Hepatic signal transducer and activator of transcription-3 signalling drives early-stage pancreatic cancer cachexia via suppressed ketogenesis.

BACKGROUND: Patients with pancreatic ductal adenocarcinoma (PDAC) often suffer from cachexia, a wasting syndrome that significantly reduces both quality of life and survival. Although advanced cachexia is associated with inflammatory signalling and elevated muscle catabolism, the early events driving wasting are poorly defined. During periods of nutritional scarcity, the body relies on hepatic ketogenesis to generate ketone bodies, and lipid metabolism via ketogenesis is thought to protect muscle from catabolizing during nutritional scarcity. METHODS: We developed an orthotopic mouse model of early PDAC cachexia in 12-week-old C57BL/6J mice. Murine pancreatic cancer cells (KPC) were orthotopically implanted into the pancreas of wild-type, IL-6-/-, and hepatocyte STAT3-/- male and female mice. Mice were subject to fasting, 50% food restriction, ad libitum feeding or ketogenic diet interventions. We measured longitudinal body composition by EchoMRI, body mass and food intake. At the endpoint, we measured tissue mass, tissue gene expression by quantitative real-time polymerase chain reaction, whole-body calorimetry, circulating hormone levels, faecal protein and lipid content, hepatic lipid content and ketogenic response to medium-chain fatty acid bolus. We assessed muscle atrophy in vivo and C2C12 myotube atrophy in vitro. RESULTS: Pre-cachectic PDAC mice did not preserve gastrocnemius muscle mass during 3-day food restriction (-13.1 ± 7.7% relative to food-restricted sham, P = 0.0117) and displayed impaired fatty acid oxidation during fasting, resulting in a hypoketotic state (ketogenic response to octanoate bolus, -83.0 ± 17.3%, P = 0.0328; Hmgcs2 expression, -28.3 ± 7.6%, P = 0.0004). PDAC human patients display impaired fasting ketones (-46.9 ± 7.1%, P < 0.0001) and elevated circulating interleukin-6 (IL-6) (12.4 ± 16.5-fold increase, P = 0.0001). IL-6-/- PDAC mice had improved muscle mass (+35.0 ± 3.9%, P = 0.0031) and ketogenic response (+129.4 ± 44.4%, P = 0.0033) relative to wild-type PDAC mice. Hepatocyte-specific signal transducer and activator of transcription 3 (STAT3) deletion prevented muscle loss (+9.3 ± 4.0%, P = 0.009) and improved fasting ketone levels (+52.0 ± 43.3%, P = 0.018) in PDAC mice. Without affecting tumour growth, a carbohydrate-free diet improved tibialis anterior myofibre diameter (+16.5 ± 3.5%, P = 0.0089), circulating ketone bodies (+333.0 ± 117.6%, P < 0.0001) and Hmgcs2 expression (+106.5 ± 36.1%, P < 0.0001) in PDAC mice. Ketone supplementation protected muscle against PDAC-induced atrophy in vitro (+111.0 ± 17.6%, P < 0.0001 myofibre diameter). CONCLUSIONS: In early PDAC cachexia, muscle vulnerability to wasting is dependent on inflammation-driven metabolic reprogramming in the liver. PDAC suppresses lipid ß-oxidation and impairs ketogenesis in the liver, which is reversed in genetically modified mouse models deficient in IL-6/STAT3 signalling or through ketogenic diet supplementation. This work establishes a direct link between skeletal muscle homeostasis and hepatic metabolism. Dietary and anti-inflammatory interventions that restore ketogenesis may be a viable preventative approach for pre-cachectic patients with pancreatic cancer.

School screening programs to identify hypertension in Hispanic youth.

Elevated blood pressure during childhood can lead to hypertension in adulthood and is associated with an increased risk of future cardiovascular disease with early identification as the best option for prevention. This study examines the prevalence of hypertension in Hispanic and White youths and reports the ability of a school-based program to identify hypertension in school-aged children. Approximately 3.5 % of students had hypertension while 7.5 % of students had elevated blood pressure. Elevated body mass index (BMI) was the most common predictor of hypertension in all three grade levels (elementary: 5th grade, middle: 7th grade, and high school: 10th grade). In the elementary school age group, the significant predictors of hypertension were an elevated BMI, sex, and height. In the middle school age group, the factors that were significant predictors of hypertension included ethnicity, an elevated BMI, and height. In high school age students, the only significant predictor of hypertension was elevated BMI; ethnicity alone was not a significant predictor. The only group that ethnicity was a significant predictor of hypertension was the middle school age. Given that at all three grade levels, the Hispanic students had a higher percentage with elevated BMIs compared to White students, they should be considered at higher risk of hypertension.

Minimally invasive, surgical, and transcatheter aortic valve replacement: A network meta-analysis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has evolved as an alternative to surgical aortic valve replacement (SAVR). In addition to full-sternotomy (FS), recent reports have shown successful minimally-invasive SAVR approaches, including mini-sternotomy (MS) and mini-thoracotomy (MT). This network-meta-analysis (NMA) seeks to provide an outcomes comparison based on these different modalities (MS, MT, TAVR) compared with FS as a reference arm for the management of aortic valve disease. METHODS: A comprehensive literature search was performed to identify studies that compared minimally-invasive SAVR (MS/MT) to conventional FS-SAVR, and/or TAVR. Bayesian NMA was performed using the random effects model. Outcomes were pooled as risk ratios (RR) with their 95 % confidence intervals (CIs). Our primary outcomes included 30-day mortality, stroke, acute kidney injury (AKI), major bleeding, new permanent pacemaker (PPM), and paravalvular leak (PVL). We also assessed long-term mortality at the latest follow-up. RESULTS: A total of 27,117 patients (56 studies) were included; 10,397 patients had FS SAVR, 9523 had MS, 5487 had MT, and 1710 had TAVR. Compared to FS, MS was associated with statistically-significantly lower rates of 30-day mortality (RR, 0.76, 95%CI 0.59-0.98), stroke (RR, 0.84, 95%CI 0.72-0.97), AKI (RR, 0.76, 95%CI 0.61-0.94), and long-term mortality (RR 0.84, 95%CI 0.72-0.97) at a weighted mean follow-up duration of 10.4 years, while MT showed statistically-significantly higher rates of 30-day PVL (RR, 3.76, 95%CI 1.31-10.85) and major bleeding (RR 1.45; 95%CI 1.08-1.94). TAVR had statistically significant lower rates of 30-day AKI (RR 0.49, 95%CI 0.31-0.77), but showed statistically-significantly higher PPM (RR 2.50; 95%CI 1.60-3.91) and 30-day PVL (RR 12.85, 95%CI 5.05-32.68) compared to FS. CONCLUSIONS: MS was protective against 30-day mortality, stroke, AKI, and long-term mortality compared to FS; TAVR showed higher rates of 30-day PVL and PPM but was protective against AKI. Conversely, MT showed higher rates of 30-day PVL and major bleeding. With the emergence of TAVR, the appropriate benchmarks for SAVR comparison in future trials should be the minimally-invasive SAVR approaches to provide clinical equipoise.

Evolving Concept of Aortic Valve Replacement in Asymptomatic Patients With Severe Aortic Stenosis.

BACKGROUND: Surgical treatment of asymptomatic severe aortic stenosis (AS) has been gaining attention ever since the results of the Early Surgery Versus Conventional Treatment in Very Severe Aortic Stenosis (RECOVERY) and Aortic Valve replacement versus conservative treatment in Asymptomatic seveRe aortic stenosis (AVATAR) trials showed survival benefits with early surgical aortic valve replacement (SAVR). This study analyzed the long-term clinical and echocardiographic outcomes of SAVR in asymptomatic severe AS. METHODS: Between 2002 and 2020, 272 patients with asymptomatic severe AS and a left ventricular ejection fraction ≥50% underwent SAVR with or without concomitant aortic surgery and met the study criteria. The median follow-up was 8.5 years (interquartile range, 6-12.8 years), for a total of 2584 patient-years. The time course of the left ventricular mass index (LVMI) and the average E/E' (ratio of the Doppler-derived E wave to the tissue Doppler-derived E' wave) were assessed using 594 postoperative echocardiograms. The association of preoperative LVMI and average E/E' with survival was assessed using Cox proportional hazards. RESULTS: There was no operative mortality. On longitudinal analyses, LVMI improved in patients who presented with moderate or severe preoperative left ventricular hypertrophy (LVH). However, after the early decline in average E/E', there was a late increase to greater than upper limit normal, particularly in patients with a preoperative average E/E'≥14. Postoperative survival was 100%, 94%, 84%, and 76% at 1, 5, 10, and 15 years, respectively, comparable to age- and sex-matched expected survival on the basis of the US general population. On adjusted Cox survival analysis, only moderate to severe LVH was associated with a survival penalty (hazard ratio], 2.32; 95% CI, 1.02-5.27; P = .045). CONCLUSIONS: In asymptomatic patients with AS, SAVR restores survival and improves LVH, but patients with diastolic dysfunction are left with persistent dysfunction. Presentation with moderate or severe LVH at the time of surgery translated to a survival penalty. This observational study supports early SAVR in this population before development of LVH, although further investigation is needed.

Incidence, characteristics, and outcomes of reintervention after mitral transcatheter edge-to-edge repair.

OBJECTIVE: The use of transcatheter edge-to-edge repair (TEER) is growing substantially, and reintervention after TEER by way of repeat TEER or mitral valve surgery (MVS) is increasing as a result. In this nationally representative study we examined the incidence, characteristics, and outcomes of reintervention after index TEER. METHODS: Between July 2013 and November 2017, we reviewed 11,396 patients who underwent index TEER using Medicare beneficiary data. These patients were prospectively tracked and identified as having repeat TEER or MVS. Primary outcomes included 30-day mortality, 30-day readmission, 30-day composite morbidity, and cumulative survival. RESULTS: Among 11,396 patients who underwent TEER, 548 patients (4.8%) required reintervention after a median time interval of 4.5 months. Overall 30-day mortality was 8.6%, 30-day readmission was 20.9%, and 30-day composite morbidity was 48.2%. According to reintervention type, 294 (53.7%) patients underwent repeat TEER, and 254 (46.3%) underwent MVS. Patients who underwent MVS were more likely to be younger and female, but had a similar comorbidity burden compared with the repeat TEER cohort. After adjustment, there were no differences in 30-day mortality (adjusted odds ratio [AOR], 1.26 [95% CI, 0.65-2.45]) or 30-day readmission (AOR, 1.14 [95% CI, 0.72-1.81]). MVS was associated with higher 30-day morbidity (AOR, 4.76 [95% CI, 3.17-7.14]) compared with repeat TEER. Requirement for reintervention was an independent risk factor for long-term mortality in a Cox proportional hazard model (hazard ratio, 3.26 [95% CI, 2.53-4.20]). CONCLUSIONS: Reintervention after index TEER is a high-risk procedure that carries a significant mortality burden. This highlights the importance of ensuring procedural success for index TEER to avoid the morbidity of reintervention altogether.

A TGF-ß/KLF10 signaling axis regulates atrophy-associated genes to induce muscle wasting in pancreatic cancer.

Cancer cachexia, and its associated complications, represent a large and currently untreatable roadblock to effective cancer management. Many potential therapies have been proposed and tested-including appetite stimulants, targeted cytokine blockers, and nutritional supplementation-yet highly effective therapies are lacking. Innovative approaches to treating cancer cachexia are needed. Members of the Kruppel-like factor (KLF) family play wide-ranging and important roles in the development, maintenance, and metabolism of skeletal muscle. Within the KLF family, we identified KLF10 upregulation in a multitude of wasting contexts-including in pancreatic, lung, and colon cancer mouse models as well as in human patients. We subsequently interrogated loss-of-function of KLF10 as a potential strategy to mitigate cancer associated muscle wasting. In vivo studies leveraging orthotopic implantation of pancreas cancer cells into wild-type and KLF10 KO mice revealed significant preservation of lean mass and robust suppression of pro-atrophy muscle-specific ubiquitin ligases Trim63 and Fbxo32, as well as other factors implicated in atrophy, calcium signaling, and autophagy. Bioinformatics analyses identified Transforming growth factor beta (TGF-ß), a known inducer of KLF10 and cachexia promoting factor, as a key upstream regulator of KLF10. We provide direct in vivo evidence that KLF10 KO mice are resistant to the atrophic effects of TGF-ß. ChIP-based binding studies demonstrated direct binding to Trim63, a known wasting-associated atrogene. Taken together, we report a critical role for the TGF-ß/KLF10 axis in the etiology of pancreatic cancer-associated muscle wasting and highlight the utility of targeting KLF10 as a strategy to prevent muscle wasting and limit cancer-associated cachexia.

Exomap1 mouse: a transgenic model for in vivo studies of exosome biology.

Exosomes are small extracellular vesicles (sEVs) of ~30-150 nm in diameter that have the same topology as the cell, are enriched in selected exosome cargo proteins, and play important roles in health and disease. To address large unanswered questions regarding exosome biology in vivo, we created the exomap1 transgenic mouse model. In response to Cre recombinase, exomap1 mice express HsCD81mNG, a fusion protein between human CD81, the most highly enriched exosome protein yet described, and the bright green fluorescent protein mNeonGreen. As expected, cell type-specific expression of Cre induced the cell type-specific expression of HsCD81mNG in diverse cell types, correctly localized HsCD81mNG to the plasma membrane, and selectively loaded HsCD81mNG into secreted vesicles that have the size (~80 nm), topology (outside out), and content (presence of mouse exosome markers) of exosomes. Furthermore, mouse cells expressing HsCD81mNG released HsCD81mNG-marked exosomes into blood and other biofluids. Using high-resolution, single-exosome analysis by quantitative single molecule localization microscopy, we show here that that hepatocytes contribute ~15% of the blood exosome population whereas neurons contribute <1% of blood exosomes. These estimates of cell type-specific contributions to blood EV population are consistent with the porosity of liver sinusoidal endothelial cells to particles of ~50-300 nm in diameter, as well as with the impermeability of blood-brain and blood-neuron barriers to particles >5 nm in size. Taken together, these results establish the exomap1 mouse as a useful tool for in vivo studies of exosome biology, and for mapping cell type-specific contributions to biofluid exosome populations. In addition, our data confirm that CD81 is a highly-specific marker for exosomes and is not enriched in the larger microvesicle class of EVs.

Comparison of Postdischarge Outcomes Between Valve-in-Valve Transcatheter Mitral Valve Replacement and Reoperative Surgical Mitral Valve Replacement.

Limited data are available comparing the postdischarge perioperative outcomes of isolated valve-in-valve transcatheter mitral valve replacement (VIV-TMVR) versus surgical reoperative mitral valve replacement (re-SMVR) on a nationwide scale. The objective of this study was to perform a robust head-to-head assessment of contemporary postdischarge outcomes between isolated VIV-TMVR and re-SMVR using a large national multicenter longitudinal database. Adult patients aged ≥18 years with failed/degenerated bioprosthetic mitral valves who underwent either isolated VIV-TMVR or re-SMVR were identified in the 2015 to 2019 Nationwide Readmissions Database. The risk-adjusted differences in 30-, 90-, and 180-day outcomes were compared using propensity score weighting with overlap weights to mimic the results of a randomized controlled trial. The differences between a transeptal and transapical VIV-TMVR approach were also compared. A total of 687 patients with VIV-TMVR and 2,047 patients with re-SMVR were included. After the overlap weighting to attain balance between treatment groups, VIV-TMVR was associated with significantly lower major morbidity within 30 (odds ratio [95% confidence interval (CI)] 0.0.31 [0.22 to 0.46]), 90 (0.34 [0.23 to 0.50]), and 180 (0.35 [0.24 to 0.51]) days. The differences in major morbidity were primarily driven by less major bleeding (0.20 [0.14 to 0.30]), new onset complete heart block (0.48 [0.28 to 0.84]) and need for permanent pacemaker placement (0.26 [0.12 to 0.55]). The differences in renal failure and stroke were not significant. VIV-TMVR was also associated with shorter index hospital stays (median difference [95% CI] -7.0 [4.9 to 9.1] days) and an increased ability for patients to be discharged home (odds ratio [95% CI] 3.35 [2.37 to 4.72]). There were no significant differences in total hospital costs; in-hospital or 30-, 90-, and 180-day mortality; or readmission. The findings remained similar when stratifying the VIV-TMVR access using a transeptal versus a transapical approach. The changes in outcomes over time suggest marked improvements for patients with VIV-TMVR relative to stagnant results for patients with re-SMVR from 2015 to 2019. In this large nationally representative cohort of patients with failed/degenerated bioprosthetic mitral valves, VIV-TMVR appears to confer a short-term advantage over re-SMVR in terms of morbidity, discharge home, and length of stay. It yielded equivalent outcomes for mortality and readmission. Longer-term studies are needed to assess further follow-up beyond 180 days.

Rituximab induced cytokine release with high serum IP-10 (CXCL10) concentrations is associated with infusion reactions.

Monoclonal antibody induced infusion reactions (IRs) can be serious and even fatal. We used clinical data and blood samples from 37 treatment naïve patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) initiating therapy for progressive disease with a single 50 mg dose of intravenous (IV) rituximab at 25 mg/h. Twenty-four (65 %) patients had IRs at a median of 78 min (range 35-128) and rituximab dose of 32 mg (range 15-50). IR risk did not correlate with patient or CLL characteristics, CLL counts or CD20 levels, or serum rituximab or complement concentrations. Thirty-five (95 %) patients had cytokine release response with a ≥ 4-fold increase in serum concentration of ≥ 1 inflammatory cytokine. IRs were associated with significantly higher post-infusion serum concentrations of gamma interferon induced cytokines IP-10, IL-6 and IL-8. IP-10 concentrations increased ≥ 4-fold in all patients with an IR and were above the upper limit of detection (40,000 pg/ml) in 17 (71 %). In contrast, to only three (23 %) patients without an IR had an ≥ 4-fold increase in serum concentrations of IP-10 (highest 22,013 pg/ml). Our data suggest that cytokine release could be initiated by activation of effector cells responsible for clearance of circulating CLL cells with IRs occurring in those with higher levels of gamma interferon induced cytokines. These novel insights could inform future research to better understand and manage IRs and understand the role of cytokines in the control of cytotoxic immune responses to mAb.

Residency Program Directors' Views on Research Conducted During Medical School: A National Survey.

PURPOSE: With the United States Medical Licensing Examination Step 1 transition to pass/fail in 2022, uncertainty exists regarding how other residency application components, including research conducted during medical school, will inform interview and ranking decisions. The authors explore program director (PD) views on medical student research, the importance of disseminating that work, and the translatable skill set of research participation. METHOD: Surveys were distributed to all U.S. residency PDs and remained open from August to November 2021 to query the importance of research participation in assessing applicants, whether certain types of research were more valued, productivity measures that reflect meaningful research participation, and traits for which research serves as a proxy. The survey also queried whether research would be more important without a numeric Step 1 score and the importance of research vs other application components. RESULTS: A total of 885 responses from 393 institutions were received. Ten PDs indicated that research is not considered when reviewing applicants, leaving 875 responses for analysis. Among 873 PDs (2 nonrespondents), 358 (41.0%) replied that meaningful research participation will be more important in offering interviews. A total of 164 of 304 most competitive specialties (53.9%) reported increased research importance compared with 99 of 282 competitive (35.1%) and 95 of 287 least competitive (33.1%) specialties. PDs reported that meaningful research participation demonstrated intellectual curiosity (545 [62.3%]), critical and analytical thinking skills (482 [55.1%]), and self-directed learning skills (455 [52.0%]). PDs from the most competitive specialties were significantly more likely to indicate that they value basic science research vs PDs from the least competitive specialties. CONCLUSIONS: This study demonstrates how PDs value research in their review of applicants, what they perceive research represents in an applicant, and how these views are shifting as the Step 1 exam transitions to pass/fail.

Muscle stem cells contribute to long-term tissue repletion following surgical sepsis.

BACKGROUND: Over the past decade, advances in sepsis identification and management have resulted in decreased sepsis mortality. This increase in survivorship has highlighted a new clinical obstacle: chronic critical illness (CCI), for which there are no effective treatment options. Up to half of sepsis survivors suffer from CCI, which can include multi-organ dysfunction, chronic inflammation, muscle wasting, physical and mental disabilities, and enhanced frailty. These symptoms prevent survivors from returning to regular day-to-day activities and are directly associated with poor quality of life. METHODS: Mice were subjected to cecal ligation and puncture (CLP) with daily chronic stress (DCS) as an in vivo model to study sepsis late-effects/sequelae on skeletal muscle components. Longitudinal monitoring was performed via magnetic resonance imaging, skeletal muscle and/or muscle stem cell (MuSCs) assays (e.g., post-necropsy wet muscle weights, minimum Feret diameter measurements, in vitro MuSC proliferation and differentiation, number of regenerating myofibres and numbers of Pax7-positive nuclei per myofibre), post-sepsis whole muscle metabolomics and MuSC isolation and high-content transcriptional profiling. RESULTS: We report several findings supporting the hypothesis that MuSCs/muscle regeneration are critically involved in post-sepsis muscle recovery. First, we show that genetic ablation of muscle stem cells (MuSCs) impairs post-sepsis muscle recovery (maintenance of 5-8% average lean mass loss compared with controls). Second, we observe impaired MuSCs expansion capacity and morphological defects at 26 days post-sepsis compared with control MuSCs (P < 0.001). Third, when subjected to an experimental muscle injury, sepsis-recovered mice exhibited evidence of impaired muscle regeneration compared with non-septic mice receiving the same muscle injury (CLP/DCS injured mean minimum Feret is 92.1% of control injured, P < 0.01). Fourth, we performed a longitudinal RNA sequencing study on MuSCs isolated from post-sepsis mice and found clear transcriptional differences in all post-sepsis samples compared with controls. At Day 28, CLP/DCS mice satellite cells have multiple altered metabolic pathways, such as oxidative phosphorylation, mitochondrial dysfunction, sirtuin signalling and oestrogen receptor signalling, compared with controls (P < 0.001). CONCLUSIONS: Our data show that MuSCs and muscle regeneration are required for effective post-sepsis muscle recovery and that sepsis triggers morphological, functional, and transcriptional changes in MuSCs. Moving forward, we strive to leverage a more complete understanding of post-sepsis MuSC/regenerative defects to identify and test novel therapies that promote muscle recovery and improve quality of life in sepsis survivors.

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) causes seizure activity in larval zebrafish via antagonism of γ-aminobutyric acid type A receptor α1ß2γ2.

Hexahydro-1,3,5-trinitro-1,3,5-triazine, or Royal Demolition Explosive (RDX), is a major component of plastic explosives such as C-4. Acute exposures from intentional or accidental ingestion are a documented clinical concern, especially among young male U.S. service members in the armed forces. When ingested in large enough quantity, RDX causes tonic-clonic seizures. Previous in silico and in vitro experiments predict that RDX causes seizures by inhibiting α1ß2γ2 γ-aminobutyric acid type A (GABAA) receptor-mediated chloride currents. To determine whether this mechanism translates in vivo, we established a larval zebrafish model of RDX-induced seizures. After a 3 h of exposure to 300 µM RDX, larval zebrafish exhibited a significant increase in motility in comparison to vehicle controls. Researchers blinded to experimental group manually scored a 20-min segment of video starting at 3.5 h post-exposure and found significant seizure behavior that correlated with automated seizure scores. Midazolam (MDZ), an nonselective GABAAR positive allosteric modulator (PAM), and a combination of Zolpidem (α1 selective PAM) and compound 2-261 (ß2/3-selective PAM) were effective in mitigating RDX-triggered behavioral and electrographic seizures. These findings confirm that RDX induces seizure activity via inhibition of the α1ß2γ2 GABAAR and support the use of GABAAR-targeted anti-seizure drugs for the treatment of RDX-induced seizures.

Developmental Neurotoxicity Screen of Psychedelics and Other Drugs of Abuse in Larval Zebrafish (Danio rerio).

In recent years, psychedelics have garnered significant interest as therapeutic agents for treating diverse neuropsychiatric disorders. However, the potential for these compounds to produce developmental neurotoxicity has not been rigorously assessed, and much of the available safety data is based on epidemiological studies with limited experimental testing in laboratory animal models. Moreover, the experimental safety data available thus far have focused on adult organisms, and the few studies conducted using developing organisms have tested a limited number of compounds, precluding direct comparisons between various chemical scaffolds. In the present study, 13 psychoactive compounds of different chemical or pharmacological classes were screened in a larval zebrafish model for teratological and behavioral abnormalities following acute and chronic developmental exposures. We found that the psychedelic tryptamines and ketamine were less neurotoxic to larval zebrafish than LSD and psychostimulants. Our work, which leverages the advantage of using zebrafish for higher throughput toxicity screening, provides a robust reference database for comparing the neurotoxicity profiles of novel psychedelics currently under development for therapeutic applications.

Relationship of Muscle Apolipoprotein E Expression with Markers of Cellular Stress, Metabolism, and Blood Biomarkers in Cognitively Healthy and Impaired Older Adults.

BACKGROUND: Individuals with mild cognitive impairment (MCI) have reduced lipid-stimulated mitochondrial respiration in skeletal muscle. A major risk factor for Alzheimer's disease (AD), the apolipoprotein E4 (APOE4) allele, is implicated in lipid metabolism and is associated with metabolic and oxidative stress that can result from dysfunctional mitochondria. Heat shock protein 72 (Hsp72) is protective against these stressors and is elevated in the AD brain. OBJECTIVE: Our goal was to characterize skeletal muscle ApoE and Hsp72 protein expression in APOE4 carriers in relationship to cognitive status, muscle mitochondrial respiration and AD biomarkers. METHODS: We analyzed previously collected skeletal muscle tissue from 24 APOE4 carriers (60y+) who were cognitively healthy (CH, n = 9) or MCI (n = 15). We measured ApoE and Hsp72 protein levels in muscle and phosphorylated tau181 (pTau181) levels in plasma, and leveraged previously collected data on APOE genotype, mitochondrial respiration during lipid oxidation, and VO2 max. RESULTS: Muscle ApoE (p = 0.013) and plasma pTau181 levels (p < 0.001) were higher in MCI APOE4 carriers. Muscle ApoE positively correlated with plasma pTau181 in all APOE4 carriers (R2 = 0.338, p = 0.003). Hsp72 expression negatively correlated with ADP (R2 = 0.775, p = <0.001) and succinate-stimulated respiration (R2 = 0.405, p = 0.003) in skeletal muscle of MCI APOE4 carriers. Plasma pTau181 negatively tracked with VO2 max in all APOE4 carriers (R2 = 0.389, p = 0.003). Analyses were controlled for age. CONCLUSION: This work supports a relationship between cellular stress in skeletal muscle and cognitive status in APOE4 carriers.

Detection of Glycosaminoglycans in Biological Specimens.

Proteoglycans (PGs) are macromolecules formed by a protein backbone to which one or more glycosaminoglycan (GAG) side chains are covalently attached. Most PGs are present in connective tissues, cell surfaces, and intracellular compartments. The major biological function of PGs derives from the GAG component of the molecule, which is involved in cell growth and proliferation, embryogenesis, maintenance of tissue hydration, and interactions of the cells via receptors. PGs are categorized into four groups based on their cellular and subcellular localization, including cell surfaces and extracellular, intracellular, and pericellular locations. GAGs are a crucial component of PGs involved in various physiological and pathological processes. GAGs also serve as biomarkers of metabolic diseases such as mucopolysaccharidoses and mucolipidoses. Detection of specific GAGs in various biological fluids helps manage various genetic metabolic disorders before it causes irreversible damage to the patient (Amendum et al., Diagnostics (Basel) 11(9):1563, 2021). There are several methods for detecting GAGs; this chapter focuses on measuring GAGs using enzyme-linked immunosorbent assay, liquid chromatographic tandem mass spectrometry, and automated high-throughput mass spectrometry.

Adrenal venous sampling for lateralization of cortisol hypersecretion in patients with bilateral adrenal masses.

OBJECTIVE: The objective of this study was to evaluate the role of adrenal venous sampling (AVS) in guiding the management of patients with corticotropin (ACTH)-independent glucocorticoid secretory autonomy and bilateral adrenal masses. DESIGN AND PATIENTS: A cohort with 25 patients underwent AVS and surgical management. MEASUREMENTS: Cortisol was measured from the adrenal veins (AVs) and inferior vena cava (IVC). AV/IVC cortisol ratio and cortisol lateralization ratio (CLR) (dominant AV cortisol concentration divided by the nondominant AV cortisol concentration) were calculated. Posthoc receiver-operating characteristic curves were generated to determine the specificity of revised AV/IVC cortisol ratio and CLR in differentiating unilateral from bilateral disease. RESULTS: Patients underwent unilateral (n = 21) or bilateral (n = 4) adrenalectomy. The mean AV/IVC cortisol ratio for unilateral adrenalectomy was 12.1 ± 9.6 (dominant) and 4.7 ± 3.8 (contralateral) with a mean CLR of 3.6 ± 3.5. The mean AV/IVC cortisol ratio for bilateral adrenalectomy was 7.5 ± 2.1, with a mean CLR of 1.1 ± 0.6. At a mean follow-up of 22 months, one patient who underwent unilateral adrenalectomy for the predicted bilateral disease developed recurrent mild autonomous cortisol secretion. Posthoc analyses demonstrated a specificity of 95%-100% for unilateral disease with AV/IVC cortisol ratio >9 for one side, <2.0 for the opposite side and a CLR > 2.3. The specificity was 80%-90% for bilateral disease with AV/IVC cortisol ratio >5.1 bilaterally and a CLR < 1.1. CONCLUSIONS: Among patients with bilateral adrenal masses and ACTH-independent autonomous cortisol secretion, AVS can distinguish between unilateral and bilateral disease with high specificity and may guide surgical management.

Forelimb Resistance Exercise Protects Against Neuromuscular Junction Denervation in the SOD1-G93A Rat Model of ALS.

Introduction: The symptoms of Amyotrophic Lateral Sclerosis (ALS) include muscle weakness and eventual paralysis. These symptoms result from denervation of the neuromuscular junction (NMJ) and motor neuron cell death in the brain and spinal cord. Due to the "dying back" pattern of motor neuron degeneration, protecting NMJs should be a therapeutic priority. Although exercise has the potential to protect against NMJ denervation, its use in ALS has been controversial. Most preclinical studies have focused on aerobic exercise, which report that exercise can be beneficial at moderate intensities. The effects of resistance exercise on NMJ preservation in limb muscles have not been explored. Methods: We trained male SOD1-G93A rats, which model ALS, to perform a unilateral isometric forelimb resistance exercise task. This task allows within-animal comparisons of trained and untrained forelimbs. We then determined the effects of isometric resistance exercise on NMJ denervation and AMP kinase (AMPK) activation in forelimb muscles. Results: Our results revealed that SOD1-G93A rats were able to learn and perform the task similarly to wildtype rats, even after loss of body weight. SOD1-G93A rats exhibited significantly greater NMJ innervation in their trained vs their untrained forelimb biceps muscles. Measures of activated (phosphorylated) AMPK (pAMPK) were also greater in the trained vs untrained forelimb triceps muscles. Discussion: These results demonstrate that isometric resistance exercise may protect against NMJ denervation in ALS. Future studies are required to determine the extent to which our findings generalize to female SOD1-G93A rats and to other subtypes of ALS.

The intergenerational effects of parental physical activity on offspring brain and neurocognition in humans: A scoping review.

Animal models suggest physical activity (PA) has intergenerational effects on brain health and neurocognition. This scoping review compiles the human literature in this area, identifies knowledge gaps, and makes recommendations for future research. We systematically searched for experimental or observational studies conducted in humans, published in English, and reporting parental PA exposure (preconception or prenatal) and subsequent offspring brain and neurocognition. Two reviewers independently screened studies according to predetermined inclusion criteria. Fourteen studies were included (four experimental and 10 observational) reporting on 93,486 parent-child dyads (100% maternal, 0% paternal). Prenatal maternal PA exposure was examined in 10 (71%) studies, while preconception and prenatal PA exposure was examined in four (29%) studies. Maternal PA exposure was positively related to offspring (0-20y) brain and neurocognitive development in 25% of experimental studies and 100% of observational studies. Little is known about the intergenerational effects of parental PA on offspring brain and neurocognition in humans, particularly paternal preconception PA. More experimental studies with longer offspring follow-up and more objective and/or mechanistic assessments are required.

Sex Difference Leads to Differential Gene Expression Patterns and Therapeutic Efficacy in Mucopolysaccharidosis IVA Murine Model Receiving AAV8 Gene Therapy.

Adeno-associated virus (AAV) vector-based therapies can effectively correct some disease pathology in murine models with mucopolysaccharidoses. However, immunogenicity can limit therapeutic effect as immune responses target capsid proteins, transduced cells, and gene therapy products, ultimately resulting in loss of enzyme activity. Inherent differences in male versus female immune response can significantly impact AAV gene transfer. We aim to investigate sex differences in the immune response to AAV gene therapies in mice with mucopolysaccharidosis IVA (MPS IVA). MPS IVA mice, treated with different AAV vectors expressing human N-acetylgalactosamine 6-sulfate sulfatase (GALNS), demonstrated a more robust antibody response in female mice resulting in subsequent decreased GALNS enzyme activity and less therapeutic efficacy in tissue pathology relative to male mice. Under thyroxine-binding globulin promoter, neutralizing antibody titers in female mice were approximately 4.6-fold higher than in male mice, with GALNS enzyme activity levels approximately 6.8-fold lower. Overall, male mice treated with AAV-based gene therapy showed pathological improvement in the femur and tibial growth plates, ligaments, and articular cartilage as determined by contrasting differences in pathology scores compared to females. Cardiac histology revealed a failure to normalize vacuolation in females, in contrast, to complete correction in male mice. These findings promote the need for further determination of sex-based differences in response to AAV-mediated gene therapy related to developing treatments for MPS IVA.