Tissue-specific and cell type–specific RNA interference in vivo

2006 ◽  
Vol 1 (3) ◽  
pp. 1494-1501 ◽  
Author(s):  
Manjeet K Rao ◽  
Miles F Wilkinson
2018 ◽  
Author(s):  
J. Darr ◽  
M. Lassi ◽  
R. Gerlini ◽  
F. Scheid ◽  
M. Hrabě de Angelis ◽  
...  
Keyword(s):  

2021 ◽  
pp. 0271678X2110103
Author(s):  
Nao Hatakeyama ◽  
Miyuki Unekawa ◽  
Juri Murata ◽  
Yutaka Tomita ◽  
Norihiro Suzuki ◽  
...  

A variety of brain cells participates in neurovascular coupling by transmitting and modulating vasoactive signals. The present study aimed to probe cell type-dependent cerebrovascular (i.e., pial and penetrating arterial) responses with optogenetics in the cortex of anesthetized mice. Two lines of the transgenic mice expressing a step function type of light-gated cation channel (channelrhodopsine-2; ChR2) in either cortical neurons (muscarinic acetylcholine receptors) or astrocytes (Mlc1-positive) were used in the experiments. Photo-activation of ChR2-expressing astrocytes resulted in a widespread increase in cerebral blood flow (CBF), extending to the nonstimulated periphery. In contrast, photo-activation of ChR2-expressing neurons led to a relatively localized increase in CBF. The differences in the spatial extent of the CBF responses are potentially explained by differences in the involvement of the vascular compartments. In vivo imaging of the cerebrovascular responses revealed that ChR2-expressing astrocyte activation led to the dilation of both pial and penetrating arteries, whereas ChR2-expressing neuron activation predominantly caused dilation of the penetrating arterioles. Pharmacological studies showed that cell type-specific signaling mechanisms participate in the optogenetically induced cerebrovascular responses. In conclusion, pial and penetrating arterial vasodilation were differentially evoked by ChR2-expressing astrocytes and neurons.


2019 ◽  
Vol 56 ◽  
pp. 160-166 ◽  
Author(s):  
Jelle van den Ameele ◽  
Robert Krautz ◽  
Andrea H Brand
Keyword(s):  

2002 ◽  
Vol 76 (24) ◽  
pp. 12783-12791 ◽  
Author(s):  
Christopher R. Logg ◽  
Aki Logg ◽  
Robert J. Matusik ◽  
Bernard H. Bochner ◽  
Noriyuki Kasahara

ABSTRACT The inability of replication-defective viral vectors to efficiently transduce tumor cells in vivo has prevented the successful application of such vectors in gene therapy of cancer. To address the need for more efficient gene delivery systems, we have developed replication-competent retroviral (RCR) vectors based on murine leukemia virus (MLV). We have previously shown that such vectors are capable of transducing solid tumors in vivo with very high efficiency. While the natural requirement of MLV infection for cell division imparts a certain degree of specificity for tumor cells, additional means for confining RCR vector replication to tumor cells are desirable. Here, we investigated the parameters critical for successful tissue-specific transcriptional control of RCR vector replication by replacing various lengths of the MLV enhancer/promoter with sequences derived either from the highly prostate-specific probasin (PB) promoter or from a more potent synthetic variant of the PB promoter. We assessed the transcriptional specificity of the resulting hybrid long terminal repeats (LTRs) and the cell type specificity and efficiency of replication of vectors containing these LTRs. Incorporation of PB promoter sequences effectively restricted transcription from the LTR to prostate-derived cells and imparted prostate-specific RCR vector replication but required the stronger synthetic promoter and retention of native MLV sequences in the vicinity of the TATA box for optimal replicative efficiency and specificity. Our results have thus identified promoter strength and positioning within the LTR as important determinants for achieving both high transduction efficiency and strict cell type specificity in transcriptionally targeted RCR vectors.


2021 ◽  
Author(s):  
Moataz Dowaidar

Autophagy is a double-edged sword in cancer, and numerous aspects should be taken into account before deciding on the most effective strategy to target the process. The fact that several clinical studies are now ongoing does not mean that the patient group that may benefit from autophagy-targeting medicines has been identified. Autophagy inhibitors that are more potent and specialized, as well as autophagy indicators, are also desperately required. The fact that these inhibitors only work against tumors that rely on autophagy for survival (RAS mutants) makes it difficult to distinguish them from tumors that continue to develop even when autophagy is absent. Furthermore, mutations such as BRAF have been shown to make tumors more susceptible to autophagy suppression, suggesting that targeting such tumours may be a viable strategy for overcoming their chemotherapy resistance. In the meantime, we are unable to identify if autophagy regulation works in vivo or whether it selectively targets a disease while inflicting injury to other healthy organs and tissues. A cell-type-specific impact appears to be observed with such therapy. As a result, it is just as important to consider the differences between tumors that originate in different organs as it is to consider the signaling pathways that are similar across them. For a therapy or cure to be effective, the proposed intervention must be tailored to the specific needs of each patient.Over the last several years, a growing amount of data has implicated autophagy in a variety of disorders, including cancer. In normal cells, this catabolic process is also required for cell survival and homeostasis. Despite the fact that medications targeting intermediates in the autophagy signaling pathway are being created and evaluated at both the preclinical and clinical levels, given the complicated function of autophagy in cancer, we still have a long way to go in terms of establishing an effective therapeutic approach. This article discusses current tactics for exploiting cancer cells' autophagy dependency, as well as obstacles in the area. We believe that the unanswered concerns raised in this work will stimulate researchers to investigate previously unknown connections between autophagy and other signaling pathways, which might lead to the development of novel, highly specialized autophagy therapies.


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