Joel Levin

Clinical mRNA delivery remains challenging, in large part because how physiology alters delivery in vivo remains underexplored. For example, mRNA delivered by lipid nanoparticles (LNPs) is being considered to treat inflammation, but whether inflammation itself changes delivery remains understudied. Relationships between immunity, endocytosis, and mRNA translation lead to hypothesize that toll-like receptor 4 (TLR4) activation reduced LNP-mediated mRNA delivery. Therefore, LNP uptake, endosomal escape, and mRNA translation with and without TLR4 activation are quantified. In vivo DNA barcoding is used to discover a novel LNP that delivers mRNA to Kupffer cells at clinical doses; unlike most LNPs, this LNP does not preferentially target hepatocytes. TLR4 activation blocks mRNA translation in all tested cell types, without reducing LNP uptake; inhibiting TLR4 or its downstream effector protein kinase R improved delivery. The discrepant effects of TLR4 on i) LNP uptake and ii) translation suggests TLR4 activation can "override" LNP targeting, even after mRNA is delivered into target cells. Given near-future clinical trials using mRNA to modulate inflammation, this highlights the need to understand inflammatory signaling in on- and off-target cells. More generally, this suggests an LNP which delivers mRNA to one inflammatory disease may not deliver mRNA to another.

Fifty-nine patients with acute gouty arthritis entered into a 7-day multicenter, double blind trial of ketoprofen versus indomethacin. Patients were randomly assigned to receive 100 mg of ketoprofen (n = 29 patients) or 50 mg of indomethacin (n = 30 patients) 3 times a day. More than 90% of the patients in each group reported pain relief within the 1st day of treatment. By Day 5, 7 patients in the ketoprofen group and 6 in the indomethacin group discontinued treatment because of complete or substantial pain relief. At the end of the study, most patients in both groups were rated as having marked improvement both by the investigators and by self-assessment. Three patients in each group withdrew prematurely because of drug related gastrointestinal disorders. Ketoprofen compared favorably for efficacy and safety with indomethacin in the treatment of gouty arthritis.

Bilateral acinic cell carcinoma of the parotid gland is rare. On the basis of one case and a review of 486 parotid acinic carcinomas, unilateral as well as bilateral, total parotidectomy seems to be the treatment of choice for this low-grade malignant neoplasm that recurs commonly following inadequate excision. If involved by tumor, the facial nerve must be taken. Metastases are more likely to lung and bone than to regional nodes. For this reason, radical neck dissection is not routinely indicated.

Long noncoding RNAs (lncRNAs) are emerging as key molecules in regulating many biological processes and have been implicated in development and disease pathogenesis. Biomarkers of cancer and normal tissue response to treatment are of great interest in precision medicine, as well as in public health and medical management, such as for assessment of radiation injury after an accidental or intentional exposure. Circulating and functional RNAs, including microRNAs (miRNAs) and lncRNAs, in whole blood and other body fluids are potential valuable candidates as biomarkers. Early prediction of possible acute, intermediate and delayed effects of radiation exposure enables timely therapeutic interventions. To address whether long noncoding RNAs (lncRNAs) could serve as biomarkers for radiation biodosimetry we performed whole genome transcriptome analysis in a mouse model after whole-body irradiation. Differential lncRNA expression patterns were evaluated at 16, 24 and 48 h postirradiation in total RNA isolated from whole blood of mice exposed to 1, 2, 4, 8 and 12 Gy of X rays. Sham-irradiated animals served as controls. Significant alterations in the expression patterns of lncRNAs were observed after different radiation doses at the various time points. We identified several radiation-induced lncRNAs known for DNA damage response as well as immune response. Long noncoding RNA targets of tumor protein 53 (P53), Trp53cor1, Dino, Pvt1 and Tug1 and an upstream regulator of p53, Meg3, were altered in response to radiation. Gm14005 ( Morrbid) and Tmevpg1 were regulated by radiation across all time points and doses. These two lncRNAs have important potential as blood-based radiation biomarkers; Gm14005 ( Morrbid) has recently been shown to play a key role in inflammatory response, while Tmevpg1 has been implicated in the regulation of interferon gamma. Precise molecular biomarkers, likely involving a diverse group of inducible molecules, will not only enable the development and effective use of medical countermeasures but may also be used to detect and circumvent or mitigate normal tissue injury in cancer radiotherapy.

CONTEXT: Accidental exposure to life-threatening radiation in a nuclear event is a major concern; there is an enormous need for identifying biomarkers for radiation biodosimetry to triage populations and treat critically exposed individuals. OBJECTIVE: To identify dose-differentiating miRNA signatures from whole blood samples of whole body irradiated mice. METHODS: Mice were whole body irradiated with X-rays (2 Gy-15 Gy); blood was collected at various time-points post-exposure; total RNA was isolated; miRNA microarrays were performed; miRNAs differentially expressed in irradiated vs. unirradiated controls were identified; feature extraction and classification models were applied to predict dose-differentiating miRNA signature. RESULTS: We observed a time and dose responsive alteration in the expression levels of miRNAs. Maximum number of miRNAs were altered at 24-h and 48-h time-points post-irradiation. A 23-miRNA signature was identified using feature selection algorithms and classifier models. An inverse correlation in the expression level changes of miR-17 members, and their targets were observed in whole body irradiated mice and non-human primates. CONCLUSION: Whole blood-based miRNA expression signatures might be used for predicting radiation exposures in a mass casualty nuclear incident.