The Pathogenesis of Noise-Induced Hearing Loss is Mediated by the Activation of AMPK via LKB1 and CaMKKβ

Noise-induced hearing loss (NIHL) is a major public health issue and an unresolved clinical problem. Here we investigate pathomechanisms of auditory sensory cell death and suggest a novel target pathway for intervention. Cellular survival from stress depends upon maintenance of energy homeostasis, largely by the adenosine monophosphate-activated protein kinase (AMPK) which coordinates metabolic pathways with the energy demands of the cell. In response to traumatic noise exposure which resulted in hair cell death, levels of p-AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via administration of siRNA or a pharmacological inhibitor attenuated noise-induced losses of hair cells and synaptic ribbons, and preserved auditory sensitivity. The phosphorylation of liver kinase B1 (p-LKB1), an AMPK kinase, was increased by noise exposure in cochlear tissues. Additionally, the phosphorylation of calcium-calmodulin kinases I and IV (p-CaMKI/IV), the targets of calcium-calmodulin kinase kinase beta (CaMKKβ), an alternative AMPK kinase that is mediated by calcium, was increased in outer hair cells (OHCs) after the exposure. Inhibition of LKB1 or CaMKKβ by siRNA or knockout mice reduced OHC loss and NIHL. Finally, the increased p-AMPKα in OHCs after noise exposure was attenuated by silencing LKB1 or using CaMKKβ knockout mice. These results indicate that noise exposure leads to hair cell death by activating AMPK via LKB1- and CaMKKβ-mediated pathways, facilitating the pathogenesis of NIHL

Selection and Characterization of a Novel DNA Aptamer for Label-Free Fluorescence Biosensing of Ochratoxin A

Nucleic acid aptamers are emerging as useful molecular recognition tools for food safety monitoring. However, practical and technical challenges limit the number and diversity of available aptamer probes that can be incorporated into novel sensing schemes. This work describes the selection of novel DNA aptamers that bind to the important food contaminant ochratoxin A (OTA). Following 15 rounds of in vitro selection, sequences were analyzed for OTA binding. Two of the isolated aptamers demonstrated high affinity binding and selectivity to this mycotoxin compared to similar food adulterants. These sequences, as well as a truncated aptamer (minimal sequence required for binding), were incorporated into a SYBR® Green I fluorescence-based OTA biosensing scheme. This label-free detection platform is capable of rapid, selective, and sensitive OTA quantification with a limit of detection of 9 nM and linear quantification up to 100 nM

Comparison of Reading Levels of Pharmacy Students and Reading Level of Primary Literature

Objectives: The project purpose was to evaluate pharmacy students’ reading levels using the Nelson-Denney Reading Test (NDRT) and compare these results with the reading level of primary literature to investigate incongruities between student’s comprehension ability and the readability level of assigned reading in the curriculum. Methods: The NDRT was administered to first- through third-year student pharmacists to determine grade equivalents (GE) for vocabulary and reading comprehension. Twenty articles previously identified as Patient-Oriented Evidence that Matters (POEMs) were analyzed to determine the Flesch-Kincaid Grade Level and Gunning-Fog Score. Student demographics, information regarding language spoken, and reading habits, were also assessed. Pearson product moment correlations, t-tests, ANOVA, and descriptive statistics were used to assess relationships between demographic data and NDRT scores. Results: One hundred students participated. The mean NDRT total grade equivalent (±SD) was 16.95 ± 2.1 (median = 17.3). NDRT grade equivalents were statistically different for students with different racial or ethnic backgrounds (t(98)=3.74, p=0.026), English as a second language (ESL) students (t(98)=5.19, p=0.021), and students that read works of fiction for pleasure (t(98)=4.31, p=0.002). The average Gunning-Fog Score for all primary literature articles was 11.48, with the introduction section being the most complex. The average Flesch-Kincaid Grade Level was 17.04, with the results section scoring the lowest average grade level. Implications: While the overall reading grade level of our pharmacy students suggests that they are capable of comprehending reading assigned in the pharmacy curriculum, minority students and students for whom English is a second language may struggle with comprehending complex text. Conflict of Interest We declare no conflicts of interest or financial interests that the authors or members of their immediate families have in any product or service discussed in the manuscript, including grants (pending or received), employment, gifts, stock holdings or options, honoraria, consultancies, expert testimony, patents and royalties.   Type: Original Researc

A Baker\u27s Dozen of Top Antimicrobial Stewardship Intervention Publications in 2018

© The Author(s) 2019 Phytochemical investigation of methanolic extract of Limonium leptophyllum (Plumbaginaceae), led to the isolation of 1 new isoflavonoid with a rare 5-membered dihydrofuran ring (1, leptoisoflavone A) and 8 known compounds. The known isolated compounds were identified as euchrenone b9 (2), auriculasin (3), kaempferol (4), avicularoside (5), myrice-tin-3-arabinoside (6), trans-N-feruloyltyramine (7), trans-N-caffeoyltyramine (8), and β-sitosterol (9). The crude methanolic extract exhibited moderate activity toward endocannabinoid receptors. Auriculasin (3) showed activity toward cannabinoid receptor type 1 (86.7% displacement with IC50 8.92 μM)

Mitochondrial Calcium Transporters Mediate Sensitivity to Noise-Induced Losses of Hair Cells and Cochlear Synapses

Mitochondria modulate cellular calcium homeostasis by the combined action of the mitochondrial calcium uniporter (MCU), a selective calcium entry channel, and the sodium calcium exchanger (NCLX), which extrudes calcium from mitochondria. In this study, we investigated MCU and NCLX in noise-induced hearing loss (NIHL) using adult CBA/J mice and noise-induced alterations of inner hair cell (IHC) synapses in MCU knockout mice. Following noise exposure, immunoreactivity of MCU increased in cochlear sensory hair cells of the basal turn, while immunoreactivity of NCLX decreased in a time- and exposure-dependent manner. Inhibition of MCU activity via MCU siRNA pretreatment or the specific pharmacological inhibitor Ru360 attenuated noise-induced loss of sensory hair cells and synaptic ribbons, wave I amplitudes, and NIHL in CBA/J mice. This protection was afforded, at least in part, through reduced cleavage of caspase 9 (CC9). Furthermore, MCU knockout mice on a hybrid genetic CD1 and C57/B6 background showed resistance to noise-induced seizures compared to wild-type littermates. Owing to the CD1 background, MCU knockouts and littermates suffer genetic high frequency hearing loss, but their IHCs remain intact. Noise-induced loss of IHC synaptic connections and reduction of auditory brainstem response (ABR) wave I amplitude were recovered in MCU knockout mice. These results suggest that cellular calcium influx during noise exposure leads to mitochondrial calcium overload via MCU and NCLX. Mitochondrial calcium overload, in turn, initiates cell death pathways and subsequent loss of hair cells and synaptic connections, resulting in NIHL

A Baker\u27s Dozen of Top Antimicrobial Stewardship Intervention Publications in 2018

With an increasing number of antimicrobial stewardship-related articles published each year, attempting to stay current is challenging. The Southeastern Research Group Endeavor (SERGE-45) identified antimicrobial stewardship-related peer-reviewed literature that detailed an actionable intervention for 2018. The top 13 publications were selected using a modified Delphi technique. These manuscripts were reviewed to highlight the actionable intervention used by antimicrobial stewardship programs to provide key stewardship literature for teaching and training as well as to identify potential intervention opportunities within one\u27s institution

Ubiquitin-like protein 3 (UBL3) is required for MARCH ubiquitination of major histocompatibility complex class II and CD86

The MARCH E3 ubiquitin (Ub) ligase MARCH1 regulates trafficking of major histocompatibility complex class II (MHC II) and CD86, molecules of critical importance to immunity. Here we show, using a genome-wide CRISPR knockout screen, that ubiquitin-like protein 3 (UBL3) is a necessary component of ubiquitination-mediated trafficking of these molecules in mice and in humans. Ubl3-deficient mice have elevated MHC II and CD86 expression on the surface of professional and atypical antigen presenting cells. UBL3 also regulates MHC II and CD86 in human dendritic cells (DCs) and macrophages. UBL3 impacts ubiquitination of MARCH1 substrates, a mechanism that requires UBL3 plasma membrane anchoring via prenylation. Loss of UBL3 alters adaptive immunity with impaired development of thymic regulatory T cells, loss of conventional type 1 DCs, increased number of trogocytic marginal zone B cells, and defective in vivo MHC II and MHC I antigen presentation. In summary, we identify UBL3 as a conserved, critical factor in MARCH1-mediated ubiquitination with important roles in immune responses