Efficient protein incorporation and release by a jigsaw-shaped self-assembling peptide hydrogel for injured brain regeneration.

During injured tissue regeneration, the extracellular matrix plays a key role in controlling and coordinating various cellular events by binding and releasing secreted proteins in addition to promoting cell adhesion. Herein, we develop a cell-adhesive fiber-forming peptide that mimics the jigsaw-shaped hydrophobic surface in the dovetail-packing motif of glycophorin A as an artificial extracellular matrix for regenerative therapy. We show that the jigsaw-shaped self-assembling peptide forms several-micrometer-long supramolecular nanofibers through a helix-to-strand transition to afford a hydrogel under physiological conditions and disperses homogeneously in the hydrogel.

Hydrogel-Stiffening and Non-Cell Adhesive Properties of Amphiphilic Peptides with Central Alkylene Chains.

Invited for the cover of this issue is the group of Takahiro Muraoka at Tokyo University of Agriculture and Technology and collaborators. The image depicts nanofiber formation of an amphiphilic peptide with a central alkylene chain that shows non-cell adhesive properties. Read the full text of the article at 10.

Hydrogel-Stiffening and Non-Cell Adhesive Properties of Amphiphilic Peptides with Central Alkylene Chains.

Amphiphilic peptides bearing terminal alkyl tails form supramolecular nanofibers that are increasingly used as biomaterials with multiple functionalities. Insertion of alkylene chains in peptides can be designed as another type of amphiphilic peptide, yet the influence of the internal alkylene chains on self-assembly and biological properties remains poorly defined. Unlike the terminal alkyl tails, the internal alkylene chains can affect not only the hydrophobicity but also the flexibility and packing of the peptides.

Sequence-Dependent Bioactivity and Self-Assembling Properties of RGD-Containing Amphiphilic Peptides as Extracellular Scaffolds.

Cell adhesion is a fundamental biological process involved in a wide range of cellular and biological activity. Integrin-ligand binding is largely responsible for cell adhesion with an extracellular matrix, and the RGD sequence is an epitope in ligand proteins such as fibronectin. The extracellular matrix consists of fibrous proteins with embedded ligands for integrins.

Near-Infrared Optogenetic Genome Engineering Based on Photon-Upconversion Hydrogels.

Photon upconversion (UC) from near-infrared (NIR) light to visible light has enabled optogenetic manipulations in deep tissues. However, materials for NIR optogenetics have been limited to inorganic UC nanoparticles. Herein, NIR-light-triggered optogenetics using biocompatible, organic TTA-UC hydrogels is reported.

Glycine Substitution Effects on the Supramolecular Morphology and Rigidity of Cell-Adhesive Amphiphilic Peptides.

Self-assembling peptides that are capable of adopting β-sheet structures can generate nanofibers that lead to hydrogel formation. Herein, to tune the supramolecular morphologies, mechanical properties, and stimuli responses of the hydrogels, we investigated glycine substitution in a β-sheet-forming amphiphilic peptide. Glycine substitution generally enhances conformational flexibility.

Dnmt1-dependent Chk1 pathway suppression is protective against neuron division.

Neuronal differentiation and cell-cycle exit are tightly coordinated, even in pathological situations. When pathological neurons re-enter the cell cycle and progress through the S phase, they undergo cell death instead of division. However, the mechanisms underlying mitotic resistance are mostly unknown.

Affinity-Immobilization of VEGF on Laminin Porous Sponge Enhances Angiogenesis in the Ischemic Brain.

Ischemic brain stroke is caused by blood flow interruption, leading to focal ischemia, neuron death, and motor, sensory, and/or cognitive dysfunctions. Angiogenesis, neovascularization from existing blood vessel, is essential for tissue growth and repair. Proangiogenic therapy for stroke is promising for preventing excess neuron death and improving functional recovery.

Cortical excitatory neurons become protected from cell division during neurogenesis in an Rb family-dependent manner.

Cell cycle dysregulation leads to abnormal proliferation and cell death in a context-specific manner. Cell cycle progression driven via the Rb pathway forces neurons to undergo S-phase, resulting in cell death associated with the progression of neuronal degeneration. Nevertheless, some Rb- and Rb family (Rb, p107 and p130)-deficient differentiating neurons can proliferate and form tumors.

High prevalence of mutations in the EYS gene in Japanese patients with autosomal recessive retinitis pigmentosa.

Purpose: To screen for disease-causing mutations in the Eyes shut homolog (EYS) gene in Japanese patients with retinitis pigmentosa (RP). Methods. Blood samples were obtained from 68 RP patients and 68 controls.

Full-length transcriptome analysis of human retina-derived cell lines ARPE-19 and Y79 using the vector-capping method.

PURPOSE. To collect an entire set of full-length cDNA clones derived from human retina-derived cell lines and to identify full-length transcripts for retinal preferentially expressed genes. METHODS.

Full-length transcriptome analysis using a bias-free cDNA library prepared with the vector-capping method.

Full-length complementary DNAs (cDNAs) are an essential resource for functional genomics. Recently, we have developed a simple and efficient method for preparing a full-length cDNA library from a small amount of total RNA, named the "vector-capping" method. The biggest advantage of this method is that the intactness of the cDNA can be assured by the presence of dG at the 5' end of the full-length cDNA.

Characterization of the arylsulfatase I (ARSI) gene preferentially expressed in the human retinal pigment epithelium cell line ARPE-19.

Purpose: The aim of this study was to characterize the arylsulfatase I (ARSI) gene that has been shown to be preferentially expressed in the human retinal pigment epithelium cell line ARPE-19 and to propose it as a candidate gene responsible for inherited eye diseases such as retinitis pigmentosa (RP).

Methods: Full-length cDNA clones encoding ARSI, arylsulfatase A (ARSA), and sulfatase modifying factor 1 (SUMF1) were isolated from ARPE-19 cDNA libraries constructed using the vector-capping method. The expression vectors for their FLAG-tagged proteins were transfected into ARPE-19 cells, and the expression products were characterized by western blot analysis and arylsulfatase assay.

Fine expression profiling of full-length transcripts using a size-unbiased cDNA library prepared with the vector-capping method.

Recently, we have developed a vector-capping method for constructing a full-length cDNA library. In the present study, we performed in-depth analysis of the vector-capped cDNA library prepared from a single type of cell. As a result of single-pass sequencing analysis of 24,000 clones randomly isolated from the unamplified library, we identified 19,951 full-length cDNA clones whose intactness was confirmed by the presence of an additional G at their 5' end.