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Biology subjects

Ran, G.

Publications and source records attributed to Ran, G..

2 recordsLinked to original sources
bioRxiv2021

Polypeptides IGF-1C and P24 synergistically promote osteogenic differentiation of bone marrow mesenchymal stem cells in vitro through the p38 and JNK signaling pathways

ObjectivesInsulin-like growth factor-1 (IGF-1) and bone morphogenetic protein 2 (BMP-2) both promote osteogenesis of bone marrow mesenchymal stem cells (BMSCs). IGF-1C, the C domain peptide of IGF-1, and P24, a BMP-2-derived peptide, both have similar biological activities as their parent growth factors. This study aimed to investigate the effects and their mechanisms of polypeptides IGF-1C and P24 on the osteogenic differentiation of BMSCs. MethodsThe optimum concentrations of IGF-IC and P24 were explored. The effects of the two polypeptides on the proliferation and osteogenic differentiation of BMSCs were examined using the Cell Counting Kit-8(CCK-8), Alkaline phosphatase (ALP) staining, ALP activity assay, alizarin red S staining, qPCR, and western blotting. In addition, specific pathway inhibitors were utilized to explore whether p38 and JNK pathways were involved in this process. ResultsThe optimal concentrations of action were both 50 g/ml. IGF-1C and P24 synergistically promoted the proliferation of BMSCs, increased ALP activity and the formation of calcified nodules and upregulated the mRNA and protein levels of osterix (Osx), runt-related transcription factor 2 (Runx2), and osteocalcin (Ocn), phosphorylation level of p38 and JNK proteins also improved. Inhibition of the pathways significantly reduced the activation of p38 and JNK, blocked the expression of Runx2 while inhibiting ALP activity and the formation of calcified nodules. ConclusionsThese findings suggest IGF-1C and P24 synergistically promote the osteogenesis of BMSCs through activation of p38 and JNK signal pathways.

cell biology↗
bioRxiv2021

Transcriptomic encoding of sensorimotor transformation in the midbrain

Sensorimotor transformation, a process that converts sensory stimuli into motor actions, is critical for the brain to initiate behaviors. Although the circuitry involved in sensorimotor transformation has been well delineated, the molecular logic behind this process remains poorly understood. Here, we performed high-throughput and circuit-specific single-cell transcriptomic analyses of neurons in the superior colliculus (SC), a midbrain structure implicated in early sensorimotor transformation. We found that SC neurons in distinct laminae express discrete marker genes. Of particular interest, Cbln2 and Pitx2 are key markers that define glutamatergic projection neurons in the optic nerve (Op) and intermediate gray (InG) layers, respectively. The Cbln2+ neurons responded to visual stimuli mimicking cruising predators, while the Pitx2+ neurons encoded prey-derived vibrissal tactile cues. By forming distinct input and output connections with other brain areas, these neuronal subtypes independently mediate behaviors of predator avoidance and prey capture. Our results reveal that, in the midbrain, sensorimotor transformation for different behaviors may be performed by separate circuit modules that are molecularly defined by distinct transcriptomic codes.

neuroscience↗