Biology subjects

Corona, A.

Publications and source records attributed to Corona, A..

7 recordsLinked to original sources

bioRxiv2024

KLHDC7B, a novel gene associated with age-related hearing loss in humans, is required for the maintenance of hearing in mice.

BackgroundAge-related hearing loss (ARHL) is the most common sensory loss in older adults, but the underlying pathological mechanisms remain unclear. Recent genome wide association studies (GWAS) have linked variation in a large number of genes with increased risk of ARHL for the first time. Amongst the strongest of these associations is variation in KLHDC7B, a gene of unknown function and one not previously linked to hearing. MethodsTo confirm whether KLHDC7B plays a role in hearing we investigated auditory function in two independent knockout mutant mouse models of Klhdc7b: Klhdc7bIMPC-/-and Klhdc7bRegn{Delta}/{Delta} on the C57BL/6N background and the B6.CAST-Cdh23753A>G background respectively. The B6.CAST-Cdh23753A>G background was backcrossed to correct a known age-related hearing loss (ahl) mutation in cadherin 23 present in both the C57BL/6N and C57BL/6J strains. ResultsWe showed that Klhdc7b is expressed exclusively in inner and outer sensory hair cells within the cochlea of mice at the RNA and protein level. Homozygous mutants for both knockout mouse models display a similar early-onset, progressive and severe hearing loss. Histological characterization of the two mouse models suggests that hair cells develop normally and are present in neonates. However, after the onset of hearing there is a progressive loss of outer hair cells in a gradient from base to apex of the cochlea consistent with the hearing deficit in the mice and the pattern of hearing loss in ARHL. Inner hair cells remain intact up to the latest age examined (~8 weeks). ConclusionsOur data suggests KLHDC7B is required for maintenance of auditory function rather than in its development, supporting the novel association with ARHL in humans detected in recent GWAS. To our knowledge, this is the first validation in mouse of an ARHL association in humans detected in a GWAS. Our work also provides two distinct mouse models to further investigate the role of KLHDC7B in auditory function and for use in the development of therapeutic tools to prevent or treat ARHL.

genetics↗

bioRxiv2023

Molecular Jackhammers Eradicate Cancer Cells by Vibronic-Driven Action

Through the actuation of vibronic modes in cell-membrane-associated aminocyanines, a new type of molecular mechanical action can be exploited to rapidly kill cells by necrosis. This is done using near-infrared light, a low energy source hitherto thought to be insufficient to permit molecular mechanical disruption of a cell membrane. Vibronic-driven action (VDA) is distinct from both photodynamic therapy and photothermal therapy in that the VDA mechanical effect on the cell membrane is not retarded by high doses of inhibitors of reactive oxygen species (ROS), and VDA does not itself induce an increase in the temperature of the media; it is also unaffected by cooling the media to 2 {degrees}C. The picosecond concerted whole-molecule-vibrations of VDA-induced mechanical disruption can be done with very low concentrations (500 nM) of the aminocyanines or low doses of light (12 Jcm-2, 80 mWcm-2 for 2.5 min) to cause in vitro necrotic cell death in >99% of human melanoma cells. The effect is also studied in vivo in murine B16-F10 and human A375 melanoma in mice, underscoring the high efficiency of this approach, achieving a survival rate of 60% at day 120, and 50% of the mice becoming tumor free. The molecules that destroy cell membranes through VDA are termed molecular jackhammers (MJH) because they undergo concerted whole-molecule vibrations. Different than traditional chemotherapy, it is unlikely that a cell could develop a resistance to molecular mechanical forces, thereby providing a new modality for inducing cancer cell death.

bioengineering↗

bioRxiv2022

A circuit from the locus coeruleus to the anterior cingulate cortex modulates offspring interactions in mice

Social sensitivity to other individuals in distress is crucial for survival. The anterior cingulate cortex (ACC) is a structure involved in making behavioral choices and is influenced by observed pain or distress. Nevertheless, our understanding of the neural circuitry underlying this sensitivity is incomplete. Here, we reveal unexpected sex-dependent activation of ACC when parental mice respond to distressed pups by returning them to the nest ( pup retrieval). We observe sex differences in the interactions between excitatory and inhibitory ACC neurons during parental care, and inactivation of ACC excitatory neurons increased pup neglect. Locus coeruleus (LC) releases noradrenaline in ACC during pup retrieval, and inactivation of the LC-ACC pathway disrupts parental care. We conclude that ACC maintains sex-dependent sensitivity to pup distress under LC modulation. We propose that ACCs involvement in parenting presents an opportunity to identify neural circuits that support sensitivity to the emotional distress of others.

neuroscience↗

bioRxiv2022

A reinforcement learning algorithm shapes maternal care in mice

The neural substrates for processing classical rewards such as food or drugs of abuse are well-understood. In contrast, the mechanisms by which organisms perceive social contact as rewarding and subsequently modify their interactions are unclear. Here we tracked the gradual emergence of a repetitive and highly-stereotyped parental behavior and show that trial-by-trial performance correlates with the history of midbrain dopamine (DA) neuron activity. We used a novel behavior paradigm to manipulate the subjects expectation of imminent pup contact and show that DA signals conform to reward prediction error, a fundamental component of reinforcement learning (RL). Finally, closed-loop optogenetic inactivation of DA neurons at the onset of pup contact dramatically slowed emergence of parental care. We conclude that this prosocial behavior is shaped by an RL mechanism in which social contact itself is the primary reward. One-Sentence SummaryMaternal interactions with offspring are shaped by a dopaminergic reinforcement learning mechanism.

neuroscience↗

bioRxiv2021

Neurotensin neurons in the central extended amygdala control energy balance

Overeating and a sedentary life style are major causes of obesity and related metabolic disorders. Identification of the neurobiological processes that regulate energy balance will facilitate development of interventions for these disorders. Here we show that the Neurotensin-expressing neurons in the mouse IPAC (IPACNts), a nucleus of the central extended amygdala, bidirectionally coordinate hedonic feeding and physical activity, thereby regulating energy balance, metabolic processes and bodyweight. IPACNts are preferentially activated by consumption of highly palatable food or exposure to its taste and smell. Activating IPACNts promotes food intake in a palatability-dependent manner and decreases locomotion. Conversely, inhibiting IPACNts selectively reduces palatable food intake and dramatically enhances physical activity and energy expenditure, and in parallel stimulates physiological responses that oppose diet-induced obesity and metabolic dysfunctions. Thus, a single neuronal population, Neurotensin-expressing neurons in the IPAC, acts to control obesogenic and leptogenic processes by synergistically coordinating energy intake and expenditure with metabolism.

neuroscience↗

bioRxiv2020

Identification of inhibitors of SARS-CoV-2 3CL-Pro enzymatic activity using a small molecule in-vitro repurposing screen

Compound repurposing is an important strategy for the identification of effective treatment options against SARS-CoV-2 infection and COVID-19 disease. In this regard, SARS-CoV-2 main protease (3CL-Pro), also termed M-Pro, is an attractive drug target as it plays a central role in viral replication by processing the viral polyproteins pp1a and pp1ab at multiple distinct cleavage sites. We here report the results of a repurposing program involving 8.7 K compounds containing marketed drugs, clinical and preclinical candidates, and small molecules regarded as safe in humans. We confirmed previously reported inhibitors of 3CL-Pro, and have identified 62 additional compounds with IC50 values below 1 M and profiled their selectivity towards Chymotrypsin and 3CL-Pro from the MERS virus. A subset of 8 inhibitors showed anti-cytopathic effect in a Vero-E6 cell line and the compounds thioguanosine and MG-132 were analysed for their predicted binding characteristics to SARS-CoV-2 3CL-Pro. The X-ray crystal structure of the complex of myricetin and SARS-Cov-2 3CL-Pro was solved at a resolution of 1.77 [A], showing that myricetin is covalently bound to the catalytic Cys145 and therefore inhibiting its enzymatic activity. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=154 SRC="FIGDIR/small/422677v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@17ca2aeorg.highwire.dtl.DTLVardef@19c5159org.highwire.dtl.DTLVardef@1a0adf6org.highwire.dtl.DTLVardef@1fd05cd_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOAbstract Figure.C_FLOATNO Workflow for identification and profiling of inhibitors of SARS-CoV-2 3CL-Pro using a large scale repurposing and bioactive compound collection (rhs). Primary assay principle based on quenched FRET peptide substrate of SARS-CoV-2 3CL-Pro (lhs). Inhibiting compounds reduce fluorescence signal relative to DMSO controls. Hit profiling using X-ray. C_FIG

molecular biology↗

bioRxiv2019

Mutation of Ebola virus VP35 Ser129 uncouples interferon antagonist and replication functions

Ebolaviruses are non-segmented, negative-sense RNA viruses (NNSVs) within the order Mononegavirales that possess the multifunctional virion protein 35 (VP35), a major determinant of virulence and pathogenesis that is indispensable for viral replication and host innate immune evasion. VP35 is functionally equivalent to the phosphoprotein (P) of other mononegaviruses such as rhabdoviruses and paramyxoviruses. Phosphorylation of the P protein is universally regarded as functionally important however, a regulatory role(s) of phosphorylation on VP35 function remains unexplored. Here, we identified a highly conserved Ser129 residue near the homo-oligomerization coiled coil motif, which is essential for VP35 functions. Affinity-purification MS followed by post-translational modification (PTM) analysis predicted phosphorylation of Ser129. Co-immunoprecipitation, cross-linking, and biochemical characterization studies revealed a moderately decreased capacity of VP35-S129A to oligomerize. Functional analysis showed that Ser-to-Ala substitution of Ebola virus (EBOV) VP35 did not affect IFN inhibitory activity but nearly abolished EBOV minigenome activity. Further coimmunoprecipitation studies demonstrated a lost interaction between VP35-S129A and the amino terminus of the viral polymerase but not between viral nucleoprotein (NP) or VP35-WT. Taken together, our findings provide evidence that phosphorylation modulates VP35 function, supporting VP35 as a NNSV P protein and providing a potentially valuable therapeutic target.\n\nImportanceEbola virus (EBOV) can cause severe disease in humans. The 2013-2016 West African epidemic and the two recent outbreaks in the Democratic Republic of the Congo underscore the urgent need for effective countermeasures, which remain lacking. A better understanding of EBOV biology and the modulation of multifunctional viral proteins is desperately needed to develop improved therapeutics. We provide evidence here that function of virion protein 35 (VP35) is modulated by phosphorylation of Ser129, a conserved residue among other ebolavirus species. These findings shed light on EBOV biology and present a potential target for broad acting anti-ebolavirus therapeutics.

microbiology↗