Immunotoxin therapy is a promising molecular cancer treatment strategy. Its main advantage is seletive cytotoxicity towards tumor cells and minimal toxicity in normal tissues. However, a short half-life and rapid clearance severely hampers its clinical application. We report here a novel genetic approach in which a recombinant adenovirus vector was used to deliver an immunotoxin gene e23(scFv)-PE40 targeted to the oncogene c-erbB-2 (also known as Her2/neu). This vector, when combined with a low dose of a conditionally replicative adenovirus vector (CRAd), has enhanced tumor-killing ability either alone or in combination with the chemotherapeutic agent etoposide. Our data show that low-dose CRAd facilitated the replication of replication-deficient Ade23(scFv)-PE40 up to 6-20 times and the transcription of e23(scFv)-PE40 gene up to 12 times. Moreover, etoposide increased the e23(scFv)-PE40 transcription up to 8.5 times. Furthermore, we show that systemic application of Ad-e23(scFv)-PE40 and enhanced expression of the immunotoxin gene was well tolerated as determined by serum biochemical markers and histological examination of most vital organs. Taken together, our data support a novel genetic immunotoxin delivery approach that may yield enhanced efficacy against a variety of Her2/neu-expressing tumors.
Retina, located in the innermost layer of the eye of human, holds the decisive role in visual perception. Dissecting the heterogeneity of retina is essential for understanding the mechanism of vision formation and even the development of central nervous system (CNS). Here, we performed single cell RNA-seq, analyzed 57,832 cells from human infant donors, resulting in 20 distinct clusters representing major cell types in retina: rod photoreceptors, cone photoreceptors, bipolar cells, horizontal cells, amacrine cells, Muller glia cells and microglia. We next constructed extensive networks of intercellular communication and identified ligand-receptor interactions playing crucial roles in regulating neural cell development and immune homeostasis in retina. Though re-clustering, we identified known subtypes in cone PRs and additional unreported subpopulations and corresponding markers in rod PRs as well as bipolar cells. Additionally, we linked inherited retinal disease to certain cell subtypes or subpopulations through enrichment analysis. Intriguingly, we found that status and functions of photoreceptors changed drastically between early and late retina. Overall, our study offers the first retinal cell atlas in human infants, dissecting the heterogeneity of retina and identifying the key molecules in the developmental process, which provides an important resource that will pave the way for retina development mechanism research and regenerative medicine concerning retinal biology.
Hypoxic preconditioning (HPC) as an endogenous mechanism
can resist
hypoxia/ischemia injury and exhibit protective effects on neurological
function including learning and memory. Although underlying molecular
mechanisms remain unclear, HPC probably regulates the expression of
protective molecules by modulating DNA methylation. Brain-derived
neurotrophic factor (BDNF) activates its signaling upon binding to
the tropomyosin-related kinase B (TrkB) receptor, which is involved
in neuronal growth, differentiation, and synaptic plasticity. Therefore,
this study focused on the mechanism by which HPC regulates BDNF and
BDNF/TrkB signaling through DNA methylation to influence learning
and memory. Initially, the HPC model was established by hypoxia stimulations
on ICR mice. We found that HPC downregulated the expression of DNA
methyltransferase (DNMT) 3A and DNMT3B. Then, the upregulation of
BDNF expression in HPC mice was generated from a decrease in DNA methylation
of the BDNF gene promoter detected by pyrophosphate
sequencing. Subsequently, upregulation of BDNF activated BDNF/TrkB
signaling and ultimately improved learning and spatial memory in HPC
mice. Moreover, after mice were intracerebroventricularly injected
with the DNMT inhibitor, the restraint of DNA methylation accompanied
by an increase of BDNF and BDNF/TrkB signaling was also discovered.
Finally, we observed that the inhibitor of BDNF/TrkB signaling prevented
HPC from ameliorating learning and memory in mice. However, the DNMT
inhibitor promoted spatial cognition in mice. Thus, we suggest that
HPC may upregulate BDNF by inhibiting DNMTs and decreasing DNA methylation
of the BDNF gene and then activate BDNF/TrkB signaling
to improve learning and memory in mice. This may provide theoretical
guidance for the clinical treatment of cognitive dysfunction caused
by ischemia/hypoxia disease.
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