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Truncating mutations in Gli3, an intracellular effector in the SHH-SMO-GLI signaling pathway, cause renal aplasia/dysplasia in humans and mice. Yet, the pathogenic mechanisms are undefined. Here, we report the effect of decreased SHH-SMO signaling on renal morphogenesis, the expression of SHH target genes and GLI binding to Shh target genes. Shh deficiency or cyclopamine-mediated SMO inhibition disrupted renal organogenesis, decreased expression of GLI1 and GLI2 proteins, but increased expression of GLI3 repressor relative to GLI3 activator. Shh deficiency decreased expression of kidney patterning genes (Pax2 and Sall1) and cell cycle regulators (cyclin D1 and MYCN). Elimination of Gli3 in Shh-/- mice rescued kidney malformation and restored expression of Pax2, Sall1, cyclin D1, MYCN, Gli1 and Gli2. To define mechanisms by which SHH-SMO signaling controls gene expression, we determined the binding of GLI proteins to 5' flanking regions containing GLI consensus binding sequences in Shh target genes using chromatin immunoprecipitation. In normal embryonic kidney tissue, GLI1 and/or GLI2 were bound to each target gene. By contrast, treatment of embryonic kidney explants with cyclopamine decreased GLI1 and/or GLI2 binding, and induced binding of GLI3. However, cyclopamine failed to decrease Gli1 and Gli2 expression and branching morphogenesis in Gli3-deficient embryonic kidney tissue. Together, these results demonstrate that SHH-SMO signaling controls renal morphogenesis via transcriptional control of Gli, renal patterning and cell cycle regulator genes in a manner that is opposed by GLI3. [ABSTRACT FROM AUTHOR]

Background: Autologous stem cell transplantation (ASCT) is a standard consolidation treatment for eligible patients with multiple myeloma (MM). There is no standardized mobilization regimen for collection of CD34+ stem cells, which is crucial to the success of ASCT. Cyclophosphamide/GCSF is an effective regimen, although reported associated toxicities include risk of febrile neutropenia (FN). Since plerixafor was introduced in Canada, this mobilization agent has been increasingly used as needed with GCSF at Kingston Health Science Centre (KHSC), with elimination of cyclophosphamide. This single center, retrospective, quality improvement study evaluates mobilization and ASCT outcomes of MM patients who had undergone stem cell mobilization at KHSC with cyclophosphamide/GCSF+/-plerixafor without antibiotics, cyclophosphamide/GCSF+/-plerixafor with antibiotics, and GCSF+/-plerixafor without antibiotics., Methods: A retrospective chart review was conducted evaluating 137 patients. The primary outcome measure was FN rates with mobilization. Balancing measures include CD34+ cell collected, plerixafor usage, days of apheresis and transplant outcomes. Chi-square, ANOVA, or Kruskal-Wallis methods were used to test statistical significance where appropriate., Results: Our study noted a higher total and day one CD34+ count in the two groups utilizing cyclophosphamide in mobilization. All nine cases of FN occurred in these two groups (P < .05). Addition of antibiotics decreased, but did not eliminate risk of FN. There were no significant differences in the rate of plerixafor usage and number of apheresis days. Difference in transplant outcomes, including engraftment and transfusion support, were statistically but not clinically significant. A larger sample size may be needed to explore this fully. There was no significant difference in length of transplant hospital stay., Conclusion: The elimination of cyclophosphamide from mobilization regimens for MM appears to significantly reduce FN rates, without increasing balancing measures such as total number of apheresis days, plerixafor usage, duration of transplant hospitalization or mortality outcomes., (© 2022 Wiley Periodicals LLC.)