rAAV/ABAD-DP-6His attenuates oxidative stressinduced injury of PC12 cells

Our previous studies have revealed that amyloidβ（Aβ）-binding alcohol dehydrogenase （ABAD） decoy peptide antagonizes Aβ42-induced neurotoxicity. However, whether it improves oxidative stress injury remains unclear. In this study, a recombinant adenovirus constitutively secreting and expressing Aβ-ABAD decoy peptide （rAAV/ABAD-DP-6His） was successfully constructed. Our results showed that rAAV/ABAD-DP-6His increased superoxide dismutase activity in hydro-gen peroxide-induced oxidative stress-mediated injury of PC12 cells. Moreover, rAAV/ABAD-DP-6His decreased malondialdehyde content, intracellular Ca2＋concentration, and the level of reactive oxygen species. rAAV/ABAD-DP-6His maintained the stability of the mitochondrial membrane potential. In addition, the ATP level remained constant, and apoptosis was reduced. Overall, the results indicate that rAAV/ABAD-DP-6His generates the fusion peptide, Aβ-ABAD decoy peptide, which effectively protects PC12 cells from oxidative stress injury induced by hy-drogen peroxide, thus exerting neuroprotective effects.

The novel amyloid-beta peptide aptamer inhibits intracellular amyloid-beta peptide toxicity

Amyloid β peptide binding alcohol dehydrogenase （ABAD） decoy peptide （DP） can competitively antagonize binding of amyloid β peptide to ABAD and inhibit the cytotoxic effects of amyloid β peptide. Based on peptide aptamers, the present study inserted ABAD-DP into the disulfide bond of human thioredoxin （TRX） using molecular cloning technique to construct a fusion gene that can express the TRX1-ABAD-DP-TRX2 aptamer. Moreover, adeno-associated virus was used to allow its stable expression. Immunofluorescent staining revealed the co-expression of the transduced fusion gene TRX1-ABAD-DP-TRX2 and amyloid β peptide in NIH-3T3 cells, indicating that the TRXl-ABAD-DP-TRX2 aptamer can bind amyloid β peptide within cells. In addition, cell morphology and MTT results suggested that TRX1-ABAD-DP-TRX2 attenuated amyloid β peptide-induced SH-SY5Y cell injury and improved cell viability. These findings confirmed the possibility of constructing TRX-based peptide aptamer using ABAD-DP. Moreover, TRXl-ABAD-DP-TRX2 inhibited the cytotoxic effect of amyloid β peptide.

All-fiber-transmission photometry for simultaneous optogenetic stimulation and multi-color neuronal activity recording

Manipulating and real-time monitoring of neuronal activities with cell-type specificity and precise spatiotemporal resolution during animal behavior are fundamental technologies for exploring the functional connectivity, information transmission, and physiological functions of neural circuits in vivo. However, current techniques for optogenetic stimulation and neuronal activity recording mostly operate independently. Here, we report an all-fiber-transmission photometry system for simultaneous optogenetic manipulation and multi-color recording of neuronal activities and the neurotransmitter release in a freely moving animal. We have designed and manufactured a wavelength-independent multi-branch fiber bundle to enable simultaneous optogenetic manipulation and multi-color recording at different wavelengths. Further, we combine a laser of narrow linewidth with the lock-in amplification method to suppress the optogenetic stimulation-induced artifacts and channel crosstalk. We show that the collection efficiency of our system outperforms a traditional epi-fluorescence system. Further, we demonstrate successful recording of dynamic dopamine(DA) responses to unexpected rewards in the nucleus accumbens(NAc) in a freely moving mouse. We also show simultaneous dual-color recording of neuronal Ca2+ signals and DA dynamics in the NAc upon delivering an unexpected reward and the simultaneous optogenetic activating at dopaminergic terminals in the same location. Thus, our multi-function fiber photometry system provides a compatible, efficient, and flexible solution for neuroscientists to study neural circuits and neurological diseases.

Drosophila homolog of the intellectual disability-related long-chain acyl-CoA synthetase 4 is required for neuroblast proliferation

Mutations in long-chain acyl-CoA synthetase 4 (ACSL4) are associated with non-syndromic X-linked intellectual disability (ID). However, the neural functions of ACSL4 and how loss of ACSL4 leads to ID remain largely unexplored. We report here that mutations in Acsl, the Drosophila ortholog of human ACSL3 and ACSL4, result in developmental defects of the mushroom body (MB), the center of olfactory learning and memory. Specifically, Acsl mutants show fewer MB neuroblasts (Nbs) due to reduced proliferation activity and premature differentiation. Consistently, these surviving Nbs show reduced expression of cyclin E, a key regulator of the G1-to S-phase cell cycle transition, and nuclear mislocalization of the transcriptional factor Prospero, which is known to repress self-renewal genes and activate differentiating genes. Furthermore, RNA-seq analysis reveals downregulated Nb-and cell-cyclerelated genes and upregulated neuronal differentiation genes in Acsl mutant Nbs. As Drosophila Acsl and human ACSL4 are functionally conserved, our findings provide novel insights into a critical and previously unappreciated role of Acsl in neurogenesis and the pathogenesis of ACSL4-related ID.