieved highest indicators, outperforms other four methods. In addition, we performed gene ontology analysis and literature validation of the key gene subset, and this subset were classified into several functional modules. Functional modules can be used as markers of disease to replace single gene which is difficult to be found repeatedly in applications of gene chip, and to study the core mechanisms of cancer.
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| 9. |
- Zhang, Wei, et al.
(författare)
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Tannic acid-mediated dual peptide-functionalized scaffolds to direct stem cell behavior and osteochondral regeneration
- 2020
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 396
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Tidskriftsartikel (refereegranskat)abstract
- The development of cell-instructive scaffolds, which provide biochemical cues to direct endogenous bone marrow-derived mesenchymal stem cells (BMSCs) behavior, has the potential to revolutionize osteochondral tissue engineering. However, scaffold material itself is generally lacking the inductive signals. Here, a novel peptide-functionalized scaffold was prepared by prime-coating Ca-alginate scaffold with tannic acid (TA) followed by conjugation of E7/P15 peptides (CA-TA-E7/P15). The system leveraged TA as a reactive intermediate between Ca-alginate and peptides due to the multiple functional groups of TA. These interactions induced by TA prime-coating contributed to enhanced scaffold stability and mechanical properties, increased peptide conjugation and sustained release of peptides without affecting their bioactivity, in a TA concentration-dependent manner. The conjugation of E7/P15 peptides endowed the scaffold with the potential to enhance BMSCs recruitment and deposition of cartilage and bone extracellular matrix (ECM). Furthermore, the prepared CA-TA-E7/P15 scaffold showed a promoted biological performance of simultaneous cartilage and subchondral bone regeneration in rabbit osteochondral defect model. These findings indicate that TA is an effective surface modification intermediate and crosslinking aid, and that the CA-TA-E7/P15 scaffold developed in this study serves as a promising cell-instructive scaffold for osteochondral regeneration.
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| 10. |
- Chen, Jialin, et al.
(författare)
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Ascorbic Acid Promotes the Stemness of Corneal Epithelial Stem/Progenitor Cells and Accelerates Epithelial Wound Healing in the Cornea
- 2017
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Ingår i: Stem Cells Translational Medicine. - : WILEY. - 2157-6564 .- 2157-6580. ; 6:5, s. 1356-1365
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Tidskriftsartikel (refereegranskat)abstract
- High concentration of ascorbic acid (vitamin C) has been found in corneal epithelium of various species. However, the specific functions and mechanisms of ascorbic acid in the repair of corneal epithelium are not clear. In this study, it was found that ascorbic acid accelerates corneal epithelial wound healing in vivo in mouse. In addition, ascorbic acid enhanced the stemness of cultured mouse corneal epithelial stem/progenitor cells (TKE2) in vitro, as shown by elevated clone formation ability and increased expression of stemness markers (especially p63 and SOX2). The contribution of ascorbic acid on the stemness enhancement was not dependent on the promotion of Akt phosphorylation, as concluded by using Akt inhibitor, nor was the stemness found to be dependent on the regulation of oxidative stress, as seen by the use of two other antioxidants (GMEE and NAC). However, ascorbic acid was found to promote extracellular matrix (ECM) production, and by using two collagen synthesis inhibitors (AzC and CIS), the increased expression of p63 and SOX2 by ascorbic acid was decreased by around 50%, showing that the increased stemness by ascorbic acid can be attributed to its regulation of ECM components. Moreover, the expression of p63 and SOX2 was elevated when TKE2 cells were cultured on collagen I coated plates, a situation that mimics the in vivo situation as collagen I is the main component in the corneal stroma. This study shows direct therapeutic benefits of ascorbic acid on corneal epithelial wound healing and provides new insights into the mechanisms involved.
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