Cardiac hypertrophy is an adaptive cardiac response to heart stress. Sustained cardiac hypertrophy indicates higher risk of heart failure. Ca2+/calmodulin-dependent protein kinase II (CaMKII) has been proved to be a key regulator of cardiac hypertrophy, but its mechanism remains largely unknown. Our study proposed to explore the regulatory mechanism of CaMKII in cardiac hypertrophy. We validated that CaMKII was upregulated in cardiac hypertrophy models in vivo and in vitro and that knockdown of CaMKII attenuated Ang II-induced cardiac hypertrophy in vitro. Furthermore, we demonstrated that signal transducer and activator of transcription 3 (STAT3) was highly expressed in cardiac hypertrophy and could stimulate the transactivation of CaMKII. Moreover, we predicted through TargetScan and confirmed that miR-625-5p targeted and inhibited STAT3 so as to reduce the expression of CaMKII. Interestingly, we also found that miR-625-5p directly targeted CaMKII and inhibited its expression. Rescue assays suggested that miR-625-5p attenuated Ang II-induced cardiac hypertrophy through CaMKII/STAT3. Consequently, this study elucidated that miR-625-5p inhibited cardiac hypertrophy through targeting STAT3 and CaMKII, suggesting miR-625-5p as a novel negative regulator of cardiac hypertrophy. Graphical abstract [Figure: see text].

Adeno-associated virus (AAV) vectors have become an important tool for delivering therapeutic genes for a wide range of neurological diseases. AAV serotypes possess differential cellular tropism in the central nervous system. Although several AAV serotypes or mutants have been reported to transduce the brain efficiently, conflicting data occur across studies with the use of various rodent strains from different genetic backgrounds. Herein, we performed a systematic comparison of the brain transduction properties among five AAV serotypes (AAV2, 5, 7, 8, and 9) in two common rodent strains (C57BL/6J and FVB/N), following local intrastriatal injection of AAV vectors encoding enhanced green fluorescent protein (EGFP) driven by the CBh promoter. Important differences were found regarding overall cellular tropism and transduction efficiency, including contralateral transduction among the AAV serotypes and between the mouse strains. We have further found loss of NeuN-immunoreactivity and microglial activation from AAV transduction in the different mouse strains. The important strain-specific differences from our study suggest that the genetic background of the mouse may affect AAV serotype transduction properties in the brain. These data can provide valuable information about how to choose an effective AAV vector for clinical application and interpret the data obtained from preclinical studies and clinical trials.

miR-203 is known to target estrogen receptor α (ERα) in various cancer cell lines, such as MCF-7. However, whether miR-203 regulates ERα and contributes to the onset and progression of osteoarthritis (OA) is poorly understood. A combined protocol of the bilateral ovariectomy and the intra-articular monosodium iodoacetate injection was applied to establish a postmenopausal OA model in rats. Real-time quantitative polymerase chain reaction was used to detect miR-203 and mRNAs and Western blotting was exploited to quantify the expression levels on the protein level. Enzyme-linked immunosorbent assays were deployed to detect the expression of matrix metalloproteinase-1 (MMP-1), MMP-3, prostaglandin E2 (PGE2), and collagen type II degradation (CTX-II) in serum samples. Dual-luciferase reporter assay was utilized to confirm the direct binding of miR-203 on ERα in postmenopausal OA rats. Expression of miR-203 was elevated; while ERα mRNA and protein were downregulated in postmenopausal OA rats, compared with sham rats. Dual-luciferase reporter assay confirmed miR-203 bound and negatively regulated ERα, resulting in promoted cellular inflammation and cartilage destruction in postmenopausal OA rats. Suppression of miR-203 using a specific inhibitor ameliorated cartilage degradation in postmenopausal OA rats. miR-203 is pivotal in the onset and progression of OA in the postmenopausal rat model, and holds promise for a therapeutic target of OA treatment.

Hepatocellular carcinoma (HCC) is the most common malignancy in liver and is one of the leading causes of cancer-induced deaths all over the world. Circular RNAs (circRNAs) have been proven to be related to cancer initiation and progression in mounting reports. However, research on the role of circRNAs in human cancers, including HCC, is still in its infancy. circVAPA has been unmasked as oncogenic in colorectal cancer. Yet the function of circVAPA in HCC has never been elucidated. circVAPA, miR-377-3p, and prosaposin (PSAP) mRNA expression levels were detected by real-time quantitative PCR. PSAP protein levels were measured by Western blot. Cell proliferation was evaluated by CCK-8, colony formation, and EdU assays. Binding capacity was assessed by dual-luciferase reporter assay. circVAPA was upregulated in HCC cell lines and circVAPA depletion was associated with decreased HCC cell proliferation. circVAPA promotes PSAP expression through sequestering miR-377-3p. The suppression of HCC cell proliferation caused by circVAPA silence was revived by PSAP overexpression. This study revealed that circVAPA contributes to HCC cell proliferation through sponging miR-377-3p and thereby disinhibiting PSAP, shedding light on a new insight into HCC initiation and progression.

The purpose of this study was to investigate the expression level of microRNA-4513 (miR-4513) in gastric cancer (GC), and to elucidate the mechanisms underlying its regulation of GC progression. Quantitative real-time PCR (qRT-PCR) was performed to measure the expression level of miR-4513 in GC cells. Transfection efficacy of synthetic miRNAs was examined by qRT-PCR. After synthetic miRNA transfection, cell counting kit-8 assay and transwell invasion assay were conducted to measure biological changes in these groups. The key molecular expression level involved in epithelial-mesenchymal transition (EMT) was analyzed by Western blot. Bioinformatic analysis and Western blot were performed to investigate the connection between miR-4513 and lysine acetyltransferase 6B (KAT6B). qRT-PCR results showed that miR-4513 expression level was upregulated in GC cell lines. Downregulation of miR-4513 expression inhibited GC cell proliferation, invasion, and EMT. KAT6B was validated as a direct target of miR-4513. In addition, KAT6B expression level can be upregulated by miR-4513 inhibitor. Collectively, we showed that miR-4513 is involved in regulating the biological function of GC cells via KAT6B. In addition, miR-4513 may serve as a potential target for the molecular therapy of GC.

In vivo viral gene therapy and somatic cell therapy products (whether autologous, allogeneic, or xenogeneic) that have been subjected to an ex vivo gene transfer procedure will normally be classified as genetically modified organisms (GMOs) in Europe, not just the gene transfer vectors used in their construction. These products are, therefore, expected to fulfill certain environmental requirements with regard to the biosafety aspects of their clinical use (which may be subject to review by government departments responsible for environmental affairs). In the European Union (EU), clinical trials using GMOs generally require three levels of review (in addition to local review processes), which are often performed by separate national agencies. In this study, the principles under which certain EU member states control use of the GMOs in clinical trials under the definitions of either "contained use" or "deliberate release" will be discussed and evaluated from a scientific and a regulatory perspective, with comparisons with non-EU expectations as described by the U.S. Food and Drug Administration and the Japanese living modified organisms (LMOs) regulations. For the latter, an understanding of the criteria under which LMOs exemptions apply, notably with respect to the nature of the viral construct used, the manufacturing process, and demonstration that there is no detectable residual replication-competent virus in the final gene-modified cells, is of paramount importance. Building on the existing European, U.S., and Japanese experience with GMOs/LMOs within the context of experimental gene and cell therapies, a through reflection on, and harmonization of, the current global GMO framework is needed to avoid unnecessary delays in clinical development and to ensure a smooth and a rapid access by patients to innovative life-saving therapies.

Editor's note: Sir Patrick Vallance is Government Chief Scientific Adviser in the United Kingdom. Here he discusses his path from academia to industry to government, and he reflects on the crucial early conversations that were instrumental in positioning gene therapy research for successful clinical development.

The purpose of this study was to examine the toxicity and side effects of a recombinant adeno-associated virus 8 (AAV8) vector, aimed to treat cyclic nucleotide gated channel alpha 3 (CNGA3)-linked achromatopsia, after a single subretinal administration in cynomolgus macaques. Animals were followed in two studies: a 13-week study with 22 animals and a 28-day study with 12 animals. Both groups were divided into subgroups receiving either vehicle only, a low (1 × 1011 vector genomes (vg)), or a high dose (1 × 1012 vg) of rAAV.hCNGA3. In the 13-week study, an extra group received single high-dose intravitreal injections. Here we present the group results of the histological examinations carried out after necropsy from the 28-day study, the retinal functional (electroretinography) in the 13-week study, and clinical observations from both studies. Treatment-related adverse effects were not found, and parameter changes were mostly related to the surgical procedure. The treatment of achromatopsia with rAAV.hCNGA3 is therefore deemed safe to apply to humans.