Exosomal hsa-miR-21-5p derived from growth hormone-secreting pituitary adenoma promotes abnormal bone formation in acromegaly

Circulating non-coding RNA biomarkers of endocrine tumours

Circulating non-coding RNA (ncRNA) molecules are being investigated as biomarkers of malignancy, prognosis and follow-up in several neoplasms, including endocrine tumours of the pituitary, parathyroid, pancreas and adrenal glands. Most of these tumours are classified as neuroendocrine neoplasms (comprised of neuroendocrine tumours and neuroendocrine carcinomas) and include tumours of variable aggressivity. We consider them together here in this Review owing to similarities in their clinical presentation, pathomechanism and genetic background. No preoperative biomarkers of malignancy are available for several forms of these endocrine tumours. Moreover, biomarkers are also needed for the follow-up of tumour progression (especially in hormonally inactive tumours), prognosis and treatment efficacy monitoring. Circulating blood-borne ncRNAs show promising utility as biomarkers. These ncRNAs, including microRNAs, long non-coding RNAs and circular RNAs, are involved in several aspects of gene expression regulation, and their stability and tissue-specific expression could make them ideal biomarkers. However, no circulating ncRNA biomarkers have yet been introduced into routine clinical practice, which is mostly owing to methodological and standardization problems. In this Review, following a brief synopsis of these endocrine tumours and the biology of ncRNAs, the major research findings, pathomechanisms and methodological questions are discussed along with an outlook for future studies.

From bench to bedside: The promising value of exosomes in precision medicine for CNS tumors

Exosomes are naturally present extracellular vesicles (EVs) released into the surrounding body fluids upon the fusion of polycystic and plasma membranes. They facilitate intercellular communication by transporting DNA, mRNA, microRNA, long non-coding RNA, circular RNA, proteins, lipids, and nucleic acids. They contribute to the onset and progression of Central Nervous System (CNS) tumors. In addition, they can be used as biomarkers of tumor proliferation, migration, and blood vessel formation, thereby affecting the Tumor Microenvironment (TME). This paper reviews the recent advancements in the diagnosis and treatment of exosomes in various CNS tumors, the promise and challenges of exosomes as natural carriers of CNS tumors, and the therapeutic prospects of exosomes in CNS tumors. Furthermore, we hope this research can contribute to the development of more targeted and effective treatments for central nervous system tumors.

A comprehensive review on the composition, biogenesis, purification, and multifunctional role of exosome as delivery vehicles for cancer therapy

All forms of life produce nanosized extracellular vesicles called exosomes, which are enclosed in lipid bilayer membranes. Exosomes engage in cell-to-cell communication and participate in a variety of physiological and pathological processes. Exosomes function via their bioactive components, which are delivered to target cells in the form of proteins, nucleic acids, and lipids. Exosomes function as drug delivery vehicles due to their unique properties of innate stability, low immunogenicity, biocompatibility, biodistribution, accumulation in desired tissues, low toxicity in normal tissues, and the stimulation of anti-cancer immune responses, and penetration capacity into distance organs. Exosomes mediate cellular communications by delivering various bioactive molecules including oncogenes, oncomiRs, proteins, specific DNA, messenger RNA (mRNA), microRNA (miRNA), small interfering RNA (siRNA), and circular RNA (circRNA). These bioactive substances can be transferred to change the transcriptome of target cells and influence tumor-related signaling pathways. After considering all of the available literature, in this review we discuss the biogenesis, composition, production, and purification of exosomes. We briefly review exosome isolation and purification techniques. We explore great-length exosomes as a mechanism for delivering a variety of substances, including proteins, nucleic acids, small chemicals, and chemotherapeutic drugs. We also talk about the benefits and drawbacks of exosomes. This review concludes with a discussion future perspective and challenges. We hope that this review will provide us a better understanding of the current state of nanomedicine and exosome applications in biomedicine.

Non-coding RNAs and exosomal non-coding RNAs in pituitary adenoma

Pituitary adenoma (PA) is the third most common primary intracranial tumor in terms of overall disease incidence. Although they are benign tumors, they can have a variety of clinical symptoms, but are mostly asymptomatic, which often leads to diagnosis at an advanced stage when surgical intervention is ineffective. Earlier identification of PA could reduce morbidity and allow better clinical management of the affected patients. Non-coding RNAs (ncRNAs) do not generally code for proteins, but can modulate biological processes at the post-transcriptional level through a variety of molecular mechanisms. An increased number of ncRNA expression profiles have been found in PAs. Therefore, understanding the expression patterns of different ncRNAs could be a promising method for developing non-invasive biomarkers. This review summarizes the expression patterns of dysregulated ncRNAs (microRNAs, long non-coding RNAs, and circular RNAs) involved in PA, which could one day serve as innovative biomarkers or therapeutic targets for the treatment of this neoplasia. We also discuss the potential molecular pathways by which the dysregulated ncRNAs could cause PA and affect its progression.

LINC00978 regulates metabolic rewiring to promote the malignancy of glioblastoma through AKR1B1

Glioma is a fatal primary brain tumor. Improved glioma treatment effectiveness depends on a better understanding of its underlying mechanisms. Herein, we reported LINC00978 overexpressed in gliomas. Downregulation of LINC00978 in glioblastoma cells inhibited cell proliferation, invasion, migration, and induced apoptosis. In vivo experiments confirmed that the CamK-A siRNA of LINC00978 could effectively inhibit the proliferation of glioma cells. The main pathway and genes regulated by LINC00978 were detected using RNA sequencing to elucidate the molecular mechanism. The results suggest that LINC00978 regulates the expression of genes related to metabolic pathways, including aldo-keto reductase family 1 member B (AKR1B1), which mediates the cytotoxicity of 2-deoxyglucose. LINC00978 positively regulated AKR1B1 expression, and 2-deoxyglucose induced AKR1B1 expression via a LINC00978-dependent mechanism. This research has revealed that LINC00978 promotes the sensitivity of glioma cells to 2DG. LINC00978 is highly expressed in most glioma patients. Thus, understanding the anticancer mechanism identified in this study may contribute to treating the majority of glioma patients. This study clarified the function and molecular mechanism of LINC00978 in glioblastoma and provided a study basis for LINC00978 to guide the clinical treatment of glioblastoma.

Advances in Therapeutic Applications of Extracellular Vesicles

Extracellular vesicles (EVs) are nanoscale bilayer phospholipid membrane vesicles released by cells. Contained large molecules such as nucleic acid, protein, and lipid, EVs are an integral part of cell communication. The contents of EVs vary based on the cell source and play an important role in both pathological and physiological conditions. EVs can be used as drugs or targets in disease treatment, and changes in the contents of EVs can indicate the progression of diseases. In recent years, with the continuous exploration of the structure, characteristics, and functions of EVs, the potential of engineered EVs for drug delivery and therapy being constantly explored. This review provides a brief overview of the structure, characteristics and functions of EVs, summarizes the advanced application of EVs and outlook on the prospect of it. It is our hope that this review will increase understanding of the current development of medical applications of EVs and help us overcome future challenges.

Imaging biomarkers associated with extra-axial intracranial tumors: a systematic review

Extra-axial brain tumors are extra-cerebral tumors and are usually benign. The choice of treatment for extra-axial tumors is often dependent on the growth of the tumor, and imaging plays a significant role in monitoring growth and clinical decision-making. This motivates the investigation of imaging biomarkers for these tumors that may be incorporated into clinical workflows to inform treatment decisions. The databases from Pubmed, Web of Science, Embase, and Medline were searched from 1 January 2000 to 7 March 2022, to systematically identify relevant publications in this area. All studies that used an imaging tool and found an association with a growth-related factor, including molecular markers, grade, survival, growth/progression, recurrence, and treatment outcomes, were included in this review. We included 42 studies, comprising 22 studies (50%) of patients with meningioma; 17 studies (38.6%) of patients with pituitary tumors; three studies (6.8%) of patients with vestibular schwannomas; and two studies (4.5%) of patients with solitary fibrous tumors. The included studies were explicitly and narratively analyzed according to tumor type and imaging tool. The risk of bias and concerns regarding applicability were assessed using QUADAS-2. Most studies (41/44) used statistics-based analysis methods, and a small number of studies (3/44) used machine learning. Our review highlights an opportunity for future work to focus on machine learning-based deep feature identification as biomarkers, combining various feature classes such as size, shape, and intensity. Systematic Review Registration: PROSPERO, CRD42022306922.

Circulating MiRNA-21-enriched extracellular vesicles promote bone remodeling in traumatic brain injury patients

Fracture combined with traumatic brain injury (TBI) is one of the most common and serious types of compound trauma in the clinic and is characterized by dysfunction of cellular communication in injured organs. Our prior studies found that TBI was capable of enhancing fracture healing in a paracrine manner. Exosomes (Exos), as small extracellular vesicles, are important paracrine vehicles for noncell therapy. However, whether circulating Exos derived from TBI patients (TBI-Exos) regulate the prohealing effects of fractures remains unclear. Thus, the present study aimed to explore the biological effects of TBI-Exos on fracture healing and reveal the potential molecular mechanism. TBI-Exos were isolated by ultracentrifugation, and the enriched miR-21-5 p was identified by qRT‒PCR analysis. The beneficial effects of TBI-Exos on osteoblastic differentiation and bone remodeling were determined by a series of in vitro assays. Bioinformatics analyses were conducted to identify the potential downstream mechanisms of the regulatory effect of TBI-Exos on osteoblasts. Furthermore, the role of the potential signaling pathway of TBI-Exos in mediating the osteoblastic activity of osteoblasts was assessed. Subsequently, a murine fracture model was established, and the effect of TBI-Exos on bone modeling was demonstrated in vivo. TBI-Exos can be internalized by osteoblasts, and in vitro, suppression of SMAD7 promoted osteogenic differentiation, whereas knockdown of miR-21-5 p in TBI-Exos strongly inhibited this bone-beneficial effect. Similarly, our results confirmed that preinjection of TBI-Exos led to enhanced bone formation, whereas knockdown of exosomal miR-21-5 p substantially impaired this bone-beneficial effect in vivo.

Exosomal RNAs in the development and treatment of pituitary adenomas

Exosomes are small extracellular vesicles that carry various bioactive molecules including various RNAs that modulate the activities of recipient cells. It has drawn considerable attention as means of cell communication and drug delivery. Exosome plays important role in various tumors, but it is rarely summarized in pituitary adenoma (PA). PA is the second most common primary central nervous system tumor, and its recurrence and persistent postoperative hormone hypersecretion lead to compromised quality of life. How exactly exosomes impact tumor development and hormone secretion is important for the development of this tumor diagnosis and treatment. In this review, we discuss how exosomal RNAs impact PAs and their potential as future clinical therapies. In our literature review, first, we found that exosomal microRNA hsa-miR-1180-3p is a potential early biomarker for NFPAs. Since NFPAs are typically difficult to diagnose, this is an especially important finding. Second, exosomal protein transcripts are potential invasive biomarker, such as MMP1, N-cadherin, CDK6, RHOU, INSM1, and RASSF10. Third, exosomal contents such as hsa-miR-21-5p promote distant bone formation of GHPA patients. Fourth, tumor suppressors in the exosome constitute novel therapeutic application of exosome, including long noncoding RNA (lncRNA) H19, miR-149-5p, miR-99a-3p, and miR-423-5p. This review discusses the possible mechanisms of exosome and their contents in PA and promotes the use of exosomes in both clinical diagnosis and treatment of this tumor.

Emerging Roles of miRNA, lncRNA, circRNA, and Their Cross-Talk in Pituitary Adenoma

Pituitary adenoma (PA) is a common intracranial tumor without specific biomarkers for diagnosis and treatment. Non-coding RNAs (ncRNAs), including microRNAs (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA), regulate a variety of cellular processes, such as cell proliferation, differentiation, and apoptosis. Increasing studies have shown that the dysregulation of ncRNAs, especially the cross-talk between lncRNA/circRNA and miRNA, is related to the pathogenesis, diagnosis, and prognosis of PA. Therefore, ncRNAs can be considered as promising biomarkers for PA. In this review, we summarize the roles of ncRNAs from different specimens (i.e., tissues, biofluids, cells, and exosomes) in multiple subtypes of PA and highlight important advances in understanding the contribution of the cross-talk between ncRNAs (e.g., competing endogenous RNAs) to PA disease.

Genetic and Epigenetic Pathogenesis of Acromegaly

Simple Summary

Various genetic and epigenetic factors are involved in the pathogenesis of somatotroph tumors. Although GNAS mutations are the most prevalent cause of somatotroph tumors, the cause of half of all pathogenesis occurrences remains unclarified. However, recent findings including the pangenomic analysis, such as genome, transcriptome, and methylome approaches, and histological characteristics of pituitary tumors, the involvement of AIP and GPR101, the mechanisms of genomic instability, and possible involvement of miRNAs have gradually unveiled the whole landscape of underlying mechanisms of somatotroph tumors. In this review, we will focus on the recent advances in the pathogenesis of somatotroph tumors.

Abstract

Acromegaly is caused by excessive secretion of GH and IGF-I mostly from somatotroph tumors. Various genetic and epigenetic factors are involved in the pathogenesis of somatotroph tumors. While somatic mutations of GNAS are the most prevalent cause of somatotroph tumors, germline mutations in various genes (AIP, PRKAR1A, GPR101, GNAS, MEN1, CDKN1B, SDHx, MAX) are also known as the cause of somatotroph tumors. Moreover, recent findings based on multiple perspectives of the pangenomic approach including genome, transcriptome, and methylome analyses, histological characterization, genomic instability, and possible involvement of miRNAs have gradually unveiled the whole landscape of the underlying mechanisms of somatotroph tumors. In this review, we will focus on the recent advances in genetic and epigenetic pathogenesis of somatotroph tumors.

Extracellular Vesicles and Their Emerging Roles as Cellular Messengers in Endocrinology: An Endocrine Society Scientific Statement

During the last decade, there has been great interest in elucidating the biological role of extracellular vesicles (EVs), particularly, their hormone-like role in cell-to-cell communication. The field of endocrinology is uniquely placed to provide insight into the functions of EVs, which are secreted from all cells into biological fluids and carry endocrine signals to engage in paracellular and distal interactions. EVs are a heterogeneous population of membrane-bound vesicles of varying size, content, and bioactivity. EVs are specifically packaged with signaling molecules, including lipids, proteins, and nucleic acids, and are released via exocytosis into biofluid compartments. EVs regulate the activity of both proximal and distal target cells, including translational activity, metabolism, growth, and development. As such, EVs signaling represents an integral pathway mediating intercellular communication. Moreover, as the content of EVs is cell-type specific, it is a "fingerprint" of the releasing cell and its metabolic status. Recently, changes in the profile of EV and bioactivity have been described in several endocrine-related conditions including diabetes, obesity, cardiovascular diseases, and cancer. The goal of this statement is to highlight relevant aspects of EV research and their potential role in the field of endocrinology.

Circulating Noncoding RNAs in Pituitary Neuroendocrine Tumors-Two Sides of the Same Coin

Pituitary neuroendocrine tumors (PitNET) are common intracranial neoplasms. While in case of hormone secreting tumors pituitary hormone measurements can be used for monitoring the disease, in non-functional tumors there is a need to discover non-invasive biomarkers. Non-coding RNAs (ncRNAs) are popular biomarker candidates due to their stability and tissue specificity. Among ncRNAs, miRNAs, lncRNAs and circRNAs have been investigated the most in pituitary tumor tissues and in circulation. However, it is still not known whether ncRNAs are originated from the pituitary, or whether they are casually involved in the pathophysiology. Additionally, there is strong diversity among different studies reporting ncRNAs in PitNET. Therefore, to provide an overview of the discrepancies between published studies and to uncover the reasons why despite encouraging experimental data application of ncRNAs in clinical routine has not yet taken hold, in this review available data are summarized on circulating ncRNAs in PitNET. The data on circulating miRNAs, lncRNAs and circRNAs are organized according to different PitNET subtypes. Biological (physiological and pathophysiological) factors behind intra- and interindividual variability and technical aspects of detecting these markers, including preanalytical and analytical parameters, sample acquisition (venipuncture) and type, storage, nucleic acid extraction, quantification and normalization, which reveal the two sides of the same coin are discussed.

Sympathetic Neurostress Drives Osteoblastic Exosomal MiR-21 Transfer to Disrupt Bone Homeostasis and Promote Osteopenia

Innervation and extracellular vesicle secretion co-exist in the local tissue microenvironment for message transfer, but whether they are interconnected to regulate organ homeostasis remains unknown. Sympatho-adrenergic activation is implicated in stress-induced depression and leads to bone loss, but the mechanisms and therapeutics are incompletely elucidated. Here, it is revealed that sympathetic neurostress through the β_1/2 -adrenergic receptor (β1/2-AR) signaling triggers the transcription response of a microRNA, miR-21, in osteoblasts, which is transferred to osteoclast progenitors via exosomes for dictating osteoclastogenesis. After confirming that miR-21 deficiency retards the β1/2-AR agonist isoproterenol (ISO)-induced osteopenia, it is shown that the pharmacological inhibition of exosome release by two clinically-relevant drugs, dimethyl amiloride and omeprazole, suppresses osteoblastic miR-21 transfer and ameliorates bone loss under both ISO and chronic variable stress (CVS)-induced depression conditions. A targeted delivery approach to specifically silence osteoblastic miR-21 is further applied, which is effective in rescuing the bone remodeling balance and ameliorating ISO- and CVS-induced osteopenias. These results decipher a previously unrecognized paradigm that neural cues drive exosomal microRNA communication to regulate organ homeostasis and help to establish feasible strategies to counteract bone loss under psychological stresses.

Pituitary Somatotroph Adenoma-derived Exosomes: Characterization of Nonhormonal Actions

CONTEXT

The identification and biological actions of pituitary-derived exosomes remain elusive.

OBJECTIVE

This work aimed to validate production of exosomes derived from human and rat pituitary and elucidate their actions.

METHODS

Isolated extracellular vesicles (EVs) were analyzed by Nanoparticle Tracking Analysis (NTA) and expressed exosomal markers detected by Western blot, using nonpituitary fibroblast FR and myoblast H9C2 cells as controls. Exosome inhibitor GW4869 was employed to detect attenuated EV release. Exosomal RNA contents were characterized by RNA sequencing. In vitro and in vivo hepatocyte signaling alterations responding to GH1-derived exosomes (GH1-exo) were delineated by mRNA sequencing. GH1-exo actions on protein synthesis, cAMP (3',5'-cyclic adenosine 5'-monophosphate) response, cell motility, and metastases were assessed.

RESULTS

NTA, exosomal marker detection, and GW4869 attenuated EV release, confirming the exosomal identity of pituitary EVs. Hydrocortisone increased exosome secretion in GH1 and GH3 cells, suggesting a stress-associated response. Exosomal RNA contents showed profiles distinct for pituitary cells, and rat primary hepatocytes exposed to GH1-exo exhibited transcriptomic alterations distinct from those elicited by growth hormone or prolactin. Intravenous GH1-exo injection into rats attenuated hepatic Eif2ak2 and Atf4 mRNA expression, both involved in cAMP responses and amino acid biosynthesis. GH1-exo suppressed protein synthesis and forskolin-induced cAMP levels in hepatocytes. GH1-exo-treated HCT116 cells showed dysregulated p53 and mitogen-activated protein kinase (MAPK) pathways and attenuated motility of malignant HCT116 cells, and decreased tumor metastases in nude mice harboring splenic HCT116 implants.

CONCLUSION

Our findings elucidate biological actions of somatotroph-derived exosomes and implicate exosomes as nonhormonal pituitary-derived messengers.

Network Integration Analysis and Immune Infiltration Analysis Reveal Potential Biomarkers for Primary Open-Angle Glaucoma

Primary open-angle glaucoma (POAG) is a progressive optic neuropathy and its damage to vision is irreversible. Therefore, early diagnosis assisted by biomarkers is essential. Although there were multiple researches on the identification of POAG biomarkers, few studies systematically revealed the transcriptome dysregulation mechanism of POAG from the perspective of pre- and post-transcription of genes. Here, we have collected multiple sets of POAG's aqueous humor (AH) tissue transcription profiles covering long non-coding RNA (lncRNA), mRNA and mircoRNA (miRNA). Through differential expression analysis, we identified thousands of significant differentially expressed genes (DEGs) between the AH tissue of POAG and non-glaucoma. Further, the DEGs were used to construct a competing endogenous RNA (ceRNA) regulatory network and 1,653 qualified lncRNA-miRNA-mRNA regulatory units were identified. Two ceRNA regulatory subnets were identified based on the random walk algorithm and revealed to be involved in the regulation of multiple complex diseases. At the pre-transcriptional regulation level, a transcriptional regulatory network was constructed and three transcription factors (FOS, ATF4, and RELB) were identified to regulate the expression of multiple genes and participate in the regulation of T cells. Moreover, we revealed the immune desert status of AH tissue for POAG patients based on immune infiltration analysis and identified a specific AL590666.2-hsa-miR-339-5p-UROD axis can be used as a biomarker of POAG. Taken together, the identification of regulatory mechanisms and biomarkers will contribute to the individualized diagnosis and treatment for POAG.

MicroRNAs as Potential Biomarkers in Pituitary Adenomas

Pituitary adenomas (PAs) are one of the most common lesions of intracranial neoplasms, occurring in approximately 15% of the general population. They are typically benign, although some adenomas show aggressive behavior, exhibiting rapid growth, drug resistance, and invasion of surrounding tissues. Despite ongoing improvements in diagnostic and therapeutic strategies, late first diagnosis is common, and patients with PAs are prone to relapse. Therefore, earlier diagnosis and prevention of recurrence are of importance to improve patient care. MicroRNAs (miRNAs) are short non-coding single stranded RNAs that regulate gene expression at the post-transcriptional level. An increasing number of studies indicate that a deregulation of their expression patterns is related with pituitary tumorigenesis, suggesting that these small molecules could play a critical role in contributing to tumorigenesis and the onset of these tumors by acting either as oncosuppressors or as oncogenes, depending on the biological context. This paper provides an overview of miRNAs involved in PA tumorigenesis, which might serve as novel potential diagnostic and prognostic non-invasive biomarkers, and for the future development of miRNA-based therapeutic strategies for PAs.

Overview of omics biomarkers in pituitary neuroendocrine tumors to design future diagnosis and treatment strategies

Pituitary neuroendocrine tumors (PitNETs) are the second most common type of intracranial neoplasia. Since their manifestation usually causes hormone hypersecretion, effective management of PitNETs is indisputably necessary. Most of the non-functioning PitNETs pose a real challenge in diagnosis as they grow without giving any signs. Despite the good response of prolactinomas to dopamine agonist therapy, some of these tumors persist or recur; also, about 20% are resistant and 10% behave aggressively. The silent corticotropinomas may not cause symptoms until the tumor mass causes a complication. In somatotropinomas, the possibility of recurrence after transsphenoidal resection is more common in pediatric patients than in adult patients. Therefore, detection of tumors at early stages or identification of recurrence and remission after transsphenoidal surgery would allow wiser management of the disease. Extensive studies have been performed to uncover potential signatures that can be used for preventive diagnosis and/or prognosis of PitNETs as well as for targeted therapy. These molecular signatures at multiple biological levels hold promise for the convergence of preventive approaches and patient-centered disease management and offer potential therapeutic strategies. In this review, we provide an overview of the omics-based biomarker research and highlight the multi-omics signatures that have been proposed as pitNET biomarkers. In addition, understanding the multi-omics data integration of current biomarker discovery strategies was discussed in terms of preventive, predictive, and personalized medicine. The topics discussed in this review will help to develop broader visions for pitNET research, diagnosis, and therapy, particularly in the context of personalized medicine.

Extracellular Vesicles: Potential Mediators of Psychosocial Stress Contribution to Osteoporosis?

Osteoporosis is characterized by low bone mass and damage to the bone tissue’s microarchitecture, leading to increased fracture risk. Several studies have provided evidence for associations between psychosocial stress and osteoporosis through various pathways, including the hypothalamic-pituitary-adrenocortical axis, the sympathetic nervous system, and other endocrine factors. As psychosocial stress provokes oxidative cellular stress with consequences for mitochondrial function and cell signaling (e.g., gene expression, inflammation), it is of interest whether extracellular vesicles (EVs) may be a relevant biomarker in this context or act by transporting substances. EVs are intercellular communicators, transfer substances encapsulated in them, modify the phenotype and function of target cells, mediate cell-cell communication, and, therefore, have critical applications in disease progression and clinical diagnosis and therapy. This review summarizes the characteristics of EVs, their role in stress and osteoporosis, and their benefit as biological markers. We demonstrate that EVs are potential mediators of psychosocial stress and osteoporosis and may be beneficial in innovative research settings.

CircPVT1 up-regulation attenuates steroid-induced osteonecrosis of the femoral head through regulating miR-21-5p-mediated Smad7/TGFβ signalling pathway

Steroid‐induced osteonecrosis of the femoral head (SIONFH) has been a common disease following corticosteroid therapy. Presently, we aim to explore the functions of circular RNA (circ) PVT1 in SIONFH rats and the underlying mechanism. Glucocorticoid (GC) was used to treat SD rats and bone marrow‐derived mesenchymal stem cells (BMSCs) to construct SIONFH model in vitro and in vivo, respectively. The pathological injury of the femoral head in the SIONFH rats was detected via haematoxylin‐eosin (HE) staining and immunohistochemistry (IHC). The osteogenic differentiation, proliferation and apoptosis of BMSCs were detected. Western blot was used to detect Smad7, Bax, Bcl2 and Smad2/3. The potential targets of circPVT1 and miR‐21‐5p were validated through luciferase reporter gene assay and RNA pull‐down assay, respectively. We found that CircPVT1 was decreased in the femoral head of SIONFH rats and GC‐treated BMSCs, while miR‐21‐5p was markedly up‐regulated. Overexpressed circPVT1 attenuated the apoptosis and cell viability inhibition of BMSCs induced by GC, while miR‐21‐5p up‐regulation had the opposite effects. What's more, the in vivo experiments confirmed that up‐regulating circPVT1 repressed osteonecrosis in SIONFH rats through repressing apoptosis. Mechanistically, circPVT1 functioned as a ceRNA of miR‐21‐5p, which targeted at the 3'untranslated region of Smad7. CircPVT1 enhancing Smad7 and mitigating GC activated TGFβ/Smad2/3 pathway through inhibiting miR‐21‐5p. In conclusion, CircPVT1 exerts protective effects against SIONFH via modulating miR‐21‐5p‐mediated Smad7/TGFβ pathway.

GH and IGF System: The Regulatory Role of miRNAs and lncRNAs in Cancer

Growth hormone (GH) and the insulin-like growth factor (IGF) system are involved in many biological processes and have growth-promoting actions regulating cell proliferation, differentiation, apoptosis and angiogenesis. A recent chapter in epigenetics is represented by microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) which regulate gene expression. Dysregulated miRNAs and lncRNAs have been associated with several diseases including cancer. Herein we report the most recent findings concerning miRNAs and lncRNAs regulating GH and the IGF system in the context of pituitary adenomas, osteosarcoma and colorectal cancer, shedding light on new possible therapeutic targets. Pituitary adenomas are increasingly common intracranial tumors and somatotroph adenomas determine supra-physiological GH secretion and cause acromegaly. Osteosarcoma is the most frequent bone tumor in children and adolescents and was reported in adults who were treated with GH in childhood. Colorectal cancer is the third cancer in the world and has a higher prevalence in acromegalic patients.

Extracellular Vesicles Loaded miRNAs as Potential Modulators Shared Between Glioblastoma, and Parkinson's and Alzheimer's Diseases

Glioblastoma (GBM) is the deadliest brain tumor. Its poor prognosis is due to cell heterogeneity, invasiveness, and high vascularization that impede an efficient therapeutic approach. In the past few years, several molecular links connecting GBM to neurodegenerative diseases (NDDs) were identified at preclinical and clinical level. In particular, giving the increasing critical role that epigenetic alterations play in both GBM and NDDs, we deeply analyzed the role of miRNAs, small non-coding RNAs acting epigenetic modulators in several key biological processes. Specific miRNAs, transported by extracellular vesicles (EVs), act as intercellular communication signals in both diseases. In this way, miRNA-loaded EVs modulate GBM tumorigenesis, as they spread oncogenic signaling within brain parenchyma, and control the aggregation of neurotoxic protein (Tau, Aβ-amyloid peptide, and α-synuclein) in NDDs. In this review, we highlight the most promising miRNAs linking GBM and NDDs playing a significant pathogenic role in both diseases.

Exosomes derived from smooth muscle cells ameliorate diabetes-induced erectile dysfunction by inhibiting fibrosis and modulating the NO/cGMP pathway

Erectile dysfunction (ED) is a major health issue among men with diabetes, and ED induced by diabetes mellitus (DMED) is particularly difficult to treat. Therefore, novel therapeutic approaches for the treatment of DMED are urgently needed. Exosomes, nanosized particles involved in many physiological and pathological processes, may become a promising tool for DMED treatment. In this study, we investigated the therapeutic effect of exosomes derived from corpus cavernosum smooth muscle cells (CCSMC‐EXOs) on erectile function in a rat model of diabetes and compared their effect with that of exosomes derived from mesenchymal stem cells (MSC‐EXOs). We incubated labelled CCSMC‐EXOs and MSC‐EXOs with CCSMCs and then observed uptake of the exosomes at different time points using laser confocal microscopy. CCSMC‐EXOs were more easily taken up by CCSMCs. The peak concentration and retention time of labelled CCSMC‐EXOs and MSC‐EXOs in the corpus cavernosum of DMED rats after intracavernous injection were compared by in vivo imaging techniques. Intracavernous injection of CCSMC‐EXOs was associated with a relatively high peak concentration and long retention time. Our data showed that CCSMC‐EXOs could improve erectile function in DMED rats. Meanwhile, CCSMC‐EXOs could exert antifibrotic effects by increasing the smooth muscle content and reducing collagen deposition. CCSMC‐EXOs also increased the expression of eNOS and nNOS, followed by increased levels of NO and cGMP. These findings initially identify the possible role of CCSMC‐EXOs in ameliorating DMED through inhibiting corporal fibrosis and modulating the NO/cGMP signalling pathway, providing a theoretical basis for a breakthrough in the treatment of DMED.

Biomarkers for Liquid Biopsies of Pituitary Neuroendocrine Tumors

Pituitary neuroendocrine tumors (PitNET) do not only belong to the most common intracranial neoplasms but seem to be generally more common than has been thought. Minimally invasive liquid biopsies have the potential to improve their early screening efficiency as well as monitor prognosis by facilitating the diagnostic procedures. This review aims to assess the potential of using liquid biopsies of different kinds of biomarker species that have only been obtained from solid pituitary tissues so far. Numerous molecules have been associated with the development of a PitNET, suggesting that it often develops from the cumulative effects of many smaller genetic or epigenetic changes. These minor changes eventually pile up to switch critical molecules into tumor-promoting states, which may be the key regulatory nodes representing the most potent marker substances for a diagnostic test. Drugs targeting these nodes may be superior for the therapeutic outcome and therefore the identification of such pituitary-specific cellular key nodes will help to accelerate their application in medicine. The ongoing genetic degeneration in pituitary adenomas suggests that repeated tumor profiling via liquid biopsies will be necessary for personalized and effective treatment solutions.

RASSF10 regulates bone invasion of growth hormone-secreting adenomas via exosomes

BACKGROUND

Invasion of pituitary growth hormone-secreting adenoma into surrounding tissues poses a challenge for complete resection in surgery, which is the main reason for recurrence of this type of cancer. Studies have shown that abnormal methylation of RASSF10 can promote the expression of MDM2 and regulate the tumor microenvironment by affecting the secretion of exosomes. In the present study, we aim to uncover the specific underlying mechanism of this effect.

METHOD

Transwell co-culture assays was performed using GT1.1 cells or exosomes and RAW264.7 cells. RAW264.7 cells were collected for invasion, proliferation and apoptosis assays, RT-qPCR and western blotting. RNA-seq was performed and used to assess the potential molecular pathways of the effect of GT1.1 cell-exosomes on RAW264.7 cells.

RESULTS

GT1.1 cells with reduced RASSF10 expression could promote the proliferation and migration of RAW264.7 cells, and promote their expression of osteoclast markers TRAP and CK. The effect of GT1.1 cell exosomes on the RAW264.7-cell phenotype was shown to be achieved through the RASSF10-MDM2 pathway. RNA-seq allowed the identification of PI3K-AKT, MAPK, and calcium signaling as important in this regulation system of RASSF10-MDM2.

CONCLUSION

Our results indicate that GT1.1 cells activate PI3K-AKT, MAPK and calcium signaling via the RASSF10-MDM2 pathway, and promote the differentiation of RAW264.7 cells into osteoclasts through exosomes. This study may provide new ideas to aid in early diagnosis, prognostic assessment and treatment of aggressive pituitary adenomas.