Irisin Mediates Effects on Bone and Fat via αV Integrin Receptors.

Irisin is secreted by muscle, increases with exercise, and mediates certain favorable effects of physical activity. In particular, irisin has been shown to have beneficial effects in adipose tissues, brain, and bone. However, the skeletal response to exercise is less clear, and the receptor for irisin has not been identified. Here we show that irisin binds to proteins of the αV class of integrins, and biophysical studies identify interacting surfaces between irisin and αV/ß5 integrin. Chemical inhibition of the αV integrins blocks signaling and function by irisin in osteocytes and fat cells. Irisin increases both osteocytic survival and production of sclerostin, a local modulator of bone remodeling. Genetic ablation of FNDC5 (or irisin) completely blocks osteocytic osteolysis induced by ovariectomy, preventing bone loss and supporting an important role of irisin in skeletal remodeling. Identification of the irisin receptor should greatly facilitate our understanding of irisin's function in exercise and human health.

Structure-based design of selective, orally available salt-inducible kinase inhibitors that stimulate bone formation in mice.

Osteoporosis is a major public health problem. Currently, there are no orally available therapies that increase bone formation. Intermittent parathyroid hormone (PTH) stimulates bone formation through a signal transduction pathway that involves inhibition of salt-inducible kinase isoforms 2 and 3 (SIK2 and SIK3). Here, we further validate SIK2/SIK3 as osteoporosis drug targets by demonstrating that ubiquitous deletion of these genes in adult mice increases bone formation without extraskeletal toxicities. Previous efforts to target these kinases to stimulate bone formation have been limited by lack of pharmacologically acceptable, specific, orally available SIK2/SIK3 inhibitors. Here, we used structure-based drug design followed by iterative medicinal chemistry to identify SK-124 as a lead compound that potently inhibits SIK2 and SIK3. SK-124 inhibits SIK2 and SIK3 with single-digit nanomolar potency in vitro and in cell-based target engagement assays and shows acceptable kinome selectivity and oral bioavailability. SK-124 reduces SIK2/SIK3 substrate phosphorylation levels in human and mouse cultured bone cells and regulates gene expression patterns in a PTH-like manner. Once-daily oral SK-124 treatment for 3 wk in mice led to PTH-like effects on mineral metabolism including increased blood levels of calcium and 1,25-vitamin D and suppressed endogenous PTH levels. Furthermore, SK-124 treatment increased bone formation by osteoblasts and boosted trabecular bone mass without evidence of short-term toxicity. Taken together, these findings demonstrate PTH-like effects in bone and mineral metabolism upon in vivo treatment with orally available SIK2/SIK3 inhibitor SK-124.

Open label trial of lofexidine-assisted non-opioid induction onto naltrexone extended-release injection for opioid use disorder.

Background: Opioid use disorder (OUD) continues to be major public health problem in the US and innovative medication strategies are needed. The extended-release injectable formulation of naltrexone (ER-NTX), an opioid receptor antagonist, is an effective treatment for OUD, but the need for an opioid-free period during the induction phase of treatment is a barrier to treatment success, particularly in the outpatient setting. Lofexidine, an alpha-2-adrenergic agonist, is an effective treatment for opioid withdrawal.Objectives: To evaluate the feasibility, safety, and tolerability of lofexidine for facilitating induction onto ER-NTX in the management of OUD.Methods: In an open-label, uncontrolled, 10-week outpatient clinical trial, 20 adults (four women) with OUD were treated with a fixed-flexible dosing strategy (maximum 0.54 mg 4×/daily) of lofexidine for up to 10 days to manage opioid withdrawal prior to receiving ER-NTX. The COVID-19 pandemic resulted in a modification of the study methods after enrolling 10 participants who attended all visits in person. The second group of 10 participants attended most induction period visits remotely.Results: Overall, 10 of the 20 participants (50%) achieved the primary outcome by receiving the first ER-NTX injection. Rates of induction success did not differ by the presence of fentanyl or remote visit attendance, although the small sample size provided limited statistical power. Six out of 20 participants (30%) initiated on lofexidine required dose adjustments. There were no study-related serious adverse events.Conclusions: This study provides preliminary evidence supporting the feasibility of inducting individuals with OUD onto ER-NTX using lofexidine.

Safety and tolerability of progesterone treatment for women with cocaine use disorder: a pilot treatment trial.

Background: Problematic cocaine use remains a significant public health issue, particularly among women. However, no concerted efforts have been made to target a pharmacological treatment option for women with cocaine use disorder (CUD) despite preclinical, human laboratory, and a limited number of clinical studies demonstrating that progesterone can attenuate the effects of cocaine to a greater extent in women than men.Objectives: To evaluate the safety, tolerability, and preliminary efficacy of progesterone for treating women with CUD.Methods: A 10-week double-blind randomized treatment trial was conducted. Prior to randomization, participants were required to achieve cocaine abstinence (1 week) before assignment to progesterone (up to 400 mg/day) or placebo. The primary efficacy outcomes were days to relapse and cocaine abstinence during the last 3 weeks of the trial. The frequency of side effects was also assessed.Results: 227 women were assessed for eligibility. Twenty-five women entered treatment and 21 were randomized to progesterone (n = 11) or placebo (n = 10). The majority of women relapsed in less than 4 days with no differences between the two groups. Further, there were no significant differences between the progesterone and placebo groups in terms of cocaine abstinence during the last 3 weeks of the trial (27% and 10% respectively). The most commonly reported side effects were headache and fatigue, but no group differences were noted.Conclusions: Progesterone was well tolerated and safe and supports further study is in a larger sample to determine if exogenous progesterone is an effective treatment option for women with CUD.(ClinicalTrials.gov Identifier: NCT00632099).

Pilot randomized placebo-controlled clinical trial of high-dose gabapentin for alcohol use disorder.

BACKGROUND: Despite advances in the development of pharmacotherapy for alcohol use disorder (AUD), there remains a need for medications that can be administered to actively drinking outpatients to promote a reduction in harmful alcohol consumption. The primary aim of this pilot study was to determine whether high-dose gabapentin (3600 mg/daily) is more effective than placebo in reducing harmful alcohol consumption in outpatients with AUD. METHODS: Forty patients (27 men) who met DSM-IV-TR criteria for alcohol dependence and reporting at least 4 heavy drinking days (HDD) per week were recruited at a single site. Participants were actively drinking at study entry and received double-blind gabapentin (3600 mg/day; n = 19) or placebo (n = 20) for 8 weeks. Study medication was titrated over 5 days and administered in three divided doses (1200 mg three times per day). The proportion of HDD (primary outcome) and percent days abstinent (PDA; secondary outcome) were analyzed using generalized longitudinal mixed models with the predictors being study arm, week, study arm by week interaction, and corresponding baseline drinking measure. RESULTS: There was a significant interaction between study arm and week for the proportion of HDD per week, F (7, 215) = 3.33, p = 0.002 . There was also a significant interaction between study arm and week for PDA per week, F (7, 215) = 3.11, p = 0.004. The overall retention rate was 67.5% with no significant difference in time-to-dropout between treatment groups. There were no serious adverse events. No participants were removed from the trial due to the development of moderate-to-severe alcohol withdrawal (CIWA-Ar ≥ 13). CONCLUSIONS: Gabapentin treatment rapidly titrated to a dosage of 3600 mg/day is associated with a reduction in the proportion of HDD per week and an increase in PDA per week in actively drinking outpatients with AUD. High-dose gabapentin is potentially a feasible approach to treating AUD and deserving of further study.

Open-label trial of a single-day induction onto buprenorphine extended-release injection for users of heroin and fentanyl.

BACKGROUND AND OBJECTIVES: Fentanyl and other highly potent synthetic opioids are the leading cause of opioid overdose deaths in the United States. METHODS: This study was an open-label, uncontrolled 12-week outpatient clinical trial to test the feasibility of a single-day induction onto extended-release buprenorphine (BXR) injection treatment for five adults (N = 5) with opioid use disorder using heroin-containing fentanyl. Participants were planned to receive three monthly BXR injections (300, 300, and 100 mg). RESULTS: After receiving 24 mg sublingual buprenorphine (SL-BUP), all five participants received the BXR 300 mg injection on the first day of induction. All five participants were retained for the full 3-month study period postinduction and received all three scheduled BXR injections. DISCUSSION AND CONCLUSION: This study provides preliminary evidence supporting the feasibility of inducting users of heroin-containing fentanyl onto BXR 300 mg in a single day. SCIENTIFIC SIGNIFICANCE: The ability to administer a long-acting injection of BXR that assures therapeutic serum levels for a month on the first day of treatment contact is a promising development for the treatment of OUD.

Open-label pilot study of lisdexamfetamine for cocaine use disorder.

Background: Cocaine use disorder (CUD) is a substantial public health problem with no FDA-approved medication treatments. Psychostimulants have shown promise as pharmacotherapy for CUD. Lisdexamfetamine, a novel prodrug psychostimulant, is roughly 40-50% as potent as dextroamphetamine.Objectives: To evaluate the safety, tolerability, and optimal dosing of lisdexamfetamine for treating CUD.Methods: Open-label, 8-week trial of 17 CUD adults. Participants were titrated to the maximum tolerated dose of 140 mg over 2-week period and maintained for 4 weeks, followed by a two-week taper period. The primary outcome measures were the maximum daily dose achieved during the study period and tolerability as measured by medication-related study drop-out.Results: Among the 16 participants with post-enrollment data, the mean dose of lisdexamfetamine achieved was 118.1 mg (standard deviation (SD) = 40.4), mean retention was 6.5 weeks (SD = 2.0), and no participants discontinued study medication due to adverse effects. Four participants had dose reductions due to adverse effects and continued in the trial. Six participants (37.5%) were abstinent for the last 3 weeks of their study participation. Mean dollars of cocaine spent per day significantly decreased from $19.72 at baseline to $7.57 during the last 3 weeks of study participation (t15 = 3.60, p = .003). The mean percent of using days significantly decreased from 25% at baseline to 12% during the last 3 weeks of study participation (t15 = 3.33, p = .005).Conclusion: The use of lisdexamfetamine for CUD in doses ranging to 140 mg daily was safe and generally well tolerated.

An open-label pilot study of pregabalin pharmacotherapy for alcohol use disorder.

Background: There is a need for alcohol use disorder (AUD) pharmacotherapy that can be administered to actively drinking outpatients. Pregabalin, a gabapentoid anticonvulsant, has preliminary evidence supporting effects on alcohol withdrawal and AUD.Objectives: To evaluate the safety, tolerability, and optimal dosing of pregabalin for treating AUD.Methods: In an open-label, 8-week, outpatient trial of eighteen adults (nine women) with AUD, participants were titrated to 600 mg/day (or the maximum tolerated dose) over 3 weeks and then maintained for 5 weeks.Results: The majority (11/14, 78.6%) of participants with at least one-week of medication exposure achieved a maximum dose of 600 mg/day. Mean retention was 6.8 weeks (SD = 2.6). Eighty percent (12/15) of participants with post-enrollment data reported any adverse effects during the trial; and for those reporting adverse effects the most common were drowsiness (33.3%, 4/12), and fogginess (25%, 3/12), dizziness (25%, 3/12), and insomnia (25%, 3/12). Two participants discontinued study medication due to adverse effects and one had a dose reduction. Mean Heavy Drinking Days (HDD)/week decreased significantly by 3.43 days (SD = 2.47; median (IQR) = 4.00 (1.00 to 5.50)); Wilcoxon signed rank test statistic ((S) = 49.5, p = .0006). Mean proportion of HDD significantly decreased on average by 48.7% (SD = 35.1%; median (IQR) = 57.1% (14.3% to 78.6%)). The proportion of abstinent days increased significantly on average by 36.1% (SD = 35.0%; median (IQR) = 17.9% (14.3% to 75.0%); S = 49.5, p = .0005).Conclusions: Pregabalin treatment of AUD appears to be safe and well tolerated in doses up to 600 mg per day.Trial Registration: clinicaltrials.gov identifier: NCT03256253.

Loss of Intestinal Alkaline Phosphatase Leads to Distinct Chronic Changes in Bone Phenotype.

BACKGROUND: The gut is becoming increasingly recognized as the source of various systemic diseases, and recently, it has been linked to bone metabolism via the so-called gut-bone axis. The microbiome and gut-derived mediators are thought to impact upon bone metabolism, and administration of probiotics has been shown to have beneficial effects in bone. The gut brush border enzyme intestinal alkaline phosphatase (IAP) plays an important role in controlling calcium absorption, inhibiting lipopolysaccharides, and other inflammatory mediators responsible for endotoxemia and appears to preserve the normal gut microbiota. Interestingly, IAP-deficient mice (AKP3-/-) also display a significant decrease in fecal Lactobacillus, the genus shown to be beneficial to bone. MATERIALS AND METHODS: IAP mRNA levels in mouse bone were measured using quantitative real-time polymerase chain reaction. Femurs of IAP-knockout (KO) and wild-type (WT) mice were analyzed by microcomputed tomography and histopathology. Serum levels of alkaline phosphatase, calcium, and phosphorus were measured. Target cell response upon exposure to serum from IAP-KO and WT mice was quantified using primary bone marrow macrophages. RESULTS: IAP was not significantly expressed in bones of WT or KO animals. IAP (alkaline phosphatase 3) expression in bone was vanishingly low compared to the duodenum (bone versus duodenum, 56.9 ± 17.7 versus 25,430.3 ± 10,884.5 relative expression, P = 0.01). Bone histology of younger IAP-KO and WT animals was indistinguishable, whereas older IAP-deficient mice showed a distinctly altered phenotype on histology and computed tomography scan. Younger KO mice did not display any abnormal levels in blood chemistry. Older IAP-KO animals showed an isolated increase in serum alkaline phosphatase levels reflecting an environment of active bone formation (IAP-WT versus IAP-KO, 80 ± 27.4 U/I versus 453 ± 107.5 U/I, P = 0.004). There was no significant difference in serum calcium or phosphorus levels between KO and WT mice. Serum from IAP-KO mice induced a significantly higher inflammatory target cell response. CONCLUSIONS: Through its multiple functions, IAP seems to play a crucial role in connecting the gut to the bone. IAP deficiency leads to chronic changes in bone formation, most likely through dysbiosis and systemic dissemination of proinflammatory mediators.

Open-label pilot study of injectable naltrexone for cannabis dependence.

BACKGROUND: There are no FDA-approved pharmacotherapies for cannabis use disorders (CUD), despite the evaluation of numerous medications. Notably, chronic dosing of oral naltrexone decreases self-administration of cannabis in human laboratory studies. OBJECTIVES: To test the feasibility of long-acting injectable naltrexone for the treatment of CUD, while obtaining preliminary safety and efficacy data. METHODS: Twelve adult participants (seven male) meeting DSM-IV-TR criteria for cannabis dependence enrolled into an 8-week, open-label pilot study conducted at an academic treatment research clinic. They received 380 mg intramuscular injections of long-acting naltrexone on study day 1 and at the start of study week 5. Outcome measures included percentages of study completers and participants who received the second injection, frequency of adverse events (AEs), and cannabis consumption measured by average daily grams, dollars, and using days per week as measured by timeline follow-back and urine oral delta-9-tetrahydrocannabinol (THC) concentrations. RESULTS: Of the 12 participants enrolled in the study, 9 completed the study and 6 received the second injection. There were no severe AEs but an unexpected AE led to the addition of supportive medications to the protocol. Number of cannabis use days per week significantly decreased over the course of the study (p = .001). Creatinine-corrected urine THC concentrations and average daily cannabis use per study week in grams and in dollars did not decrease over the course of the study. CONCLUSIONS: Long-acting injectable naltrexone is a feasible intervention for CUD worthy of further study in a placebo-controlled, double-blinded randomized clinical trial.

Polarizable charge equilibration model for predicting accurate electrostatic interactions in molecules and solids.

Electrostatic interactions play a critical role in determining the properties, structures, and dynamics of chemical, biochemical, and material systems. These interactions are described well at the level of quantum mechanics (QM) but not so well for the various models used in force field simulations of these systems. We propose and validate a new general methodology, denoted PQEq, to predict rapidly and dynamically the atomic charges and polarization underlying the electrostatic interactions. Here the polarization is described using an atomic sized Gaussian shaped electron density that can polarize away from the core in response to internal and external electric fields, while at the same time adjusting the charge on each core (described as a Gaussian function) so as to achieve a constant chemical potential across all atoms of the system. The parameters for PQEq are derived from experimental atomic properties of all elements up to Nobelium (atomic no. = 102). We validate PQEq by comparing to QM interaction energy as probe dipoles are brought along various directions up to 30 molecules containing H, C, N, O, F, Si, P, S, and Cl atoms. We find that PQEq predicts interaction energies in excellent agreement with QM, much better than other common charge models such as obtained from QM using Mulliken or ESP charges and those from standard force fields (OPLS and AMBER). Since PQEq increases the accuracy of electrostatic interactions and the response to external electric fields, we expect that PQEq will be useful for a large range of applications including ligand docking to proteins, catalytic reactions, electrocatalysis, ferroelectrics, and growth of ceramics and films, where it could be incorporated into standard force fields as OPLS, AMBER, CHARMM, Dreiding, ReaxFF, and UFF.

Mixed-amphetamine salts increase abstinence from marijuana in patients with co-occurring attention-deficit/hyperactivity disorder and cocaine dependence.

BACKGROUND AND OBJECTIVES: The prevalence of ADHD is greater in substance use disorders than the general population, and ADHD and substance use disorders share neurobiological features such as dysregulation of reward circuitry. We tested the hypothesis that stimulants would decrease marijuana use in a randomized controlled trial of extended release mixed amphetamine salts (MAS-XR) for treatment of co-occurring ADHD and cocaine use disorders. METHODS: Marijuana users were defined as participants reporting use in the 30 days before study initiation, collected with timeline follow-back. The original 14-week trial utilized a 3-arm randomized design, comparing placebo, MAS-XR 60 mg, and MAS-XR 80 mg. For this analysis, both MAS-XR groups were combined, leaving n = 20 in the placebo group and n = 37 in the MAS-XR group. The primary outcome was proportion of subjects reporting any marijuana use per study week. Comparisons between groups were made using a logistic mixed effects model incorporating multiple predictors and modeling time-by-treatment interactions. RESULTS: There were no significant baseline differences in marijuana use frequency and quantity. There was a significant decrease in the proportion of participants using marijuana over time in the MAS-XR group, but no difference in the proportion of marijuana-use days over time. DISCUSSION AND CONCLUSIONS: Treatment of ADHD and comorbid cocaine use disorders with MAS-XR is associated with increased weekly abstinence from marijuana but not with a decrease in the proportion of marijuana using days per week. SCIENTIFIC SIGNIFICANCE: Stimulant treatment of ADHD and cocaine use disorders may diminish co-occurring cannabis use. (Am J Addict 2016;25:666-672).

Thermal relaxation of lithium dendrites.

The average lengths λ̅ of lithium dendrites produced by charging symmetric Li(0) batteries at various temperatures are matched by Monte Carlo computations dealing both with Li(+) transport in the electrolyte and thermal relaxation of Li(0) electrodeposits. We found that experimental λ̅(T) variations cannot be solely accounted by the temperature dependence of Li(+) mobility in the solvent but require the involvement of competitive Li-atom transport from metastable dendrite tips to smoother domains over ΔE(++)(R) ∼ 20 kJ mol(-1) barriers. A transition state theory analysis of Li-atom diffusion in solids yields a negative entropy of activation for the relaxation process: ΔS(++)(R) ≈ -46 J mol(-1) K(-1) that is consistent with the transformation of amorphous into crystalline Li(0) electrodeposits. Significantly, our ΔE(++)(R) ∼ 20 kJ mol(-1) value compares favorably with the activation barriers recently derived from DFT calculations for self-diffusion on Li(0)(001) and (111) crystal surfaces. Our findings suggest a key role for the mobility of interfacial Li-atoms in determining the morphology of dendrites at temperatures above the onset of surface reconstruction: TSR ≈ 0.65 TMB (TMB = 453 K: the melting point of bulk Li(0)).

Combined effects of botulinum toxin injection and hind limb unloading on bone and muscle.

Bone receives mechanical stimulation from two primary sources, muscle contractions and external gravitational loading; but the relative contribution of each source to skeletal health is not fully understood. Understanding the most effective loading for maintaining bone health has important clinical implications for prescribing physical activity for the treatment or prevention of osteoporosis. Therefore, we investigated the relative effects of muscle paralysis and reduced gravitational loading on changes in muscle mass, bone mineral density, and microarchitecture. Adult female C57Bl/6J mice (n = 10/group) underwent one of the following: unilateral botulinum toxin (BTX) injection of the hind limb, hind limb unloading (HLU), both unilateral BTX injection and HLU, or no intervention. BTX and HLU each led to significant muscle and bone loss. The effect of BTX was diminished when combined with HLU, though generally the leg that received the combined intervention (HLU+BTX) had the most detrimental changes in bone and muscle. We found an indirect effect of BTX affecting the uninjected (contralateral) leg that led to significant decreases in bone mineral density and deficits in muscle mass and bone architecture relative to the untreated controls; the magnitude of this indirect BTX effect was comparable to the direct effect of BTX treatment and HLU. Thus, while it was difficult to definitively conclude whether muscle force or external gravitational loading contributes more to bone maintenance, it appears that BTX-induced muscle paralysis is more detrimental to muscle and bone than HLU.

Quantifying the dependence of dead lithium losses on the cycling period in lithium metal batteries.

We quantify the effects of the duration of the charge-discharge cycling period on the irreversible loss of anode material in rechargeable lithium metal batteries. We have developed a unique quantification method for the amount of dead lithium crystals (DLCs) produced by sequences of galvanostatic charge-discharge periods of variable duration τ in a coin battery of novel design. We found that the cumulative amount of dead lithium lost after 144 Coulombs circulated through the battery decreases sevenfold as τ shortens from 16 to 2 hours. We ascribe this outcome to the faster electrodissolution of the thinner dendrite necks formed in the later stages of long charging periods. This phenomenon is associated with the increased inaccessibility of the inner voids of the peripheral, late generation dendritic structures to incoming Li(+).

Verbal learning in marijuana users seeking treatment: a comparison between depressed and non-depressed samples.

BACKGROUND: Both individuals with marijuana use and depressive disorders exhibit verbal learning and memory decrements. OBJECTIVES: This study investigated the interaction between marijuana dependence and depression on learning and memory performance. METHODS: The California Verbal Learning Test-Second Edition (CVLT-II) was administered to depressed (n = 71) and non-depressed (n = 131) near-daily marijuana users. The severity of depressive symptoms was measured by the self-rated Beck Depression Inventory (BDI-II) and the clinician-rated Hamilton Depression Rating Scale (HAM-D). Multivariate analyses of covariance statistics (MANCOVA) were employed to analyze group differences in cognitive performance. Pearson's correlation coefficients were calculated to examine the relative associations between marijuana use, depression and CVLT-II performance. Findings from each group were compared to published normative data. RESULTS: Although both groups exhibited decreased CVLT-II performance relative to the test's normative sample (p < 0.05), marijuana-dependent subjects with a depressive disorder did not perform differently than marijuana-dependent subjects without a depressive disorder (p > 0.05). Further, poorer CVLT-II performance was modestly associated with increased self-reported daily amount of marijuana use (corrected p < 0.002), but was not significantly associated with increased scores on measures of depressive symptoms (corrected p > 0.002). CONCLUSION: These findings suggest an inverse association between marijuana use and verbal learning function, but not between depression and verbal learning function in regular marijuana users.

Mixed amphetamine salts-extended release (MAS-ER) as a behavioral treatment augmentation strategy for cocaine use disorder: A randomized clinical trial.

Psychosocial interventions remain the primary strategy for addressing cocaine use disorder (CUD), although many individuals do not benefit from these approaches. Amphetamine-based interventions have shown significant promise and may improve outcomes among individuals continuing to use cocaine in the context of behavioral interventions. One hundred forty-five adults (122 males) who used cocaine a minimum of 4 days in the prior month and met the criteria for a CUD enrolled in a two-stage intervention. All participants received a computer-delivered skills intervention and contingency management for reinforcing abstinence for a 1-month period. Participants demonstrating less than 3 weeks of abstinence in the first month were randomized to receive mixed amphetamine salts-extended release (MAS-ER) or placebo (80 mg/day) for 10 weeks under double-blind conditions. All participants continued with the behavioral intervention. The primary outcome was the proportion of individuals who achieved 3 consecutive weeks of abstinence as measured by urine toxicology confirmed self-report at the study end. The proportion of participants demonstrating 3 consecutive weeks of abstinence at study end did not differ between the medication groups: MAS-ER = 15.6% (7/45) and placebo = 12.2% (5/41). Participants who received MAS-ER reported greater reductions in the magnitude of wanting cocaine, although no group differences were noted in either the perceived improvement or the frequency of wanting cocaine. Retention rates were greater for both medication groups compared to behavioral responders. Overall, augmenting a behavioral intervention with MAS-ER did not significantly increase the abstinence rate among individuals continuing to use cocaine following a month of behavioral therapy alone. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Amyloid-ß neuropathology induces bone loss in male mice by suppressing bone formation and enhancing bone resorption.

Alzheimer's disease (AD) and osteoporosis often coexist in the elderly. Although observational studies suggest an association between these two diseases, the pathophysiologic link between AD and skeletal health has been poorly defined. We examined the skeletal phenotype of 5xFAD mice, an AD model with accelerated neuron-specific amyloid-ß accumulation causing full-blown AD phenotype by the age of 8 months. Micro-computed tomography indicated significantly lower trabecular and cortical bone parameters in 8-month-old male, but not female, 5xFAD mice than sex-matched wild-type littermates. Dynamic histomorphometry revealed reduced bone formation and increased bone resorption, and quantitative RT-PCR showed elevated skeletal RANKL gene expression in 5xFAD males. These mice also had diminished body fat percentage with unaltered lean mass, as determined by dual-energy X-ray absorptiometry (DXA), and elevated Ucp1 mRNA levels in brown adipose tissue, consistent with increased sympathetic tone, which may contribute to the osteopenia observed in 5xFAD males. Nevertheless, no significant changes could be detected between male 5xFAD and wild-type littermates regarding the serum and skeletal concentrations of norepinephrine. Thus, brain-specific amyloid-ß pathology is associated with osteopenia and appears to affect both bone formation and bone resorption. Our findings shed new light on the pathophysiologic link between Alzheimer's disease and osteoporosis.

The PYY/Y2R-deficient male mouse is not protected from bone loss due to Roux-en-Y gastric bypass.

BACKGROUND: Peptide YY (PYY) is an anorexigenic gut hormone that also has anti-osteogenic effects, inhibiting osteoblastic activity and inducing catabolic effects. It has been postulated that increases in PYY after Roux-en-Y gastric bypass (RYGB) contribute to declines in bone mineral density (BMD) and increases in bone turnover. The aim of this study is to determine the role of the PYY Y2-receptor in mediating bone loss post-RYGB in mice. METHODS: We compared adult male wildtype (WT) and PYY Y2 receptor-deficient (KO) C57BL/6 mice that received RYGB (WT: n = 8; KO: n = 9), with sham-operated mice (Sham; WT: n = 9; KO: n = 10) and mice that were food-restricted to match the weights of the RYGB-treated group (Weight-Matched, WM; WT: n = 7; KO: n = 5). RYGB or sham surgery was performed at 15-16 weeks of age, and mice sacrificed 21 weeks later. We characterized bone microarchitecture with micro-computed tomography (µCT) at the distal femur (trabecular) and femoral midshaft (cortical). Differences in body weight, bone microarchitecture and biochemical bone markers (parathyroid hormone, PTH; C-telopeptide, CTX; and type 1 procollagen, P1NP) were compared using 2-factor ANOVA with Tukey's adjustments for multiple comparisons. RESULTS: Body weights were similar in the WT-RYGB, WT-WM, KO-RYGB, and KO-WM: 41-44 g; these groups weighed significantly less than the Sham surgery groups: 55-57 g. Trabecular BMD was 31-43 % lower in RYGB mice than either Sham or WM in WT and KO groups. This deficiency in trabecular bone was accompanied by a lower trabecular number (19 %-23 %), thickness (22 %-30 %) and increased trabecular spacing (25 %-34 %) in WT and KO groups (p < 0.001 for all comparisons vs. RYGB). RYGB led to lower cortical thickness, cortical tissue mineral density, and cortical bone area fraction as compared to Sham and WM in WT and KO groups (p ≤ 0.004 for all). There were no interactions between genotype and bone microarchitecture, with patterns of response to RYGB similar in both WT and KO groups. CTX and P1NP were significantly higher in RYGB mice than WM in WT and KO groups. PTH did not differ among groups. CONCLUSIONS: RYGB induced greater trabecular and cortical deficits and high bone turnover than observed in weight-matched mice, with a similar pattern in the WT and Y2RKO mice. Thus, skeletal effects of RYGB are independent of weight loss, and furthermore, PYY signaling through Y2R is not a key mediator of bone loss post-RYGB.