Involvement of HSP70 and HO-1 in the protective effects of raloxifene on multiple organ dysfunction syndrome by endotoxemia in ovariectomized rats

Screening of orthopedic medicines identifies raloxifene hydrochloride as a novel ferroptosis inhibitor for spinal cord injury therapy

Spinal cord injury (SCI) is a severe condition that can lead to irreversible central nervous system damage. Spinal cord injury patients frequently present with coexisting orthopedic conditions, and many of them also have underlying bone and joint diseases. Recent studies have identified ferroptosis as a significant contributor that exacerbates the progression of spinal cord injury. This study conducted a screening in common orthopedic medications, which includes anti-osteoporosis agents and calcium supplements, in order to identify potential ferroptosis inhibitors and investigate their therapeutic effects on spinal cord injury. Among the 8 drugs screened, raloxifene hydrochloride was found to significantly inhibit ferroptosis induced by RSL3 in neural cells. Subsequent studies confirmed its inhibitory effect on ferroptosis both in vitro and in vivo. It was also demonstrated that Nrf2 inhibitor Brusatol could reverse the anti-ferroptotic effect of Raloxifene hydrochloride in neural cells in vitro as well as its therapeutic effect on SCI in vivo, suggesting its inhibitory effect on ferroptosis is through Nrf2. This study identifies a novel ferroptosis inhibitor among orthopedic medicines and also confirms the therapeutic effect of Raloxifene hydrochloride on SCI. The results of the current study may provide reference for the clinical administration of SCI.

AEBS inhibition in macrophages: Augmenting reality for SERMs repurposing against infections

Beyond their clinical use as selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen have attracted recent attention for their favorable activity against a broad range of dangerous human pathogens. While consistently demonstrated to occur independently on classic estrogen receptors, the mechanisms underlying SERMs antimicrobial efficacy remain still poorly elucidated, but fundamental to benefit from repurposing strategies of these drugs. Macrophages are innate immune cells that protect from infections by rapidly reprogramming their metabolic state, particularly cholesterol disposal, which is at the center of an appropriate macrophage immune response as well as of the anabolic requirements of both the pathogen and the host cells. The microsomal antiestrogen binding site (AEBS) comprises enzymes involved in the last stages of cholesterol biosynthesis and is a high affinity off-target site for SERMs. We review here recent findings from our laboratory and other research groups in support of the hypothesis that AEBS multiprotein complex represents the candidate pre-genomic target of SERMs immunomodulatory activity. The cholesterol restriction resulting from SERMs-mediated AEBS inhibition may be responsible for boosting inflammatory and antimicrobial pathways that include inflammasome activation, modulation of Toll-like receptors (TLRs) responses, induction of interferon regulatory factor (IRF3) and nuclear factor erythroid 2-related factor 2 (NRF2)-mediated transcriptional programs and, noteworthy, the mitigation of excessive inflammatory and proliferative responses, leading to the overall potentiation of the macrophage response to infections.

The beneficial roles and mechanisms of estrogens in immune health and infection disease

Multiple epidemiologic studies have revealed that gender is considered one of the important factors in the frequency and severity of certain infectious diseases, in which estrogens may play a vital role. There is growing evidence that estrogens as female sex hormone can modulate multiple biological functions outside of the reproductive system, such as in brain and cardiovascular system. However, it is largely unknown about the roles and mechanisms of estrogens/estrogen receptors in immune health and infection disease. Thence, by reading a lot of literature, we summarized the regulatory mechanisms of estrogens/estrogen receptors in immune cells and their roles in certain infectious diseases with gender differences. Therefore, estrogens may have therapeutic potentials to prevent and treat these infectious diseases, which needs further clinical investigation.

Benefits of Chlorella vulgaris against Cadmium Chloride-Induced Hepatic and Renal Toxicities via Restoring the Cellular Redox Homeostasis and Modulating Nrf2 and NF-KB Pathways in Male Rats

In our life scenarios, we are involuntarily exposed to many heavy metals that are well-distributed in water, food, and air and have adverse health effects on animals and humans. Cadmium (Cd) is one of the most toxic 10 chemicals reported by The World Health Organization (WHO), affecting organ structure and function. In our present study, we use one of the green microalga Chlorella vulgaris (ChV, 500 mg/kg body weight) to investigate the beneficial effects against CdCl2-induced hepato-renal toxicity (Cd, 2 mg/kg body weight for 10 days) on adult male Sprague-Dawley rats. In brief, 40 adult male rats were divided into four groups (n = 10); Control, ChV, Cd, and Cd + ChV. Cadmium alters liver and kidney architecture and disturbs the cellular signaling cascade, resulting in loss of body weight, alteration of the hematological picture, and increased ALT, AST, ALP, and urea in the blood serum. Moreover, cadmium puts hepatic and renal cells under oxidative stress due to the up-regulation of lipid peroxidation resulting in a significant increase in the IgG level as an innate immunity protection and induction of the pro-inflammatory cytokines (IL-1β and TNF-α) that causes hepatic hemorrhage, irregular hepatocytes in the liver and focal glomeruli swelling and proximal tubular degeneration in the kidney. ChV additive to CdCl2, could organize the protein translation process via NF-kB/Nrf2 pathways to prevent oxidative damage by maintaining cellular redox homeostasis and improving the survival of and tolerance of cells against oxidative damage caused by cadmium. The present study shed light on the anti-inflammatory and antioxidative properties of Chlorella vulgaris that suppress the toxicity influence of CdCl2.

ROS-NLRP3 signaling pathway induces sterile inflammation after thulium laser resection of the prostate

The sterile inflammation (SI) of the urinary tract is a common problem requiring serious consideration after prostatectomy. This study mainly focuses on the role of the reactive oxygen species-NLR family, pyrin domain-containing 3 (ROS-NLRP3) signaling pathway in SI after thulium laser resection of the prostate (TmLRP). Urinary cytokines were determined in patients who received TmLRP, and heat shock protein 70 (HSP70) was detected in the resected tissues. The involvement of ROS signaling in HSP70-induced inflammation was explored in THP-1 cells with or without N-acetyl- l-cysteine (NAC) pretreatment. The function of NLRP3 and Caspase-1 was determined by Western blot analysis, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction. These phenomena and mechanisms were verified by the beagle models that received TmLRP. Clinical urine samples after TmLRP showed high expression of inflammatory factors and peaked 3-5 days after surgery. The high expression of HSP70 in the resected tissues was observed. After HSP70 stimulation, the expression of ROS, NLRP3, Caspase-1, and interleukin-18 (IL-18) increased significantly and could be reduced by ROS inhibitor NAC. The expression of IL-1β and IL-18 could be inhibited by NLRP3 or Caspase-1 inhibitors. In beagle models that received TmLRP, HSP70, NLRP3, Caspase-1, IL-1β, and IL-18 were highly expressed in the wound tissue or urine, and could also be reduced by NAC pretreatment. Activation of the ROS-NLRP3 signaling pathway induces SI in the wound after prostatectomy. Inhibition of this pathway may be effective for clinical prevention and treatment of SI and related complications after prostatectomy.

DNA-PKcs promotes sepsis-induced multiple organ failure by triggering mitochondrial dysfunction

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DNA-PKcs inhibition attenuates sepsis-related MODS by preserving mitochondrial function and homeostasis.

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Organ-specific deletion of DNA-PKcs sustained myocardial contraction, liver function, and kidney performance in LPS-challenged mice.

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DNA-PKcs deficiency supported cardiomyocyte function through improving mitochondrial respiration.

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DNA-PKcs deficiency alleviated liver dysfunction by inhibiting LPS-induced mitochondrial oxidative stress and apoptosis.

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DNA-PKcs deficiency attenuated kidney dysfunction by normalizing mitochondrial dynamics and biogenesis, as well as mitophagy.

Introduction

Multiple organ failure is the commonest cause of death in septic patients.

Objectives

This study was undertaken in an attempt to elucidate the functional importance of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) on mitochondrial dysfunction associated with the development and progression of sepsis-related multiple organ dysfunction syndrome (MODS).

Methods

Cardiomyocyte-specific DNA-PKcs knockout (DNA-PKcs^CKO) mice, liver-specific DNA-PKcs knockout (DNA-PKcs^LKO) mice, and kidney tubular cell-specific DNA-PKcs knockout (DNA-PKcs^TKO) mice were used to generate an LPS-induced sepsis model. Echocardiography, serum biochemistry, and tissue microscopy were used to analyze organ damage and morphological changes induced by sepsis. Mitochondrial function and dynamics were determined by qPCR, western blotting, ELISA, and mt-Keima and immunofluorescence assays following siRNA-mediated DNA-PKCs knockdown in cardiomyocytes, hepatocytes, and kidney tubular cells.

Results

DNA-PKcs deletion attenuated sepsis-mediated myocardial damage through improving mitochondrial metabolism. Loss of DNA-PKcs protected the liver against sepsis through inhibition of mitochondrial oxidative damage and apoptosis. DNA-PKcs deficiency sustained kidney function upon LPS stress through normalization of mitochondrial fission/fusion events, mitophagy, and biogenesis.

Conclusion

We conclude that strategies targeting DNA-PKcs expression or activity may be valuable therapeutic options to prevent or reduce mitochondrial dysfunction and organ damage associated with sepsis-induced MODS.

Estrogen and estrogen receptors in kidney diseases

Acute kidney injury (AKI) and chronic kidney disease (CKD) are posing great threats to global health within this century. Studies have suggested that estrogen and estrogen receptors (ERs) play important roles in many physiological processes in the kidney. For instance, they are crucial in maintaining mitochondrial homeostasis and modulating endothelin-1 (ET-1) system in the kidney. Estrogen takes part in the kidney repair and regeneration via its receptors. Estrogen also participates in the regulation of phosphorus homeostasis via its receptors in the proximal tubule. The ERα polymorphisms have been associated with the susceptibilities and outcomes of several renal diseases. As a consequence, the altered or dysregulated estrogen/ERs signaling pathways may contribute to a variety of kidney diseases, including various causes-induced AKI, diabetic kidney disease (DKD), lupus nephritis (LN), IgA nephropathy (IgAN), CKD complications, etc. Experimental and clinical studies have shown that targeting estrogen/ERs signaling pathways might have protective effects against certain renal disorders. However, many unsolved problems still exist in knowledge regarding the roles of estrogen and ERs in distinct kidney diseases. Further research is needed to shed light on this area and to enable the discovery of pathway-specific therapies for kidney diseases.

Nicotine uncovers endotoxic-like cardiovascular manifestations in female rats: Estrogen and nitric oxide dependency

Endotoxic manifestations are diminished in female populations due to immune boosting actions of sex steroids. Considering that tobacco constituents including nicotine inhibit estrogen synthesis, we tested the hypothesis that nicotine exposure unveils cardiovascular anomalies of endotoxemia in female rats. Studies were undertaken in conscious female rats treated with i.v. lipopolysaccharide (LPS, 10 mg/kg) in absence and presence of nicotine. In contrast to no effects for LPS when used alone, dose-related decreases in blood pressure (BP) and serum estrogen were noted in endotoxic rats treated consequently with nicotine (25, 50, or 100 μg/kg i.v.). Signs of cardiac autonomic dysfunction appeared in LPS/nicotine-treated rats such as (i) decreased time-domain indices of heart rate variability (HRV), e.g. standard deviation of R-R intervals (SDNN) and root mean square of successive differences in R-R interval durations (rMSSD), and (ii) reduced total power of the frequency spectrum and shifted cardiac sympathovagal balance toward sympathetic dominance. Nicotine reversed the LPS-evoked modest rises in serum TNFα and IL-1β while had no effect on associated arterial baroreflex dysfunction, inferring no roles for inflammation or baroreflexes in LPS-nicotine interaction. Estrogen or aminoguanidine (iNOS inhibitor), but not pentoxifylline (TNFα inhibitor), abolished LPS/nicotine hypotension. Together, nicotine acts probably via reducing estrogen availability to uncover nitric oxide-dependent hypotension and autonomic dysregulation in endotoxic female rats.

Oxidative stress and decreased tissue HSP70 are involved in the genesis of sepsis: HSP70 as a therapeutic target

Sepsis is a systemic infection that causes multiple organ dysfunction. HSP70 is a protein responsive to cell stress, in particular oxidative stress. Therefore, this literature review sought to investigate the roles of HSP70 and oxidative stress in the pathophysiology of sepsis and the possibility of HSP70 as a therapeutic target. HSP70 exerts a protective effect when located in cells (iHSP70), and its decrease, as well as its increase in the extracellular environment (eHSP70), under oxidative stress is a biomarker of sepsis severity. In addition, therapies that increase iHSP70 and treatment with HSP70 promote sepsis improvement.

Anti-heat shock protein 70 levels in gingival crevicular fluid of Japanese patients with chronic periodontitis

Periodontitis is an inflammatory disease involving complex tripartite cross-interactions among bacterial, host and environment factors. Heat shock proteins (Hsps) are a protein family produced in response to stress conditions. Hsps protect cells under adverse circumstances such as infection, inflammation and disease. One of the causes of periodontal disease is thought to be an imbalance in the expression of Hsps and anti-Hsp antibodies. Hsps are classified according to their molecular weight, and one of the major ones is Hsp70. In the present study, enzyme-linked immunosorbent assay was used to measure the levels of anti-Hsp70 antibody in gingival crevicular fluid (GCF) from two gingival sulci in each of nine patients with chronic periodontitis (CP): one healthy control (HC) site with a probing pocket depth (PPD) of ≤3 mm and one CP site with a PPD of >5 mm. Anti-Hsp70 antibody levels in GCF were higher at HC sites than at CP sites. Moreover, the anti-Hsp70 antibody levels were found to increase after initial periodontal therapy at both HC and CP sites. These results suggest an association of anti-Hsp70 antibody with periodontitis.

Integration Analysis of m6A-SNPs and eQTLs Associated With Sepsis Reveals Platelet Degranulation and Staphylococcus aureus Infection are Mediated by m6A mRNA Methylation

Sepsis is a major threat with high mortality rate for critically ill patients. Response to pathogen infection by the host immune system is a key biological process involved in the onset and development of sepsis. Heterogeneous host genome variation, especially single nucleotide polymorphisms (SNPs), has long been suggested to contribute to differences in disease progression. However, the function of SNPs located in non-coding regions remains to be elucidated. Recently, m⁶A mRNA modification levels were revealed to differ at SNPs. As m⁶A is a crucial regulator of gene expression, these SNPs might control genes by changing the m⁶A level on mRNA. To investigate the potential role of m⁶A SNPs in sepsis, we integrated m⁶A-SNP and expression quantitative trait loci (eQTLs) data. Analysis revealed 15,720 m⁶A-cis-eQTLs and 381 m⁶A-trans-eQTLs associated with sepsis. We identified 1321 genes as locations of m⁶A-cis-eQTLs. These were enriched in platelet degranulation and Staphylococcus aureus infection pathways, which are vital for the pathophysiological process of sepsis. We conclude that m⁶A modification of mRNA plays a very important role in sepsis, with m⁶A-cis-eQTLs potentially having the most effect on individual variation in sepsis progression.

Ovariectomy provokes inflammatory and cardiovascular effects of endotoxemia in rats: Dissimilar benefits of hormonal supplements

The female gender is protected against immunological complications of endotoxemia. Here we investigated whether gonadal hormone depletion by ovariectomy (OVX) uncovers inflammatory and cardiovascular effects of endotoxemia and whether these effects are reversed by hormone replacement therapies. Changes in inflammatory cytokines, blood pressure (BP), left ventricular (LV) function, and cardiac autonomic activity caused by lipopolysaccharide (LPS) in conscious female rats with different hormonal states were determined. In contrast to no effects in sham-operated females, treatment of OVX rats with LPS (i) decreased BP, (ii) increased spectral low-frequency/high-frequency ratio of HRV, denoting enhanced cardiac sympathetic dominance, (iii) attenuated reflex tachycardic responses to sodium nitroprusside, and (iv) increased systolic contractility (dP/dt_max). The developed hypotension was (i) fully eliminated in estrogen (E₂)-pretreated OVX rats, (ii) partially counteracted after selective activation of estrogen receptor-α (PPT) or β (DPN). All estrogenic compounds abrogated LPS enhancement of cardiac sympathetic drive. However, PPT was more successful than E2 or DPN in compromising LPS depression in baroreflex activity and elevation in dP/dt_max. Molecular studies showed that PPT was most effective in attenuating the upregulated myocardial expressions of NF-κB and iNOS in endotoxic OVX rats. Myocardial expression of the defensive HSP70 was comparably increased by all estrogenic products. Except for improved cardiac spectral activity, none of these functional or molecular entities was affected by medroxyprogesterone acetate (MPA). Overall, our data suggest diverse therapeutic advantages for gonadal hormones in the worsened endotoxic complications in rats with surgical menopause, with probably more favorable role for ERα agonism within this context.

RNA Expression Profile and Alternative Splicing Signatures of Genistein-Treated Breeder Hens Revealed by Hepatic Transcriptomic Analysis

Little information has been available about the influence of dietary genistein (GEN) on hepatic transcriptome of laying broiler breeder (LBB) hens. The study is aimed at broadening the understanding of RNA expression profiles and alternative splicing (AS) signatures of GEN-treated breeder hens and thereby improving laying performance and immune function of hens during the late egg-laying period. 720 LBB hens were randomly allocated into three groups with supplemental dietary GEN doses (0, 40 mg/kg, and 400 mg/kg). Each treatment has 8 replicates of 30 birds. Dietary GEN enhanced the antioxidative capability of livers, along with the increased activities of glutathione peroxidase and catalase. Furthermore, it improved lipid metabolic status and apoptotic process in the liver of hens. 40 mg/kg dietary GEN had the better effects on improving immune function and laying performance. However, transcriptome data indicated that 400 mg/kg dietary GEN did negative regulation of hormone biosynthetic process. Also, it upregulated the expressions of EDA2R and CYR61 by the Cis regulation of neighbouring genes (lncRNA_XLOC_018890 and XLOC_024242), which might activate NF-κB and immune-related signaling pathway. Furthermore, dietary GEN induced AS events in the liver, which also enriched into immune and metabolic process. Therefore, the application of 40 mg/kg GEN in the diet of breeder hens during the late egg-laying period can improve lipid metabolism and immune function. We need to pay attention to the side-effects of high-dose GEN on the immune function.

Overall systematic approach to sepsis damages on urogenital tissues: protective power of lacosamide

PURPOSE

The aim of the study was to evaluate the harmful effects of sepsis on the urogynecological tissues and the ability of Lacosamide (LCM) on Lipopolysaccharide (LPS)-induced cytokine production, oxidative stress and apoptotic pathways, in the experimental rat sepsis model.

METHODS

Twenty-four female Wistar albino rats (12 months old) were divided into 3 groups as follows: control group (Group I) (0.1 ml/oral and i.p. saline, single dose), sepsis group (Group II) (5 mg/kg LPS, i.p. single dose) and sepsis + LCM group (Group III) (5 mg/kg LPS, i.p. single dose and 40 mg/kg LCM). Six hours after the last LPS administration, the animals were sacrificed. Subsequently, the analyses of urogenital tissues total oxidant/antioxidant status, histopathological and immunohistochemical analyses were performed.

RESULTS

Total oxidant capacity (TOC) and oxidative stress index (OSI) values in the urogenital tissues were increased in the urogenital tissues in Group II [Total antioxidant capacity (TAC) was decreased] compared to group I (p < 0.05). LCM improved these values (p < 0.05). The immunohistochemical markers (Tumor Necrosis Factor-alpha (TNF-α), interleukin-1 beta (IL-1β), heat shock protein 70 (HSP-70), C-reactive protein (CRP), Malondialdehyde (MDA) were significantly increased in Group II (p < 0.001). With the administration of LCM (Group III), the expressions of above-mentioned markers were markedly decreased (p < 0.001). Marked hyperemia and slight hemorrhages with neutrophil leukocyte infiltrations were seen histopathologically in Group II. LCM treatment ameliorated the pathological findings.

CONCLUSION

These findings demonstrated that sepsis caused oxidative stress, apoptosis and inflammation in the urogenital tissues. We revealed that LCM ameliorated the damage caused by sepsis in urogenital tissue.

Sexual dimorphism in bacterial infections

Background

Sex differences are important epidemiological factors that impact in the frequency and severity of infectious diseases. A clear sexual dimorphism in bacterial infections has been reported in both humans and animal models. Nevertheless, the molecular mechanisms involved in this gender bias are just starting to be elucidated. In the present article, we aim to review the available data in the literature that report bacterial infections presenting a clear sexual dimorphism, without considering behavioral and social factors.

Main body

The sexual dimorphism in bacterial infections has been mainly attributed to the differential levels of sex hormones between males and females, as well as to genetic factors. In general, males are more susceptible to gastrointestinal and respiratory bacterial diseases and sepsis, while females are more susceptible to genitourinary tract bacterial infections. However, these incidences depend on the population evaluated, animal model and the bacterial species. Female protection against bacterial infections and the associated complications is assumed to be due to the pro-inflammatory effect of estradiol, while male susceptibility to those infections is associated with the testosterone-mediated immune suppression, probably via their specific receptors. Recent studies indicate that the protective effect of estradiol depends on the estrogen receptor subtype and the specific tissue compartment involved in the bacterial insult, suggesting that tissue-specific expression of particular sex steroid receptors contributes to the susceptibility to bacterial infections. Furthermore, this gender bias also depends on the effects of sex hormones on specific bacterial species. Finally, since a large number of genes related to immune functions are located on the X chromosome, X-linked mosaicism confers a highly polymorphic gene expression program that allows women to respond with a more expanded immune repertoire as compared with men.

Conclusion

Notwithstanding there is increasing evidence that confirms the sexual dimorphism in certain bacterial infections and the molecular mechanisms associated, further studies are required to clarify conflicting data and to determine the role of specific hormone receptors involved in the gender bias of bacterial infections, as well as their potential as therapeutic targets.

Nitric oxide-heat shock protein axis in menopausal hot flushes: neglected metabolic issues of chronic inflammatory diseases associated with deranged heat shock response

BACKGROUND

Although some unequivocal underlying mechanisms of menopausal hot flushes have been demonstrated in animal models, the paucity of similar approaches in humans impedes further mechanistic outcomes. Human studies might show some as yet unexpected physiological mechanisms of metabolic adaptation that permeate the phase of decreased oestrogen levels in both symptomatic and asymptomatic women. This is particularly relevant because both the severity and time span of hot flushes are associated with increased risk of chronic inflammatory disease. On the other hand, oestrogen induces the expression of heat shock proteins of the 70 kDa family (HSP70), which are anti-inflammatory and cytoprotective protein chaperones, whose expression is modulated by different types of physiologically stressful situations, including heat stress and exercise. Therefore, lower HSP70 expression secondary to oestrogen deficiency increases cardiovascular risk and predisposes the patient to senescence-associated secretory phenotype (SASP) that culminates in chronic inflammatory diseases, such as obesities, type 2 diabetes, neuromuscular and neurodegenerative diseases.

OBJECTIVE AND RATIONALE

This review focuses on HSP70 and its accompanying heat shock response (HSR), which is an anti-inflammatory and antisenescent pathway whose intracellular triggering is also oestrogen-dependent via nitric oxide (NO) production. The main goal of the manuscript was to show that the vasomotor symptoms that accompany hot flushes may be a disguised clue for important neuroendocrine alterations linking oestrogen deficiency to the anti-inflammatory HSR.

SEARCH METHODS

Results from our own group and recent evidence on hypothalamic control of central temperature guided a search on PubMed and Google Scholar websites.

OUTCOMES

Oestrogen elicits rapid production of the vasodilatory gas NO, a powerful activator of HSP70 expression. Whence, part of the protective effects of oestrogen over cardiovascular and neuroendocrine systems is tied to its capacity of inducing the NO-elicited HSR. The hypothalamic areas involved in thermoregulation (infundibular nucleus in humans and arcuate nucleus in other mammals) and whose neurons are known to have their function altered after long-term oestrogen ablation, particularly kisspeptin-neurokinin B-dynorphin neurons, (KNDy) are the same that drive neuroprotective expression of HSP70 and, in many cases, this response is via NO even in the absence of oestrogen. From thence, it is not illogical that hot flushes might be related to an evolutionary adaptation to re-equip the NO-HSP70 axis during the downfall of circulating oestrogen.

WIDER IMPLICATIONS

Understanding of HSR could shed light on yet uncovered mechanisms of menopause-associated diseases as well as on possible manipulation of HSR in menopausal women through physiological, pharmacological, nutraceutical and prebiotic interventions. Moreover, decreased HSR indices (that can be clinically determined with ease) in perimenopause could be of prognostic value in predicting the moment and appropriateness of starting a HRT.