Glucocorticoid Resistance Research Articles

A glucocorticoid-mediated immunoregulatory circuit integrated at brain levels: our early studies and a present view.

Background It was known since the 1940's that pharmacological administration of glucocorticoids can inhibit inflammatory and immune processes, and these hormones are still today among the most widely used therapeutic tools to treat diseases with immune components. However, it became clear later that endogenous glucocorticoids can either support or restrain immune processes. Summary Early studies showed that: a) endogenous levels of glucocorticoids can modulate immune cell activity; b) the immune response itself can stimulate the hypothalamus-pituitary-adrenal (HPA) axis to release glucocorticoids to levels that can exert immunoregulatory effects; c) immune products, later identified as cytokines, mediate this effect. On these bases, the existence of a glucocorticoid-mediated immunoregulatory circuit was proposed. It was also shown that increased levels of endogenous glucocorticoids exert protective effects during infections and other diseases with immune components. However, it was found in animal models and in humans that these effects can be blunted in several immune-linked diseases by defects at several levels, for example by glucocorticoid resistance or by adrenal insufficiency. Evidence was later provided that the glucocorticoid-mediated immunoregulatory circuit can also be activated by cytokines produced not only as consequence of immune stimulation but also following psycho/sensorial and physical stimuli. Thus, this circuit can be integrated at brain levels and, besides stimulating the HPA axis, cytokines can also affect synaptic plasticity, most likely via a tripartite synapse, with astrocytes as neuro-immune cells acting as the third component. Key Messages It is now well established that the glucocorticoid-mediated immunoregulatory circuit plays a central role in maintaining health. However, several variables can condition the efficacy of the effect of endogenous glucocorticoids. Furthermore, since cytokines and other immune products have many other neuro-endocrine and metabolic effects, other neuro-endocrine-immune circuits could simultaneously operate or become predominant during different pathologies. The consideration of these aspects might help to implement strategies to eventually decrease therapeutic doses of exogenous glucocorticoids.

The role of immunity in comorbid pain and depression

The narrative review aims to shed light on the influence of inflammation in the comorbid chronic pain and major depressive disorder (MDD). This connection is known to be multifactorial, with a dynamic interaction between genetic and epigenetic factors. However, a growing body of evidence has shown that the co-presence of MDD and pain is underlain by immune mechanisms involved in the persistence of the inflammatory process. In particular, the cytokines released following activation of the innate immune system during inflammation cause changes at the endocrine level that result in glucocorticoid resistance, as well as altering the synthesis and metabolism of some central nervous system (CNS) mediators. Cytokines appear to generate neuroinflammation by activating normally protective microglia. Various other mechanisms, including changes in the function of the glutamatergic, GABAergic, and serotonergic systems are also implicated, but inflammation-induced reduction of BDNF (brain-derived neurotrophic factor) appears to be the deciding factor. In turn, neuroinflammation leads to sickness behavior, which is characterized by anhedonia and social withdrawal. This review explored these mechanisms, which may be at the root of comorbid pain and MDD. Although intriguing, however, most available evidence comes from animal studies, and rigorous clinical exploration is warranted.

Tanshinone IIA potentiates the therapeutic efficacy of glucocorticoids in lipopolysaccharide-treated HEI-OC1 cells through modulation of the FOXP3/Nrf2 signaling pathway.

Glucocorticoids (GCs) are commonly used to treat sudden sensorineural hearing loss (SSNHL), although some patients are resistant to this therapeutic approach. Clinical studies have demonstrated the efficacy of tanshinone IIA (TA) in combination with GC for managing various human ailments. However, it remains unclear whether TA can mitigate GC resistance in SSNHL. Our aim is to elucidate the role of NRF2-induced transcriptional regulation of HDAC2 in influencing GC resistance and investigate the involvement of TA-related molecular pathways in GC resistance. Here, HEI-OC1 cells are treated with lipopolysaccharide (LPS) to establish an in vitro model for SSNHL. The cells are subsequently treated with dexamethasone (DXE) or DXE+TA. RT-qPCR and western blot analysis are used to measure the mRNA and protein levels of Forkhead box P3 (FOXP3), nuclear factor erythroid 2-related factor 2 (NRF2), and histone deacetylase 2 (HDAC2). Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays are carried out to assess cell proliferation. Flow cytometry analysis is performed to evaluate apoptosis. Mechanistic studies involve chromatin immunoprecipitation (ChIP), luciferase reporter, and DNA pull-down assays. Our results show that treatment with TA+DEX significantly increases proliferation and suppresses apoptosis in LPS-treated HEI-treated OC1 cells. TA upregulates HDAC2 expression by activating NRF2-mediated transcription of HDAC2, with the NRF2-HDAC2 binding site located at bases 419-429 (ATGACACTCCA) in the promoter sequence of HDAC2. Furthermore, TA upregulates FOXP3 expression to activate NRF2 transcription, with the predicted FOXP3-binding site located at bases 864-870 (GCAAACA) in the promoter sequence of NRF2. In summary, these findings suggest that TA enhances the therapeutic effects of GC on the proliferation and apoptosis of HEI OC1 cells by increasing FOXP3/Nrf2 expression. These results indicate that TA may be promising for ameliorating GC resistance in patients with SSNHL.

Augmented cortisol and antiglucocorticoid therapy in mood disorders: the hippocampus as a potential drug target

The pathophysiology of many mood disorders is closely related to abnormal stress response associated with the dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis and cortisol overproduction. The hippocampus, a key structure of the limbic system responsible for both cognitive and emotional spheres, is selectively vulnerable to excess of glucocorticoids (GCs) inducing neuroinflammation and neurodegeneration. The antiGC therapy of psychiatric diseases, in particular depressive disorders, may be a useful additional treatment. Among other approaches, targeting glucocorticoid receptors, abounded in the hippocampus, is regarded as highly promising. However, though the preclinical data provide fairly firm evidence to the concept of antiGC therapy for stress-related diseases, clinical studies still are at the proof-of-concept stage. Noteworthy, chronic GC excess is associated not only with mood diseases, but also with cognitive decline, metabolic disorders, diabetes. Potentially, antiGC (HPA axis modifying) therapy may alleviate affective symptoms, cognitive disturbances, GC and insulin resistance and adverse side effects of conventional drugs through beneficial effects on the hippocampus mitigating its dysfunction and neurodegeneration, neuroinflammation, and impairment of neurogenesis. Since stress/GC-associated neuroinflammation-mediated pathology of the limbic system and, specifically, the hippocampus, is a general feature typical for many brain diseases, the concept of antiGC therapy may be extended, tested and validated in a wider spectrum of cerebral pathologies.

Prediction of post-ESD esophageal stricture by a nomogram and risk factor analysis of ineffective oral steroids prophylaxis

Background and aimsSeveral risk models for esophageal stricture after endoscopic submucosal dissection have been developed. However, some of them did not include the use of steroids in the risk analysis. Glucocorticoid sensitivity mediated by glucocorticoid receptor expression has not been discussed in this condition.MethodsClinical and endoscopic characteristics were included in the logistic regression model to establish a nomogram for stenosis prediction. The score for each risk factor was estimated. Risk factors of ineffective oral steroid prophylaxis were analyzed and glucocorticoid receptor expressions were detected by immunohistochemistry.ResultsThree hundred fourteen patients of endoscopic submucosal dissection for esophageal superficial neoplasms were included to develop the nomogram. The circumferential range(≤ 3/4, 3/4–1 or the whole circumference), longitudinal diameter reached 4 cm (yes or not) and lesion location (the cervical and upper thoracic part, the middle thoracic part or the lower thoracic part) consisted of the nomogram. Patients have a high risk of esophageal stricture if they have a total point greater than 36. In the simplified risk score model, the corresponding cutoff score was 1. 92 patients with oral steroid prophylaxis were separately analyzed and the circumferential mucosal defect involving 7/8 or more was an independent risk factor of ineffective prevention (OR 12.2, 95%CI 5.27–28.11). The expression of glucocorticoid receptor β was higher in the stricture group (p = 0.042 for AOD; p = 0.016 for the scoring system).ConclusionsWe established a nomogram for esophageal stricture prediction. Depending on the characteristics of lesions, it is possible to estimate the risk of stricture under routine post-ESD treatments (no steroids or oral steroids). Alternative treatments should be considered if the risk is extremely high, especially for patients with mucosal defects involving 7/8 or more of circumference in which oral steroid treatment tends to be ineffective. The higher glucocorticoid receptor β may indicate potential glucocorticoid resistance.

8644 Dynamic Insights into Glucocorticoid Receptor Dysfunction: Novel patient-derived T437I Mutation and Its Impact on Glucocorticoid Receptor Function

Abstract Disclosure: T. Tettey: None. S. Kim: None. K. Wagh: None. Q. Lao: None. L.R. Schiltz: None. D.A. Stavreva: None. D.M. Presman: None. D.P. Merke: None. G.L. Hager: None. The glucocorticoid receptor (GR) is a hormone regulated transcription factor which binds chromatin to regulate many genes, including stress-response and inflammatory genes. Dexamethasone, a GR agonist, is widely used in the treatment of severe inflammation, including COVID-19. GR is vital for life and several GR mutations have been linked to severe pathophysiological conditions. Here we report a novel mutation in the DNA binding domain (DBD) of GR (T437I) in a patient with partial glucocorticoid resistance, a rare genetic disorder characterized by generalized insensitivity to glucocorticoids and a consequent hyperactivation of the hypothalamic pituitary adrenal axis. While the clinical manifestations of this hT437I GR mutation are apparent, its molecular mechanisms remain unexplored. Employing a comprehensive approach that integrates biophysical methods, molecular biology, and genomics, we investigate the molecular underpinnings of this genetic anomaly. Using CRISPR/Cas9 gene editing, we introduce GFP or Halo-tagged hT437I GR mutant into GR null mouse cells. Our findings indicate that the T437I GR variant exhibits normal hormone binding and nuclear translocation. Live-cell imaging using number and brightness analysis reveals that the mutant receptor maintains a wildtype-like oligomeric state but adopts a heterodimeric conformation in the presence of endogenous GR. Global transcriptomics analyses of the mouse hT437I mutant show that most dexamethasone-regulated genes are unresponsive following hormone treatment. We hypothesize that this mutation within the DBD compromises the binding of GR to regulatory sites of target genes. Leveraging fluorescence high-resolution microscopy, we employ single molecule tracking to study the dynamic behavior of Halo-tagged hT437I GR in mouse cells. Our results indicate that the GR mutant has a higher dwell-time on chromatin compared to the wild-type receptor. This suggests that the hT437I mutation impairs the receptor's binding to genomic sites, potentially leading to a failure in regulating GR target genes. This ongoing exploration of the molecular intricacies aims to deepen our understanding of the clinical phenotype observed in the patient. Presentation: 6/2/2024

8057 Unveiling Gender Dysphoria and Gender Change in a Large Cohort of DSD

Abstract Disclosure: R.L. Batista: None. M. Inacio: None. T.A. Bachega: None. N.L. Gomes: None. G. Madureira: None. M.C. Miranda: None. R.T. dallago: None. M.M. Ferrari: None. L.M. Lousada: None. J.A. Batatinha: None. E.F. Costa: None. M.P. Sircili: None. F. Denes: None. M.Y. Nishi: None. S. Domenice: None. B.B. Mendonca: None. Disorders/Differences of Sex Development (DSD) encompass a wide range of genetic conditions that affect sex development. Individuals with DSD may experience gender dysphoria and undergo gender changes throughout their lives. To analyze gender dysphoria and gender changes in individuals with DSD, we conducted a retrospective study involving all DSD cases from a single Brazilian tertiary medical center followed by a multidisciplinary team. We included 696 subjects considering their DSD diagnosis, sex assignment, age at DSD diagnosis, gender change, age at gender change, and phenotypic features. Among the three categories of DSD, chromosomal DSD was diagnosed in 264 subjects (135 with a 45,X karyotype, 101 mosaics with 45,X/46,Xi(Xq)), and three exhibited chimerism (all with ovotesticular DSD). Thirteen patients with chromosomal DSD and Y material were assigned as male, while two patients initially assigned as female underwent gender changes. Among the 258 subjects with 46,XY DSD, 69 had undetermined DSD, 64 had gonadal dysgenesis, 36 had 5-αRD2 deficiency, 18 had 17β-HSD3 deficiency, 11 had 17α-hydroxylase deficiency, 9 had Leydig cell hypoplasia, 25 had CAIS, 18 had PAIS, and 8 had AMH defects. Out of the 192 XY subjects with atypical genitalia, 89 (46%) were raised as female, and 13% changed from female to male, predominantly in cases of 5αRD2 deficiency (45%), followed by 17β-HSD3 deficiency (33%). Only 2.9% of those raised as male changed to female gender. Among the 46,XX DSD cases, congenital adrenal hyperplasia (CAH), mainly 21-hydroxylase deficiency, was diagnosed in 123 cases (115 initially assigned as female). Six cases of CAH resulted in gender changes from female to male, notably in the virilizing salt-wasting (VS) form (5/6; p=.004), all of which had a late onset of treatment (>2 years old) and poor compliance. Among the remaining 55 cases with 46,XX DSD, 24 had ovotesticular DSD (all with atypical genitalia), while 16 had 46,XX testicular DSD (seven with atypical genitalia); four cases underwent gender changes, with three changing from female to male. Twelve patients with 46,XX DSD had an undetermined diagnosis (all with atypical genitalia, three with syndromic features). Additionally, one patient had aromatase deficiency, one had POR deficiency, and one had glucocorticoid resistance syndrome. In conclusion, our study highlights a clear trend: gender changes, notably from female to male, were more prevalent in 46,XY DSD, particularly in 5αRD2 and 17β-HSD3 deficiencies. This underscores the importance of considering male sex assignment for individuals with these diagnoses. Additionally, factors such as the VS form of CAH, delayed treatment initiation, and inadequate compliance significantly contributed to female-to-male gender changes among 46,XX DSD cases. These findings offer critical insights guiding more effective and targeted interventions for DSD individuals. Presentation: 6/2/2024

Up-regulation of HIF-1α in refractory sudden sensorineural hearing loss.

To investigate the expression of hypoxia-inducible factor-1α (HIF-1α) in patients with refractory sudden sensorineural hearing loss (SSNHL). Thirty patients with refractory SSNHL were treated with intratympanic methylprednisolone perfusion (IMP) for 10 days. Expression of HIF-1α and histone deacetylase 2 (HDAC2) was evaluated in peripheral blood mononuclear cells (PBMCs) and in vitro. Significant hearing improvement (≥ 15 dB) was observed in 16 patients [IMP glucocorticoid sensitive (GCS) group], while 14 patients had no therapeautic hearing recovery [IMP GC resistance (GCR) group]. The expression of HDAC2 decreased and HIF-1a increased in all refractory SSNHL patients before IMP. The expression of HDAC2 and HIF-1α after IMP was significantly changed in the GCS group, but not in the GCR group. The same expression profile was also observed in House Ear Institute-organ of Corti-1 (HEI-OC1) cells exposed to oxidative stress (OS). The results of gene manipulation experiments indicate that HIF-1α up-regulation significantly reduced HDAC2 expression in HEI-OC1 cells, especially under conditions of OS. This study suggests that HIF-1α activation inhibits HDAC2 expression, causing glucocorticoid resistance in refractory SSNHL. HIF-1α might serve as a potential biomarker to predict prognosis of refractory SSNHL.

6776 A case of non-neoplastic hypercortisolism leading to the diagnosis of glucocorticoid resistance syndrome due to a novel NR3C1 variant

6776 A case of non-neoplastic hypercortisolism leading to the diagnosis of glucocorticoid resistance syndrome due to a novel NR3C1 variant

Salt-sensitive hypertension in GR mutant rats is associated with altered plasma polyunsaturated fatty acid levels and aortic vascular reactivity.

In humans, glucocorticoid resistance is attributed to mutations in the glucocorticoid receptor (GR). Most of these mutations result in decreased ligand binding, transactivation, and/or translocation, albeit with normal protein abundances. However, there is no clear genotype‒phenotype relationship between the severity or age at disease presentation and the degree of functional loss of the receptor. Previously, we documented that a GR+/- rat line developed clinical features of glucocorticoid resistance, namely, hypercortisolemia, adrenal hyperplasia, and salt-sensitive hypertension. In this study, we analyzed the GR+/em4 rat model heterozygously mutant for the deletion of exon 3, which encompasses the second zinc finger, including the domains of DNA binding, dimerization, and nuclear localization signals. On a standard diet, mutant rats exhibited a trend toward increased corticosterone levels and a normal systolic blood pressure and heart rate but presented with adrenal hyperplasia. They exhibited increased adrenal soluble epoxide hydroxylase (sEH), favoring an increase in less active polyunsaturated fatty acids. Indeed, a significant increase in nonactive omega-3 and omega-6 polyunsaturated fatty acids, such as 5(6)-DiHETrE or 9(10)-DiHOME, was observed with advanced age (10 versus 5weeks old) and following a switch to a high-salt diet accompanied by salt-sensitive hypertension. In thoracic aortas, a reduced soluble epoxide hydrolase (sEH) protein abundance resulted in altered vascular reactivity upon a standard diet, which was blunted upon a high-salt diet. In conclusion, mutations in the GR affecting the ligand-binding domain as well as the dimerization domain resulted in deregulated GR signaling, favoring salt-sensitive hypertension in the absence of obvious mineralocorticoid excess.

Effect of allyl isothiocyanate on 4-HNE induced glucocorticoid resistance in COPD and the underlying mechanism

Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory condition, and its clinical management primarily targets bronchodilation and anti-inflammatory therapy. However, these treatments often fail to directly address the progression of COPD, particularly its associated glucocorticoid (GC) resistance. This study elucidates the mechanisms underlying GC resistance in COPD and explores the therapeutic potential of allyl isothiocyanate (AITC) in modulating MRP1 transport. We assessed the levels of the oxidative stress product 4-HNE, HDAC2 protein, inflammatory markers, and pulmonary function indices using animal and cell models of GC-resistant COPD. The cascade effects of these factors were investigated through interventions involving AITC, protein inhibitors, and dexamethasone (DEX). Cigarette smoke-induced oxidative stress in COPD leads to the accumulation of the lipid peroxidation product 4-HNE, which impairs HDAC2 protein activity and diminishes GC-mediated anti-inflammatory sensitivity due to disrupted histone deacetylation. AITC regulates MRP1, facilitating the effective efflux of 4-HNE from cells, thereby reducing HDAC2 protein degradation and restoring dexamethasone sensitivity in COPD. These findings elucidate the mechanism of smoking-induced GC resistance in COPD and highlight MRP1 as a potential therapeutic target, as well as the enormous potential of AITC for combined GC therapy in COPD, promoting their clinical applications.

NG2 is a target gene of MLL-AF4 and underlies glucocorticoid resistance in MLLr B-ALL by regulating NR3C1 expression

AbstractB-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer, with long-term overall survival rates of ∼85%. However, B-ALL harboring rearrangements of the MLL gene (also known as KMT2A), referred to as MLLr B-ALL, is common in infants and is associated with poor 5-year survival, relapses, and refractoriness to glucocorticoids (GCs). GCs are an essential part of the treatment backbone for B-ALL, and GC resistance is a major clinical predictor of poor outcome. Elucidating the mechanisms of GC resistance in MLLr B-ALL is, therefore, critical to guide therapeutic strategies that deepen the response after induction therapy. Neuron-glial antigen-2 (NG2) expression is a hallmark of MLLr B-ALL and is minimally expressed in healthy hematopoietic cells. We recently reported that NG2 expression is associated with poor prognosis in MLLr B-ALL. Despite its contribution to MLLr B-ALL pathogenesis, the role of NG2 in MLLr-mediated leukemogenesis/chemoresistance remains elusive. Here, we show that NG2 is an epigenetically regulated direct target gene of the leukemic MLL-ALF transcription elongation factor 4 (AF4) fusion protein. NG2 negatively regulates the expression of the GC receptor nuclear receptor subfamily 3 group C member 1 (NR3C1) and confers GC resistance to MLLr B-ALL cells. Mechanistically, NG2 interacts with FLT3 to render ligand-independent activation of FLT3 signaling (a hallmark of MLLr B-ALL) and downregulation of NR3C1 via activating protein-1 (AP-1)–mediated transrepression. Collectively, our study elucidates the role of NG2 in GC resistance in MLLr B-ALL through FLT3/AP-1–mediated downregulation of NR3C1, providing novel therapeutic avenues for MLLr B-ALL.

The histone methyltransferase KMT2D maintains cellular glucocorticoid responsiveness by shielding the glucocorticoid receptor from degradation

Because of their ability to induce lymphocyte apoptosis, glucocorticoids (GC) are widely used to treat hematological malignancies such as lymphomas and multiple myeloma. Their effectiveness is often limited, however, due to the development of glucocorticoid resistance by a variety of molecular mechanisms. Here we performed an unbiased genome-wide CRISPR screen with the human T cell leukemia cell line Jurkat to find previously unidentified genes required for GC-induced apoptosis. One such gene was KMT2D (also known as MLL2 or MLL4), which encodes a histone lysine methyltransferase whose mutations are associated with a variety of cancers, blood malignancies in particular, and are considered markers of poor prognosis. Knockout of KMT2D by CRISPR/Cas9 gene editing in Jurkat and several multiple myeloma cell lines downregulated GR protein expression. Surprisingly, this was not due to a reduction in GR transcripts, but rather to a decrease in the protein's half-life, primarily due to proteasomal degradation. Reconstitution of KMT2D expression restored GR levels. In contrast to the known ability of KMT2D to control gene transcription through covalent histone methylation, KMT2D-mediated upregulation of GR levels did not require its methyltransferase activity. Co-immunoprecipitation and proximity ligation assays found constitutive binding of KMT2D to the GR, which was enhanced in the presence of GC. These observations reveal KMT2D to be essential for stabilization of cellular GR levels, and suggest a possible mechanism by which KMT2D mutations may lead to GC resistance in some malignancies.

Advances in glucocorticoid resistance in otorhinolaryngological diseases

Glucocorticoids（GC） are widely used in the clinical treatment of autoimmune inner ear diseases, sudden sensorineural hearing loss, Meniere's disease, sinusitis and other otolaryngology diseases. However, GC resistance remains a major factor contributing to the poor efficacy of clinical treatments. The mechanism of GC resistance is still unclear. This paper reviews the related mechanisms of GC resistance from the perspectives of GC receptor factors and non-GC receptor factors. Additionally, it summarizes the latest research progress on GC resistance in otolaryngological diseases, with the aim of identifying effective clinical alternative treatment options for reversing GC resistance in the future.

Fermented goat milk by selenium-enriched Lactobacillus paracasei alleviates depressive psychological disturbance.

Depression is a prevalent psychiatric disease with the characteristic of persistently gloomy mood. The treatment of depression with traditional therapeutic medications suffers from low efficacy and adverse side effects due to the extremely unpredictable courses and uneven responses to treatment. The goal of this paper was to investigate the preparation of selenium-enriched fermented goat milk and the potential mechanism of its intervention on the chronic unpredictable stress-induced depression mice model. The results showed that Se-Lactobacillus paracasei 20241 (Se-20241) significantly alleviated depressive behavior, reversed the upregulation of inflammatory factors, and attenuated glucocorticoid resistance. Meanwhile, the results showed a modulatory function on oxidative stress dysfunction in the liver, hippocampus, and prefrontal cortex. The change in abundance of Ileibacterium, Muribaculaceae, Turicibacter, Dubosiella, and Bifidobacterium was also modified. These results provided the theoretical groundwork for the development of psychoactive probiotic supplements for depressed patients and clarified the probable mechanism of Se-20241 for antidepressant impact on the CUMS model.

Glucocorticoids paradoxically promote steroid resistance in B cell acute lymphoblastic leukemia through CXCR4/PLC signaling

Glucocorticoid (GC) resistance in childhood relapsed B-cell acute lymphoblastic leukemia (B-ALL) represents an important challenge. Despite decades of clinical use, the mechanisms underlying resistance remain poorly understood. Here, we report that in B-ALL, GC paradoxically induce their own resistance by activating a phospholipase C (PLC)-mediated cell survival pathway through the chemokine receptor, CXCR4. We identify PLC as aberrantly activated in GC-resistant B-ALL and its inhibition is able to induce cell death by compromising several transcriptional programs. Mechanistically, dexamethasone (Dex) provokes CXCR4 signaling, resulting in the activation of PLC-dependent Ca2+ and protein kinase C signaling pathways, which curtail anticancer activity. Treatment with a CXCR4 antagonist or a PLC inhibitor improves survival of Dex-treated NSG mice in vivo. CXCR4/PLC axis inhibition significantly reverses Dex resistance in B-ALL cell lines (in vitro and in vivo) and cells from Dex resistant ALL patients. Our study identifies how activation of the PLC signalosome in B-ALL by Dex limits the upfront efficacy of this chemotherapeutic agent.

Prospective associations of leucocyte subtypes and obesity with the risk of developing cutaneous malignant melanoma in the UK Biobank cohort

BackgroundObesity is associated with chronic low-grade inflammation, which is linked to cancer development. Abdominal obesity (a body mass index, ABSI), however, has unusually been associated inversely with cutaneous malignant melanoma (CMM), while general obesity (body mass index, BMI) is associated positively. Leucocytes participate in inflammation and are higher in obesity, but prospective associations of leucocytes with cutaneous malignant melanoma are unclear.MethodsWe examined the prospective associations of neutrophil, lymphocyte, and monocyte counts (each individually), as well as the prospective associations of ABSI and BMI, with cutaneous malignant melanoma in UK Biobank. We used multivariable Cox proportional hazards models and explored heterogeneity according to sex, menopausal status, age (≥ 50 years at recruitment), smoking status, ABSI (dichotomised at the median: ≥73.5 women; ≥79.8 men), BMI (normal weight, overweight, obese), and time to diagnosis.ResultsDuring a mean follow-up of 10.2 years, 2174 CMM cases were ascertained in 398,450 participants. There was little evidence for associations with neutrophil or lymphocyte counts. Monocyte count, however, was associated inversely in participants overall (HR = 0.928; 95%CI: 0.888–0.971; per one standard deviation increase; SD = 0.144*109/L women; SD = 0.169*109/L men), specifically in older participants (HR = 0.906; 95%CI: 0.862–0.951), and more clearly in participants with low ABSI (HR = 0.880; 95%CI: 0.824–0.939), or with BMI ≥ 25 kg/m2 (HR = 0.895; 95%CI: 0.837–0.958 for overweight; HR = 0.923; 95%CI: 0.848–1.005 for obese). ABSI was associated inversely in pre-menopausal women (HR = 0.810; 95%CI: 0.702–0.935; SD = 4.95) and men (HR = 0.925; 95%CI: 0.867–0.986; SD = 4.11). BMI was associated positively in men (HR = 1.148; 95%CI: 1.078–1.222; SD = 4.04 kg/m2). There was little evidence for heterogeneity according to smoking status. The associations with monocyte count and BMI were retained to at least 8 years prior to diagnosis, but the association with ABSI was observed up to 4 years prior to diagnosis and not for longer follow-up time.ConclusionsMonocyte count is associated prospectively inversely with the risk of developing CMM in older individuals, while BMI is associated positively in men, suggesting a mechanistic involvement of factors related to monocytes and subcutaneous adipose tissue in melanoma development. An inverse association with ABSI closer to diagnosis may reflect reverse causality or glucocorticoid resistance.

Diagnosis and management of non-CAH 46,XX disorders/differences in sex development.

Prenatal-onset androgen excess leads to abnormal sexual development in 46,XX individuals. This androgen excess can be caused endogenously by the adrenals or gonads or by exposure to exogenous androgens. The most common cause of 46,XX disorders/differences in sex development (DSD) is congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, comprising >90% of 46,XX DSD cases. Deficiencies of 11β-hydroxylase, 3β-hydroxysteroid dehydrogenase, and P450-oxidoreductase (POR) are rare types of CAH, resulting in 46,XX DSD. In all CAH forms, patients have normal ovarian development. The molecular genetic causes of 46,XX DSD, besides CAH, are uncommon. These etiologies include primary glucocorticoid resistance (PGCR) and aromatase deficiency with normal ovarian development. Additionally, 46,XX gonads can differentiate into testes, causing 46,XX testicular (T) DSD or a coexistence of ovarian and testicular tissue, defined as 46,XX ovotesticular (OT)-DSD. PGCR is caused by inactivating variants in NR3C1, resulting in glucocorticoid insensitivity and the signs of mineralocorticoid and androgen excess. Pathogenic variants in the CYP19A1 gene lead to aromatase deficiency, causing androgen excess. Many genes are involved in the mechanisms of gonadal development, and genes associated with 46,XX T/OT-DSD include translocations of the SRY; copy number variants in NR2F2, NR0B1, SOX3, SOX9, SOX10, and FGF9, and sequence variants in NR5A1, NR2F2, RSPO1, SOX9, WNT2B, WNT4, and WT1. Progress in cytogenetic and molecular genetic techniques has significantly improved our understanding of the etiology of non-CAH 46,XX DSD. Nonetheless, uncertainties about gonadal function and gender outcomes may make the management of these conditions challenging. This review explores the intricate landscape of diagnosing and managing these conditions, shedding light on the unique aspects that distinguish them from other types of DSD.

Chronic sensory contact with subordinated conspecifics promotes splenic glucocorticoid resistance in experimentally wounded C57BL/6N male mice

Chronic psychosocial stress induced by the chronic subordinate colony housing (CSC, 19 Days) paradigm promotes functional splenic in vitro glucocorticoid (GC) resistance, but only if associated with significant bite wounding or prior abdominal transmitter implantation. Moreover, sensory contact to social defeat of conspecifics represents a social stressor for the observer individual. As the occurence and severity of bite wounding is not adequately controllable, the present study aimed to develop an animal model, allowing a bite wound-independent, more reliable generation of chronically-stressed mice characterized by functional splenic in vitro GC resistance. Therefore, male C57BL/6N mice received a standardized sterile intraperitoneal (i.p.) incision surgery or SHAM treatment one week prior to 19-days of (i) CSC, (ii) witnessing social defeat during CSC exposure in sensory contact (SENS) or (iii) single-housing for control (SHC), before assessing basal and LPS-induced splenic in vitro cell viability and GC resistance. Our results indicate that individually-housed SENS but not CSC mice develop mild signs of splenic in vitro GC resistance, when undergoing prior i.p.-wounding. Taken together and considering that future studies are warranted, our findings support the hypothesis that the combination of repeated standardized i.p.-wounding with chronic sensory stress exposure represents an adequate tool to induce functional splenic in vitro GC resistance independent of the occurrence of uncontrollable bite wounds required in social stress paradigms to induce a comparable phenotype.

Glucocorticoid Resistance Increases PPARγ Activity and Drives Hepatic Lipid Accumulation via Increased Eicosanoid and Monoacylglyceride Synthesis

A diet high in fat induces adiposity and obesity, and chronic feeding can lead to multiple metabolic complications, including type II diabetes, non-alcoholic fatty liver disease, and cardiovascular disease. The glucocorticoid receptor (GR) regulates genes that control metabolism. The GR has two isoforms (GRα and GRβ) that arise from the GR gene ( NR3C1) due to the alternative splicing of exon 9. The GRα isoform is the classical receptor that binds to glucocorticoids. However, the GRβ isoform has a truncated C-terminus. It cannot bind glucocorticoid steroids, and as a result, this isoform induces a glucocorticoid-resistant state when its expression is increased. We hypothesized that increasing levels of GRβ from long-term excess glucocorticoid exposure or a high-fat diet induces adiposity by affecting lipid metabolism and lipogenesis, causing fat to accumulate in the adipose and liver tissues. We first overexpressed GRβ (GRβ-Ad) or control (Vec-Ad) using adenovirus delivery and fed the mice a normal chow diet. The GRβ-Ad mice had significantly higher lipid accumulation within five days. Western blotting analysis revealed a significant increase (p-value <0.05) in the GRβ-Ad livers for fatty acid synthase (FAS) expression, and there was a remodeling of the hepatic lipid content as measured by mass spectrometry lipidomic analysis. The data indicate an increased level of monoacylglyceride lipid species and some species of long-chain triacylglycerides and diacylglycerides. mRNA analysis revealed a significant increase (p-value <0.05) in Carbohydrate-responsive element-binding protein (ChREBP), PPARγ, and Cyp2j6, indicating an increase in de novo lipogenesis and eicosanoid synthesis. We conclude that glucocorticoid resistance due to increased levels of GRβ drives de novo lipogenesis and increases eicosanoid synthesis, possibly via synergism with PPARγ. A better understanding of the GR isoforms and glucocorticoid resistance could benefit people with obesity and other metabolic disorders to improve obesity-associated comorbidities. R01DK121797 (T.D.H.J.), R01DA058933 (T.D.H.J.). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.