Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

Pharmacokinetic Drug Interaction Between Raloxifene and Cholecalciferol in Healthy Volunteers

Osteoporosis is a common skeletal disorder, often leading to fragility fracture. Combination therapy with raloxifene, a selective estrogen receptor modulator, and cholecalciferol (vitamin D₃) has been proposed to improve the overall efficacy and increase compliance of raloxifene therapy for postmenopausal osteoporosis. To our knowledge, there has been no report of any study on the pharmacokinetic interaction between raloxifene and cholecalciferol. This study aimed to evaluate the possible pharmacokinetic interactions between raloxifene and cholecalciferol in healthy adult male Korean volunteers. Twenty subjects completed this open‐label, randomized, single‐dose, 3‐period, 6‐sequence, crossover phase 1 study with a 14‐day washout period. Serial blood samples were collected from 20 hours before dosing to 96 hours after dosing. The plasma concentrations of raloxifene and cholecalciferol were determined using a validated method for high‐performance liquid chromatography with tandem mass spectrometry. The geometric mean ratios (90%CIs) for area under the plasma concentration–time curve from time 0 to the last quantifiable time point and maximum plasma concentration of raloxifene with or without cholecalciferol were 1.02 (0.87‐1.20) and 0.87 (0.70‐1.08), respectively. For baseline‐corrected cholecalciferol, geometric mean ratios (90%CIs) of area under the plasma concentration–time curve from time 0 to the last quantifiable time point and maximum plasma concentration with or without raloxifene were 1.01 (0.93‐1.09) and 0.99 (0.92‐1.06), respectively. Concurrent treatment with raloxifene and cholecalciferol was generally well tolerated. These results suggest that raloxifene and cholecalciferol have no clinically relevant pharmacokinetic drug‐drug interactions when administered concurrently. All treatments were well tolerated, with no serious adverse events.

Raloxifene Modulates Microglia and Rescues Visual Deficits and Pathology After Impact Traumatic Brain Injury

Mild traumatic brain injury (TBI) involves widespread axonal injury and activation of microglia, which initiates secondary processes that worsen the TBI outcome. The upregulation of cannabinoid type-2 receptors (CB2) when microglia become activated allows CB2-binding drugs to selectively target microglia. CB2 inverse agonists modulate activated microglia by shifting them away from the harmful pro-inflammatory M1 state toward the helpful reparative M2 state and thus can stem secondary injury cascades. We previously found that treatment with the CB2 inverse agonist SMM-189 after mild TBI in mice produced by focal cranial blast rescues visual deficits and the optic nerve axon loss that would otherwise result. We have further shown that raloxifene, which is Food and Drug Administration (FDA)-approved as an estrogen receptor modulator to treat osteoporosis, but also possesses CB2 inverse agonism, yields similar benefit in this TBI model through its modulation of microglia. As many different traumatic events produce TBI in humans, it is widely acknowledged that diverse animal models must be used in evaluating possible therapies. Here we examine the consequences of TBI created by blunt impact to the mouse head for visual function and associated pathologies and assess raloxifene benefit. We found that mice subjected to impact TBI exhibited decreases in contrast sensitivity and the B-wave of the electroretinogram, increases in light aversion and resting pupil diameter, and optic nerve axon loss, which were rescued by daily injection of raloxifene at 5 or 10 mg/ml for 2 weeks. Raloxifene treatment was associated with reduced M1 activation and/or enhanced M2 activation in retina, optic nerve, and optic tract after impact TBI. Our results suggest that the higher raloxifene dose, in particular, may be therapeutic for the optic nerve by enhancing the phagocytosis of axonal debris that would otherwise promote inflammation, thereby salvaging less damaged axons. Our current work, together with our prior studies, shows that microglial activation drives secondary injury processes after both impact and cranial blast TBI and raloxifene mitigates microglial activation and visual system injury in both cases. The results thus provide a strong basis for phase 2 human clinical trials evaluating raloxifene as a TBI therapy.

The Impact of Improving Dermal Permeation on the Efficacy and Targeting of Liposome Nanoparticles as a Potential Treatment for Breast Cancer

Breast cancer is the most frequent malignancy in women. This work focuses on developing deformable liposomes as a potential carrier for breast cancer treatment and studying the impact of improving dermal permeation on the efficacy and targeting of liposomes. Raloxifene (RXF), an oestrogen antagonist, was used as a model drug. Using Box-Behnken design, different formulations of RXF-loaded deformable liposome (RLDL) were prepared using different propylene glycol, phospholipid and cholesterol concentrations. The percentage of entrapment efficiency (Y₁), particle size (Y₂), zeta potential (Y₃) and steady-state flux (Y₄) of the prepared formulations were all evaluated. Y₁ and Y₄ were significantly increased and Y₂ and Y₃ were significantly decreased when the propylene glycol concentration was increased. The optimization was obtained and the optimum formulation was that including phospholipid (1.40% w/w), cholesterol (0.15% w/w) and propylene glycol (10% v/v). The selected optimum formulation displayed a % EE of 78.34 ± 1.04% with a steady-state flux of 4.21 ± 0.02 µg/cm²/h. In order to investigate bioavailability, antitumor effectiveness and permeation, the optimum formulation was selected and included in a carbopol gel. The optimum gel formulation had 2.77 times higher bioavailability and, as a result, considerable antitumor action as compared to oral RXF. In conclusion, optimum RLDL gel may be an effective breast cancer treatment.

Raloxifene Protects Cisplatin-Induced Renal Injury in Mice via Inhibiting Oxidative Stress

Purpose

Cisplatin is one of the most widely used antineoplastic drugs but has limited therapeutic effects due to nephrotoxicity. The aim of this study was to determine the possible renoprotective effect of the antioxidant raloxifene on cisplatin-induced nephrotoxicity in mice.

Materials and Methods

Cisplatin-induced acute renal injury was established in female C57 mice that were treated with saline (normal control) or raloxifene over a 7-day period. The body weight of the mice was recorded. Histopathological examinations of the kidney tissues were performed using H&E, PAS staining and TEM. The histomorphology of liver and other organs was observed by H&E staining. The serum levels of creatinine, blood urea nitrogen (BUN), alanine transaminase (ALT) and glutamic oxalacetic transaminase (AST) were analyzed by specific kits. Superoxide dismutase (SOD) and glutathione (GSH) activity, and the content of malondialdehyde (MDA) in the kidney, liver homogenates and HK-2 cells were measured by WST-8 and thiobarbituric acid colorimetric methods. Moreover, the mitochondrial structures of HK-2 cells were performed using TEM. The viability and proliferation of HK-2 cells were examined by CCK-8 and EdU incorporation assays. The mitochondrial membrane potential was measured by JC-1 fluorescence.

Results

Raloxifene significantly reduced the levels of serum creatinine, urea, ALT and AST in the cisplatin-treated mice, and alleviated cisplatin-induced renal and hepatic tissue injury. Furthermore, raloxifene also increased the activity of GSH and SOD in the renal tissues and HK-2 cells, and reduced MDA levels, thereby limiting oxidative stress in the kidney.

Conclusion

Raloxifene protected against cisplatin-induced nephrotoxicity by activating the antioxidant system, along with alleviating liver damage. It should be considered as a potential adjuvant in cisplatin-based chemotherapeutic protocols.

Molecular and Metabolomic Investigation of Celecoxib Antiproliferative Activity in Mono-and Combination Therapy Against Breast Cancer Cell Models

BACKGROUND

Chronic inflammation plays a crucial role in the initiation, promotion, and invasion of tumors, and thus the antiproliferative effects of numerous anti-inflammatory drugs have been frequently reported in the literature. Upregulation of the pro-inflammatory enzyme cyclooxygenase-2 (COX-2) has been linked to various human cancers, including breast cancer.

OBJECTIVES

This research aims to investigate the antiproliferative activity of different Non-steroidal anti-inflammatory drugs (NSAIDs), including COX-2 selective and non-selective agents, against various breast cancer cell lines and to elucidate possible molecular pathways involved in their activity.

METHODS

The antiproliferative and combined effects of NSAIDs with raloxifene were evaluated by MTT assay. Cell migration was assessed using a wound-healing assay. The mechanism of cell death was determined using the Annexin V-FITC/ propidium iodide staining flow cytometry method. A mass spectrometry-based targeted metabolomics approach was used to profile the metabolomic changes induced in the T47d cells upon drug treatment.

RESULTS

Our results have demonstrated that celecoxib, a potent and selective COX-2 inhibitor, resulted in significant antiproliferative activity against all examined breast cancer cell lines with IC50 values of 95.44, 49.50. and 97.70 μM against MDA-MB-231, T47d, and MCF-7, respectively. Additionally, celecoxib exhibited a synergistic effect against T47d cells combined with raloxifene, a selective estrogen receptor modulator. Interestingly, celecoxib treatment increased cell apoptosis and resulted in substantial inhibition of cancer cell migration. In addition, the metabolomic analysis suggests that celecoxib may have affected metabolites (n = 43) that are involved in several pathways, including the tricarboxylic acid cycle, amino acids metabolism pathways, and energy production pathways in cancer cells.

CONCLUSION

Celecoxib may possess potential therapeutic utility for breast cancer treatment as monotherapy or in combination therapy. The reported metabolic changes taking place upon celecoxib treatment may shed light on possible molecular targets mediating the antiproliferative activity of celecoxib in an independent manner of its COX-2 inhibition.

The Effect of Raloxifene Treatment on Lipid Profile in Elderly Individuals: A Systematic Review and Meta-analysis of Randomized Clinical Trials

PURPOSE

To perform a systematic review and meta-analysis of randomized clinical trials (RCTs) to elucidate the effects of raloxifene on the lipid profile in elderly individuals.

METHODS

A systematic review and meta-analysis of RCTs was performed following the PRISMA statement. Data on triglycerides (TGs), total cholesterol (TC), HDL-C, and LDL-C were extracted. Relevant publications up to October 2020 were detected through searches in the PubMed/MEDLINE, Web of Science, Scopus, and Embase databases. Changes were reported as weighted mean differences (WMDs) and 95% CIs using random-effects models.

FINDINGS

Nine studies were selected, with a duration of intervention ranging from 2 and 12 months and a raloxifene dose of 60 to 120 mg/d. Studies were performed in healthy individuals and in those with disorders, such as osteoporosis, type 2 diabetes, and kidney disease required long-term hemodialysis. Overall, TG (WMD, -6.50 mg/dL; 95% CI, -34.18 to 21.20 mg/eL; P = 0.646), LDL-C (WMD, -17.86 mg/dL; 95% CI, -42.44 to 6.72 mg/dL; P = 0.154), and HDL-C (WMD, 2.35 mg/dL; 95% CI, -1.14 to 5.84 mg/dL; P = 0.187) levels did not change significantly after the administration of raloxifene. In contrast, TC levels decreased after raloxifene therapy (WMD, -6.59 mg/dL; 95% CI, -13.13 to -0.05 mg/dL; P = 0.048).

IMPLICATIONS

Raloxifene therapy decreased TC levels but did not alter TG, HDL-C, and LDL-C concentrations in elderly individuals. Regarding the LDL-C levels, although the finding lacked statistical significance, we believe that there was a mean reduction that deserves further clinical attention as much as TC.

Raloxifene Ameliorates Glucosamine-Induced Insulin Resistance in Ovariectomized Rats

Osteoarthritis (OA) and osteoporosis (OP) are common among older women, especially postmenopausal women. Glucosamine (GlcN) is a common medication for OA, but it may induce insulin resistance and β-cell dysfunction, especially if ovarian hormones are lacking. Raloxifene (RLX) is a selective estrogen receptor modulator and also an OP drug. Previously, we found that estrogen could improve GlcN-induced insulin resistance in ovariectomized (OVX) rats. Here, we further hypothesized that RLX, similarly to estrogen, can ameliorate GlcN-induced insulin resistance in OVX rats. We used GlcN to induce insulin resistance in OVX rats as a model for evaluating the protective effects of RLX in vivo. We used a pancreatic β-cell line, MIN-6, to study the mechanisms underlying the effect of RLX in GlcN-induced β-cell dysfunction in vitro. Increases in fasting plasma glucose, insulin, and homeostasis model assessments of insulin resistance in OVX Sprague Dawley rats treated with GlcN were reversed by RLX treatment (n = 8 in each group). Skeletal muscle GLUT-4 increased, liver PEPCK decreased, pancreatic islet hypertrophy, and β-cell apoptosis in OVX rats treated with GlcN was ameliorated by RLX. The negative effects of GlcN on insulin secretion and cell viability in MIN-6 cells were related to the upregulation of reticulum (ER) stress-associated proteins (C/EBP homologous protein, phospho-extracellular signal-regulated kinase, phospho-c-JunN-terminal kinase), the expression of which was reduced by RLX. Pretreatment with estrogen receptor antagonists reversed the protective effects of RLX. GlcN can induce insulin resistance, β-cell dysfunction, and apoptosis in OVX rats and increase ER stress-related proteins in β-cells, whereas RLX can reverse these adverse effects. The effects of RLX act mainly through estrogen receptor α; therefore, RLX may be a candidate drug for postmenopausal women with OA and OP.

Pharmacotherapeutic options for the treatment of menopausal symptoms

Introduction: Menopausal symptoms can be very overwhelming for women. Over the years, many pharmacotherapeutic options have been tested, and others are still being developed. Hormone therapy (HT) is the most efficient therapy for managing vasomotor symptoms and related disturbances. The term HT comprises estrogens and progestogens, androgens, tibolone, the tissue-selective estrogen complex (TSEC), a combination of bazedoxifene and conjugated estrogens, and the selective estrogen receptor modulators, such as ospemifene. Estrogens and progestogens and androgens may differ significantly for chemical structure and can be delivered through different routes, thereby displaying various pharmacological and clinical properties. Tibolone, TSEC and SERM also exhibit unique pharmacodynamics that can be exploited to obtain distinctive therapeutic effects. Non-hormonal options fall mainly into the selective serotonin reuptake inhibitor (SSRI) and selective noradrenergic reuptake inhibitor (SNRI), GABA-analogue drug classes.Areas covered: Herein, the authors describe the pharmacokinetics and pharmacodynamics of hormonal (androgens, estrogens, progestogens, tibolone, TSEC, SERMs) and non-hormonal (SSRIs, SNRIs, Gabapentin, Pregabalin, Oxybutynin, Neurokinin antagonists) treatments for menopausal symptoms and report essential clinical trial data in humans.Expert opinion: Patient tailoring of treatment is key to managing symptoms of menopause. Physicians must have in-depth knowledge of the pharmacology of compounds to tailor therapy to the individual patient's characteristics and needs.

Skeletal Muscle Interleukin-6 Contributes to the Innate Immune Response in Septic Mice

ABSTRACT

Interleukin-6 (IL-6) is a major cytokine released by skeletal muscle. Although IL-6 plays complex but well-known roles in host defense, the specific contribution of skeletal muscle IL-6 to innate immunity remains unknown. We tested its functional relevance by exposing inducible skeletal muscle IL-6 knockdown (skmIL-6KD) mice to a cecal slurry model of polymicrobial peritonitis and compared responses to strain-matched controls and skeletal muscle Cre-matched controls at 3, 6, and 12 h postinfection. In both sexes, skmIL-6KD mice at 6 h of infection exhibited marked changes to leukocyte trafficking in the peritoneum, characterized by ∼1.75-fold elevation in %neutrophils, a ∼3-fold reduction in %lymphocytes and a ∼2 to 3-fold reduction in %basophils. A similar pattern was seen at 12 h. No changes were observed in plasma leukocyte counts. Circulating cytokines in female skmIL-6KD mice at 6 h consistently showed modest reductions in IL-6, but marked reductions in a broad range of both pro- and anti-inflammatory cytokines, e.g., TNFα and IL-10. In both sexes at 12 h, a generalized suppression of plasma cytokines was also seen after the effects of Cre-induction with raloxifene were addressed. There were no significant effects of skmIL-6KD on mortality in either sex. Collectively, our results are consistent with skmIL-6 playing an important and previously unrecognized role in immune cell trafficking and cytokine regulation during septic shock.

Primary Hyperparathyroidism: A Narrative Review of Diagnosis and Medical Management

Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia in the outpatient setting. Symptomatic presentation includes non-specific signs and symptoms of hypercalcemia, skeletal fragility, nephrolithiasis and nephrocalcinosis. The majority of individuals present at an asymptomatic stage following routine biochemical screening, without any signs or symptoms of calcium or parathyroid hormone (PTH) excess or target organ damage. Indications for surgery have recently been revised as published in recent guidelines and consensus statements. Parathyroidectomy is advised in patients younger than 50 years old and in the presence of either significant hypercalcemia, impaired renal function, renal stones or osteoporosis. Surgery is always appropriate in suitable surgical candidates, however, medical management may be considered in those with mild asymptomatic disease, contraindications to surgery or failed previous surgical intervention. We summarized the optimal medical interventions available in the care of PHPT patients not undergoing parathyroidectomy. Calcium and vitamin D intake should be optimized. Antiresorptive therapy may be used for skeletal protection in patients with an increased fracture risk. Cinacalcet, a calcimimetic agent, has been shown to effectively lower serum calcium and PTH levels. The effect of medical treatment on the reduction in fracture risk is unknown and should be the focus of future research.

Green Nanotechnology in the Formulation of a Novel Solid Dispersed Multilayered Core-Sheath Raloxifene-Loaded Nanofibrous Buccal Film; In Vitro and In Vivo Characterization

Green nanotechnology utilizes the principles of green chemistry to formulate eco-friendly nanocarrier systems to mitigate patients and environment hazards. Raloxifene (RLX) demonstrates poor aqueous solubility (BCS class II) and low bioavailability, only 2% (extensive first-pass metabolism). The aim of this study is to enhance RLX solubility and bioavailability via development of novel solid dispersed multilayered core-sheath RLX-loaded nanofibers (RLX-NFs) without the involvement of organic solvents. A modified emulsion electrospinning technique was developed. Electrospinning of an RLX-nanoemulsion (RLX-NE) with polymer solution (poly vinyl alcohol (PVA), hydroxypropyl methylcellulose (HPMC), and chitosan (CS) in different volume ratios (1:9, 2:8, and 4:6) using D-optimal response surface methodology was adopted. In vitro characterization of RLX-loaded NFs was performed; scanning electron microscope (SEM), thermal analysis, drug content, release studies, and bioadhesion potential. The optimum NFs formula was evaluated for morphology using high-resolution transmission electron microscopy (HRTEM), and ex vivo drug permeation. The superiority of E2 (comprising RLX-NE and PVA (2:8)) over other NF formulae was statistically observed with respect to Q60 (56.048%), Q240 (94.612%), fiber size (594.678 nm), mucoadhesion time 24 h, flux (5.51 µg/cm2/h), and enhancement ratio (2.12). RLX pharmacokinetics parameters were evaluated in rabbits following buccal application of NF formula E2, relative to RLX oral dispersion. E2 showed significantly higher Cmax (53.18 ± 4.56 ng/mL), and relative bioavailability (≈2.29-fold).

Mg,Si-Co-Substituted Hydroxyapatite/Alginate Composite Beads Loaded with Raloxifene for Potential Use in Bone Tissue Regeneration

Osteoporosis is a worldwide chronic disease characterized by increasing bone fragility and fracture likelihood. In the treatment of bone defects, materials based on calcium phosphates (CaPs) are used due to their high resemblance to bone mineral, their non-toxicity, and their affinity to ionic modifications and increasing osteogenic properties. Moreover, CaPs, especially hydroxyapatite (HA), can be successfully used as a vehicle for local drug delivery. Therefore, the aim of this work was to fabricate hydroxyapatite-based composite beads for potential use as local carriers for raloxifene. HA powder, modified with magnesium and silicon ions (Mg,Si-HA) (both of which play beneficial roles in bone formation), was used to prepare composite beads. As an organic matrix, sodium alginate with chondroitin sulphate and/or keratin was applied. Cross-linking of beads containing raloxifene hydrochloride (RAL) was carried out with Mg ions in order to additionally increase the concentration of this element on the material surface. The morphology and porosity of three different types of beads obtained in this work were characterized by scanning electron microscopy (SEM) and mercury intrusion porosimetry, respectively. The Mg and Si released from the Mg,Si-HA powder and from the beads were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). In vitro RAL release profiles were investigated for 12 weeks and studied using UV/Vis spectroscopy. The beads were also subjected to in vitro biological tests on osteoblast and osteosarcoma cell lines. All the obtained beads revealed a spherical shape with a rough, porous surface. The beads based on chondroitin sulphate and keratin (CS/KER-RAL) with the lowest porosity resulted in the highest resistance to crushing. Results revealed that these beads possessed the most sustained drug release and no burst release effect. Based on the results, it was possible to select the optimal bead composition, consisting of a mixture of chondroitin sulphate and keratin.

Green tea extract synergistically enhances the effectiveness of an antiresorptive drug on management of osteoporosis induced by ovariectomy in a rat model

Antiresorptive drugs are effective for reducing bone loss in postmenopausal women, but their long-term application may be associated with adverse effects. The present study aimed to investigate the potential in vivo synergistic effects of green tea extract (GTE) and alendronate or raloxifene on the management of osteoporosis. Ovariectomized rats were fed orally with GTE, alendronate and raloxifene at different concentrations and various combinations for 4 weeks. Bone mineral density (BMD) at the lumbar spine, femur and tibia was monitored weekly using peripheral quantitative computed tomography. Bone microarchitecture in the left distal femur was analyzed using micro-CT, while serum biochemical levels were measured using ELISA kits at the end of the study. GTE alone effectively mitigated BMD loss and improved bone microarchitecture in rats. The co-administration of GTE and alendronate increased total BMD in the lumbar spine, femur and tibia. Particularly, GTE synergistically enhanced the effect of alendronate at a low dose on bone microarchitecture and decreased serum tartrate-resistant acid phosphatase. These findings imply that the dosage of certain antiresorptive agents could be reduced when they are administrated simultaneously with GTE, so that their adverse effects are minimized. The findings may be used to support the development of a new synergistic intervention between food therapy and pharmacotherapy on the management of osteoporosis in a long-term basis.

Raloxifene, identified as a novel LSD1 inhibitor, suppresses the migration of renal cell carcinoma

Aim: As an important epigenetic modulator, histone lysine-specific demethylase 1 (LSD1) has been proved to be associated with the progression of renal cell carcinoma (RCC). Discovering novel LSD1 inhibitors offers therapeutic potential for RCC treatment. Methods & Results: We identified raloxifene as a novel LSD1 inhibitor (IC₅₀ = 2.08 μM) through small compound library screening. Molecular docking indicated raloxifene might bind LSD1 in the flavin adenine dinucleotide (FAD) binding cavity in a reversible manner. Cell viability and migration assays showed raloxifene could suppress the proliferation and migration of RCC cells bearing overexpressed LSD1. Conclusion: Our findings indicated that LSD1 might be a promising therapeutic target for RCC and that raloxifene could serve as a lead compound for further anti-RCC metastasis drug discovery.

Raloxifene is a Female-specific Proteostasis Therapeutic in the Spinal Cord

Several neurodegenerative disorders are characterized by proteasome dysfunctions leading to protein aggregations and pathogenesis. Since we showed that estrogen receptor alpha (ERα) activates the proteasome, drugs able to stimulate ERα in the central nervous system (CNS) could hold potential for therapeutic intervention. However, the transcriptional effects of selective estrogen receptor modulators (SERMs), such as tamoxifen and raloxifene, can be tissue specific. A direct comparison of the effects of different SERMs on gene transcription in the CNS has never been performed. Here, we report an RNA-seq analysis of the spinal cord treated with estrogen, tamoxifen, or raloxifene. We find stark SERM and sex-specific differences in gene expression profiles in the spinal cord. Notably, raloxifene, but not estrogen or tamoxifen, modulates numerous deubiquitinating enzymes, proteasome subunits and assembly factors, and these effects translate into decreased protein aggregates. In the SOD1-G93A mouse model of amyotrophic lateral sclerosis, we found that even a low dose of raloxifene causes a significant decrease in mutant SOD1 aggregates in the spinal cord, accompanied by a delay in the decline of muscle strength in females, but not in males. These results strongly indicate SERM-selective as well as sex-specific effects, and emphasize the importance of sex as a biological variable to be considered for the careful selection of specific SERM for use in clinical trials for neurodegenerative diseases.

Effects of Raloxifene Combined with Low-dose Conjugated Estrogen on the Endometrium in Menopausal Women at High Risk for Breast Cancer

OBJECTIVES

To compare the effects of low-dose conjugated estrogen (CE), raloxifene, and the combination thereof on the endometrium of postmenopausal women.

METHODS

Postmenopausal women between 45 and 60 years of age, with Gail score≥1.67 and no endometrial disorders, were randomly assigned to receive low-dose CE (0.3 mg), raloxifene (60 mg), or combined therapy for 1 year. Transvaginal ultrasound was performed at baseline and every 3 months; the Kupperman Index was assessed at baseline and every 6 months. Endometrial biopsies were performed if endometrial thickness (ET) was ≥5 mm or if vaginal bleeding occurred. The primary outcome was the occurrence of ET≥5 mm over the one-year period.

RESULTS

Seventy-three women were randomly assigned and analyzed on an intent-to-treat basis. Eight, three, and four women in the CE, raloxifene, and combination groups, respectively, exhibited ET≥5 mm. No genital bleeding was reported in the combination group. Endometrial biopsy revealed atrophy or polyps in all groups, with one patient in the CE group exhibiting a proliferative endometrium without atypia. At 6 months, there was a progressive increase in mean ET in the CE group, but not in the other two groups, with statistically significant differences at 6, 9, and 12 months. Mean scores for vasomotor symptoms and Kupperman Index favored the CE and combination groups over raloxifene.

CONCLUSION

Combined raloxifene and low-dose CE decreased the severity of menopausal symptoms to a similar extent as CE alone and had similar effects as raloxifene alone on the endometrium.

Raloxifene-induced osteonecrosis of the jaw (MRONJ) with no exposure to bisphosphonates: clinical and radiographic findings

Raloxifene is a selective estrogen receptor modulator (SERM) that is used to manage osteoporosis in women. Because of its tissue selectivity, raloxifene has fewer side effects than estrogen therapy; however, raloxifene-associated osteonecrosis of the jaw (ONJ) has recently been reported. While most of the reported cases were treated with antiresorptive therapy in addition to raloxifene, ONJ can also occur with the isolated use of raloxifene. This report presents a case where there was no prior exposure to bisphosphonates, in which the patient incidentally had florid cemento-osseous dysplasia (FCOD). Raloxifene-associated ONJ has never been reported before in a patient with FCOD. It is unclear whether the presence of FCOD increases the risk of ONJ. Case report: Clinical and radiographic findings regarding an African-American patient with FCOD and raloxifene-induced ONJ are described. The patient underwent a battery of investigations and surgical debridement of the area in question. She has remained disease free in the 2 years following the treatment. Conclusions: The aim of this report is to shed some light on a serious complication of raloxifene, a medication that is increasingly encountered in dental practices. Dental practitioners should use this knowledge to increase their awareness of possible ONJ development after the use of raloxifene. Brief recommendations and guidance in general dental practice for management of patients on raloxifene are also presented.

Raloxifene as a treatment option for viral infections

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused corona virus disease 2019 (COVID-19) pandemic and led to mass casualty. Even though much effort has been put into development of vaccine and treatment methods to combat COVID-19, no safe and efficient cure has been discovered. Drug repurposing or drug repositioning which is a process of investigating pre-existing drug candidates for novel applications outside their original medical indication can speed up the drug development process. Raloxifene is a selective estrogen receptor modulator (SERM) that has been approved by FDA in 1997 for treatment and prevention of postmenopausal osteoporosis and cancer. Recently, raloxifene demonstrates efficacy in treating viral infections by Ebola, influenza A, and hepatitis C viruses and shows potential for drug repurposing for the treatment of SARS-CoV-2 infection. This review will provide an overview of raloxifene's mechanism of action as a SERM and present proposed mechanisms of action in treatment of viral infections.

The Role of Estrogen Receptors and Their Signaling across Psychiatric Disorders

Increasing evidence suggests estrogen and estrogen signaling pathway disturbances across psychiatric disorders. Estrogens are not only crucial in sexual maturation and reproduction but are also highly involved in a wide range of brain functions, such as cognition, memory, neurodevelopment, and neuroplasticity. To add more, the recent findings of its neuroprotective and anti-inflammatory effects have grown interested in investigating its potential therapeutic use to psychiatric disorders. In this review, we analyze the emerging literature on estrogen receptors and psychiatric disorders in cellular, preclinical, and clinical studies. Specifically, we discuss the contribution of estrogen receptor and estrogen signaling to cognition and neuroprotection via mediating multiple neural systems, such as dopaminergic, serotonergic, and glutamatergic systems. Then, we assess their disruptions and their potential implications for pathophysiologies in psychiatric disorders. Further, in this review, current treatment strategies involving estrogen and estrogen signaling are evaluated to suggest a future direction in identifying novel treatment strategies in psychiatric disorders.

Discovery of a Bradykinin B2 Partial Agonist Profile of Raloxifene in a Drug Repurposing Campaign

Covid-19 urges a deeper understanding of the underlying molecular mechanisms involved in illness progression to provide a prompt therapeutical response with an adequate use of available drugs, including drug repurposing. Recently, it was suggested that a dysregulated bradykinin signaling can trigger the cytokine storm observed in patients with severe Covid-19. In the scope of a drug repurposing campaign undertaken to identify bradykinin antagonists, raloxifene was identified as prospective compound in a virtual screening process. The pharmacodynamics profile of raloxifene towards bradykinin receptors is reported in the present work, showing a weak selective partial agonist profile at the B2 receptor. In view of this new profile, its possible use as a therapeutical agent for the treatment of severe Covid-19 is discussed.

Development and validation of ultra-high-performance liquid chromatography-mass spectrometry method for the determination of raloxifene and its phase II metabolites in plasma: Application to pharmacokinetic studies in rats

The aim of this study is to establish a reliable liquid chromatography-mass spectrometry method to simultaneously quantitate raloxifene, and its major metabolites, raloxifene-6-glucuronide, raloxifene-4'-glucuronide, and raloxifene-6-sulfate in rat plasma samples for pharmacokinetic studies. The separation of the analytes was achieved on a Waters BEH C₁₈ column. Water (0.1% formic acid) and acetonitrile were used as the mobile phases for elution. A one-step protein precipitation using a mixture solvent was applied for plasma sample preparation. The method was validated following the FDA guidance. The results showed that the linear range were 1.95-1000 nM for raloxifene-6-glucuronide, and raloxifene-4'-glucuronide, 0.195-100 nM for raloxifene-6-sulfate, and 0.195-200 nM for raloxifene, respectively. The lower limit of quantification was 1.95, 1.95, 0.195, and 0.195 nM for raloxifene-6-glucuronide, raloxifene-4'-glucuronide, raloxifene-6-sulfate, and raloxifene, respectively. Only 20 µl of plasma sample was required since the method is sensitive. The intra- and interday variance is <15% and the accuracy is within 85-115%. The variance of matrix effect and recovery were <15%. The method was successfully applied in a pharmacokinetic study in rats with oral administration of raloxifene.

Photothermal Generation of Oxygen-Irrelevant Free Radicals with Simultaneous Suppression of Glutathione Synthesis for an Enhanced Photonic Thermodynamic Cancer Therapy

Reactive oxygen species (ROS) as one kind of oxygen-dependent toxic free radical has been widely adopted in ROS-mediated therapies (RMT). However, two shackles, known as tumor hypoxia and high intratumor glutathione (GSH) levels, respectively, limit RMT as the former prevents ROS from generating, while the latter scavenges the ROS generated. Herein, we developed a novel nanoplatform to simultaneously overcome the two shackles by facile preparation of mesoporous carbon nanospheres (MCNs) with AIBI and raloxifene loaded inside as an initiator and inhibitor, respectively, and phase-change materials (PCMs) capped outside as gatekeepers. Upon 808 nm NIR light irradiation, the photothermal effect of MCNs melted PCMs causing the loaded AIBI and raloxifene to be released, during which the AIBI was further decomposed into oxygen-irrelevant radicals to kill cancer cells, while the raloxifene suppressed GSH synthesis, synergistically enabling an enhanced photonic thermodynamic cancer therapy.

Randomized head-to-head comparison of minodronic acid and raloxifene for fracture incidence in postmenopausal Japanese women: the Japanese Osteoporosis Intervention Trial (JOINT)-04

AIMS

We conducted a head-to-head randomized trial of minodronate, a bisphosphonate, and raloxifene, a selective estrogen receptor modulator, to obtain clinical evidence and information about their efficacy and safety.

METHODS

The Japanese Osteoporosis Intervention Trial protocol number 4 (JOINT-04) trial is a multi-center, open-labeled, blinded endpoints, head-to-head randomized trial of minodronate and raloxifene. Ambulatory elderly women with osteoporosis (age, >60 years) were randomly allocated to the raloxifene or minodronate group by central registration. The co-primary endpoints included any one of osteoporotic fractures (vertebral, humeral, femoral, and radial fractures), vertebral fractures, and major osteoporotic fractures (clinical vertebral, humeral, femoral, and radial fractures). The biological effects of each drug, patients' quality of life, and drug safety were assessed based on the secondary outcomes. This study was registered at the University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) under trial identification number UMIN000005433.

RESULTS

A total of 3896 patients were randomized to the minodronate and raloxifene groups, and drug efficacy assessments were performed for 3247 patients (1623 and 1624 patients, respectively). Among these patients, 1176 and 1187 patients received allocated treatment for 2 years. The incidence rate ratios for osteoporotic, vertebral, and major osteoporotic fractures in the minodronate group were 0.94 (95% CI: 0.78-1.13, p = .494), 0.86 (95% CI: 0.70-1.05, p = .147), and 1.22 (95% CI: 0.86-1.74, p = .274), respectively. Compared to the raloxifene group, the minodronate group showed significantly increased bone mineral density of the lumbar spine for each visit (6 months: p = .007, 12 months: p = .0003, 24 months: p<.0001). Also, serious adverse reactions were observed for four and six patients in the minodronate and raloxifene groups, respectively.

CONCLUSIONS

Overall, there were no statistical differences in the incidence rates of osteoporotic, vertebral, or major osteoporotic fractures between the two groups. Serious adverse reactions were rare in both groups.

Raloxifene and n-Acetylcysteine Ameliorate TGF-Signalling in Fibroblasts from Patients with Recessive Dominant Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe skin disease caused by mutation of the COL7A1 gene. RDEB is associated with high levels of TGF-β1, which is likely to be involved in the fibrosis that develops in this disease. Endoglin (CD105) is a type III coreceptor for TGF-β1 and its overexpression in fibroblasts deregulates physiological Smad/Alk1/Alk5 signalling, repressing the synthesis of TGF-β1 and extracellular matrix (ECM) proteins. Raloxifene is a specific estrogen receptor modulator designated as an orphan drug for hereditary hemorrhagic telangiectasia, a rare vascular disease. Raloxifene stimulates endoglin synthesis, which could attenuate fibrosis. By contrast, the antioxidant N-acetylcysteine may have therapeutic value to rectify inflammation, fibrosis and endothelial dysfunction. Thus, we present here a repurposing strategy based on the molecular and functional screening of fibroblasts from RDEB patients with these drugs, leading us to propose the repositioning of these two well-known drugs currently in clinical use, raloxifene and N-acetylcysteine, to counteract fibrosis and inflammation in RDEB. Both compounds modulate the profibrotic events that may ultimately be responsible for the clinical manifestations in RDEB, suggesting that these findings may also be relevant for other diseases in which fibrosis is an important pathophysiological event.