Cerebral palsy (CP) encompasses a group of non-progressive brain disorders that are often acquired through perinatal hypoxic-ischemic (HI) brain injury. Injury leads to a cascade of cell death events, resulting in lifetime motor and cognitive deficits. There are currently no treatments that can repair the resulting brain damage and improve functional outcomes. To date, preclinical research using neural precursor cell (NPC) transplantation as a therapy for HI brain injury has shown promise. To translate this treatment to the clinic, it is essential that human-derived NPCs also be tested in animal models, however, a major limitation is the high risk of xenograft rejection. A solution is to transplant the cells into immune-deficient rodents, but there are currently no models of HI brain injury established in such a cohort of animals. Here, we demonstrate that a model of HI brain injury can be generated in immune-deficient Prkdc knockout (KO) rats. Long-term deficits in sensorimotor function were similar between KO and wildtype (WT) rats. Interestingly, some aspects of the injury were more severe in KO rats. Additionally, human induced pluripotent stem cell derived (hiPSC)-NPCs had higher survival at 10 weeks post-transplant in KO rats when compared to their WT counterparts. This work establishes a reliable model of neonatal HI brain injury in Prkdc KO rats that will allow for future transplantation, survival, and long-term evaluation of the safety and efficacy of hiPSC-NPCs for neonatal brain damage. This model will enable critical preclinical translational research using human NPCs.

As a result of restrictions imposed by COVID-19, many researchers have responded to the call for remote, advanced pharmacy practice experiences (APPEs) that do not involve direct patient care. The influx of materials on online pedagogy may be difficult for new preceptors to digest while familiarizing themselves with the APPE program. To complement the available guidance on remote learning for new preceptors, we describe our experiences with implementing a remote, research-focused APPE during COVID-19. Common challenges are discussed and potential solutions that may help new preceptors anticipate and overcome barriers to achieving the educational outcomes of researchfocused APPE are proposed.

The nuclear envelope is a membrane separating nuclear from cytoplasmic processes. Existing models suggest that damaged DNA moves to the envelope at the edge of the nucleus for repair. Yet, most damaged human DNA does not reposition to the nuclear periphery during repair. Here we show that human cells relocate the nuclear envelope to non-peripheral damaged DNA, providing solid support promoting the reconnection of DNA break ends. Upon DNA double-strand break (DSB) induction, cytoplasmic microtubules poke the nuclear envelope inwards, inducing an extensive network of DSB-capturing nuclear envelope tubules (dsbNETs). The formation of dsbNETs, which encompass the nuclear lamina and the inner and outer nuclear membranes, depends on DNA damage response kinases, dynamic microtubules, the linker of the nucleoskeleton and cytoskeleton (LINC) proteins SUN1 and SUN2, nuclear pore protein NUP153, and kinesin KIF5B. Repressing dsbNETs compromises the reassociation of DSB ends. The timely reversal of dsbNETs by the kinesin KIFC3 also promotes repair. DSB ends reconnection is restored in dsbNETs-deficient cells by enlarging the 53BP1 DNA repair center. The lamina-binding domain of SUN1 mediates its entry into the tubules and DSB capture by the envelope. Fusing truncated SUN1 to the NHEJ repair protein KU70 fails to localize SUN1 to the tubules but rescues DSB targeting only to the boundary envelope. Although dsbNETs typically promote accurate DSB repair and cell survival, they are co-opted by the PARP inhibitor olaparib to induce aberrant chromosomes restraining BRCA1-deficient breast cancer cells. We uncover dsbNETs, which bring the nuclear envelope to DSBs for repair and potentiate the efficacy of anti-cancer agents. Our findings revise theories of the structure-function relationship of the nuclear envelope and identify dsbNETs as a critical factor in DNA repair and nuclear organization, with implications for health and disease.