Several previous studies support the possibility that RPC

Several previous studies support the possibility that RPC differentiation into podocytes may be involved in remission of different types of diseases, including proliferative glomerulonephritis (Rizzo et al., 2013), gestational pre-eclampsia (Penning et al., 2014), and diabetic nephropathy (Pichaiwong et al., 2013). In addition, drugs that are already used in clinical practice to delay disease progression, such as renin-angiotensin-aldosterone system blockers, not only prevent progressive renal damage but also promote the regression of glomerulosclerosis in several models of CKD (Remuzzi et al., 2006), suggesting that they may also exert their beneficial effects by promoting RPC differentiation into podocytes (Benigni et al., 2011). In addition, leptin replacement promotes disease regression in animal models of advanced diabetic nephropathy by increasing podocyte number, another effect that may reasonably be mediated by podocyte regeneration provided by RPCs (Pichaiwong et al., 2013). Further studies are necessary to verify these points. However, the observation that an efficient differentiation of RPCs into podocytes determines the outcome of glomerular disorders and that this process can be pharmacologically enhanced has important implications for the treatment of patients with CKD.
Experimental Procedures
Author Contributions
Acknowledgments
Introduction Traumatic spinal cord injury (SCI) results in the death of neural sphingosine kinase and a disruption of interneuronal connectivity with sensory/motor functional deficits (Bradbury and McMahon, 2006). Notably, severe SCI patients suffer from permanent complete paraplegia, which imposes considerable mental and economic burdens compared with those of patients with mild and moderate SCI (Coleman et al., 2015; Krueger et al., 2013). Therefore, there is a great demand for developing therapeutic approaches, particularly for severe SCI. The transplantation of stem cells for SCI, such as neural stem/progenitor cells (NSPCs), is a promising therapeutic approach to alleviate the inflammatory response and replace lost neural cells (Volarevic et al., 2013). This stem cell-based strategy has been shown to have therapeutic evidence for SCI in many experimental animals (Mothe and Tator, 2013; Tetzlaff et al., 2011). However, most studies have shown that NSPC transplantation promoted functional recovery following mild and moderate SCI, while its therapeutic efficacy for severe SCI has been unclear, and the detailed mechanism underlying such efficacy still remains to be elucidated. In contrast to severe SCI, varying degrees of spontaneous recovery are observed following mild and moderate SCI in both humans and experimental animals (Bareyre et al., 2004; Kobayakawa et al., 2014). Such recovery is attributed to the endogenous plasticity of neural circuits, which means that propriospinal relay connections bypass the lesions (Courtine et al., 2008). A neurobiological approach toward enhancing the propriospinal relay connections could be a therapeutic option for SCI. However, little is known about whether transplanted NSPCs integrate into the spared neural circuits and reassemble the propriospinal relay connections. In the present study, we thus focused on the synaptogenic potential of engrafted NSPCs and the reorganization of the propriospinal circuits after transplantation. Conventional methods for assessing the cellular properties of the engrafted NSPCs mainly have relied on histological examinations (Abematsu et al., 2010; Nori et al., 2011), and there have been few methods available to analyze the in vivo function of NSPCs in the injured spinal cord. To obtain a detailed understanding of the synaptogenic potential of the engrafted NSPCs, it is necessary to develop a method to quantify the molecular properties of NSPCs in situ. We applied laser microdissection (LMD), which is a powerful tool for isolating specific cell types from heterogeneous tissues, to investigate the transcriptional activity of engrafted NSPCs.