Easy cancer recurrence and wound infections have been clinical challenges after surgical treatment of melanoma. Herein, a silk‐inspired in situ gelation system containing methacrylated silk fibroin (SF) and chlorine e6 for improved cancer therapy with enhanced wound healing is developed. Favored by the macrophage recruitment capacity of the SF hydrogel, promising antitumor immune responses can be turned “on” via near infrared irradiation in a controllable manner to achieve combination therapy with photodynamic therapy to significantly suppress melanoma recurrence. Moreover, the effective photodynamic antibacterial activity of this bioactive system with the capacity of light‐controllable modulating macrophage phenotype promotes remarkable tissue ingrowth with hair follicle regeneration for Staphylococcus aureus infected wound healing. Thus, this multifunctional silk‐based hydrogel system, as a desirable wound dressing, provides a new platform for promising melanoma therapy and skin regeneration.

Fign regulates cultured astrocyte migration by severing tyrosinated microtubules (MTs). Inhibition of cellular migration induced by Fign knockdown can be rescued with concomitant knockdown of kinesin-12. A working model is given for the MT reconfiguration underlying cellular migration elicited by the cooperation of two distinct MT-related proteins.

Kinesin-12 (also named Kif15) participates in important events during neuronal development, such as cell division of neuronal precursors, migration of young neurons and establishment of axons and dendritic arbors, by regulating microtubule organization. Little is known about the molecular mechanisms behind the functions of kinesin-12, and even less is known about its roles in other cell types of the nervous system. Here, we show that kinesin-12 depletion from cultured rat cortical astrocytes decreases cell proliferation but increases migration. Co-immunoprecipitation, GST pulldown and small interfering RNA (siRNA) experiments indicated that kinesin-12 directly interacts with myosin-IIB through their tail domains. Immunofluorescence analyses indicated that kinesin-12 and myosin-IIB colocalize in the lamellar region of astrocytes, and fluorescence resonance energy transfer analyses revealed an interaction between the two. The phosphorylation at Thr1142 of kinesin-12 was vital for their interaction. Loss of their interaction through expression of a phosphorylation mutant of kinesin-12 promoted astrocyte migration. We suggest that kinesin-12 and myosin-IIB can form a hetero-oligomer that generates force to integrate microtubules and actin filaments in certain regions of cells, and in the case of astrocytes, that this interaction can modulate their migration.

Spinal cord injury (SCI), one of the most severe types of neurological damage, results in persistent motor and sensory dysfunction and involves complex gene alterations. Circular RNAs (circRNAs) are a recently discovered class of regulatory molecules, and their roles in SCI still need to be addressed. This study comprehensively investigated circRNA alterations in rats across a set time course (days 0, 1, 3, 7, 14, 21, and 28) after hemisection SCI at the right T9 site. A total of 360 differentially expressed circRNAs were identified using RNA sequencing. From these, the functions of the exonic circRNA_01477 were further explored in cultured spinal cord astrocytes. Knockdown of circRNA_01477 significantly inhibited astrocyte proliferation and migration. The circRNA_01477/microRNAs (miRNA)/messenger RNA (mRNA) interaction network was visualized following microarray assay. Among the downregulated differentially expressed mRNAs, four of the seven validated genes were controlled by miRNA-423-5p. We then demonstrated that miRNA-423-5p is significantly upregulated after circRNA_01477 depletion. In summary, this study provides, for the first time, a systematic evaluation of circRNA alterations following SCI and an insight into the transcriptional regulation of the genes involved. It further reveals that circRNA_01477/miR-423-5p could be a key regulator involved in regulating the changeable regeneration environment that occurs during recovery from SCI.

Brusatol, a quassinoid isolated from the fruit of Bruceajavanica, has recently been shown to inhibit nuclear factor erythroid 2-related factor 2 (Nrf2) via Keap1-dependent ubiquitination and proteasomal degradation or protein synthesis. Nrf2 is a transcription factor that regulates the cellular defense response. Most studies have focused on the effects of Nrf2 in tumor development. Here, the critical roles of Nrf2 in mouse early embryonic development were investigated. We found that brusatol treatment at the zygotic stage prevented the early embryo development. Most embryos stayed at the two-cell stage after 5 days of culture (P < 0.05). This effect was associated with the cell cycle arrest, as the mRNA level of CDK1 and cyclin B decreased at the two-cell stage after brusatol treatment. The embryo development potency was partially rescued by the injection of Nrf2 CRISPR activation plasmid. Thus, brusatol inhibited early embryo development by affecting Nrf2-related cell cycle transition from G2 to M phase that is dependent on cyclin B-CDK1 complex.

Spinal cord injury (SCI) is a challenging clinical problem worldwide. The cellular state and molecular expression in spinal cord tissue after injury are extremely complex and closely related to functional recovery. However, the spatial and temporal changes of gene expression and regulation in various cell types after SCI are still unclear. Here, we collected the rostral and caudal regions to the lesion at 11 time points over a period of 28 days after rat hemisection SCI. Combining whole-transcriptome sequencing and bioinformatic analysis, we identified differentially expressed genes (DEGs) between spinal cord tissue from injured and sham-operated animals. Significantly altered biological processes were enriched from DEGs in astrocytes, microglia, oligodendrocytes, immune cells, and vascular systems after SCI. We then identified dynamic trends in these processes using the average expression profiles of DEGs. Gene expression and regulatory networks for selected biological processes were also constructed to illustrate the complicate difference between rostral and caudal tissues. Finally, we validated the expressions of some key genes from these networks, including α-synuclein, heme oxygenase 1, bone morphogenetic protein 2, activating transcription factor 3, and leukemia inhibitory factor. Collectively, we provided a comprehensive network of gene expression and regulation to shed light on the molecular characteristics of critical biological processes that occur after SCI, which will broaden the understanding of SCI and facilitate clinical therapeutics for SCI.

SAM and SH3 domain-containing 1 (SASH1), a scaffold protein, is regarded as a tumor suppressor. Recent studies have verified the decreased expression of SASH1 in many tumors. Our previous clinical investigation found that SASH1 was widely expressed in normal brain tissues but reduced or absent in glioma tissues. However, the functions of SASH1 in normal astrocytes and the reasons for the reductions in SASH1 levels in glioma tissues are unclear. In this study, we found that in astrocytes, SASH1 functions in cell adhesion. We observed that knockdown of SASH1 expression in cultured astrocytes significantly decreased cell adhesion and increased invasion. Conversely, overexpression of SASH1 in C6 cells markedly promoted cell adhesion and decreased cell invasion. In addition, we found that the expression level of one member of the integrin family, integrin β8, was significantly reduced in SASH1-downregulated astrocytes and elevated in SASH1-upregulated C6 cells. Furthermore, the results of methylation and ChIP assays showed that the methylation level of the SASH1 gene was markedly higher in C6 cells than in astrocytes and that HMGB1 could bind to the CpG islands of the SASH1 gene. HMGB1 overexpression in astrocytes significantly increased the methylation level of the SASH1 gene. This study reveals, for the first time, that HMGB1 contributes to the methylation of the SASH1 gene, and our findings suggest that methylation downregulates the expression of the SASH1 gene and later reduces integrin β8 expression, thereby reducing cell adhesion and promoting cell migration.

Discovering safe and effective drugs that promote neuron regeneration is an essential strategy for the recovery of central nervous system injuries. In this study, we found that L-leucine, an essential amino acid obtained from both supplements and food sources, could dramatically boost axonal outgrowth and regeneration. First, the effects of L-leucine on neurons were evaluated by cell apoptosis, survival, and death assays, and the results showed no changes in these processes after treatment. By live cell imaging, L-leucine was found to remarkably increase axonal length and growth velocity after axotomy. We also verified that L-leucine enhanced p-mTOR/p-S6K activation in neurons by testing with an mTOR inhibitor, rapamycin. Thereafter, we investigated the effects of L-leucine on the spinal cord injury in vivo. A mouse model of spinal cord hemi-section was established, and L-leucine was administered by tail intravenous injection. Basso mouse scale values revealed that L-leucine could improve functional recovery after injury. It was also notable that L-leucine treatment promoted axon growth across chondroitin sulfate proteoglycan (CSPG) areas.Furthermore, we used CSPGs as inhibitory environmental cues and clarified that L-leucine significantly enhanced axonal outgrowth and regeneration by promoting p-mTOR and p-S6K activation. Therefore, our study is the first to report that L-leucine promotes axonal regeneration in vitro and in vivo and could be candidate drug for axonal re-growth and nervous functional recovery.