SUMMARYTransgenesis for Strongyloides and Parastrongyloides was accomplished in 2006 and is based on techniques derived for Caenorhabditis elegans over two decades earlier. Adaptation of these techniques has been possible because Strongyloides and related parasite genera carry out at least one generation of free-living development, with adult males and females residing in soil contaminated by feces from an infected host. Transgenesis in this group of parasites is accomplished by microinjecting DNA constructs into the syncytia of the distal gonads of free-living females. In Strongyloides stercoralis, plasmid-encoded transgenes are expressed in promoter-regulated fashion in the F1 generation following gene transfer but are silenced subsequently. Stable inheritance and expression of transgenes in S. stercoralis requires their integration into the genome, and stable lines have been derived from integrants created using the piggyBac transposon system. More direct investigations of gene function involving expression of mutant transgene constructs designed to alter intracellular trafficking and developmental regulation have shed light on the function of the insulin-regulated transcription factor Ss-DAF-16. Transgenesis in Strongyloides and Parastrongyloides opens the possibility of powerful new methods for genome editing and transcriptional manipulation in this group of parasites. Proof of principle for one of these, CRISPR/Cas9, is presented in this review.

Increasing evidence indicates a bidirectional relationship between epilepsy and Alzheimer’s disease (AD) with 22% of AD patients additionally suffering from seizures, which may be a targetable component of disease progression. Since epileptogenesis is associated with changes in excitatory: inhibitory (E:I) balance, we examined postmortem AD brain tissue from patients with and without seizure history and five times familial AD (5XFAD) mice for changes in several markers of E:I balance, including the inhibitory GABAAreceptor, the chloride cotransporters, sodium potassium chloride cotransporter 1 (NKCC1) and potassium chloride cotransporter 2 (KCC2), and the excitatory NMDA and AMPA type glutamate receptors. We hypothesized that seizure history in AD patients would be associated with greater E:I imbalances, and that such changes would also be observed in the 5XFAD mice following pentylenetetrazol (PTZ) kindling. We found that seizures in AD patients were associated with alterations in NKCC1 and KCC2 expression, indicative of depolarizing GABA, and exacerbated cognitive deficits. Seizures also significantly contributed to E:I imbalance in the 5XFAD mouse model, as similar changes in NKCC1 and KCC2 expression were found in PTZ treated 5XFAD mice, along with altered AMPA receptor protein expression indicative of calcium permeable-AMPA receptors. In addition, we found that chronic treatment with the mTOR inhibitor rapamycin at doses we have previously shown to attenuate seizure-inducedβ-amyloid pathology and cognitive deficits in 5XFAD mice, can mitigate the dysregulation of markers of E:I balance in this model. These data suggest that mTOR activation plays a role in modifying the E:I imbalance and network hyperexcitability in AD and that the FDA-approved mTOR inhibitors such as rapamycin may have potential for therapy in AD patients with a seizure history.