Estrogen receptor-beta is the predominant estrogen receptor subtype in normal human synovia

Advances in the care of breast cancer survivors

Breast cancer survivors may experience significant after effects from diagnoses of breast cancer and cancer directed therapies. This review synthesizes the evidence about optimal management of the sequelae of a diagnosis of breast cancer. It describes the side effects of chemotherapy and endocrine therapy and evidence based strategies for management of such effects, with particular attention to effects of therapies with curative intent. It includes strategies to promote health and wellness among breast cancer survivors, along with data to support the use of integrative oncology strategies. In addition, this review examines models of survivorship care and ways in which digital tools may facilitate communication between clinicians and patients. The strategies outlined in this review are paramount to supporting breast cancer survivors' quality of life.

Low back pain and osteoarthritis pain: a perspective of estrogen

Low back pain (LBP) is the world's leading cause of disability and is increasing in prevalence more rapidly than any other pain condition. Intervertebral disc (IVD) degeneration and facet joint osteoarthritis (FJOA) are two common causes of LBP, and both occur more frequently in elderly women than in other populations. Moreover, osteoarthritis (OA) and OA pain, regardless of the joint, are experienced by up to twice as many women as men, and this difference is amplified during menopause. Changes in estrogen may be an important contributor to these pain states. Receptors for estrogen have been found within IVD tissue and nearby joints, highlighting the potential roles of estrogen within and surrounding the IVDs and joints. In addition, estrogen supplementation has been shown to be effective at ameliorating IVD degeneration and OA progression, indicating its potential use as a therapeutic agent for people with LBP and OA pain. This review comprehensively examines the relationship between estrogen and these pain conditions by summarizing recent preclinical and clinical findings. The potential molecular mechanisms by which estrogen may relieve LBP associated with IVD degeneration and FJOA and OA pain are discussed.

Sex-dependent variation in cartilage adaptation: from degeneration to regeneration

Despite acknowledgement in the scientific community of sex-based differences in cartilage biology, the implications for study design remain unclear, with many studies continuing to arbitrarily assign demographics. Clinically, it has been well-established that males and females differ in cartilage degeneration, and accumulating evidence points to the importance of sex differences in the field of cartilage repair. However, a comprehensive review of the mechanisms behind this trend and the influence of sex on cartilage regeneration has not yet been presented. This paper aims to summarize current findings regarding sex-dependent variation in knee anatomy, sex hormones' effect on cartilage, and cartilaginous degeneration and regeneration, with a focus on stem cell therapies. Findings suggest that the stem cells themselves, as well as their surrounding microenvironment, contribute to sex-based differences. Accordingly, this paper underscores the contribution of both stem cell donor and recipient sex to sex-related differences in treatment efficacy. Cartilage regeneration is a field that needs more research to optimize strategies for better clinical results; taking sex into account could be a big factor in developing more effective and personalized treatments. The compilation of this information emphasizes the importance of investing further research in sex differences in cartilage biology.

Evidence for Menopause as a Sex-Specific Risk Factor for Glaucoma

Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by progressive loss of visual function and retinal ganglion cells (RGC). Current epidemiological, clinical, and basic science evidence suggest that estrogen plays a role in the aging of the optic nerve. Menopause, a major biological life event affecting all women, coincides with a decrease in circulating sex hormones, such as estrogen. While 59% of the glaucomatous population are females, sex is not considered a risk factor for developing glaucoma. In this review, we explore whether menopause is a sex-specific risk factor for glaucoma. First, we investigate how menopause is defined as a sex-specific risk factor for other pathologies, including cardiovascular disease, osteoarthritis, and bone health. Next, we discuss clinical evidence that highlights the potential role of menopause in glaucoma. We also highlight preclinical studies that demonstrate larger vision and RGC loss following surgical menopause and how estrogen is protective in models of RGC injury. Lastly, we explore how surgical menopause and estrogen signaling are related to risk factors associated with developing glaucoma (e.g., intraocular pressure, aqueous outflow resistance, and ocular biomechanics). We hypothesize that menopause potentially sets the stage to develop glaucoma and therefore is a sex-specific risk factor for this disease.

Sleep apnea in postmenopausal women is associated with joint pain severity and fatigability: a cross-sectional study

OBJECTIVE

This study aimed to investigate the relationships between sleep apnea parameters and various symptoms in postmenopausal women who had treatment-resistant sleep disorders.

METHODS

The respiratory disturbance index (RDI), the number of times apnea-hypopnea occurred in an hour, and transcutaneous oxygen saturation (SpO2) were monitored during one night of sleep using a portable monitoring device in 51 postmenopausal women who did not have an improved subjective sleep quality with the use of hypnotics. Physical and psychological health statuses and subjective sleep disturbance were evaluated using validated questionnaires, including the Epworth Sleepiness Scale, the Cornell Medical Index, and the Questionnaire for Assessment of Climacteric Syndrome in Japanese Women. The associations between RDI, nadir SpO2 and various symptoms, as well as cardiovascular parameters, such as blood pressure, serum lipid profile, and glucose tolerance, were analyzed separately.

RESULTS

Among the 51 study participants, seven (13.7%) were diagnosed with obstructive sleep apnea. After adjustment for age, body mass index, and the background factors related to RDI and nadir SpO2, the association remained significant between a higher RDI and joint pain (Questionnaire for Assessment of Climacteric Syndrome in Japanese Women) (standardized partial regression coefficient [β] = 0.423, P  = 0.016), and between lower nadir SpO2 and fatigability (Cornell Medical Index) (β = -0.472, P  = 0.007).

CONCLUSIONS

Detailed examination of sleep-disordered breathing is warranted in women with severe joint pain and fatigability.

Gender-Related Aspects in Osteoarthritis Development and Progression: A Review

Osteoarthritis (OA) is a common degenerative joint disease treated mostly symptomatically before approaching its definitive treatment, joint arthroplasty. The rapidly growing prevalence of OA highlights the urgent need for a more efficient treatment strategy and boosts research into the mechanisms of OA incidence and progression. As a multifactorial disease, many aspects have been investigated as contributors to OA onset and progression. Differences in gender appear to play a role in the natural history of the disease, since female sex is known to increase the susceptibility to its development. The aim of the present review is to investigate the cues associated with gender by analyzing various hormonal, anatomical, molecular, and biomechanical parameters, as well as their differences between sexes. Our findings reveal the possible implications of gender in OA onset and progression and provide evidence for gaps in the current state of art, thus suggesting future research directions.

Estrogen receptor Alpha in human knee articular cartilage of healthy and osteoarthritic females

Objective

Estrogen and osteoarthritis association has previously been proposed. This study evaluates the presence of estrogen receptors (ER)-α in articular cartilage, and its association.

Methods

A prospective cohort study of women undergoing anterior cruciate ligament reconstruction (controls) or total knee arthroplasty (cases) was performed. Cartilage samples were processed and ER-α expression was quantified.

Results

Twenty patients were included: 12 cases and 8 controls. ER-α expression was higher in the case subjects.

Conclusion

Increased ER-α expression is associated with age, and degeneration. This suggests estrogen deficiency is a risk for osteoarthritis and is inversely related to proliferative looking chondrocytes.

Association of estrogen receptor alpha 1 and TMJ dysfunction: A pilot study

OBJECTIVE

Temporomandibular disorder (TMD) is a multifactorial condition and the most common cause of orofacial pain, affecting mostly women, which points to a female hormone predilection. Therefore, the aim of this study was to analyze the association between TMD and estrogen receptor alpha 1 expression in disks of patients with TMD and condyle fracture (CFx).

STUDY DESIGN

Forty specimens (from 27 patients) included n = 8 CFx, n = 21 anterior disk displacement with reduction (ADDwR), and n = 11 anterior disk displacement without reduction (ADDwoR). Age, area, and intensity of immunostaining were statistically compared between CFx, ADDwR, and ADDwoR groups using analysis of variance and Kruskal-Wallis analysis (P < .05).

RESULTS

No significant difference between CFx, ADDwR, and ADDwoR groups with respect to age and expression of estrogen receptor alpha 1 was observed on immunohistochemical examination.

CONCLUSION

No association of estrogen receptor alpha 1 expression and age was found in the CFx, ADDwR, and ADDwoR groups.

Setting up distinctive outcome measures for each osteoarthritis phenotype

Osteoarthritis (OA) is an evolving chronic joint disease with a huge global impact. Given the intricate nature of the etiopathogenesis and subsequent high heterogeneity in the clinical course of OA, it is crucial to discriminate between etiopathogenic endotypes and clinical phenotypes, especially in the early stages of the disease. In this sense, we propose that an OA phenotype should be properly assessed with a set of outcome measures including those specifically related to the main underlying pathophysiological mechanisms. Thus, each OA phenotype can be related to different and clinically meaningful outcomes. OA phenotyping would lead to an adequate patient stratification in well-designed clinical trials and the discovery of precise therapeutic approaches. A significant effort will be required in this field in light of inconclusive results of clinical trials of tissue-targeting agents for the treatment of OA.

A randomized, double-blind, placebo-controlled trial of testosterone for treatment of postmenopausal women with aromatase inhibitor-induced arthralgias: Alliance study A221102

PURPOSE

To evaluate the efficacy of testosterone supplementation for improving aromatase inhibitor musculoskeletal symptoms (AIMSS).

METHODS

Postmenopausal women experiencing moderate-to-severe arthralgias while taking adjuvant aromatase inhibitors for breast cancer were enrolled in this trial. Initially, patients were randomly allocated to receive either a subcutaneous testosterone pellet versus a placebo pellet. Due to slow accrual, the protocol was modified such that additional participants were randomized to receive either a topical testosterone gel or a placebo gel. Changes in patient-reported joint pain were compared between patients receiving testosterone and those receiving placebo using a two-sample t test. Changes in hot flashes and other vasomotor symptoms were also analyzed. Further analyses were conducted to evaluate whether 27 single nucleotide polymorphisms (SNPs) in 14 genes previously associated with AIMSS were associated with testosterone supplementation benefit.

RESULTS

While 64% of patients reported an improvement in joint pain at 3 months, there were no significant differences in average pain or joint stiffness at 3 or 6 months between testosterone and placebo arms. Patients receiving testosterone did report improvements in strength, lack of energy, urinary frequency, and stress incontinence (p < 0.05). The subset of patients receiving subcutaneous testosterone also experienced improvements in hot flashes and mood swings. An inherited variant (rs7984870 CC genotype) in TNFSF11 was more likely to be associated with improvements in hot flashes in patients receiving testosterone.

CONCLUSION

The doses of testosterone supplementation used in this study did not significantly improve AIMSS.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01573442.

Soybean isoflavone can protect against osteoarthritis in ovariectomized rats

Osteoarthritis (OA) is a chronic and incurable disease and a leading cause of significant pain and disability that is closely associated with aging and obesity. An appropriate long-term therapy regimen is presently unknown. An estrogen deficiency after menopause increases the incidence and severity of OA in women. Soybean isoflavone have weak estrogenic effects in several organs and have been considered as a potentially safe natural selective estrogen receptor modulator. The present study aimed to determine the effects of isoflavone on cartilage degradation in ovariectomized rats. Six-month-old female Sprague-Dawley (SD) rats (n = 40) were randomly assigned to sham operation (n = 10), ovariectomy (OVX) (n = 15) or OVX + isoflavone (OVXI) (n = 15) groups. The OVXI group was fed with soybean isoflavone (51.0 mg/kg/day) for nine weeks, then knee joints were excised. Cartilage degradation was evaluated by toluidine blue staining joint specimens, and by comparing values for serum C-telopeptides of Type II collagen (CTX-II) and cartilage oligomeric matrix protein (COMP) between baseline and the end of the study. Cartilage damage scored by Toluidine blue staining was significantly lower in the OXVI, than the OVX group (P < 0.016). The CTX-II values before the surgical procedure and the end of experiment, did not significantly differ among the groups. Values for COMP in all samples were below detection limits in all samples. Soy bean isoflavone limited the degeneration of cartilage induced by OVX in rats.

Possible association between craniofacial dimensions and genetic markers in ESR1 and ESR2

OBJECTIVE

To investigate the association of genetic markers in ESR1 and ESR2 with craniofacial measurements.

DESIGN

Cross-sectional study.

SETTING

School of Dentistry of Ribeirão Preto, University of São Paulo.

PARTICIPANTS

A total of 146 biologically unrelated, self-reported Caucasian Brazilians with no syndromic conditions were included.

METHODS

Sagittal and vertical measurements (ANB, S-N, Ptm'-A', Co-Gn, Go-Pg, N-Me, ANS-Me, S-Go and Co-Go) from lateral cephalograms were examined for craniofacial evaluation. DNA was extracted from saliva and genetic markers in ESR1 (rs2234693 and rs9340799) and in ESR2 (rs1256049 and rs4986938) were analysed by real-time polymerase chain reaction. Hardy-Weinberg equilibrium was evaluated using the Chi-square test within each marker. The associations between craniofacial dimensions and genotypes were analysed by linear regression and adjusted by sex and age. The established alpha was 5%.

RESULTS

Individuals carrying CC in ESR1 rs2234693 had a decrease of -3.146 mm in ANS-Me (P = 0.044). In addition, rs4986938 in ESR2 was associated with S-N measurement (P = 0.009/ ß = -3.465). This marker was also associated with Go-Pg measurement, in which the CC genotype had a decrease of -3.925 mm in the length of the mandibular body (P = 0.043).

CONCLUSION

The present study suggests that in ESR1 and ESR2 are markers for variations in the craniofacial dimensions. However, further research should confirm the results.

Gene-expression changes in knee-joint tissues with aging and menopause: implications for the joint as an organ

Background

When considering the “joint as an organ”, the tissues in a joint act as complementary components of an organ, and the “set point” is the cellular activity for homeostasis of the joint tissues. Even in the absence of injury, joint tissues have adaptive responses to processes, like aging and menopause, which result in changes to the set point.

Purpose

The purpose of this study in a preclinical model was to investigate age-related and menopause-related changes in knee-joint tissues with the hypothesis that tissues will change in unique ways that reflect their differing contributions to maintaining joint function (as measured by joint laxity) and the differing processes of aging and menopause.

Methods

Rabbit knee-joint tissues from three groups were evaluated: young adult (gene expression, n=8; joint laxity, n=7; water content, n=8), aging adult (gene expression, n=6; joint laxity, n=7; water content, n=5), and menopausal adult (gene expression, n=8; joint laxity, n=7; water content, n=8). Surgical menopause was induced with ovariohysterectomy surgery and gene expression was assessed using reverse-transcription quantitative polymerase chain reaction.

Results

Aging resulted in changes to 37 of the 150 gene–tissue combinations evaluated, and menopause resulted in changes to 39 of the 150. Despite the similar number of changes, only eleven changes were the same in both aging and menopause. No differences in joint laxity were detected comparing young adult rabbits with aging adult rabbits or with menopausal adult rabbits.

Conclusion

Aging and menopause affected the gene-expression patterns of the tissues of the knee joint differently, suggesting unique changes to the set point of the knee. Interestingly, aging and menopause did not affect knee-joint laxity, suggesting that joint function was maintained, despite changes in gene expression. Taken together, these findings support the theory of the joint as an organ where the tissues of the joint adapt to maintain joint function.

Female hormonal factors and osteoarthritis of the knee, hip and hand: a narrative review

Osteoarthritis is a leading cause of disability with no cure. The incidence of osteoarthritis is sexually dimorphic: women have a higher rate of osteoarthritis than men after the age of 50. Research has investigated the contribution of sex hormones, reproductive factors and hormone supplementation to osteoarthritis. It has been recognized that different joints are susceptible to different risk factors for osteoarthritis. We reviewed the evidence for the effect of endogenous sex hormones, reproductive factors and hormone supplementation on joint-specific osteoarthritis of the knee, hip and hand. Although the role of these hormonal factors in the pathogenesis of osteoarthritis is complex, data suggest that endogenous hormones and reproductive factors have a role in the pathogenesis of osteoarthritis, especially knee osteoarthritis, with uncertainty for the effect of exogenous hormones. From the available data, it is hard to conclude whether this is a direct effect of hormonal factors, or whether other factors related to these hormonal factors, i.e. obesity and inflammation, have a role in this association. Further studies should consider the mediation effect of body weight and inflammation, change in body weight throughout life, circulatory levels of all endogenous hormones and circulatory levels of hormones after hormone supplementation in this complex relationship.

Association Between Polymorphisms in the Genes of Estrogen Receptors and the Presence of Temporomandibular Disorders and Chronic Arthralgia

PURPOSE

The high prevalence of painful temporomandibular disorders (TMDs) in women suggests that estrogen and its receptors play a fundamental etiologic role in the development of this joint pathology through complex action mechanisms. The aim of this study was to evaluate the possible association between polymorphisms in the ESR1 (estrogen receptor-1) and ESRRB (estrogen-related receptor-β) genes and the risk of simultaneous development of TMDs and pain in other joints in the body.

MATERIALS AND METHODS

All participants were clinically evaluated for the presence of TMD (Research Diagnostic Criteria for TMD) and asked about the presence of chronic joint pain. The control group consisted of 72 patients without TMD and without pain. Participants with arthralgia were divided into 3 groups: with muscular TMD (n = 42), with articular TMD (n = 16), and without TMD and with systemic arthralgia (n = 82). Eight single-nucleotide polymorphisms in the ESR1 (rs12154178, rs1884051, rs2273206, rs7774230) and ESRRB (rs1676303, rs4903399, rs10132091, rs7151924) genes were investigated. The χ² test and Student t and Mann-Whitney tests were used to assess the relevance of nominal and continuous variables, respectively. A P value less than .05 was considered significant.

RESULTS

The TT (timin/timin) genotype for the ESR1 (rs2273206) gene was strongly associated with the risk of developing muscle TMDs and temporomandibular joint pain (P = .04). For the ESRRB (rs1676303) gene, an association was observed between the CC (cytosine/cytosine) genotype and the presence of articular TMDs associated with other chronic arthralgia (P = .02). These results were confirmed by the increased risk of developing articular TMDs associated with the C allele (P = .04).

CONCLUSIONS

This study supports the hypothesis that changes in the ESR1 and ESRRB genes influence the presence of TMDs associated with chronic joint pain.

Relationship between hormone replacement therapy and spinal osteoarthritis: a nationwide health survey analysis of the elderly Korean population

OBJECTIVES

To identify the effects of hormone replacement therapy (HRT) on spinal osteoarthritis (OA).

METHODS AND DESIGN

A cross-sectional study of a nationwide survey was performed.

SETTING

This study collected data from the fifth Korean National Health and Nutrition Examination Survey (2010-2012).

PARTICIPANTS

After excluding ineligible respondents, the total number of participants in this study was 4265 females. Participants were asked to report symptoms and disabilities related to spinal OA. In addition, plain radiographs of the spine were taken of all patients.

PRIMARY AND SECONDARY OUTCOME MEASURES

Demographic and lifestyle variables were compared between the HRT and non-HRT groups. In addition, radiographic examination and symptom assessment were performed to determine the existence of spinal OA.

RESULTS

Marital status, education, income and HRT were correlated with spinal OA. A risk analysis of related factors showed that HRT and age had effects on spinal OA (ORs 0.717 and 1.257). Nevertheless, in the HRT group, smokers had a increased risk of spinal OA. In addition, the HRT group demonstrated a lower prevalence of spinal OA. The calculated risk for compromised morbidity with HRT compared with the prevalence of spinal OA was 0.717 (OR). The duration of HRT was also related to the risk for spinal OA. The group that had been taking HRT for more than 1 year showed decreased risk (OR 0.686) compared with patients with <1 year of HRT (OR 0.744; P<0.05).

CONCLUSION

Women receiving HRT showed a lower prevalence of spinal OA. HRT also correlated with a decrease in spinal OA morbidity.

Estradiol inhibits NLRP3 inflammasome in fibroblast-like synoviocytes activated by lipopolysaccharide and adenosine triphosphate

OBJECTIVE

Nucleotide binding domain and leucine-rich repeat pyrin 3 domain (NLRP3) inflammasome is known for activating pro-inflammatory cytokines in knee osteoarthritis (OA). This study was performed to identify whether NLRP3 inflammasome can be triggered by lipopolysaccharides (LPS) and adenosine triphos adenine (ATP), which are positively related with knee OA severity in joint-spaces, in human fibroblast-like synoviocytes (FLS), and to identify whether estrogen would inhibit the activation of NLRP3 inflammasome.

METHODS

In the present study, human FLS were isolated from the knee OA in patients during arthroplasty, and were treated with LPS and ATP in the presence or absence of estradiol (E2). The messenger RNA (mRNA) and protein levels of NLRP3 components were analyzed by real-time polymerase chain reaction and western blotting, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to examine interleukin (IL)-1β and IL-18 content in the supernatant. Estrogen receptor α inhibitor MPP and β inhibitor PHTPP were used to explore how E2 works.

RESULTS

Our results demonstrated that treatment with LPS and ATP increased significantly both in mRNA and protein levels of all the NLRP3 inflammasome components, and triggered the NLRP3 inflammasome, followed by upregulated IL-1β and IL-18 in the cell supernatant. E2 appeared to inhibit the activation of NLRP3 inflammasome by diminishing mRNA and protein levels of NLRP3 through estrogen receptor β, and decreased the expression of IL-1β and IL-18 as well.

CONCLUSION

These results suggested the increased LPS and ATP in joint-space may promote knee OA by NLRP3 inflammasome and E2 may exert a protective effect by inhibiting the activation of NLRP3 inflammasome in FLS.

Breastfeeding for One Month or Longer is Associated with Higher Risk of Osteoarthritis in Older Adults: NHANES 1999-2012

Breastfeeding is associated with many health benefits to the mother but the association between osteoarthritis (OA) is not known. Menopause, a state of rapid estrogen loss, is associated with OA. To test whether lactation, another physiological state of low estrogen status, is associated with OA, a nationally representative dataset National Health and Nutrition Examination Survey (NHANES) 1999–2012 was analyzed. Information of OA diagnosis history and lactation for at least one month was self-reported by women 50 years and older that had given birth to at least one child. Women that breastfed for less than one month had a higher proportion of those that were 60 years and older, Hispanic (than non-Hispanic Black), and higher current/self-reported greatest body mass index. Women that breastfed for one month or longer had a higher proportion of those that had 3 or more children, higher poverty-income ratio, were post-menopausal and performed vigorous physical activity. Weighted percentage of OA patients was 22%, and did not differ between the two groups. However, when logistic regression was performed adjusting for multiple covariates, lactation for one month or longer was positively associated with OA. Women that breastfed for one month or longer had an adjusted odds ratio of 1.21 (95% confidence interval, 1.05–1.40) for OA compared to those that breastfed for less than one month. The results indicate that women that breastfed for at least one month have a higher risk of OA than women that delivered a child but breastfed for less than one month.

Estrogen deficiency accelerates lumbar facet joints arthritis

Dramatic increase in the prevalence of lumbar facet joint (LFJ) arthritis in women around the age of menopause indicates a protective role for estrogen in LFJ arthritis. To date, there is no evidence for this indication and the mechanism of such an effect remains poorly understood. In this study, ovariectomized (OVX) mice were used to mimic the estrogen-deficient status of post-menopausal women. Micro-CT and immunohistochemistry was employed to assess the morphological and molecular changes in ovariectomy-induced LFJ arthritis. The results show that the LFJ subchondral bone mass was significantly decreased in OVX mice, with increased cavities on the interface of the subchondral bone. Severe cartilage degradation was observed in ovariectomy-induced LFJ arthritis. Increased blood vessels and innervations were also found in degenerated LFJ, particularly in the subchondral bone area. 17β-Estradiol treatment efficiently suppressed LFJ subchondral bone turnover, markedly inhibited cartilage degradation, and increased blood vessel and nerve ending growth in degenerated LFJ in OVX mice. Our study reveals that estrogen is a key factor in regulating LFJ metabolism. Severe LFJ degeneration occurs when estrogen is absent in vivo. Collapsed subchondral bone may be the initiation of this process, and estrogen replacement therapy can effectively prevent degeneration of LFJ under estrogen-deficient conditions.

Postmenopausal Chinese women show accelerated lumbar disc degeneration compared with Chinese men

Background/Objective

Postmenopausal women may have accelerated disc degeneration due to relative oestrogen deficiency. Two new studies supporting this concept were carried out.

Methods

Study I: The data were from the Osteoporotic Fractures in Men (Hong Kong) and Women (Hong Kong) studies. Both were population-based studies on bone health for elderly Chinese men and women (age ≥ 65 years, n = 2000 for men and n = 2000 for women). Based on lumbar spine radiographs, changes in L1/2-L4/5 disc space height were classified into four categories: 0 = normal; 1 = mild narrowing (< 30% reduction in disc height); 2 = moderate narrowing (30-60% reduction in disc height); and 3 = severe narrowing (> 60% reduction in disc height). Sums of the disc space narrowing scores of each participant were plotted against their age. Study II: 12 healthy individuals and 53 persons who had mild nonspecific low back pain (30 males and 35 females; mean age, 53.4 years; age range, 23-76 years) were recruited. Magnetic resonance imaging was performed on a 3-T system. A multiecho turbo spin echo pulse sequence was used for lumbar disc T2 mapping. Regions of interest were manually drawn over nucleus pulposus on the T2 map of the discs. The means of T2 relaxation times of discs L1/2-L4/5 of the participants were plotted against their age.

Results

Study I: Elderly women had a higher disc space narrowing score than elderly men, and the slope of the plot was steeper for females than for males. When the plots were extrapolated to younger age, they intersected at 59.67 years. Study II: An age-related reduction of T2 value in the nucleus pulposus was demonstrated, which was faster in females than in males. Although females tended to have initial higher T2 value before 50 years, this trend was reversed in elderly persons, with an intersection at 52.4 years.

Conclusion

Postmenopausal Chinese women show accelerated lumbar disc degeneration compared with Chinese men.

Protective effect of liquiritigenin against methylglyoxal cytotoxicity in osteoblastic MC3T3-E1 cells

Methylglyoxal (MG), a reactive dicarbonyl compound, is a metabolic byproduct of glycolysis and elevated MG levels contribute to diabetic complications. Glycation reactions of MG with amino acids can induce oxidative stress, leading to subsequent cytotoxicity. In the present study, the effect of liquiritigenin on MG-induced cytotoxicity was investigated using osteoblastic MC3T3-E1 cells. Pretreatment of MC3T3-E1 cells with liquiritigenin prevented the MG-induced cell death and production of protein adduct, intracellular reactive oxygen species, mitochondrial superoxide, cardiolipin peroxidation, and TNF-α in osteoblastic MC3T3-E1 cells. In addition, liquiritigenin increased the activity of glyoxalase I inhibited by MG. These findings suggest that liquiritigenin provides a protective action against MG-induced cell damage by reducing oxidative stress and by increasing MG detoxification. Pretreatment with liquiritigenin prior to MG exposure reduced MG-induced mitochondrial dysfunction by preventing mitochondrial membrane potential dissipation and adenosine triphosphate loss. Additionally, the nitric oxide and PGC-1α levels were significantly increased by liquiritigenin, suggesting that liquiritigenin may induce mitochondrial biogenesis. Our findings indicate that liquiritigenin might exert its therapeutic effects via enhancement of glyoxalase I activity and mitochondrial function, and anti-oxidant and anti-inflammatory activities. Taken together, liquiritigenin has potential as a preventive agent against the development of diabetic osteopathy related to MG-induced oxidative stress in diabetes.

Estrogens, osteoarthritis and inflammation

Estrogens participate in several biological processes through different molecular mechanisms. Their final actions consist of a combination of both direct and indirect effects on different organ and tissues. Estrogen may have pro- and anti-inflammatory properties depending on the situation and the involved tissue. In general, acute loss of estrogens increases the levels of reactive oxygen species and activates nuclear factor-κB and pro-inflammatory cytokine production, indicating their predominant anti-inflammatory properties. Furthermore, pro-inflammatory cytokine expression has been shown to be attenuated by estrogen replacement. Osteoarthritis and cardiovascular disease are two of the more prevalent diseases once menopause is established, which has suggested the link between estrogens and both processes. In addition, deletion of estrogen receptors in female mice results in cartilage damage, osteophytosis and changes in the subchondral bone of the joints suggesting that estrogens have a protective role on the maintenance of joint homeostasis. Furthermore, in spite of the negative effect of estrogen replacement reported in 2002 by the Women's Health Initiative study, several works published afterwards have explored the potential protective effect of estrogen supplementation in animal models and have postulated that these actions may justify a beneficial role of estrogens in different diseases where inflammation is the major feature. In this review, we will analyze the effects of estrogens on certain pathological situations such as osteoarthritis, some autoimmune diseases and coronary heart disease, especially in postmenopausal women.

Etiology, assessment, and management of aromatase inhibitor-related musculoskeletal symptoms

Aromatase inhibitors (AIs) are recommended as adjuvant endocrine therapy for postmenopausal women with hormone-responsive breast cancer. With the widespread use of AI adjuvant endocrine therapy, a significant profile of musculoskeletal symptoms has emerged. Moderate to severe musculoskeletal symptoms have led some women to discontinue therapy, compromising the survival benefit. The etiology of AI-related musculoskeletal symptoms is poorly understood, which challenges development of effective management strategies. The purpose of this article is to describe AI-related musculoskeletal symptoms, review possible causes, provide assessment guidelines, and recommend management strategies based on the best available evidence. Little evidence exists for effective management strategies of AI-related musculoskeletal symptoms, and randomized clinical trials are needed to establish effective interventions. A thorough musculoskeletal assessment can help guide clinical decision making for the best individual management approach. Providers need to manage symptoms with the best available evidence to minimize symptom distress and maximize adherence to AI therapy.

Effect of combined sex hormone replacement on bone/cartilage turnover in a murine model of osteoarthritis

Background

Estrogens act on estrogen receptors distributed in articular cartilages, synovial membrane, and ligaments, which are thought to be related with degenerative changes. Meanwhile, progesterone is known to have a weak anabolic action on bone formation This study evaluates the effects of estrogen and progesterone hormone on bone/cartilage turnover in ovariectomized (OVX) rats.

Methods

Thirty-five 7-month-old female Sprague-Dawley rats were randomly divided into 5 groups and then ovariectomized bilaterally except the sham control group. The first and the second group acting as controls did not receive hormonal therapy, the third group received estrogen, the fourth group received progesterone, and the fifth group received combination of both hormones 10 weeks after surgery. Evaluations were done using the serum levels of cartilage oligomeric matrix protein (COMP) for cartilage turnover, collagen type I C-telopeptide (CTX-1) and osteocalcin (OC) for bone turnover at 11, 15, 19 weeks after OVX and histology using the Osteoarthritis Research Society International (OARSI) osteoarthritis (OA) cartilage histopathology assessment system.

Results

Significantly less cartilage degradation (decreased levels of COMP) was found in the combined hormone treated group in comparison with OVX group. Similarly, both hormonal treatment resulted in increased bone formation and decreased bone resorption i.e., a low overall bone turnover status (decrease in the serum OC and CTX-1 levels).

Conclusions

Combined estrogen and progesterone therapy was found to be convincing in terms of reducing the severity of OA in this experimental model.

Oestrogen is important for maintenance of cartilage and subchondral bone in a murine model of knee osteoarthritis

INTRODUCTION

Oestrogen depletion may influence onset and/or progression of osteoarthritis. We investigated in an ovariectomized mouse model the impact of oestrogen loss and oestrogen supplementation on articular cartilage and subchondral bone in tibia and patella, and assessed bone changes in osteoarthritis development.

METHODS

C3H/HeJ mice were divided into four groups: sham-operated, oestrogen depletion by ovariectomy (OVX), OVX with estradiol supplementation (OVX+E) and OVX with bisphosphonate (OVX+BP). Each mouse had one knee injected with low-dose iodoacetate (IA), and the contralateral knee was injected with saline. Cartilage was analysed histologically 12 weeks postsurgery; bone changes were monitored over time using in vivo micro-computed tomography.

RESULTS

In tibiae, OVX alone failed to induce cartilage damage, but OVX and IA combination significantly induced cartilage damage. In patellae, OVX alone induced significant cartilage damage, which was enhanced by IA. In both tibiae and patellae, OVX in combination with IA significantly decreased subchondral cortical thickness in an additive manner. OVX+E and OVX+BP inhibited tibial and patellar subchondral cortical thinning, inhibited patellar and tended to diminish tibial cartilage damage. In patellae, IA interacted with BP, leading to increased subchondral cortical and trabecular bone.

CONCLUSIONS

This study demonstrates the significance of oestrogen for articular cartilage and subchondral bone and maintenance of healthy joints, supporting an etiological role for altered oestrogen signaling in osteoarthritis either by directly affecting cartilage or increasing susceptibility for an osteoarthritis trigger. The data strongly support the concept of involvement of subchondral bone plate in osteoarthritis.

Estrogen modulates iodoacetate-induced gene expression in bovine cartilage explants

Estrogen loss may be involved in onset or progression of osteoarthritis. Estrogen receptors are present in chondrocytes, thus estrogen may exert effects directly on cartilage. However, studies on direct estrogen effects on cartilage are limited. We investigated, in an in vitro cartilage explant model, whether estrogen prevents damage or stimulates repair after damage induced by addition of iodoacetate (IA), as an experimental model for osteoarthritis. We used healthy bovine cartilage explants. Prevention experiment: Explants precultured with/without estradiol (E) for 3 days were cultured with IA for 4 h on day 0, and subsequently cultured as in preculture: with/without E. Explants were harvested at day 2 for gene expression analysis. Repair experiment: At day 0, explants were cultured with IA for 4 h on day 0, and subsequently cultured without E or with E. Explants were harvested at days 2, 10, and 14 for gene expression analysis. IA transiently downregulated most genes tested, whereas vascular endothelial growth factor (VEGF) was upregulated on day 2. On day 14, transforming growth factor beta (TGFB)1 and TGFB3 were upregulated, and matrix metalloproteinase (MMP)13 and VEGF downregulated. Estradiol affected gene expression of aggrecan (AGC)1, MMP2, MMP14, tissue inhibitor of metalloproteinase (TIMP)2, TGFB2, and TGFB3. Prevention experiment: Estradiol did not significantly affect IA-induced changes in gene expression (no significant interaction). Repair experiment: Estradiol affected IA-induced changes in expression of collagen (COL)2, MMP2, MMP3, MMP13, MMP14, TIMP2, TGFB2, TGFB3, and VEGF. Estradiol affects expression of anabolic and catabolic genes in bovine cartilage explants and modulates the effects of IA. These effects of estradiol may be beneficial for cartilage maintenance and repair.

Aromatase inhibitor-induced arthralgia in early breast cancer: what do we know and how can we find out more?

Aromatase inhibitors (AIs) are a standard of care for the adjuvant treatment of hormone responsive early carcinoma of the breast as demonstrated in a number of large international phase III randomised trials. Arthralgia was a somewhat unexpected side effect of this class of agents and has proven to be potentially problematic in clinical practice. Although rates of up 35% have been reported in the randomised trials, the figure has been much higher in subsequent case series. There is concern that these symptoms are significant and may affect compliance and thus the overall efficacy of treatment. It is therefore extremely important that we evaluate this syndrome with a view to gaining more information regarding its clinical features and possible aetiological mechanism. The potential aetiological mechanisms and evidence for aromatase inhibitor-induced arthralgia (AIA) are reviewed in this article. Looking forward, it is now important that prospective clinical trials are well designed to evaluate this syndrome and potential therapeutic strategies to circumvent it. Radiological imaging and biochemical analyses may help our understanding of AIA and these are discussed.

Osteoarthritis associated with estrogen deficiency

Osteoarthritis (OA) affects all articular tissues and finally leads to joint failure. Although articular tissues have long been considered unresponsive to estrogens or their deficiency, there is now increasing evidence that estrogens influence the activity of joint tissues through complex molecular pathways that act at multiple levels. Indeed, we are only just beginning to understand the effects of estrogen deficiency on articular tissues during OA development and progression, as well as on the association between OA and osteoporosis. Estrogen replacement therapy and current selective estrogen receptor modulators have mixed effectiveness in preserving and/or restoring joint tissue in OA. Thus, a better understanding of how estrogen acts on joints and other tissues in OA will aid the development of specific and safe estrogen ligands as novel therapeutic agents targeting the OA joint as a whole organ.

Primary osteoarthritis no longer primary: three subsets with distinct etiological, clinical, and therapeutic characteristics

BACKGROUND

Osteoarthritis (OA) has been historically divided into primary and secondary. Primary OA has been defined as an idiopathic condition developing in previously undamaged joints in the absence of an obvious causative mechanism. During the last few years a large amount of evidence has provided new insights into the biochemistry and molecular biology of cartilage, subchondral bone, and other articular tissues, which suggest distinct etiopathogenetic mechanisms in some forms of primary OA.

OBJECTIVE

To propose an etiopathogenic classification of primary OA in the light of the significant progress in the understanding of the disease.

METHODS

A review of the literature was performed by searching the Medline and PubMed databases from 1952 to November 2008 using the following keywords: genetic alteration, heritability, estrogen, menopause, and aging either alone or in various combinations with joint, cartilage, subchondral bone, synovium, ligaments, muscle, tendons, OA, and osteoporosis.

RESULTS

Numerous studies have shown that genetic alterations, menopause-related estrogen deficiency, and aging play crucial roles in the molecular pathophysiological events involved in the process of cartilage and joint damage and thus in development of OA. We propose classifying primary OA into 3 distinct although interrelated subsets: type I OA, genetically determined; type II OA, estrogen hormone dependent; and type III OA, aging related.

CONCLUSIONS

The 3 proposed subsets of OA display distinct etiological, clinical, and therapeutic characteristics and should therefore no longer be considered to be "Primary OA."

Animal models for osteoarthritis: the effect of ovariectomy and estrogen treatment - a systematic approach

OBJECTIVE

The prevalence of osteoarthritis (OA) increases dramatically in women after the age of 50. Animal models are used to study the effects of hormone depletion [by ovariectomy (OVX)] and estrogen treatment on OA. This review summarizes these animal studies, in order to get a better insight in the role of hormones on OA.

METHOD

The literature was systematically reviewed until May 2007. The results were divided into two parts: the effect of OVX on cartilage, and the effect of estrogen treatment on cartilage. Only studies with an appropriate control group (e.g., sham-operated) were included.

RESULTS AND DISCUSSION

Eleven out of 16 animal studies showed that OVX resulted in cartilage damage. When only studies using sexually mature animals were included, we saw that 11 out of 14 studies showed a detrimental effect, indicating considerable evidence for a relation between cartilage degeneration and OVX in mature animals. The effect of estrogen treatment was inconclusive with only 11 out of 22 animal studies reporting a beneficial effect on cartilage, whereas all six studies administering selective estrogen receptor modulators (SERMs) after OVX described protective effects. The discrepancy between the studies may be caused by the large variation in experimental set-up. We suggested a list of quality criteria for animal models since standardisation of design and outcome parameters of animal experiments may help to compare different studies and to gain better insight in the role of hormones in the osteoarthritic process.

Anti-inflammatory effects of liquiritigenin as a consequence of the inhibition of NF-kappaB-dependent iNOS and proinflammatory cytokines production

BACKGROUND AND PURPOSE

Glycyrrhizae radix has been widely used as a cytoprotective, plant-derived medicine. We have identified a flavanoid, liquiritigenin, as an active component in extracts of Glycyrrhizae radix. This research investigated the effects of liquiritigenin on the induction of inducible NOS (iNOS) and proinflammatory cytokines by lipopolysaccharide (LPS) in Raw264.7 cells, and on paw oedema in rats.

EXPERIMENTAL APPROACH

iNOS expression was determined by western blotting, real-time reverse transcription-PCR and reporter gene analyses. Tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta and IL-6 were assayed by ELISA. Gel shift assay and immunoblotting were used to assess NF-kappaB activation. The effect of liquiritigenin on acute inflammation in vivo was evaluated using carrageenan-induced paw oedema.

KEY RESULTS

Treatment of Raw264.7 cells with liquiritigenin caused inhibition of LPS-induced NF-kappaB DNA binding activity, due to repression of I-kappaBalpha phosphorylation and degradation. Liquiritigenin treatment prevented LPS from increasing the levels of iNOS protein and mRNA in a concentration-dependent manner. Liquiritigenin also suppressed the production of TNF-alpha, IL-1beta and IL-6 from Raw264.7 cells after LPS. In rats, liquiritigenin treatment inhibited formation of paw oedema induced by carrageenan.

CONCLUSION AND IMPLICATIONS

These results demonstrate that liquiritigenin exerts anti-inflammatory effects, which results from the inhibition of NF-kappaB activation in macrophages, thereby decreasing production of iNOS and proinflammatory cytokines. Our findings showing inhibition by liquiritigenin of paw oedema as well as inflammatory gene induction will help to understand the pharmacology and mode of action of liquiritigenin, and of the anti-inflammatory use of Glycyrrhizae radix.