Gene therapy for CNS disorders: modalities, delivery and translational challenges.

Gene therapy is emerging as a powerful tool to modulate abnormal gene expression, a hallmark of most CNS disorders. The transformative potentials of recently approved gene therapies for the treatment of spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and active cerebral adrenoleukodystrophy are encouraging further development of this approach. However, most attempts to translate gene therapy to the clinic have failed to make it to market. There is an urgent need not only to tailor the genes that are targeted to the pathology of interest but to also address delivery challenges and thereby maximize the utility of genetic tools. In this Review, we provide an overview of gene therapy modalities for CNS diseases, emphasizing the interconnectedness of different delivery strategies and routes of administration. Important gaps in understanding that could accelerate the clinical translatability of CNS genetic interventions are addressed, and we present lessons learned from failed clinical trials that may guide the future development of gene therapies for the treatment and management of CNS disorders.

Bariatric surgery reveals a gut-restricted TGR5 agonist with anti-diabetic effects.

Bariatric surgery, the most effective treatment for obesity and type 2 diabetes, is associated with increased levels of the incretin hormone glucagon-like peptide-1 (GLP-1) and changes in levels of circulating bile acids. The levels of individual bile acids in the gastrointestinal (GI) tract after surgery have, however, remained largely unstudied. Using ultra-high performance liquid chromatography-mass spectrometry-based quantification, we observed an increase in an endogenous bile acid, cholic acid-7-sulfate (CA7S), in the GI tract of both mice and humans after sleeve gastrectomy. We show that CA7S is a Takeda G-protein receptor 5 (TGR5) agonist that increases Tgr5 expression and induces GLP-1 secretion. Furthermore, CA7S administration increases glucose tolerance in insulin-resistant mice in a TGR5-dependent manner. CA7S remains gut restricted, minimizing off-target effects previously observed for TGR5 agonists absorbed into the circulation. By studying changes in individual metabolites after surgery, the present study has revealed a naturally occurring TGR5 agonist that exerts systemic glucoregulatory effects while remaining confined to the gut.

Sleep disturbances and inflammatory gene expression among pregnant women: Differential responses by race.

Excessive inflammation in pregnancy predicts adverse birth outcomes, including shortened gestational length and lower birthweight, with African American women at greater risk. As substantial racial disparities in sleep quality, and evidence that African Americans have increased vulnerability for sleep-induced inflammatory dysregulation, sleep may be a critical, modifiable health behavior that contributes to racial disparities in birth outcomes. The present study examined sleep disturbance as a predictor of genome-wide transcriptome profiles of peripheral blood samples from 103 pregnant women (33 African American, 70 white) assessed at 18.7 ± 7.2 weeks gestation. We hypothesized that pregnant women with significant sleep disturbances would have gene expression profiles indicating over-expression of inflammatory pathways, with greater effects among African American compared to white women. Promoter-based bioinformatics analyses of differentially expressed genes indicated greater activation of NF-кB, AP1, and CREB transcription factors among African American women with sleep disturbances (all p < 0.05), and enhanced activation of AP1, but not NF-кB and reduced CREB activity among white women with sleep disturbances (p < 0.05). Differences in glucocorticoid receptor (GR) activity were also observed, in which African American women with sleep disturbances had reduced GR activity (p < 0.05), but white women with sleep disturbances showed a trend for enhanced GR activity (p = 0.11). Similarly, Interferon Response Factor (IRF) activity was reduced in African American women while increased in white women with sleep disturbances (p < 0.05). The current study provides novel evidence for gene expression related to inflammation, glucocorticoids, and anti-viral immunity among pregnant women with sleep disturbances, with differential effects by race. African Americans showed greater breadth and magnitude in these proinflammatory and anti-viral pathways than whites, with divergence in anti-inflammatory glucocorticoid, proinflammatory adrenergic-mediated cAMP, and anti-viral interferon responses. These data elucidate the role of sleep disturbances in intracellular inflammatory and anti-viral immunity in pregnancy and provide a potential target for intervention.

Ultra-Long-Term Delivery of Hydrophilic Drugs Using Injectable In Situ Cross-Linked Depots.

Achieving ultra-long-term release of hydrophilic drugs over several months remains a significant challenge for existing long-acting injectables (LAIs). Existing platforms, such as in situ forming implants (ISFI), exhibit high burst release due to solvent efflux and microsphere-based approaches lead to rapid drug diffusion due to significant water exchange and large pores. Addressing these challenges, we have developed an injectable platform that, for the first time, achieves ultra-long-term release of hydrophilic drugs for over six months. This system employs a methacrylated ultra-low molecular weight pre-polymer (polycaprolactone) to create in situ cross-linked depots (ISCD). The ISCD's solvent-free design and dense mesh network, both attributed to the ultra-low molecular weight of the pre-polymer, effectively minimizes burst release and water influx/efflux. In vivo studies in rats demonstrate that ISCD outperforms ISFI by achieving lower burst release and prolonged drug release. We demonstrated the versatility of ISCD by showcasing ultra-long-term delivery of several hydrophilic drugs, including antiretrovirals (tenofovir alafenamide, emtricitabine, abacavir, and lamivudine), antibiotics (vancomycin and amoxicillin) and an opioid antagonist naltrexone. Additionally, ISCD achieved ultra-long-term release of the hydrophobic drug tacrolimus and enabled co-delivery of hydrophilic drug combinations encapsulated in a single depot. We also identified design parameters to tailor the polymer network, tuning drug release kinetics and ISCD degradation. Pharmacokinetic modeling predicted over six months of drug release in humans, significantly surpassing the one-month standard achievable for hydrophilic drugs with existing LAIs. The platform's biodegradability, retrievability, and biocompatibility further underscore its potential for improving treatment adherence in chronic conditions.

A Mechanically Resilient Soft Hydrogel Improves Drug Delivery for Treating Post-Traumatic Osteoarthritis in Physically Active Joints.

Intra-articular delivery of disease-modifying osteoarthritis drugs (DMOADs) is likely to be most effective in early post-traumatic osteoarthritis (PTOA) when symptoms are minimal and patients are physically active. DMOAD delivery systems therefore must withstand repeated mechanical loading without affecting the drug release kinetics. Although soft materials are preferred for DMOAD delivery, mechanical loading can compromise their structural integrity and disrupt drug release. Here, we report a mechanically resilient soft hydrogel that rapidly self-heals under conditions resembling human running while maintaining sustained release of the cathepsin-K inhibitor L-006235 used as a proof-of-concept DMOAD. Notably, this hydrogel outperformed a previously reported hydrogel designed for intra-articular drug delivery, used as a control in our study, which neither recovered nor maintained drug release under mechanical loading. Upon injection into mouse knee joints, the hydrogel showed consistent release kinetics of the encapsulated agent in both treadmill-running and non-running mice. In a mouse model of aggressive PTOA exacerbated by treadmill running, L-006235 hydrogel markedly reduced cartilage degeneration. To our knowledge, this is the first hydrogel proven to withstand human running conditions and enable sustained DMOAD delivery in physically active joints, and the first study demonstrating reduced disease progression in a severe PTOA model under rigorous physical activity, highlighting the hydrogel's potential for PTOA treatment in active patients.

Transforming Hypertension Diagnosis and Management in The Era of Artificial Intelligence: A 2023 National Heart, Lung, and Blood Institute (NHLBI) Workshop Report.

Hypertension is among the most important risk factors for cardiovascular disease, chronic kidney disease, and dementia. The artificial intelligence (AI) field is advancing quickly, and there has been little discussion on how AI could be leveraged for improving the diagnosis and management of hypertension. AI technologies, including machine learning tools, could alter the way we diagnose and manage hypertension, with potential impacts for improving individual and population health. The development of successful AI tools in public health and health care systems requires diverse types of expertise with collaborative relationships between clinicians, engineers, and data scientists. Unbiased data sources, management, and analyses remain a foundational challenge. From a diagnostic standpoint, machine learning tools may improve the measurement of blood pressure and be useful in the prediction of incident hypertension. To advance the management of hypertension, machine learning tools may be useful to find personalized treatments for patients using analytics to predict response to antihypertension medications and the risk for hypertension-related complications. However, there are real-world implementation challenges to using AI tools in hypertension. Herein, we summarize key findings from a diverse group of stakeholders who participated in a workshop held by the National Heart, Lung, and Blood Institute in March 2023. Workshop participants presented information on communication gaps between clinical medicine, data science, and engineering in health care; novel approaches to estimating BP, hypertension risk, and BP control; and real-world implementation challenges and issues.

Toward a Radically Simple Multi-Modal Nasal Spray for Preventing Respiratory Infections.

Nasal sprays for pre-exposure prophylaxis against respiratory infections show limited protection (20-70%), largely due to their single mechanism of action-either neutralizing pathogens or blocking their entry at the nasal lining, and a failure to maximize the capture of respiratory droplets, allowing them to potentially rebound and reach deeper airways. This report introduces the Pathogen Capture and Neutralizing Spray (PCANS), which utilizes a multi-modal approach to enhance efficacy. PCANS coats the nasal cavity, capturing large respiratory droplets from the air, and serving as a physical barrier against a broad spectrum of viruses and bacteria, while rapidly neutralizing them with over 99.99% effectiveness. The formulation consists of excipients identified from the FDA's Inactive Ingredient Database and Generally Recognized as Safe list to maximize efficacy for each step in the multi-modal approach. PCANS demonstrates nasal retention for up to 8 hours in mice. In a severe Influenza A mouse model, a single pre-exposure dose of PCANS leads to a >99.99% reduction in lung viral titer and ensures 100% survival, compared to 0% in the control group. PCANS suppresses pathological manifestations and offers protection for at least 4 hours. This data suggest PCANS as a promising daily-use prophylactic against respiratory infections.

Reliability of the NACC Telephone-administered Neuropsychological Battery (T-cog) and Montreal Cognitive Assessment for participants in the USC ADRC.

Introduction: Restrictions during the COVID-19 pandemic necessitated remote administration of neuropsychological testing. We assessed the test-retest reliability for a telephone-administered cognitive battery, recommended for use in the National Institute on Aging Alzheimer's Disease Research Center (ADRC). Methods: 64 participants in the University of Southern California ADRC clinical core underwent repeat telephone evaluation using the T-cog Neuropsychological Battery. Reliability was measured by intraclass correlation coefficient (ICC) for continuous variables and weighted Kappa coefficient for categorical variables. Mean scores for Montreal Cognitive Assessment (MoCA) total and Craft Story 21 Immediate and Delayed Recall were compared using paired t tests. Results: Mean age was 74.8 (8.3 standard deviation); 73.4% were female. ICCs ranged from 0.52 to 0.84, indicating moderate test-retest reliability except for number span backward, which showed poor reliability. Weighted Kappa for MoCA items ranged from -0.016 to 0.734; however, relatively good observed agreement was seen across all items (70.3% to 98.4%). Although MoCA total scores did not significantly change, Craft Story 21 Immediate and Delayed Recall mean scores increased between first and second administrations (P < 0.0001). Discussion: Test-retest reliability for the T-cog Neuropsychological Battery is adequate. The variation seen in testing is similar to results seen from face-to-face testing, with Craft Story 21 recall showing modest and expected practice effects. Highlights: Moderate test-retest reliability is seen in most measures of the National Alzheimer's Coordinating Center Neuropsychological Test Battery and the Montreal Cognitive Assessment (MoCA).Intraclass correlation coefficients ranged from 0.52 to 0.84, except for number Span backward.Weighted Kappa for MoCA items varied, but good observed agreement was seen.MoCA total mean score did not change significantly between administrations.Craft Story 21 Immediate and Delayed Recall means increased on repeat testing (P < 0.0001).

Progress in non-viral localized delivery of siRNA therapeutics for pulmonary diseases.

Emerging therapies based on localized delivery of siRNA to lungs have opened up exciting possibilities for treatment of different lung diseases. Localized delivery of siRNA to lungs has shown to result in severalfold higher lung accumulation than systemic route, while minimizing non-specific distribution in other organs. However, to date, only 2 clinical trials have explored localized delivery of siRNA for pulmonary diseases. Here we systematically reviewed recent advances in the field of pulmonary delivery of siRNA using non-viral approaches. We firstly introduce the routes of local administration and analyze the anatomical and physiological barriers towards effective local delivery of siRNA in lungs. We then discuss current progress in pulmonary delivery of siRNA for respiratory tract infections, chronic obstructive pulmonary diseases, acute lung injury, and lung cancer, list outstanding questions, and highlight directions for future research. We expect this review to provide a comprehensive understanding of current advances in pulmonary delivery of siRNA.

Overcoming barriers for intra-articular delivery of disease-modifying osteoarthritis drugs.

Despite four decades of research in intra-articular drug delivery systems (DDS) and two decades of advances in disease-modifying osteoarthritis drugs (DMOADs), there is still no clinically available disease-modifying therapy for osteoarthritis (OA). Multiple barriers compromise intra-articular DMOAD delivery. Although multiple exciting approaches have been developed to overcome these barriers, there are still outstanding questions. We make several recommendations that can help in fully overcoming these barriers. Considering OA heterogeneity, we also propose a patient-centered, bottom-up workflow to guide preclinical development of DDS-based intra-articular DMOAD therapies. Overall, we expect this review to inspire paradigm-shifting innovations for developing next-generation DDS that can enable clinical translation of intra-articular DMOADs.

Role of bioaerosol in virus transmission and material-based countermeasures.

Respiratory pathogens transmit primarily through particles such as droplets and aerosols. Although often overlooked, the resuspension of settled droplets is also a key facilitator of disease transmission. In this review, we discuss the three main mechanisms of aerosol generation: direct generation such as coughing and sneezing, indirect generation such as medical procedures, and resuspension of settled droplets and aerosols. The size of particles and environmental factors influence their airborne lifetime and ability to cause infection. Specifically, humidity and temperature are key factors controlling the evaporation of suspended droplets, consequently affecting the duration in which particles remain airborne. We also suggest material-based approaches for effective prevention of disease transmission. These approaches include electrostatically charged virucidal agents and surface coatings, which have been shown to be highly effective in deactivating and reducing resuspension of pathogen-laden aerosols.

Physiologic Mechanisms of Weight Loss Following Metabolic/Bariatric Surgery.

Bariatric and metabolic surgery has evolved from simple experimental procedures for a chronic problem associated with significant morbidity into a sophisticated multidisciplinary treatment modality rooted in biology and physiology. Although the complete mechanistic narrative of bariatric surgery cannot yet be written, significant advance in knowledge has been made in the past 2 decades. This article provides a brief overview of the most studied hypotheses and their supporting evidence. Ongoing research, especially in frontier areas, such as the microbiome, will continue to refine, and perhaps even revise, current mechanistic understanding.

Progress and Research Priorities in Imaging Genomics for Heart and Lung Disease: Summary of an NHLBI Workshop.

Imaging genomics is a rapidly evolving field that combines state-of-the-art bioimaging with genomic information to resolve phenotypic heterogeneity associated with genomic variation, improve risk prediction, discover prevention approaches, and enable precision diagnosis and treatment. Contemporary bioimaging methods provide exceptional resolution generating discrete and quantitative high-dimensional phenotypes for genomics investigation. Despite substantial progress in combining high-dimensional bioimaging and genomic data, methods for imaging genomics are evolving. Recognizing the potential impact of imaging genomics on the study of heart and lung disease, the National Heart, Lung, and Blood Institute convened a workshop to review cutting-edge approaches and methodologies in imaging genomics studies, and to establish research priorities for future investigation. This report summarizes the presentations and discussions at the workshop. In particular, we highlight the need for increased availability of imaging genomics data in diverse populations, dedicated focus on less common conditions, and centralization of efforts around specific disease areas.

A microbial metabolite remodels the gut-liver axis following bariatric surgery.

Bariatric surgery is the most effective treatment for type 2 diabetes and is associated with changes in gut metabolites. Previous work uncovered a gut-restricted TGR5 agonist with anti-diabetic properties-cholic acid-7-sulfate (CA7S)-that is elevated following sleeve gastrectomy (SG). Here, we elucidate a microbiome-dependent pathway by which SG increases CA7S production. We show that a microbial metabolite, lithocholic acid (LCA), is increased in murine portal veins post-SG and by activating the vitamin D receptor, induces hepatic mSult2A1/hSULT2A expression to drive CA7S production. An SG-induced shift in the microbiome increases gut expression of the bile acid transporters Asbt and Ostα, which in turn facilitate selective transport of LCA across the gut epithelium. Cecal microbiota transplant from SG animals is sufficient to recreate the pathway in germ-free (GF) animals. Activation of this gut-liver pathway leads to CA7S synthesis and GLP-1 secretion, causally connecting a microbial metabolite with the improvement of diabetic phenotypes.

Involvement of the Commensal Organism Bacillus subtilis in the Pathogenesis of Anastomotic Leak.

Background: It is now well established that microbes play a key and causative role in the pathogenesis of anastomotic leak. Yet, in patients, determining whether a cultured pathogen retrieved from an anastomotic leak site is a cause or a consequence of the complication remains a challenge. The aim of this study was to test a methodology to invoke causality between a retrieved microbe from a leak site and its role in anastomotic leak. Methods: The commensal organism Bacillus subtilis was isolated from an esophagojejunostomy leak site in a 35-year-old patient with a CDH1 mutation after a prophylactic gastrectomy whose body mass index (BMI) was 35 kg/m2. The organism was screened for its ability to degrade collagen, shift human recombinant matrix metalloprotease-9 (MMP9) to its active form, and induce a clinical anastomotic leak when introduced to anastomotic tissues of mice fed their standard diet (SD) of chow or an obesogenic Western-type diet (WD). Results: The Bacillus subtilis strain retrieved from the anastomotic leak site displayed a high degree of collagenolytic activity and was able to activate human MMP9 consistent with other pathogens expressing this characteristic "leak phenotype." Exposure of the Bacillus subtilis to the anastomotic tissues of obese mice fed a WD led to dehiscence of the anastomosis, abscess formation with peritonitis, and mortality in 50% of mice (3/6). When anastomotic healing was evaluated by a validated anastomotic healing score (AHS), substantially worse healing was observed (i.e., higher AHS) in WD-fed mice exposed to Bacillus subtilis compared to SD-fed mice (analysis of variance [ANOVA], p = 0.0006). Conclusions: Microbial strains obtained from patients' anastomotic leak sites can be evaluated for their pathogenic in the leak process by assessing their ability to produce collagenase, activate MMP9 and cause clinical leaks in mice fed a WD. These studies may aid in identifying those bacterial strains that play a causal role in patients with an anastomotic leak.

The Influence of Host Stress on the Mechanism of Infection: Lost Microbiomes, Emergent Pathobiomes, and the Role of Interkingdom Signaling.

Mammals constantly face stressful situations, be it extended periods of starvation, sleep deprivation from fear of predation, changing environmental conditions, or loss of habitat. Today, mammals are increasingly exposed to xenobiotics such as pesticides, pollutants, and antibiotics. Crowding conditions such as those created for the purposes of meat production from animals or those imposed upon humans living in urban environments or during world travel create new levels of physiologic stress. As such, human progress has led to an unprecedented exposure of both animals and humans to accidental pathogens (i.e., those that have not co-evolved with their hosts). Strikingly missing in models of infection pathogenesis are the various elements of these conditions, in particular host physiologic stress. The compensatory factors released in the gut during host stress have profound and direct effects on the metabolism and virulence of the colonizing microbiota and the emerging pathobiota. Here, we address unanswered questions to highlight the relevance and importance of incorporating host stress to the field of microbial pathogenesis.

Optimum Operating Room Environment for the Prevention of Surgical Site Infections.

BACKGROUND: Surgical site infections (SSI), whether they be incisional or deep, can entail major morbidity and death to patients and additional cost to the healthcare system. A significant amount of effort has gone into optimizing the surgical patient and the operating room environment to reduce SSI. METHODS: Relevant guidelines and literature were reviewed. RESULTS: The modern practice of surgical antisepsis involves the employment of strict sterile techniques inside the operating room. Extensive guidelines are available regarding the proper operating room antisepsis as well as pre-operative preparation. The use of pre-operative antimicrobial prophylaxis has become increasingly prevalent, which also presents the challenge of opportunistic and nosocomial infections. Ongoing investigative efforts have brought about a greater appreciation of the surgical patient's endogenous microflora, use of non-bactericidal small molecules, and pre-operative microbial screening. CONCLUSIONS: Systematic protocols exist for optimizing the surgical sterility of the operating room to prevent SSIs. Ongoing research efforts aim to improve the precision of peri-operative antisepsis measures and personalize these measures to tailor the patient's unique microbial environment.

Morphine Promotes Colonization of Anastomotic Tissues with Collagenase - Producing Enterococcus faecalis and Causes Leak.

BACKGROUND: Despite ever more powerful antibiotics, newer surgical techniques, and enhanced recovery programs, anastomotic leaks remain a clear and present danger to patients. Previous work from our laboratory suggests that anastomotic leakage may be caused by Enterococcus faecalis strains that express a high collagenase phenotype (i.e., collagenolytic). Yet the mechanisms by which the practice of surgery shifts or selects for collagenolytic phenotypes to colonize anastomotic tissues remain unknown. METHODS: Here, we hypothesized that morphine, an analgesic agent universally used in gastrointestinal surgery, promotes tissue colonization with collagenolytic E. faecalis and causes anastomotic leak. To test this, rats were administered morphine in a chronic release form as would occur during routine surgery or vehicle. Rats were observed for 6 days and then underwent exploratory laparotomy for anastomotic inspection and tissue harvest for microbial analysis. These results provide further rationale to enhanced recovery after surgery (i.e., ERAS) programs that suggest limiting or avoiding the use of opioids in gastrointestinal surgery. RESULTS: Results demonstrated that compared to placebo-treated rats, morphine-treated rats demonstrated markedly impaired anastomotic healing and gross leaks that correlated with the presence of high collagenase-producing E. faecalis adherent to anastomotic tissues. To determine the direct role of morphine on this response, various isolates of E. faecalis from the rats were exposed to morphine and their collagenase activity and adherence capacity determined in vitro. Morphine increased both the adhesiveness and collagenase production of four strains of E. faecalis harvested from anastomotic tissues, two that were low collagenase producers at baseline, and two that were high collagenase producers at baseline. CONCLUSION: These results provide further rationale to enhanced recovery after surgery (i.e., ERAS) programs that suggest limiting or avoiding the use of opioids in gastrointestinal surgery.