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Biology subjects

Yu, A. C.

Publications and source records attributed to Yu, A. C..

4 recordsLinked to original sources

Early life stress modulates behavioral sensitivity to alcohol and promotes escalation of alcohol drinking

Adverse childhood experiences significantly increase the risk of developing alcohol use disorder (AUD) in adulthood. We used a model of combined limited bedding/nesting and maternal separation (LBN+MS) in C57BL/6J background mice to investigate how early life stress (ELS) modulates behavioral sensitivity to alcohol, long-term alcohol drinking patterns, and the effects of alcohol on social behaviors. Our findings reveal that ELS increased sensitivity to the stimulatory locomotor effects of alcohol (1.75 g/kg) selectively in females and reduced sensitivity to the sedative effects of alcohol (4.0 g/kg) particularly in males. This pattern of enhanced stimulation and diminished sedation is consistent with phenotypes observed in human subjects at high risk for developing AUD. ELS also significantly enhanced escalation of voluntary alcohol intake and preference over eight weeks of two-bottle choice intermittent access drinking particularly in males. Additionally, social behavior assessments revealed that ELS impaired sociability selectively in females with a history of alcohol drinking, highlighting the detrimental interactive effects of ELS and alcohol exposure on adaptive behaviors. These results underscore the complex interplay between ELS, alcohol responses, and sex differences, suggesting that ELS creates a high-risk phenotype for AUD through altered alcohol behavioral sensitivity. Our study highlights the importance of future studies that seek to identify the neurobiological mechanisms underlying these interactions, which may pave the way for targeted interventions in populations affected by childhood adversity and excessive alcohol consumption.

neuroscience↗

Sex-Specific Roles of Hypocretin Receptor Signaling in CRF Neurons on Alcohol Drinking, Anxiety, and BNST Neuronal Excitability

Alcohol use disorder (AUD) is characterized by compulsive alcohol consumption and negative emotional states during withdrawal, often perpetuating a cycle of addiction through arousal dysfunction. The hypocretin/orexin (Hcrt) neuropeptide system, a key regulator of arousal, has been implicated in these processes, particularly in its interactions with corticotropin-releasing factor (CRF) neurons within the bed nucleus of the stria terminalis (BNST). We investigated the role of Hcrt receptor signaling in CRF neurons in modulating alcohol intake, anxiety behaviors, and BNST excitability, with a focus on sex-specific differences. Using CRF-specific genetic deletion of HcrtR1 and/or HcrtR2 receptors in mice, we found that deletion of HcrtR1 significantly reduced alcohol intake, with sex-specific effects on BNST excitability. CRF-specific HcrtR2 deletion, while not affecting alcohol consumption, decreased baseline anxiety-like behaviors in males relative to females. Moreover, the double deletion of both Hcrt receptors from CRF neurons led to reduced alcohol drinking in males and dampened anxiety behaviors and BNST excitability in both sexes during protracted withdrawal. These findings suggest that Hcrt signaling in CRF neurons plays a critical role in the persistence of excessive alcohol consumption and the development of negative affective states, with distinct contributions from HcrtR1 and HcrtR2. The observed sex-specific differences underscore the need for tailored therapeutic approaches targeting the Hcrt system in the treatment of AUD.

neuroscience↗

Subcutaneous delivery of an antibody against SARS-CoV-2 from a supramolecular hydrogel depot

Prolonged maintenance of therapeutically-relevant levels of broadly neutralizing antibodies (bnAbs) is necessary to enable passive immunization against infectious disease. Unfortunately, protection only lasts for as long as these bnAbs remain present at a sufficiently high concentration in the body. Poor pharmacokinetics and burdensome administration are two challenges that need to be addressed in order to make pre- and post-exposure prophylaxis with bnAbs feasible and effective. In this work, we develop a supramolecular hydrogel as an injectable, subcutaneous depot to encapsulate and deliver antibody drug cargo. This polymer-nanoparticle (PNP) hydrogel exhibits shear-thinning and self-healing properties that are required for an injectable drug delivery vehicle. In vitro drug release assays and diffusion measurements indicate that the PNP hydrogels prevent burst release and slow the release of encapsulated antibodies. Delivery of bnAbs against SARS-CoV-2 from PNP hydrogels is compared to standard routes of administration in a preclinical mouse model. We develop a multi-compartment model to understand the ability of these subcutaneous depot materials to modulate the pharmacokinetics of released antibodies; the model is extrapolated to explore the requirements needed for novel materials to successfully deliver relevant antibody therapeutics with different pharmacokinetic characteristics.

bioengineering↗

Injectable hydrogels for sustained co-delivery of subunit vaccines enhance humoral immunity

Vaccines aim to elicit a robust, yet targeted, immune response. Failure of a vaccine to elicit such a response arises in part from inappropriate temporal control over antigen and adjuvant presentation to the immune system. In this work, we sought to exploit the immune systems natural response to extended pathogen exposure during infection by designing an easily administered slow-delivery vaccine platform. We utilized an injectable and self-healing polymer-nanoparticle (PNP) hydrogel platform to prolong the co-delivery of vaccine components to the immune system. We demonstrated that these hydrogels exhibit unique delivery characteristics whereby physicochemically distinct compounds (such as antigen and adjuvant) could be co-delivered over the course of weeks. When administered in mice, hydrogel-based sustained vaccine exposure enhanced the magnitude, duration, and quality of the humoral immune response compared to standard PBS bolus administration of the same model vaccine. We report that the creation of a local inflammatory niche within the hydrogel, coupled with sustained release of vaccine cargo, enhanced the magnitude and duration of germinal center responses in the lymph nodes. This strengthened germinal center response promoted greater antibody affinity maturation, resulting in a more than 1000-fold increase in antigen-specific antibody affinity in comparison to bolus immunization. In summary, this work introduces a simple and effective vaccine delivery platform that increases the potency and durability of subunit vaccines.

bioengineering↗