Huntingtin is an RNA binding protein and participates in NEAT1-mediated paraspeckles.

Huntingtin protein, mutated in Huntington's disease, is implicated in nucleic acid-mediated processes, yet the evidence for direct huntingtin-nucleic acid interaction is limited. Here, we show wild-type and mutant huntingtin copurify with nucleic acids, primarily RNA, and interact directly with G-rich RNAs in in vitro assays. Huntingtin RNA-immunoprecipitation sequencing from patient-derived fibroblasts and neuronal progenitor cells expressing wild-type and mutant huntingtin revealed long noncoding RNA NEAT1 as a significantly enriched transcript. Altered NEAT1 levels were evident in Huntington's disease cells and postmortem brain tissues, and huntingtin knockdown decreased NEAT1 levels. Huntingtin colocalized with NEAT1 in paraspeckles, and we identified a high-affinity RNA motif preferred by huntingtin. This study highlights NEAT1 as a huntingtin interactor, demonstrating huntingtin's involvement in RNA-mediated functions and paraspeckle regulation.

Tumor-Tailored Ionizable Lipid Nanoparticles Facilitate IL-12 Circular RNA Delivery for Enhanced Lung Cancer Immunotherapy.

The advancement of message RNA (mRNA) -based immunotherapies for cancer is highly dependent on the effective delivery of RNA (Ribonucleic) payloads using ionizable lipid nanoparticles (LNPs). However, the clinical application of these therapies is hindered by variable mRNA expression among different cancer types and the risk of systemic toxicity. The transient expression profile of mRNA further complicates this issue, necessitating frequent dosing and thus increasing the potential for adverse effects. Addressing these challenges, a high-throughput combinatorial method is utilized to synthesize and screen LNPs that efficiently deliver circular RNA (circRNA) to lung tumors. The lead LNP, H1L1A1B3, demonstrates a fourfold increase in circRNA transfection efficiency in lung cancer cells over ALC-0315, the industry-standard LNPs, while providing potent immune activation. A single intratumoral injection of H1L1A1B3 LNPs, loaded with circRNA encoding interleukin-12 (IL-12), induces a robust immune response in a Lewis lung carcinoma model, leading to marked tumor regression. Immunological profiling of treated tumors reveals substantial increments in CD45+ leukocytes and enhances infiltration of CD8+ T cells, underscoring the ability of H1L1A1B3 LNPs to modulate the tumor microenvironment favorably. These results highlight the potential of tailored LNP platforms to advance RNA drug delivery for cancer therapy, broadening the prospects for RNA immunotherapeutics.

Confidence score: a data-driven measure for inclusive systematic reviews considering unpublished preprints.

OBJECTIVES: COVID-19, since its emergence in December 2019, has globally impacted research. Over 360 000 COVID-19-related manuscripts have been published on PubMed and preprint servers like medRxiv and bioRxiv, with preprints comprising about 15% of all manuscripts. Yet, the role and impact of preprints on COVID-19 research and evidence synthesis remain uncertain. MATERIALS AND METHODS: We propose a novel data-driven method for assigning weights to individual preprints in systematic reviews and meta-analyses. This weight termed the "confidence score" is obtained using the survival cure model, also known as the survival mixture model, which takes into account the time elapsed between posting and publication of a preprint, as well as metadata such as the number of first 2-week citations, sample size, and study type. RESULTS: Using 146 preprints on COVID-19 therapeutics posted from the beginning of the pandemic through April 30, 2021, we validated the confidence scores, showing an area under the curve of 0.95 (95% CI, 0.92-0.98). Through a use case on the effectiveness of hydroxychloroquine, we demonstrated how these scores can be incorporated practically into meta-analyses to properly weigh preprints. DISCUSSION: It is important to note that our method does not aim to replace existing measures of study quality but rather serves as a supplementary measure that overcomes some limitations of current approaches. CONCLUSION: Our proposed confidence score has the potential to improve systematic reviews of evidence related to COVID-19 and other clinical conditions by providing a data-driven approach to including unpublished manuscripts.

Rational design and combinatorial chemistry of ionizable lipids for RNA delivery.

In 2018, LNPs enabled the first FDA approval of a siRNA drug (Onpattro); two years later, two SARS-CoV-2 vaccines (Comirnaty, Spikevax) based on LNPs containing mRNA also arrived at the clinic, saving millions of lives during the COVID-19 pandemic. Notably, each of the three FDA-approved LNP formulations uses a unique ionizable lipid while the other three components, i.e., cholesterol, helper lipid, and PEGylated lipid, are almost identical. Therefore, ionizable lipids are critical to the delivery efficiency of mRNA. This review covers recent advances in ionizable lipids used in RNA delivery over the past several decades. We will discuss chemical structures, synthetic routes, and structure-activity relationships of ionizable lipids.

Quantification of Usaramine and its N-Oxide Metabolite in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry.

A sensitive, fast and robust liquid chromatography--tandem mass spectrometry (LC-MS-MS) method was developed and validated for the determination of usaramine (URM) and usaramine N-oxide (UNO) in rat plasma. The separation was conducted on an ACQUITY UPLC BEH C18 Column (50 × 2.1 mm, 1.7 µm) and gradient eluted with mobile phase A (0.1% formic acid with 5 mM ammonium acetate in water) and B (0.1% formic acid in acetonitrile/methanol, 9/1, v/v). The method was linear over the range of 1-2,000 ng/mL for both analytes. The validated method was applied to investigate the pharmacokinetic behaviors and sex differences of URM and its N-oxide metabolite in rats. After intravenous administration of URM at 1 mg/kg, the AUC0-t values for URM and UNO were 363 ± 65 and 172 ± 32 ng/mL*h in male rats, while 744 ± 122 and 30.7 ± 7.4 ng/mL*h in females, respectively. The clearance of URM was significantly higher in male rats than in females (2.77 ± 0.50 vs 1.35 ± 0.19 L/h/kg, P < 0.05). After oral administration of URM at 10 mg/kg, the AUC0-t values of URM and UNO were 1,960 ± 208 and 1,637 ± 246 ng/mL*h in male rats, while 6,073 ± 488 and 300 ± 62 ng/mL*h in females, respectively. The oral bioavailability of URM in female rats (81.7%) was much higher than in males (54.0%). In conclusion, sex-based differences were observed in the pharmacokinetics, N-oxide metabolism and oral bioavailability of URM.

Simultaneous determination of monocrotaline and its N-oxide metabolite in rat plasma using LC-MS/MS: Application to a pharmacokinetic study.

Monocrotaline (MCT) is a pyrrolizidine alkaloid that can induce hepatic sinusoidal damage, pulmonary hypertension, renal toxicity, and heart disease. Monocrotaline N-oxide (MNO), the primary metabolite of MCT, is less toxic; however, it can convert back to MCT to exhibit its toxicity. This study developed and validated a rapid and sensitive LC-MS/MS method for the simultaneous determination of MCT and monocrotaline N-oxide in rat plasma. The method has a linearity over the concentration range of 1-2000 ng/mL with correlation coefficients (r) >0.997 for each analyte. The results of selectivity, matrix effect, accuracy and precision, and recovery were all within the acceptance criteria. The validated method has been successfully applied to study pharmacokinetic behaviors and bioavailability of MCT in rats. MCT was rapidly absorbed (Tmax : 0.400 ± 0.149 h) after oral administration, and the absolute bioavailability of MCT was 78.2%.

Quantitative imaging of intracellular nanoparticle exposure enables prediction of nanotherapeutic efficacy.

Nanoparticle internalisation is crucial for the precise delivery of drug/genes to its intracellular targets. Conventional quantification strategies can provide the overall profiling of nanoparticle biodistribution, but fail to unambiguously differentiate the intracellularly bioavailable particles from those in tumour intravascular and extracellular microenvironment. Herein, we develop a binary ratiometric nanoreporter (BiRN) that can specifically convert subtle pH variations involved in the endocytic events into digitised signal output, enabling the accurately quantifying of cellular internalisation without introducing extracellular contributions. Using BiRN technology, we find only 10.7-28.2% of accumulated nanoparticles are internalised into intracellular compartments with high heterogeneity within and between different tumour types. We demonstrate the therapeutic responses of nanomedicines are successfully predicted based on intracellular nanoparticle exposure rather than the overall accumulation in tumour mass. This nonlinear optical nanotechnology offers a valuable imaging tool to evaluate the tumour targeting of new nanomedicines and stratify patients for personalised cancer therapy.

Evaluating HIFU-mediated local drug release using thermal strain imaging: Phantom and preliminary in-vivo studies.

PURPOSE: High-intensity focused ultrasound (HIFU)-mediated drug release becomes a promising therapeutic technique for treatment of cancer, which has merits of deep penetration, noninvasive approach and nonionizing radiation. However, conventional thermocouple-based approach for treatment monitoring would encounter big challenges such as the viscous heating artifact and difficulty in monitoring in the deep region. In this study, we develop an effective method based on thermal strain imaging (TSI) for the evaluation of HIFU-mediated drug release. METHODS: Both phantom experiments and preliminary animal experiments were performed to investigate the feasibility of the proposed approach. Doxorubicin (DOX)-loaded cerasomes (HIFU and temperature-sensitive cerasomes, HTSCs) were prepared. In the phantom experiments, the HTSC solution is contained inside a cylindrical chamber within a tissue-mimicking phantom. In the animal experiments, the HTSCs are intravenously injected into tumor-bearing mice. An HIFU transducer is used to trigger DOX release from the HTSCs within the phantom or mice, and TSI is performed during HIFU heating. In the phantom experiments, the accuracy of temperature estimation using TSI is validated by measuring with a thermocouple. In animal experiments, the spatial consistency between the distribution of DOX released within the tumor and the location of the heating region estimated by TSI is validated using a spectrofluorophotometer. RESULTS: In the phantom experiments, the HTSCs show a burst release of DOX when the temperature of the HTSC solution estimated by TSI reaches about 42°C, which is in agreement with the condition for drug release from the HTSCs. The temperature estimation using TSI has high accuracy with error below 2.5%. In animal experiments, fluorescence imaging of the tumor validates that the heating region of HIFU could be localized by the low-strain region of TSI. CONCLUSION: The present framework demonstrates a reliable and effective solution to the evaluation of HIFU-mediated local drug delivery.

Localized co-delivery of collagenase and trastuzumab by thermosensitive hydrogels for enhanced antitumor efficacy in human breast xenograft.

Modulation of the collagen-rich extracellular matrix (ECM) in solid tumors by the treatment with collagenase has been proved effective in enhancement of the interstitial transport and antitumor efficacy of antibodies. We, therefore, developed a PLGA-PEG-PLGA polymer-based thermosensitive hydrogel, which incorporated a HER2-targeted monoclonal antibody trastuzumab and collagenase (Col/Tra/Gel) for peritumoral administration. HER2-positvie BT474 tumor-bearing mice were selected as a model. The Col/Tra/Gel showed the continuous and biphasic release of protein drugs for 9 days in vitro. NIR imaging studies demonstrated a long-term retention of Col/Tra/Gel hydrogel in the peritumoral area for over 20 days. Treatment with Col/Tra/Gel reduced the collagen density and enhanced apoptotic cell death in tumor tissue, resulting in superior treatments with increased efficacy and reduced toxicity compared with other control groups. Moreover, a quarter-dose of Col/Tra/Gel exhibited a better antitumor efficacy than that of intravenous injection of clinical trastuzumab formulation. This localized co-delivery system offers a potential strategy for the modulation of dense ECM and enhancement of antibody efficacy.