Vitamin D supplementation protects against bone loss associated with chronic alcohol administration in female mice

A vitamin D deficient diet increases weight gain and compromises bone biomechanical properties without a reduction in BMD in adult female mice

Vitamin D contributes to the development and maintenance of bone. Evidence suggests vitamin D status can also alter energy balance and gut health. In young animals, vitamin D deficiency (VDD) negatively affects bone mineral density (BMD) and bone microarchitecture, and these effects may also occur due to chronic ethanol intake. However, evidence is limited in mature models, and addressing this was a goal of the current study. Seven-month-old female C57BL/6 mice (n = 40) were weight-matched and randomized to one of four ad libitum diets: control, alcohol (Alc), vitamin D deficient (0 IU/d), or Alc+VDD for 8 weeks. A purified (AIN-93) diet was provided with water or alcohol (10 %) ad libitum. Body weight and food intake were recorded weekly, and feces were collected at 0, 4, and 8 weeks. At the age of 9 months, intestinal permeability was assessed by oral gavage of fluorescein isothiocyanate-dextran. Thereafter, bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. The microarchitecture of the distal femur was assessed by micro-computed tomography and biomechanical properties were evaluated by cyclic reference point indentation. VDD did not affect BMD or most bone microarchitecture parameters, however, the polar moment of inertia (p < 0.05) was higher in the VDD groups compared to vitamin D sufficient groups. VDD mice also had lower whole bone water content (p < 0.05) and a greater average unloading slope (p < 0.01), and energy dissipated (p < 0.01), indicating the femur displayed a brittle phenotype. In addition, VDD caused a greater increase in energy intake (p < 0.05), weight gain (p < 0.05), and a trend for higher intestinal permeability (p = 0.08). The gut microbiota of the VDD group had a reduction in alpha diversity (p < 0.05) and a lower abundance of ASVs from Rikenellaceae, Clostridia_UCG-014, Oscillospiraceae, and Lachnospiraceae (p < 0.01). There was little to no effect of alcohol supplementation on outcomes. Overall, these findings suggest that vitamin D deficiency causes excess weight gain and reduces the biomechanical strength of the femur as indicated by the higher average unloading slope and energy dissipated without an effect on BMD in a mature murine model.

Evaluation of Adherence to Guideline-Based Bone Mineral Density Screening in Veterans with HIV

People with HIV (PWH) have a higher prevalence of bone mineral density (BMD) loss compared to people without HIV. The Infectious Diseases Society of America (IDSA) recommends BMD screening through dual energy X-ray absorptiometry (DXA) in PWH starting at age 50. We aimed to evaluate adherence to this recommendation in a population of Veterans with HIV (VWH). Retrospective cross-sectional analysis of VWH followed from 2014 to 2018 at the Michael E. DeBakey VA Medical Center Infectious Diseases Clinic, Houston, Texas. We collected data through registry extraction and chart review. We calculated the percentage of VWH with timely BMD loss screening by DXA within 5 years of turning 50. Secondary outcomes included prevalence of osteopenia, osteoporosis, and vitamin D deficiency. We included data from 1,243 VWH. Their average age was 52 years (range 18-86). Most were male (95%), and 59% were black. Of the 346 VWH who turned 50 years old during the study period, 78 (22.5%) underwent DXA within 5 years. Of these, 42 (53.8%) had normal BMD, 28 (35.9%) had osteopenia, and 8 (10.3%) had osteoporosis. Nine hundred ninety-three (79.9%) VWH had available 25-hydroxyvitamin D levels; of these, 453 (45%) had normal levels, 304 (30.6%) had vitamin D insufficiency, 184 (18.5%) had vitamin D deficiency, and 52 (5.2%) had severe vitamin D deficiency. Fewer than 25% of eligible VWH underwent timely BMD loss screening by DXA per IDSA guidelines. Almost half of screened VWH showed evidence of BMD loss. Although limited by lack of follow-up and fracture data, this study emphasizes the importance of improving BMD loss screening in this vulnerable population.

A Traditional Chinese Medicine Plant Extract Prevents Alcohol-Induced Osteopenia

Traditional Chinese medicine (TCM) has been practiced in the treatment of bone diseases and alcoholism. Chronic excessive alcohol use results in alcohol-induced bone diseases, including osteopenia and osteoporosis, which increases fracture risk, deficient bone repair, and osteonecrosis. This preclinical study investigated the therapeutic effects of TCM herbal extracts in animal models of chronic excessive alcohol consumption-induced osteopenia. TCM herbal extracts (Jing extracts) were prepared from nine Chinese herbal medicines, a combinative herbal formula for antifatigue and immune regulation, including Astragalus, Cistanche deserticola, Dioscorea polystachya, Lycium barbarum, Epimedium, Cinnamomum cassia, Syzygium aromaticum, Angelica sinensis, and Curculigo orchioides. In this study, Balb/c male mice were orally administrated alcohol (3.2 g/kg/day) with/without TCM herbal extracts (0.125 g/kg, 0.25 g/kg, or 0.5 g/kg) by gavage. Our results showed that after 50 days of oral administration, TCM herbal extracts prevented alcohol-induced osteopenia demonstrated by μ-CT bone morphological analysis in young adults and middle-aged/old Balb/c male mice. Biochemical analysis demonstrated that chronic alcohol consumption inhibits bone formation and has a neutral impact on bone resorption, suggesting that TCM herbal extracts (Jing extracts) mitigate the alcohol-induced abnormal bone metabolism in middle-aged/old male mice. Protocatechuic acid, a natural phenolic acid in Jing extracts, mitigates in vivo alcohol-induced decline of alkaline phosphatase (ALP) gene expression in the bone marrow of Balb/c male mice and in vitro ALP activity in pre-osteoblast MC3T3-E1 cells. Our study suggests that TCM herbal extracts prevent chronic excessive alcohol consumption-induced osteopenia in male mice, implying that traditional medicinal plants have the therapeutic potential of preventing alcohol-induced bone diseases.

Alcohol consumption induces murine osteoporosis by downregulation of natural killer T-like cell activity

Introduction

Chronic alcohol consumption (CAC) can induce several deleterious effects on the body, including the promotion of osteoporosis; however, the immunological mechanism underlying alcohol‐induced osteoporosis is still unclear.

Methods

We administered alcohol to mice for 4 weeks as the experimental CAC model and analyzed the bone and immune cells that are located in the vicinity of a bone.

Results

IL‐4 is known to be a suppressive factor for osteoclastogenesis, and we found that natural killer T (NKT)‐like cells, which showed NK1.1‐positive, CD3‐positive, and α‐galactosylceramide‐loaded CD1d tetramer‐negative, produced IL‐4 more effectively than CD4⁺ T and natural killer (NK) cells. The alcohol consumption facilitated a significant decrease of bone mineral density with the upregulation of nuclear factor of activated T cells 1 and receptor activator of NF‐κB ligand expression. Meanwhile, we confirmed that alcohol consumption suppressed the activity of antigen‐presenting cells (APCs) and NKT‐like cells, leading to decreased IL‐4 secretion. Moreover, these harmful effects of alcohol consumption were reduced by simultaneous treatment with a glycolipid antigen OCH.

Conclusions

Our results indicate that the inactivation of innate immune cells, APCs, and NKT‐like cells are likely to be crucial for alcohol‐induced osteoporosis and provide a new therapeutic approach for preventing osteoporosis.

Correlation Between Serum 25(OH)D and Abdominal Visceral Fat Area in Patients with Type 2 Diabetes Mellitus in the Context of different Bone Mass

OBJECTIVE

To investigate the correlation between serum levels of 25-hydroxy vitamin D [25(OH)D] and the visceral fat area of patients with type 2 diabetes mellitus (T2DM) in the context of different bone mass.

MATERIALS AND METHODS

A total of 180 patients with T2DM were randomly selected for bone mineral density (BMD) examination. According to the results, they were divided into three groups: T2DM normal bone group (group A); T2DM bone mass reduction group (group B); T2DM osteoporosis group (group C).

RESULT

Serum 25(OH)D levels in NC group, A group, B group and C group decreased in turn, and Visceral fat area (VFA) in group B and group C were significantly higher than those in group A and NC [(29.41±4.87) vs. (22.76±4.23) vs. (17.78±3.61) vs. (9.70±3.01), P<0.05], [(117.76±38.79), (125.08±37.90) vs. (89.79±26.51), (97.53±28.61), P<0.05]. Pearson correlation analysis showed that L1-L4 lumbar vertebrae bone density was positively correlated with 25(OH)D and VFA; left femoral neck bone density was positively correlated with 25(OH)D, and negatively correlated with VFA.

CONCLUSION

Serum 25(OH)D and VFA may be associated with the development of T2DM combined with OP.

Chronic ethanol consumption does not reduce true bone density in male Wistar rats

Osteoporosis is characterized by reduced bone mineral density (BMD) and increased bone fragility, which may be modified by lifestyle behaviors. In observational studies, chronic moderate ethanol consumption is associated with higher BMD, but results are inconsistent and underlying mechanisms are unknown. To understand the influence of chronic ethanol consumption on true bone density (Archimedes principal), bone mechanical properties (Young's Modulus of bend), and osteogenic gene expression, 12-month-old male Wistar rats were randomly assigned to a control group or ethanol intervention (20% ethanol in drinking water on alternate days) group for 13 weeks and tibiae and femurs were collected. Blood was collected to assess alcohol content and antioxidant enzyme activities. We hypothesized that chronic ethanol consumption would increase true bone density and mechanical properties and increase osteoblastic gene expression and serum antioxidant enzyme activity. Ethanol consumption did not influence femoral or tibial true bone density but did result in lower tibial Young's modulus of bend (p = 0.0002). However, there was no influence of ethanol on other measures of mechanical properties. Femoral pro-osteoclastic gene expression of Dkk1 was lower (p = 0.0006) and pro-osteoblastic gene expression of Ctnnb1 was higher (p = 0.02) with ethanol consumption. We observed no differences in circulating antioxidant activities between groups, other than a tendency for greater (p = 0.08) glutathione peroxidase in the ethanol group. Results showed chronic ethanol consumption did not influence true bone density, only modestly reduced tibial mechanical properties (lower Young's modulus of bend), and moderately impacted expression of genes within the femur known to regulate both osteoblast and osteoclast activities.

Antagonistic Impact of Acrylamide and Ethanol on Biochemical and Morphological Parameters Consistent with Bone Health in Mice

Simple Summary

Alcohol consumption, the drinking of beverages containing ethanol, represents a growing problem worldwide. Alcohol intake is often combined with an improper diet based on highly processed starch products that are rich in acrylamide. Both acrylamide and alcohol have a harmful impact on bone health. We previously demonstrated that adverse effects of ethanol on cortical bone structure were partly reduced by a relatively high dose of acrylamide in mice after one remodelling cycle. The present research was designated to reveal whether the antagonistic impact of both aforementioned toxins can also be achieved using a lower dose of acrylamide. According to our results, individual administrations of acrylamide and ethanol had adverse impacts on biochemical and morphological parameters consistent with bone health in mice. However, the most detrimental effects of ethanol were again alleviated by acrylamide at the dose used in this study.

Abstract

The aim of present study was to verify antagonistic effect of acrylamide (AA) and ethanol (Et) on bone quality parameters. Adult mice (n = 20) were segregated into four groups following 2 weeks administration of toxins: group E1, which received AA (20 mg/kg body weight daily); group E2, which received 15% Et (1.7 g 100% Et/kg body weight daily); group E12, which received simultaneously both toxins; and a control group. An insignificant impact of individual applications of AA, Et or their simultaneous supplementation on the total body weight of mice and the length and weight of their femoral bones was identified. In group E1, higher levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), a decreased level of glutathione (GSH) and elevated endocortical bone remodelling were determined. A significantly lower relative volume of cortical bone, bone mineral density (BMD), elevated endocortical bone remodelling and cortical porosity, higher levels of ALT, AST, lower values for total proteins (TP), GSH, alkaline phosphatase (ALP), calcium, and phosphorus were recorded in group E2. In the mice from group E12, the highest endocortical bone remodelling, decreased values for BMD, TP, GSH and ALP and increased levels of ALT and AST were found. Our findings confirmed the antagonistic impact of AA and Et at doses used in this study on biochemical and morphological parameters consistent with bone health in an animal model.

Impact of Alcohol on Bone Health, Homeostasis and Fracture repair

Purpose of review

Alcohol use continues to rise globally. We review the current literature on the effect of alcohol on bone health, homeostasis and fracture repair to highlight what has been learned in people and animal models of alcohol consumption.

Recent findings

Recently, forkhead box O (FoxO) has been found to be upregulated and activated in mesenchymal stem cells (MSC) exposed to alcohol. FoxO has also been found to modulate Wnt/β-catenin signaling, which is necessary for MSC differentiation. Recent evidence suggests alcohol activates FoxO signaling, which may be dysregulating Wnt/β-catenin signaling in MSCs cultured in alcohol.

Summary

This review highlights the negative health effects learned from people and chronic and episodic binge alcohol consumption animal models. Studies using chronic alcohol exposure or alcohol exposure then bone fracture repair model have explored several different cellular and molecular signaling pathways important for bone homeostasis and fracture repair, and offer potential for future experiments to explore additional signaling pathways that may be dysregulated by alcohol exposure.

Skeletal Toxicity of Coplanar Polychlorinated Biphenyl Congener 126 in the Rat Is Aryl Hydrocarbon Receptor Dependent

Epidemiological evidence links polychlorinated biphenyls (PCBs) to skeletal toxicity, however mechanisms whereby PCBs affect bone are poorly studied. In this study, coplanar PCB 126 (5 μmol/kg) or corn oil vehicle was administered to N = 5 and 6 male and female, wild type (WT) or AhR -/- rats via intraperitoneal injection. Animals were sacrificed after 4 weeks. Bone length was measured; bone morphology was assessed by microcomputed tomography and dynamic histomorphometry. Reduced bone length was the only genotype-specific effect and only observed in males (p < .05). WT rats exposed to PCB 126 had reduced serum calcium, and smaller bones with reduced tibial length, cortical area, and medullary area relative to vehicle controls (p < .05). Reduced bone formation rate observed in dynamic histomorphometry was consistent with inhibition of endosteal and periosteal bone growth. The effects of PCB 126 were abolished in AhR -/- rats. Gene expression in bone marrow and shaft were assessed by RNA sequencing. Approximately 75% of the PCB-regulated genes appeared AhR dependent with 89 genes significantly (p < .05) regulated by both PCB 126 and knockout of the AhR gene. Novel targets significantly induced by PCB 126 included Indian hedgehog (Ihh) and connective tissue growth factor (Ctgf/Ccn2), which regulate chondrocyte proliferation and differentiation in the bone growth plate and cell-matrix interactions. These data suggest the toxic effects of PCB 126 on bone are mediated by AhR, which has direct effects on the growth plate and indirect actions related to endocrine disruption. These studies clarify important mechanisms underlying skeletal toxicity of dioxin-like PCBs and highlight potential therapeutic targets.

Protective Effects of Methoxsalen Supplementation on Chronic Alcohol-Induced Osteopenia and Steatosis in Rats

Osteopenia or osteoporosis occurs frequently in alcoholics and patients with alcoholic fatty liver disease. Methoxsalen (MTS), 8-methoxypsoralen, improved osteoporosis in ovariectomized and diabetic mouse models; however, its effects on alcohol-induced osteopenia and steatosis have not been reported. This study examined the effects of MTS on alcohol-induced bone loss and steatosis. Rats in the alcohol groups were fed a Liber-DeCarli liquid diet containing 36% of its calories as alcohol. MTS was at 0.005% in their diet, while alendronate (positive control; 500 μg/kg BW/day) was administered orally for eight weeks. The pair-fed group received the same volume of isocaloric liquid diet containing dextrin-maltose instead of alcohol as the alcohol control group consumed the previous day. In the alcohol-fed rats, the MTS and alendronate increased the bone volume density, bone surface density and trabecular number, while the bone specific surface, trabecular separation and structure model index were decreased in the tibia. MTS down-regulated tibial tartrate-resistant acid phosphatase 5 (TRAP) expression compared to the alcohol control group. MTS or alendronate prevented chronic alcohol-induced hepatic lipid accumulation and the triglyceride level in the alcohol-fed rats by decreasing the lipogenic enzyme activities and increasing the fatty acid oxidation enzyme activities. MTS reduced significantly the serum levels of alcohol, TRAP and tumor necrosis factor-α compared to the alcohol control group. Overall, these results suggest that MTS is likely to be an alternative agent for alcoholic osteopenia and hepatosteatosis.

Single and simultaneous effects of acrylamide and ethanol on bone microstructure of mice after one remodeling cycle

Background

This study aimed to examine femoral bone microstructure of mice after single and simultaneous administration to acrylamide and ethanol since both substances are often consumed separately and/or together by humans. Interactive effects of these toxins were analysed after one remodeling cycle.

Methods

Twenty clinically healthy adult mice were randomly divided into four groups following 2 weeks administration of toxins: A group - mice were fed with acrylamide (40 mg/kg bw); E group - mice were ethanol-fed (15% ethanol); AE group - mice were simultaneously fed with both toxins, and a C group – control (without acrylamide and/or ethanol supplementation). Generally, 2D and 3D imaging methods were used to determine cortical and trabecular bone tissues microstructure. Biochemical analyses of plasma parameters were also realized using commercially available ELISA tests and spectrophotometrically.

Results

Single and simultaneous exposure to acrylamide and ethanol affected only cortical bone microstructure. No significant changes in trabecular bone morphometry were detected among all groups. In mice from the A group, increased endocortical remodeling associated with a higher level of serum calcium and vasoconstriction of primary osteon’s vascular canals (POVC) were identified. On the contrary, increased cortical porosity consistent with a decreased relative bone volume, bone mineral density (BMD) and lower levels of alkaline phosphatase (ALP), glutathione (GSH), calcium in plasma and also with vasodilation of POVC were observed in the E group. In the AE group, the highest density of secondary osteons associated with a lower BMD and decreased levels of ALP, GSH were documented. The parameters of POVC and Haversian canals approximated to the C group. In addition, single and simultaneous exposure to both toxins caused liver disease consistent with a higher values of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in plasma of all experimental groups.

Conclusions

Single administration to acrylamide and ethanol had negative effects on cortical bone structure of mice after one remodeling cycle. However, we identified possible antagonistic impact of these toxins on the structure of the cortical bone.

Hepatic Osteodystrophy-Molecular Mechanisms Proposed to Favor Its Development

Almost all patients with chronic liver diseases (CLD) show altered bone metabolism. Depending on the etiology, this manifests in a severe osteoporosis in up to 75% of the affected patients. Due to high prevalence, the generic term hepatic osteodystrophy (HOD) evolved, describing altered bone metabolism, decreased bone mineral density, and deterioration of bone structure in patients with CLD. Once developed, HOD is difficult to treat and increases the risk of fragility fractures. Existing fractures affect the quality of life and, more importantly, long-term prognosis of these patients, which presents with increased mortality. Thus, special care is required to support the healing process. However, for early diagnosis (reduce fracture risk) and development of adequate treatment strategies (support healing of existing fractures), it is essential to understand the underlying mechanisms that link disturbed liver function with this bone phenotype. In the present review, we summarize proposed molecular mechanisms favoring the development of HOD and compromising the healing of associated fractures, including alterations in vitamin D metabolism and action, disbalances in transforming growth factor beta (TGF-β) and bone morphogenetic protein (BMP) signaling with histone deacetylases (HDACs) as secondary regulators, as well as alterations in the receptor activator of nuclear factor kappa B ligand (RANKL)–osteoprotegerin (OPG) system mediated by sclerostin. Based on these mechanisms, we give an overview on the limitations of early diagnosis of HOD with established serum markers.

Compounding effect of vitamin D3 diet, supplementation, and alcohol exposure on macrophage response to mycobacterium infection

Vitamin D₃ is known to be a key component in the defense against Mycobacterium tuberculosis (Mtb) infection through the regulation of cytokine and effector molecules. Conversely, alcohol exposure has been recognized as an immune dysregulator. Macrophages were extracted from D₃ deficient and sufficient diet mice and supplemented with D₃ or exposed to ethanol during ex vivo infection using M. bovis BCG, as a surrogate for Mtb. Results of our study indicate that while exogenous supplementation or alcohol exposure did alter immune response, in vivo diet was the greatest determinant of cytokine and effector molecule production. Alcohol exposure was found to profoundly dysregulate primary murine macrophages, with ethanol-exposed cells generally characterized as hyper- or hyporesponsive. Exogenous D₃ supplementation had a normative effect for diet deficient host, however supplementation was not sufficient to compensate for the effects of diet deficiency. Vitamin D₃ sufficient diet resulted in reduced cell cytotoxicity for the majority of time points. Results provide insight into the ramifications of both the individual and combined health risks of D₃ deficiency or alcohol exposure. Given the clinical relevance of D₃ deficiency and alcohol use comorbidities, outcomes of this study have implications in therapeutic approaches for the treatment of tuberculosis disease.

Prenatal vitamin D deficiency does not exacerbate behavioural impairments associated with prenatal ethanol exposure in juvenile male mice

There is a high prevalence of vitamin D deficiency and exposure to low levels of ethanol in pregnant women. However, there are a paucity of studies that have addressed the impact of both vitamin D deficiency and ethanol exposure on the offspring's vulnerability to neurodevelopmental disorders later in life. The aim of this study was to examine whether the absence of vitamin D during gestation in mice would alter the effects of prenatal exposure to low dose ethanol on the behaviour and dopaminergic gene expression patterns of juvenile mice. Four-week old female C57BL/6J mice were placed on a prenatal vitamin D deficient (PVD) or standard diet for 6 weeks and mated at 10 weeks of age. Females were exposed to either 10%(v/v) ethanol or water between gestational days 0-8 and all were offered water thereafter. We found that blood ethanol concentration in the dams was not affected by maternal diet. Behavioural analyses of the offspring included ultrasonic vocalizations (USV) at postnatal day (P) 7, locomotion and social interaction at P21. The main findings were increased USV calling rate and impaired social interaction in males with prenatal ethanol exposure (PrEE). Gene expression analysis of transcripts involved in dopamine regulation revealed a main effect of ethanol exposure on dopamine- and cyclic adenosine monophosphate- regulated neuronal phosphoprotein (Darpp-32), a main effect of vitamin D diet on Dopamine 2 Receptors (D2R) and a main effect of Sex on Tyrosine Hydroxylase (TH) expression. The combination of PVD-PrEE did not exacerbate the alterations resulting from PVD or PrEE. Despite the limited evidence to support the interaction of PVD and PrEE during the postnatal period, males were more vulnerable than female offspring to the detrimental effects of PrEE. Therefore, based on these studies in mice we suggest that maintenance of optimal vitamin D levels and abstinence from ethanol during pregnancy would reduce risk of later disruption to brain function and behaviour in the offspring.

Changes in the microstructure of compact and trabecular bone tissues of mice subchronically exposed to alcohol

BACKGROUND

Alcohol is one of the most commonly consumed neurotoxins by humans. Its negative effect on bone health is known for a long time. However, its impact on qualitative and quantitative 2D characteristics of the compact bone is still unclear. Therefore, the aim of this study was to investigate in detail the effects of subchronic alcohol exposure on compact and trabecular bone tissues microstructure of laboratory mice using 2D and 3D imaging methods. Ten clinically healthy 12 weeks-old mice (males) were randomly divided into two groups. Animals from experimental group (group E; n = 5) drank a solution composed of 15% ethanol and water (1.7 g 100% ethanol kg-1 b.w. per day) for 8 weeks, while those from control group (group C; n = 5) drank only water.

RESULTS

Subchronic exposure to alcohol leads to several changes in qualitative 2D characteristics of the compact bone such as the presence of primary vascular radial bone tissue in pars anterior of endosteal border and a higher number of resorption lacunae (five times more) in the middle part of substantia compacta. Morphometrical 2D evaluations of the compact bone showed significantly increased sizes of primary osteons' vascular canals (p < 0.05) in mice from the experimental group (E group). Sizes of Haversian canals and secondary osteons were not affected by alcohol consumption. In mice from the E group, significantly lower values for relative bone volume and bone mineral density of the compact bone were observed. In the trabecular bone, decreased values for bone volume, trabecular number, trabecular thickness and bone surface (p < 0.05) were documented.

CONCLUSIONS

Alcohol decreased not only bone volume and density of the compact bone, but it also reduced trabecular bone volume and leads to trabecular thinning. It caused vasodilation of primary osteons' vascular canals and increased porosity in the compact bone.

Cholecalciferol in ethanol-preferring rats muscle fibers increases the number and area of type II fibers

The chronic use of ethanol causes neuropathy and atrophy of type II fibers and promotes vitamin D decrease. This study evaluated cholecalciferol effects on the deep fibular nerve and extensor digitorum longus (EDL) muscle using an UChB ethanol-preferring rats model. Blood analyses were carried out to measure levels of 25-hydroxycholecalciferol (25(OH)D), calcium (Ca²⁺), Phosphorus (P), and parathyroid hormone (PTH). It was used EDL muscle to evaluate oxidative stress. The deep fibular nerve and EDL muscle were used for morphologic and morphometric assessment. 25(OH)D plasma levels were higher in the supplemented group and no alterations were observed in other parameters including the oxidative stress evaluation. The G ratio remained constant which indicates nervous conduction normality. Cholecalciferol supplementation promoted an increase in the number and area of type II fibers and a decrease in the area of type I fibers. In the studied model, there was neither alcoholic myopathy nor neuropathy. The EDL muscle glycolytic patterns in the high-drinker UChB rats may be associated with the differential effects of cholecalciferol on metabolism and protein synthesis in skeletal muscle.

Subacute exposure to alcohol in relation to bone microstructure of mice

Our study aimed to investigate subacute exposure to alcohol in relation to bone microstructure of mice. Animals from experimental (E) group drank a solution composed of 15 % ethanol and water for 14 days (one remodeling cycle), while those from control (C) group drank only water. In the compact bone of E group, decreased bone formation and increased porosity were observed which corresponds with lower levels of serum alkaline phosphatase and glutathione. Alcohol significantly increased sizes of primary osteon's vascular canals and decreased those of secondary osteons, Haversian canals. Relative bone volume, bone mineral density (BMD), relative bone volume without marrow cavity were also lower in E group. On the contrary, trabecular bone microstructure did not differ significantly between E and C groups. Liver function test showed higher levels of alanine aminotransferase, aspartate aminotransferase in alcohol-fed mice. Serum calcium, phosphate were significantly lower in E group. According to our study, only changes in compact bone microstructure of mice following one remodeling cycle were observed due to both direct and indirect effects of alcohol.

Role of sclerostin and dkk1 in bone remodeling in type 2 diabetic patients

PURPOSE

This study aimed to investigate the role of sclerostin and dkk1 in the bone metabolism of type 2 diabetic patients.

METHODS

This cross-sectional study included 95 inpatients with type 2 diabetes mellitus. We divided the patients into three groups (i.e., the normal bone mineral density (BMD) group, osteopenia group and osteoporosis group) based on their different BMD levels and measured the serum levels of sclerostin, dkk1, 25-hydroxyvitamin D₃ (25OHD₃), bone turnover markers and other biochemical data in each group.

RESULTS

Significantly increased levels of serum sclerostin and dkk1 were found in the osteoporosis group, even when the male and female cohorts were considered separately. Ordinal logistic regression analysis suggested that the levels of serum sclerostin were independently associated with the presence of osteopenia and osteoporosis after adjusting for age, gender and 25OHD₃ (sclerostin: OR = 1.02, p = 0.001). The areal BMDs were negatively correlated with the levels of serum sclerostin and dkk1 and positively correlated with 25OHD₃. In addition, age, glycosylated hemoglobin and serum sclerostin levels were predictors for N-terminal propeptide of type 1 procollagen and serum dkk1 levels were the only predictors for crosslinked carboxyterminal telopeptide in type 1 collagen.

CONCLUSIONS

The sclerostin and dkk1 levels increased in conjunction with the reduction of BMD, confirming that the Wnts, inhibited by sclerostin and dkk1, were potentially responsible for bone fragility in type 2 diabetes patients with osteoporosis. Note that the serum sclerostin levels were predictors for bone formation, while the DKK1 levels predicted bone resorption.

Cellular and molecular mechanisms of alcohol-induced osteopenia

Alcoholic beverages are widely consumed, resulting in a staggering economic cost in different social and cultural settings. Types of alcohol consumption vary from light occasional to heavy, binge drinking, and chronic alcohol abuse at all ages. In general, heavy alcohol consumption is widely recognized as a major epidemiological risk factor for chronic diseases and is detrimental to many organs and tissues, including bones. Indeed, recent findings demonstrate that alcohol has a dose-dependent toxic effect in promoting imbalanced bone remodeling. This imbalance eventually results in osteopenia, an established risk factor for osteoporosis. Decreased bone mass and strength are major hallmarks of osteopenia, which is predominantly attributed not only to inhibition of bone synthesis but also to increased bone resorption through direct and indirect pathways. In this review, we present knowledge to elucidate the epidemiology, potential pathogenesis, and major molecular mechanisms and cellular effects that underlie alcoholism-induced bone loss in osteopenia. Novel therapeutic targets for correcting alcohol-induced osteopenia are also reviewed, such as modulation of proinflammatory cytokines and Wnt and mTOR signaling and the application of new drugs.

Vitamin D Deficiency in Pregnant Ukrainian Women: Effects of Alcohol Consumption on Vitamin D Status

OBJECTIVE

Heavy alcohol consumption can alter vitamin D status; however, the relationships between alcohol consumption and vitamin D concentrations in pregnant women have not been well studied. The aim of this study was to investigate the vitamin D status in a population of alcohol-exposed (N = 180) and low/unexposed control (N = 179) Ukrainian pregnant women.

METHODS

Women who attended prenatal care facilities in 2 regions of Ukraine (Rivne and Khmelnytsky) for a routine prenatal visit were screened for the study. At the time of enrollment (20.4 ± 7.0 weeks of gestation), blood samples and alcohol consumption data (during a typical week around conception and the most recent 2 weeks) were collected. Vitamin D status was assessed by 25-hydroxyvitamin D [25(OH)D] concentrations.

RESULTS

A high prevalence of suboptimal vitamin D status in pregnant Ukrainian women was observed. Overall, 50.1% and 33.4% of the women were classified as vitamin D deficient [25(OH)D < 20 ng/mL] or insufficient [25(OH)D ≥ 20 ng/mL and ≤30 ng/mL], respectively, based on 2011 Endocrine Society guidelines. Alcohol-exposed women had significantly lower 25(OH)D concentrations than low/unexposed women in Spring (p = 0.006) and Winter (p = 0.022). When vitamin D concentrations were grouped into sunny season (Summer + Fall) compared to not sunny season (Winter + Spring), there was a significant ethanol by season interaction (p = 0.0028), with alcohol-drinking women having lower circulating vitamin D compared to low/unexposed women in seasons of low sun availability.

CONCLUSIONS

These data suggest that when vitamin D concentrations are generally low (e.g., during seasons of low sun availability), alcohol consumption during pregnancy has a negative impact on vitamin D status.

Chronic moderate ethanol intake differentially regulates vitamin D hydroxylases gene expression in kidneys and xenografted breast cancer cells in female mice

Factors affecting vitamin D metabolism may preclude anti-carcinogenic effects of its active metabolite calcitriol. Chronic ethanol consumption is an etiological factor for breast cancer that affects vitamin D metabolism; however, the mechanisms underlying this causal association have not been fully clarified. Using a murine model, we examined the effects of chronic moderate ethanol intake on tumoral and renal CYP27B1 and CYP24A1 gene expression, the enzymes involved in calcitriol synthesis and inactivation, respectively. Ethanol (5% w/v) was administered to 25-hydroxyvitamin D₃-treated or control mice during one month. Afterwards, human breast cancer cells were xenografted and treatments continued another month. Ethanol intake decreased renal Cyp27b1 while increased tumoral CYP24A1 gene expression.Treatment with 25-hydroxyvitamin D₃ significantly stimulated CYP27B1 in tumors of non-alcohol-drinking mice, while increased both renal and tumoral CYP24A1. Coadministration of ethanol and 25-hydroxyvitamin D₃ reduced in 60% renal 25-hydroxyvitamin D₃-dependent Cyp24a1 upregulation (P<0.05). We found 5 folds higher basal Cyp27b1 than Cyp24a1 gene expression in kidneys, whereas this relation was inverted in tumors, showing 5 folds more CYP24A1 than CYP27B1. Tumor expression of the calcitriol target cathelicidin increased only in 25-hydroxyvitamin D₃-treated non-ethanol drinking animals (P<0.05). Mean final body weight was higher in 25-hydroxyvitamin D₃ treated groups (P<0.001). Overall, these results suggest that moderate ethanol intake decreases renal and tumoral 25-hydroxyvitamin D₃ bioconversion into calcitriol, while favors degradation of both vitamin D metabolites in breast cancer cells. The latter may partially explain why alcohol consumption is associated with vitamin D deficiency and increased breast cancer risk and progression.

Partial Protection by Dietary Antioxidants Against Ethanol-Induced Osteopenia and Changes in Bone Morphology in Female Mice

BACKGROUND

Chronic alcohol consumption leads to increased fracture risk and an elevated risk of osteoporosis by decreasing bone accrual through increasing osteoclast activity and decreasing osteoblast activity. We have shown that this mechanism involves the generation of reactive oxygen species (ROS) produced by NADPH oxidases. It was hypothesized that different dietary antioxidants, N-acetyl cysteine (NAC; 1.2 mg/kg/d), and α-tocopherol (Vit.E; 60 mg/kg/d) would be able to attenuate the NADPH oxidase-mediated ROS effects on bone due to chronic alcohol intake.

METHODS

To study the effects of these antioxidants, female mice received a Lieber-DeCarli liquid diet containing ethanol (EtOH) with or without additional antioxidant for 8 weeks.

RESULTS

Tibias displayed decreased cortical bone mineral density in both the EtOH and EtOH + antioxidant groups compared to pair-fed (PF) and PF + antioxidant groups (p < 0.05). However, there was significant protection from trabecular bone loss in mice fed either antioxidant (p < 0.05). Microcomputed tomography analysis demonstrated a significant decrease in bone volume (bone volume/tissue volume) and trabecular number (p < 0.05), along with a significant increase in trabecular separation in the EtOH compared to PF (p < 0.05). In contrast, the EtOH + NAC and EtOH + Vit.E did not statistically differ from their respective PF controls. Ex vivo histologic sections of tibias were stained for nitrotyrosine, an indicator of intracellular damage by ROS, and tibias from mice fed EtOH exhibited significantly more staining than PF controls. EtOH treatment significantly increased the number of marrow adipocytes per mm as well as mRNA expression of aP2, an adipocyte marker in bone. Only NAC was able to reduce the number of marrow adipocytes to PF levels. EtOH-fed mice exhibited reduced bone length (p < 0.05) and had a reduced number of proliferating chondrocytes within the growth plate. NAC and Vit.E prevented this (p < 0.05).

CONCLUSIONS

These data show that alcohol's pathological effects on bone extend beyond decreasing bone mass and suggest a partial protective effect of the dietary antioxidants NAC and Vit.E at these doses with regard to alcohol effects on bone turnover and bone morphology.

Reactive Oxygen Species Differentially Regulate Bone Turnover in an Age-Specific Manner in Catalase Transgenic Female Mice

Chronic ethyl alcohol (EtOH) consumption results in reactive oxygen species (ROS) generation in bone and osteopenia due to increased bone resorption and reduced bone formation. In this study, transgenic C57Bl/6J mice overexpressing human catalase (TgCAT) were used to test whether limiting excess hydrogen peroxide would protect against EtOH-mediated bone loss. Micro-computed tomography analysis of the skeletons of 6-week-old female chow-fed TgCAT mice revealed a high bone mass phenotype with increased cortical bone area and thickness as well as significantly increased trabecular bone volume (P < 0.05). Six-week-old wild-type (WT) and TgCAT female mice were chow fed or pair fed (PF) liquid diets with or without EtOH, approximately 30% of calories, for 8 weeks. Pair feeding of WT had no demonstrable effect on the skeleton; however, EtOH feeding of WT mice significantly reduced cortical and trabecular bone parameters along with bone strength compared with PF controls (P < 0.05). In contrast, EtOH feeding of TgCAT mice had no effect on trabecular bone compared with PF controls. At 14 weeks of age, there was significantly less trabecular bone and cortical cross-sectional area in TgCAT mice than WT mice (P < 0.05), suggesting impaired normal bone accrual with age. TgCAT mice expressed less collagen1α and higher sclerostin mRNA (P < 0.05), suggesting decreased bone formation in TgCAT mice. In conclusion, catalase overexpression resulted in greater bone mass than in WT mice at 6 weeks and lower bone mass at 14 weeks. EtOH feeding induced significant reductions in bone architecture and strength in WT mice, but TgCAT mice were partially protected. These data implicate ROS signaling in the regulation of bone turnover in an age-dependent manner, and indicate that excess hydrogen peroxide generation contributes to alcohol-induced osteopenia.

Osteoprotegerin Levels Decrease in Abstinent Alcohol-Dependent Patients

BACKGROUND

Osteoprotegerin (OPG) is a parameter of increasing interest in the search for pathophysiological mechanisms of reduced bone mineral density (BMD). It has been shown to be increased in alcohol-dependent subjects. In our study, we wanted to examine whether changes in OPG and receptor activator of the nuclear factor-κB ligand (RANKL) levels during an 8-week abstinence period in alcohol-dependent patients treated in an alcohol rehabilitation clinic would occur and whether alcohol-related variables, smoking, status, or physical activity prior to the study served as an influence on BMD and on OPG/RANKL levels.

METHODS

Forty-three patients, who were abstinent not longer than a week, were included in the study. OPG and RANKL as well as other markers of bone metabolism were measured at baseline, and after 8 weeks of treatment, BMD was measured once.

RESULTS

OPG levels decreased significantly, while osteocalcin, a marker of bone formation, increased significantly. RANKL as well as RANKL/OPG ratio, Serum CrossLaps, and all examined hormones showed no significant changes over time. Inflammatory parameters showed a significant reduction after 8 weeks. We detected no influence of potentially confounding variables of alcohol dependency on the course of OPG or other laboratory values.

CONCLUSIONS

Our results could point to the well-known risk for reduced BMD in these patients being reversible with abstinence through an excess of bone formation. We also confirmed earlier findings that inflammatory processes play a role in the pathogenesis of alcohol-induced disturbances in bone metabolism.

Alcohol: A Simple Nutrient with Complex Actions on Bone in the Adult Skeleton

BACKGROUND

Alcohol is an important nonessential component of diet, but the overall impact of drinking on bone health, especially at moderate levels, is not well understood. Bone health is important because fractures greatly reduce quality of life and are a major cause of morbidity and mortality in the elderly. Regular alcohol consumption is most common following skeletal maturity, emphasizing the importance of understanding the skeletal consequences of drinking in adults.

METHODS

This review focuses on describing the complex effects of alcohol on the adult skeleton. Studies assessing the effects of alcohol on bone in adult humans as well as skeletally mature animal models published since the year 2000 are emphasized.

RESULTS

Light to moderate alcohol consumption is generally reported to be beneficial, resulting in higher bone mineral density (BMD) and reduced age-related bone loss, whereas heavy alcohol consumption is generally associated with decreased BMD, impaired bone quality, and increased fracture risk. Bone remodeling is the principal mechanism for maintaining a healthy skeleton in adults and dysfunction in bone remodeling can lead to bone loss and/or decreased bone quality. Light to moderate alcohol may exert beneficial effects in older individuals by slowing the rate of bone remodeling, but the impact of light to moderate alcohol on bone remodeling in younger individuals is less certain. The specific effects of alcohol on bone remodeling in heavy drinkers are even less certain because the effects are often obscured by unhealthy lifestyle choices, alcohol-associated disease, and altered endocrine signaling.

CONCLUSIONS

Although there have been advances in understanding the complex actions of alcohol on bone, much remains to be determined. Limited evidence implicates age, skeletal site evaluated, duration, and pattern of drinking as important variables. Few studies systematically evaluating the impact of these factors have been conducted and should be made a priority for future research. In addition, studies performed in skeletally mature animals have potential to reveal mechanistic insights into the precise actions of alcohol and associated comorbidity factors on bone remodeling.

Vitamin D supplementation protects against bone loss following inhalant organic dust and lipopolysaccharide exposures in mice

Systemic bone loss is associated with airway inflammatory diseases; yet, strategies to halt disease progression from inhalant exposures are not clear. Vitamin D might be a potentially protective approach against noxious respirable environmental exposures. We sought to determine whether vitamin D supplementation represents a viable lung- and bone-protective strategy following repetitive inhalant treatments with organic dust extract (ODE) or lipopolysaccharide (LPS) in mice. C57BL/5 mice were maintained on diets with low (1 IU/D/g) or high (10 IU/D/g) vitamin D for 5 weeks and treated with ODE from swine confinement facilities, LPS, or saline daily for 3 weeks per established intranasal inhalation protocol. Lungs, hind limbs, and sera were harvested for experimental outcomes. Serum 25-hydroxyvitamin D levels were tenfold different between low and high vitamin D treatment groups with no differences between inhalant agents and saline treatments. Serum calcium levels were not affected. There was no difference in the magnitude of ODE- or LPS-induced inflammatory cell influx or lung histopathology between high and low vitamin D treatment groups. However, high vitamin D treatment reversed the loss of bone mineral density, bone volume, and bone micro-architecture deterioration induced by ODE or LPS as determined by micro-CT analysis. Bone-resorbing osteoclasts were also reduced by high vitamin D treatment. In the low vitamin D treatment groups, ODE induced the greatest degree of airway inflammatory consequences, and LPS induced the greatest degree of bone loss. Collectively, high-concentration vitamin D was protective against systemic bone loss, but not airway inflammation, resulting from ODE- or LPS-induced airway injury.

Bu-Shen-Jian-Pi-Yi-Qi Therapy Prevents Alcohol-Induced Osteoporosis in Rats

Bu-Shen-Jian-Pi-Yi-Qi therapy, which refers to reinforcing kidney, regulating qi, and invigorating spleen, is a traditional Chinese medicine, and we investigated its efficacy in treatment of alcohol-induced osteoporosis and its underlying mechanism. Forty adult male Sprague-Dawley rats were randomly assigned into alcohol-supplemented group, JIAN-GU-LING (JGL) group, calcium D3 + alfacalcidol group, and sham-treated group. Bone mineral density (BMD), bone mineral content (BMC), and bone biomechanical properties were assessed. Biochemical analyses of serum and urine specimens were detected. Reverse transcription-polymerase chain reaction was used to detect the mRNA level of vitamin D receptor (VDR). There were markedly lower bone metabolic markers and biomechanical properties in alcohol-supplemented group compared with sham-treated group (all P < 0.05). BMD, BMC, 25(OH)D3, and 1,25(OH)2D3 were elevated in JGL group relative to calcium D3 + alfacalcidol group (all P < 0.05). U-Ca/Cr and U-P/Cr in JGL group were higher than those in the calcium D3 + alfacalcidol group (all P < 0.05). VDR mRNA level in the JGL group was elevated markedly in comparison with alcohol + calcium D3 + alfacalcidol group (P < 0.05). Based on our results, Bu-Shen-Jian-Pi-Yi-Qi therapy inhibits bone loss, promotes bone formation, and effectively improves bone metabolism in rats with experimental alcoholic osteoporosis. The disease reversal is evidenced by increased BMD and BMC, improved biomechanical properties, elevated VDR mRNA level, enhanced response sensitivity of 1, 25(OH)2D3, and reduced S-Ca/P.

Bone changes in alcoholic liver disease

Alcoholism has been associated with growth impairment, osteomalacia, delayed fracture healing, and aseptic necrosis (primarily necrosis of the femoral head), but the main alterations observed in the bones of alcoholic patients are osteoporosis and an increased risk of fractures. Decreased bone mass is a hallmark of osteoporosis, and it may be due either to decreased bone synthesis and/or to increased bone breakdown. Ethanol may affect both mechanisms. It is generally accepted that ethanol decreases bone synthesis, and most authors have reported decreased osteocalcin levels (a “marker” of bone synthesis), but some controversy exists regarding the effect of alcohol on bone breakdown, and, indeed, disparate results have been reported for telopeptide and other biochemical markers of bone resorption. In addition to the direct effect of ethanol, systemic alterations such as malnutrition, malabsorption, liver disease, increased levels of proinflammatory cytokines, alcoholic myopathy and neuropathy, low testosterone levels, and an increased risk of trauma, play contributory roles. The treatment of alcoholic bone disease should be aimed towards increasing bone formation and decreasing bone degradation. In this sense, vitamin D and calcium supplementation, together with biphosphonates are essential, but alcohol abstinence and nutritional improvement are equally important. In this review we study the pathogenesis of bone changes in alcoholic liver disease and discuss potential therapies.

Alcohol consumption, Wnt/β-catenin signaling, and hepatocarcinogenesis

Alcohol is a well-established risk factor for hepatocellular carcinoma, and the mechanisms by which alcohol liver cancer is complex. It has been suggested that ethanol (EtOH) metabolism may enhance tumor progression by increasing hepatocyte proliferation. To test this hypothesis, ethanol (EtOH) feeding of male mice began 7 weeks post-injection of the chemical carcinogen diethylnitrosamine (DEN), and continued for 16 weeks, with a final EtOH concentration of 28% of total calories. As expected, EtOH increased the total number of cancerous foci and liver tumors identified in situ fixed livers from the EtOH+DEN group compared to corresponding pair-fed (PF)+DEN and chow+DEN control groups. In the EtOH+DEN group, tumor multiplicity corresponded to a 3- to 4-fold increase in proliferation and immunohistochemical staining of β-catenin in non-tumorigenic hepatocytes when compared to the PF+DEN and chow+DEN groups, p<0.05. Analysis of EtOH-treated livers from a previously published rat model of chronic liver disease revealed increases in hepatocyte proliferation accompanied by a hepatic depletion of retinol and retinoic acid stores (p<0.05), nuclear accumulation of β-catenin (p<0.05), increased cytosolic expression p-GSK3β (p<0.05), significant upregulation of soluble Wnts, Wnt2, and Wnt7a, and increased expression of several β-catenin targets involved in tumor promotion and progression, cyclin D1, c-myc, WISP1, and MMP7 (p<0.05). These data suggest that chronic EtOH consumption activates the Wnt/β-catenin signaling pathway, which increases hepatocyte proliferation thus promoting tumorigenesis following an initiating insult in the liver.

Genistein supplementation increases bone turnover but does not prevent alcohol-induced bone loss in male mice

Chronic alcohol consumption results in bone loss through increased bone resorption and decreased bone formation. These effects can be reversed by estradiol (E2) supplementation. Soy diets are suggested to have protective effects on bone loss in men and women, as a result of the presence of soy protein-associated phytoestrogens such as genistein (GEN). In this study, male mice were pair-fed (PF), a control diet, an ethanol (EtOH) diet, or EtOH diet supplemented with 250 mg/kg of GEN for 8 weeks to test if GEN protects against bone loss associated with chronic drinking. Interestingly, alcohol consumption reduced cortical area and thickness and trabecular bone volume in both EtOH and EtOH/GEN groups when compared to the corresponding PF and PF/GEN controls, P < 0.05. However, in the trabecular bone compartment, we observed a significant increase in overall trabecular bone density in the PF/GEN group compared to the PF controls. Bone loss in the EtOH-treated mice was associated with the inhibition of osteoblastogenesis as indicated by decreased alkaline phosphatase staining in ex vivo bone marrow cultures, P < 0.05. GEN supplementation improved osteoblastogenesis in the EtOH/GEN cultures compared to the EtOH group, P < 0.05. Vertebral expression of bone-formation markers, osteocalcin, and runt-related transcription factor 2 (Runx2) was also significantly up-regulated in the PF/GEN and EtOH/GEN groups compared to the PF and EtOH-treated groups. GEN supplementation also increased the expression of receptor activator of nuclear factor κ-B ligand (RANKL) in the PF/GEN, an increase that persisted in the EtOH/GEN-treated animals (P < 0.05), and increased basal hydrogen peroxide production and RANKL mRNA expression in primary bone marrow cultures in vitro, P < 0.05. These findings suggest that GEN supplementation increases the overall bone remodeling and, in the context of chronic alcohol consumption, does not protect against the oxidative stress-associated EtOH-mediated bone resorption.

Alcohol consumption promotes diethylnitrosamine-induced hepatocarcinogenesis in male mice through activation of the Wnt/β-catenin signaling pathway

Although alcohol effects within the liver have been extensively studied, the complex mechanisms by which alcohol causes liver cancer are not well understood. It has been suggested that ethanol (EtOH) metabolism promotes tumor growth by increasing hepatocyte proliferation. In this study, we developed a mouse model of tumor promotion by chronic EtOH consumption in which EtOH feeding began 46 days after injection of the chemical carcinogen diethylnitrosamine (DEN) and continued for 16 weeks. With a final EtOH concentration of 28% of total calories, we observed a significant increase in the total number of preneoplastic foci and liver tumors per mouse in the EtOH+DEN group compared with corresponding pair-fed (PF)+DEN and chow+DEN control groups. We also observed a 4-fold increase in hepatocyte proliferation (P < 0.05) and increased cytoplasmic staining of active-β-catenin in nontumor liver sections from EtOH+DEN mice compared with PF+DEN controls. In a rat model of alcohol-induced liver disease, we found increased hepatocyte proliferation (P < 0.05); depletion of retinol and retinoic acid stores (P < 0.05); increased expression of cytosolic and nuclear expression of β-catenin (P < 0.05) and phosphorylated-glycogen synthase kinase 3β (p-GSK3β), P < 0.05; significant upregulation in Wnt7a mRNA expression; and increased expression of several β-catenin targets, including, glutamine synthetase (GS), cyclin D1, Wnt1 inducible signaling pathways protein (WISP1), and matrix metalloproteinase-7(MMP7), P < 0.05. These data suggest that chronic EtOH consumption activates the Wnt/β-catenin signaling pathways to increase hepatocyte proliferation, thus promoting tumorigenesis following an initiating insult to the liver.

Influence of fat/carbohydrate ratio on progression of fatty liver disease and on development of osteopenia in male rats fed alcohol via total enteral nutrition (TEN)

Alcohol abuse is associated with the development of fatty liver disease and also with significant osteopenia in both genders. In this study, we examined ethanol-induced pathology in response to diets with differing fat/carbohydrate ratios. Male Sprague-Dawley rats were fed intragastrically with isocaloric liquid diets. Dietary fat content was either 5% (high carbohydrate, HC) or 45% (high fat, HF), with or without ethanol (12-13 g/kg/day). After 14, 28, or 65 days, livers were harvested and analyzed. In addition, bone morphology was analyzed after 65 days. HC rats gained more weight and had larger fat pads than HF rats with or without ethanol. Steatosis developed in HC + ethanol (HC + EtOH) compared to HF + ethanol (HF + EtOH) rats, accompanied by increased fatty acid (FA) synthesis and increased nuclear carbohydrate response element binding protein (ChREBP) (p < 0.05), but in the absence of effects on hepatic silent mating type information regulation 2 homolog (SIRT-1) or nuclear sterol regulatory binding element protein (SREBP-1c). Ethanol reduced serum leptin (p < 0.05) but not adiponectin. Over time, HC rats developed fatty liver independent of ethanol. FA degradation was significantly elevated by ethanol in both HC and HF groups (p < 0.05). HF + EtOH rats had increased oxidative stress from 28 days, increased necrosis compared to HF controls and higher expression of cytochromes P450, CYP2E1, and CYP4A1 compared to HC + EtOH rats (p < 0.05). In contrast, HC + EtOH rats had no significant increase in oxidative stress until day 65 with no observed increase in necrosis. Unlike liver pathology, no dietary differences were observed on ethanol-induced osteopenia in HC compared to HF groups. These data demonstrate that interactions between diet composition and alcohol are complex, dependent on the length of exposure, and are an important influence in development of fatty liver injury. Importantly, it appears that diet composition does not affect alcohol-associated skeletal toxicity.

Alcohol and bone

Alcohol is widely consumed across the world in different cultural and social settings. Types of alcohol consumption differ between (a) light, only occasional consumption, (b) heavy chronic alcohol consumption, and (c) binge drinking as seen as a new pattern of alcohol consumption among teenagers and young adults. Heavy alcohol consumption is detrimental to many organs and tissues, including bones. Osteoporosis is regularly mentioned as a secondary consequence of alcoholism, and chronic alcohol abuse is established as an independent risk factor for osteoporosis. The review will present the different mechanisms and effects of alcohol intake on bone mass, bone metabolism, and bone strength, including alcoholism-related "life-style factors" such as malnutrition, lack of exercise, and hormonal changes as additional causative factors, which also contribute to the development of osteoporosis due to alcohol abuse.

Loss of functional NADPH oxidase 2 protects against alcohol-induced bone resorption in female p47phox-/- mice

BACKGROUND

In bone, NADPH oxidase (NOX)-derived reactive oxygen species (ROS) superoxide and/or hydrogen peroxide are an important stimulus for osteoclast differentiation and activity. Previously, we have demonstrated that chronic ethanol (EtOH) consumption generates excess NOX-dependent ROS in osteoblasts, which functions to stimulate nuclear factor kappa-β receptor ligand (RANKL)-RANK signaling, thus increasing osteoclastogenesis and activity. This activity can be blocked by co-administration of EtOH with the pan-NOX inhibitor diphenylene idonium (DPI).

METHODS

To test whether EtOH-induced bone loss is dependent on a functional NOX2 enzyme, 6-week-old female C57BL/6J-Ncf1/p47phox(-/-) (p47phox KO) and wild-type (WT) mice were pair-fed EtOH diets for 40 days. Bone loss was assessed by 3-point bending, micro-computed tomography and static histomorphometric analysis. Additionally, ST2 cultured cells were co-treated with EtOH and NOX inhibitors, DPI, gliotoxin, and plumbagin, after which changes in ROS production, and in RANKL and NOX mRNA expression were analyzed.

RESULTS

In WT mice, EtOH treatment significantly reduced bone density and mechanical strength, and increased total osteoclast number and activity. In EtOH-treated p47phox KO mice, bone density and mechanical strength were completely preserved. EtOH p47phox KO mice had no changes in osteoclast numbers or activity, and no elevations in serum CTX or RANKL gene expression (p < 0.05). In both WT and p47phox KO mice, EtOH feeding reduced biochemical markers of bone formation (p < 0.05). In vitro EtOH exposure of ST2 cells increased ROS, which was blocked by pretreating with DPI or the NOX2 inhibitor gliotoxin. EtOH-induced RANKL and NOX2 gene expression were inhibited by the NOX4-specific inhibitor plumbagin.

CONCLUSIONS

These data suggest that NOX2-derived ROS is necessary for EtOH-induced bone resorption. In osteoblasts, NOX2 and NOX4 appear to work in tandem to increase RANKL expression, whereas EtOH-mediated inhibition of bone formation occurs via a NOX2-independent mechanism.

25-Hydroxyvitamin D(3)-loaded PLA microspheres: in vitro characterization and application in diabetic periodontitis models

This study aimed at the preparation of a sustained-release 25-hydroxyvitamin D(3) (25OHD) treatment for diabetic periodontitis, a known complication of diabetes. 25OHD-loaded polylactic acid (PLA) microspheres were prepared using oil-in-water emulsion-solvent evaporation method. The prepared microspheres exhibited intact surfaces, with average sizes ranging from 42.3 to 119.4 μm. The encapsulation efficiency ranged from 79.2% (w/w) to 88.5% (w/w), and the drug content was between 15.8% (w/w) and 17.8% (w/w). Drug release from the produced microspheres followed a near-to-zero-order release pattern and lasted over 10 weeks. In an in vitro model of diabetic periodontitis, the abnormal morphological changes and the decrease in the cell viability of bone marrow stromal cells could be effectively attenuated after the 25OHD-loaded microsphere application. Additionally, in a rat model of diabetic periodontitis, alveolar bone loss was inhibited and osteoid formation in the periodontium was promoted upon 25OHD-loaded microsphere treatment. In conclusion, 25OHD-loaded PLA microspheres may provide an effective approach for the treatment of this disease.

Excessive ethanol consumption under exposure to lead intensifies disorders in bone metabolism: a study in a rat model

It was investigated whether ethanol (Et) modifies the damaging impact of lead (Pb) on bone metabolism in a rat model reflecting excessive alcohol consumption by humans exposed to relatively high levels of this metal. For this purpose, markers of bone formation (osteocalcin, procollagen I, osteoprotegerin, alkaline phosphatase) and resorption (telopeptides of collagen I, soluble receptor activator of nuclear factor-κB ligand), calciotropic hormones (parathormone, calcitonin, 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D) in the serum, and the femur content of mineral (including calcium - Ca and inorganic phosphorus - P(i)) and organic components were estimated in the rats exposed to 500 mg Pb/l (in drinking water) or/and Et (5 g/kg b.wt./24 h, by oral gavage) for 12 weeks. Moreover, Ca and P(i) in the serum and urine, alkaline phosphatase in the bone tissue and Pb in the blood and femur were determined. The exposure to Pb or/and Et decreased bone formation and increased its resorption resulting in the bone demineralization. These effects were accompanied by destroying the hormonal regulation of mineral metabolism, and Ca and P(i) imbalance. The co-exposure to Pb and Et-induced disorders in bone metabolism were more advanced than those caused by Pb alone. Et co-administration increased Pb concentration in the blood and decreased its accumulation in the bone. This paper is the first report providing evidence that consumption of Et under exposure to Pb intensifies disorders in bone metabolism and that destroying of the receptor activator nuclear factor-κB (RANK)/RANK ligand/osteoprotegerin system is involved in the mechanisms of interactive action of these xenobiotics on the skeleton. The modifying impact of Et may be an effect of its independent osteotropic action and interaction with Pb. Based on the results it can be concluded that alcohol abuse by subjects excessively exposed to Pb considerably increases the risk of bone damage.