The role of long non-coding RNA NORAD in digestive system tumors.

In recent years, it has been discovered that the expression of long non-coding RNAs is highly deregulated in several types of cancer and contributes to its progression and development. Recently, it has been described that in tumors of the digestive system, such as colorectal cancer, pancreatic cancer, and gastric cancer, DNA damage-activated lncRNA (NORAD) was frequently up-regulated. The purpose of this review is to elucidate the functions of NORAD in tumors of the digestive system, emphasizing its involvement in important cellular processes such as invasion, metastasis, proliferation, and apoptosis. NORAD acts as a ceRNA (competitive endogenous RNA) that sponges microRNAs and regulates the expression of target genes involved in tumorigenesis. Thus, the mechanisms underlying the effects of NORAD are complex and involve multiple signaling pathways. This review consolidates current knowledge on the role of NORAD in digestive cancers and highlights the need for further research to explore its potential as a therapeutic target. Understanding the intricate functions of NORAD could elucidate the way for innovative approaches to cancer treatment.

Circular RNA circRNA_100349 functions as a miR-218-5p sponge for suppressing the cell proliferation of gastric cancer via regulation of IGF2 expression.

BACKGROUND: Circular RNAs (circRNAs) hold critical importance due to their notable function in developing Gastric Cancer (GC), which is a malignancy with the third most frequent occurrence worldwide. The aim of this study was to see if circRNA_0044516 would control GC cell proliferation and establish more effective therapeutic strategies. METHODS: In GC tissues or cells, quantitative Real­Time Polymerase Chain Reaction (qRT-PCR) was employed for the detection of the expression of circRNA_100349, Insulin-like Growth Factor II (IGF2), and miR-218-5p. CCK-8 assays were employed to gauge the proliferation of cells. A luciferase reporter was employed to establish the relationship of circRNA_100349 or IGF2 with miR-218-5p. RESULTS: CircRNA_100349 was observed to undergo upregulation in GC cell lines along with tissues. GC cell proliferation was prevented by downregulating circRNA_100349. MiR-149 was targeted by CircRNA_100349, and its downregulation increased the amount of miR-218-5p in GC cells. Simultaneously silencing circRNA_100349 decreased IGF2 expression via miR-218-5p, and thus suppressed GC cell proliferation. Furthermore, in nude mice, circRNA_100349 knockdown prevented the tumor development of GC cells. CONCLUSIONS: The findings furnished evidence of the critical involvement of circRNA_100349 in GC and that its downregulation impedes GC cell proliferation via the miR-218-5p/IGF2 axis.

Roles of LncRNA ARSR in tumor proliferation, drug resistance, and lipid and cholesterol metabolism.

Cancer is one of the most serious diseases that threaten human life and health. Among all kinds of diseases, the mortality rate of malignant tumors is the second highest, second only to cardio-cerebrovascular diseases. Cancer treatment typically involves imaging, surgery, and pathological analysis. When patients are identified as carcinoma by the above means, there are often problems of distant metastasis, delayed treatment, and drug tolerance, indicating that patients have some poor prognosis and overall survival. Hence, the development of novel molecular biomarkers is of great clinical importance. In recent years, as an important mediator of material and information exchange between cells in the tumor microenvironment, lncRNA have attracted widespread attention for their roles in tumor development. In this review, we comprehensively summarize the up-to-date knowledge of lncARSR on diverse cancer types which mainly focuses on tumor proliferation, drug tolerance, and lipid and cholesterol metabolism, highlighting the potential of lncARSR as a diagnostic and prognostic biomarker and even a therapeutic target. In our final analysis, we provide a synthesized overview of the directions for future inquiry into lncARSR, and we are eager to witness the advancement of research that will elucidate the multifaceted nature of this lncRNA.

Further biological characterization of small molecules UM171 and SR1: In vitro effects on three hematopoietic cell populations from human cord blood.

Small molecules UM171 and SR1 have already been taken into clinically-oriented protocols for the ex vivo expansion of hematopoietic stem (HSCs) and progenitor (HPCs) cells. In order to gain further insight into their biology, in the present study we have assessed their effects, both individually and in combination, on the in vitro long-term proliferation and expansion of HSCs and HPCs contained within three different cord blood-derived cell populations: MNCs (CD34+ cells = 0.8 %), LIN- cells (CD34+ cells = 41 %), and CD34+ cells (CD34+ cells >98 %). Our results show that when added to cultures in the absence of recombinant stimulatory cytokines, neither molecule had any effect. In contrast, when added in the presence of hematopoietic cytokines, UM171 and SR1 had significant stimulatory effects on cell proliferation and expansion in cultures of LIN- and CD34+ cells. No significant effects were observed in cultures of MNCs. The effects of both molecules were more pronounced in cultures with the highest proportion of CD34+ cells, and the greatest effects were observed when both molecules were added in combination. In the absence of small molecules, cell numbers reached a peak by days 25-30, and then declined; whereas in the presence of UM171 or/and SR1 cell numbers were sustained up to day 45 of culture. Our results indicate that besides CD34+ cells, LIN- cells could also be used as input cells in clinically-oriented expansion protocols, and that using both molecules simultaneously would be a better approach than using only one of them.

PTN from Leydig cells activates SDC2 and modulates human spermatogonial stem cell proliferation and survival via GFRA1.

BACKGROUND: Spermatogonial stem cells (SSCs) are essential for the maintenance and initiation of male spermatogenesis. Despite the advances in understanding SSC biology in mouse models, the mechanisms underlying human SSC development remain elusive. RESULTS: Here, we analyzed the signaling pathways involved in SSC regulation by testicular somatic cells using single-cell sequencing data (GEO datasets: GSE149512 and GSE112013) and identified that Leydig cells communicate with SSCs through pleiotrophin (PTN) and its receptor syndecan-2 (SDC2). Immunofluorescence, STRING prediction, and protein immunoprecipitation assays confirmed the interaction between PTN and SDC2 in spermatogonia, but their co-localization was observed only in approximately 50% of the cells. The knockdown of SDC2 in human SSC lines impaired cell proliferation, DNA synthesis, and the expression of PLZF, a key marker for SSC self-renewal. Transcriptome analysis revealed that SDC2 knockdown downregulated the expression of GFRA1, a crucial factor for SSC proliferation and self-renewal, and inhibited the HIF-1 signaling pathway. Exogenous PTN rescued the proliferation and GFRA1 expression in SDC2 knockdown SSC lines. In addition, we found downregulation of PTN and SDC2 as well as altered localization in non-obstructive azoospermia (NOA) patients, suggesting that downregulation of PTN and SDC2 may be associated with impaired spermatogenesis. CONCLUSIONS: Our results uncover a novel mechanism of human SSC regulation by the testicular microenvironment and suggest a potential therapeutic target for male infertility.

Leishmania major telomerase RNA knockout: From altered cell proliferation to decreased parasite infectivity.

This study focuses on the biological impacts of deleting the telomerase RNA from Leishmania major (LeishTER), a parasite responsible for causing leishmaniases, for which no effective treatment or prevention is available. TER is a critical player in the telomerase ribonucleoprotein complex, containing the template sequence copied by the reverse transcriptase component during telomere elongation. The success of knocking out both LeishTER alleles was confirmed, and no off-targets were detected. LmTER-/- cells share similar characteristics with other TER-depleted eukaryotes, such as altered growth patterns and partial G0/G1 cell cycle arrest in early passages, telomere shortening, and elevated TERRA expression. They also exhibit increased γH2A phosphorylation, suggesting that the loss of LeishTER induces DNA damage signaling. Moreover, pro-survival autophagic signals and mitochondrion alterations were shown without any detectable plasma membrane modifications. LmTER-/- retained the ability to transform into metacyclics, but their infectivity capacity was compromised. Furthermore, the overexpression of LeishTER was also deleterious, inducing a dominant negative effect that led to telomere shortening and growth impairments. These findings highlight TER's vital role in parasite homeostasis, opening discussions about its potential as a drug target candidate against Leishmania.

Paricalcitol prevents MAPK pathway activation and inflammation in adriamycin-induced kidney injury in rats.

BACKGROUND: Activation of the mitogen-activated protein kinase (MAPK) pathway induces uncontrolled cell proliferation in response to inflammatory stimuli. Adriamycin (ADR)-induced nephropathy (ADRN) in rats triggers MAPK activation and pro-inflammatory mechanisms by increasing cytokine secretion, similar to chronic kidney disease (CKD). Activation of the vitamin D receptor (VDR) plays a crucial role in suppressing the expression of inflammatory markers in the kidney and may contribute to reducing cellular proliferation. This study evaluated the effect of pre-treatment with paricalcitol on ADRN in renal inflammation mechanisms. METHODS: Male Sprague-Dawley rats were implanted with an osmotic minipump containing activated vitamin D (paricalcitol, Zemplar, 6 ng/day) or vehicle (NaCl 0.9%). Two days after implantation, ADR (Fauldoxo, 3.5 mg/kg) or vehicle (NaCl 0.9%) was injected. The rats were divided into four experimental groups: control, n = 6; paricalcitol, n = 6; ADR, n = 7 and, ADR + paricalcitol, n = 7. RESULTS: VDR activation was demonstrated by increased CYP24A1 in renal tissue. Paricalcitol prevented macrophage infiltration in the glomeruli, cortex, and outer medulla, prevented secretion of tumor necrosis factor-α, and interleukin-1ß, increased arginase I and decreased arginase II tissue expressions, effects associated with attenuation of MAPK pathways, increased zonula occludens-1, and reduced cell proliferation associated with proliferating cell nuclear antigen expression. Paricalcitol treatment decreased the stromal cell-derived factor 1α/chemokine C-X-C receptor type 4/ß-catenin pathway. CONCLUSIONS: Paricalcitol plays a renoprotective role by modulating renal inflammation and cell proliferation. These results highlight potential targets for treating CKD.

Insulin resistance in nonobese type 2 diabetic Goto Kakizaki rats is associated with a proinflammatory T lymphocyte profile.

Goto-Kakizaki (GK) rats develop a well-defined insulin resistance (IR) and type 2 diabetes mellitus (T2DM) without presenting obesity. The lymphocyte profile in nonobese diabetic conditions is not yet characterized. Therefore, GK rats were chosen to explore T lymphocyte (TL) dynamics at various stages (21, 60, and 120 days) compared to Wistar rats. GK rats exhibit progressive disruption of glucose regulation, with early glucose intolerance at 21 days and reduced insulin sensitivity at 60 days, confirming IR. Glucose transporter 1 (GLUT1) expression was consistently elevated in GK rats, suggesting heightened TL activation. T-regulatory lymphocyte markers diminished at 21 days. However, GK rats showed increased Th1 markers and reduced Gata-3 expression (crucial for Th2 cell differentiation) at 120 days. These findings underscore an early breakdown of anti-inflammatory mechanisms in GK rats, indicating a proinflammatory TL profile that may worsen chronic inflammation in T2DM.

Single-cell transcriptomic sequencing analysis of mechanistic insights into the IFN-γ signaling pathway in different tumor cells.

PURPOSE: This study aimed to investigate the relationship between the interferon-gamma (IFN-γ) pathway in different tumor microenvironments (TME) and patients' prognosis, as well as the regulatory mechanisms of this pathway in tumor cells. METHODS: Using RNA-seq data from the TCGA database, we analyzed the predictive value of the IFN-γ pathway across various tumors. We employed a univariate Cox regression model to assess the prognostic significance of IFN-γ signaling in different tumor types. Additionally, we analyzed single-cell RNA sequencing (scRNA-seq) data from the Gene Expression Omnibus (GEO) database to examine the distribution characteristics of the IFN-γ pathway and explore its regulatory mechanisms, highlighting how IFN-γ influenced cellular interactions within the TME. RESULTS: Our analysis revealed a significant association between the IFN-γ pathway and adverse prognosis in pan-cancer tissues (P < 0.001). Interestingly, this correlation varied regarding positive and negative regulation across different tumor types. Through a detailed examination of scRNA-seq data, we found that the IFN-γ pathway exerted substantial regulatory effects on stromal and immune cells. In contrast, its expression and regulatory patterns in tumor cells exhibited diversity and heterogeneity. Further analysis indicated that the IFN-γ pathway not only enhanced the immunogenicity of tumor cells but also inhibited their proliferation. Cell-cell interaction analysis confirmed the pivotal role of the IFN-γ pathway within the overall regulatory network. Moreover, we identified HMGB2 (high mobility group box 2) in T cells as a potential key regulator of tumor cell proliferation. CONCLUSIONS: The IFN-γ pathway exhibited a dual function by both suppressing tumor cell proliferation and enhancing their immunogenicity, positioning it as a pivotal target for refined cancer diagnosis and cancer strategies.

Morphologic, Proliferative, and Cytogenetic Changes during In Vitro Propagation of Cat Adipose Tissue-Derived Mesenchymal Stromal/Stem Cells.

Stem cell therapy in cat patients needs a high quantity of mesenchymal stromal/stem cells (MSCs) requiring in vitro propagation under culture conditions which may potentially impact cellular characteristics and genetic stability. This study aimed to assess the in vitro characteristics and cytogenetic stability of cat adipose tissue-derived MSCs (cAT-MSCs). For this purpose, morphological features, clonogenic potential, and proliferative capacity of cAT-MSCs were assessed at passages 2 (P2), P4, and P6. Multipotency and immunophenotype were evaluated. Cytogenetic analyses were conducted up to P6. The cAT-MSCs exhibited a spindle-shaped morphology in early passages. The doubling time increased from 2.5 days at P2 to 9.4 at P4 and 10.5 at P6, accompanied by the observation of nuclear abnormalities such as cluster formation, karyorrhexis, karyolysis, and a decline in the mitotic index at P4. Cells demonstrated multipotency capacity and were CD45-, CD90+, and CD44+. Metaphase analysis at P2 and P4 revealed some indications of structural instability such as gaps, breaks, deletions, duplications, and early chromatid segregation, but these alterations did not show an increase across passages. In conclusion, cAT-MSCs decreased their proliferative capacity after P4, accompanied by morphological alterations and signs of structural instability.

Perinatal Exposure to Glyphosate or a Commercial Formulation Alters Uterine Mechanistic Pathways Associated with Implantation Failure in Rats.

Perinatal exposure to a glyphosate-based herbicide (GBH) or its active ingredient, glyphosate (Gly), has been demonstrated to increase implantation failure in rats. This study investigates potential mechanisms of action, analyzing uterine preparation towards the receptive state. Pregnant Wistar rats (F0) were treated orally with GBH or Gly (3.8 and 3.9 mg Gly/kg/day, respectively) from gestational day (GD) 9 until weaning. Adult F1 females became pregnant and uterine samples were collected on GD5 (preimplantation period). Histomorphological uterine parameters were assessed. Immunohistochemistry was applied to evaluate cell proliferation and protein expression of estrogen receptors (ERα and ERß), cell cycle regulators (PTEN, cyclin G1, p27, and IGF1R-α), and the Wnt5a/ß-catenin/FOXA2/Lif pathway. Both GBH and Gly females showed increased stromal proliferation, associated with a high expression of ERs. Dysregulation of PTEN and cyclin G1 was also observed in the Gly group. Reduced gland number was observed in both groups, along with decreased expression of Wnt5a/ß-catenin/FOXA2/Lif pathway in the glandular epithelium. Overall, GBH and Gly perinatal exposure disrupted intrinsic uterine pathways involved in endometrial proliferation and glandular function, providing a plausible mechanism for glyphosate-induced implantation failure by compromising uterine receptivity. Similar effects between GBH and Gly suggest the active principle mainly drives the adverse outcomes.

In-vitro study on type I collagen synthesis in low-level laser therapy on the early ligament fibroblasts' healing process.

BACKGROUND: Low-level Laser Therapy (LLLT) has demonstrated its potential in promoting fiber matrix maturation, collagen synthesis, and fibroblast proliferation, contributing to tissue regeneration. Our study aimed to investigate the impact of LLLT on collagen type I synthesis, cell proliferation, and viability in human ligament fibroblasts derived from the Anterior Cruciate Ligament (ACL). METHODS: Tissue samples were obtained from individuals undergoing arthroscopic ACL reconstruction surgery. Primary human fibroblasts were isolated, and immunohistochemical assays confirmed their characteristics. LLLT at 850 nm was administered in three groups: Low dose (1.0 J/cm²), High dose (5.0 J/cm²), and Control (0.0 J/cm²). Cell viability was calculated using a membrane integrity assay, proliferation was determined by automated counting, and collagen type I concentration in cell culture was measured using an immunoassay. RESULTS: Fibroblasts showed decreased viability after low and high doses of LLLT, increased proliferation at the low dose, and increased collagen synthesis at the high dose on day 10 for both sexes after treatment. CONCLUSION: Our study demonstrated that LLLT may improve the early ligament healing process by increasing cell proliferation at the low dose and enhancing collagen type I synthesis at the high dose in human ligament fibroblasts.

Effects and action mechanism of gonadotropins on ovarian follicular cells: A novel role of Sphingosine-1-Phosphate (S1P). A review.

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) control antral follicular growth by regulating several processes, such as the synthesis of hormones and signaling molecules, proliferation, survival, apoptosis, luteinization, and ovulation. To exert these effects, gonadotropins bind to their respective Gs protein-coupled receptors, activating the protein kinase A (PKA) pathway or recruiting Gq proteins to activate protein kinase C (PKC) signaling. Although the action mechanism of FSH and LH is clear, recently, it has been shown that both gonadotropins promote the synthesis of sphingosine-1-phosphate (S1P) in granulosa and theca cells through the activation of sphingosine kinase 1. Moreover, the inhibition of SPHKs reduces S1P synthesis, cell viability, and the proliferation of follicular cells in response to gonadotropins, and the addition of S1P to the culture medium increases the proliferation of granulosa and theca cells without apparent effects on sexual steroid synthesis. Therefore, we consider that S1P is a crucial signaling molecule that complements the canonical gonadotropin pathway to promote the proliferation and viability of granulosa and theca cells.

Conductive extracellular matrix derived/chitosan methacrylate/ graphene oxide-pegylated hybrid hydrogel for cell expansion.

Electrical stimulation has emerged as a cornerstone technique in the rapidly evolving field of biomedical engineering, particularly within the realms of tissue engineering and regenerative medicine. It facilitates cell growth, proliferation, and differentiation, thereby advancing the development of accurate tissue models and enhancing drug-testing methodologies. Conductive hydrogels, which enable the conduction of microcurrents in 3D in vitro cultures, are central to this advancement. The integration of high-electroconductive nanomaterials, such as graphene oxide (GO), into hydrogels has revolutionized their mechanical and conductivity properties. Here, we introduce a novel electrostimulation assay utilizing a hybrid hydrogel composed of methacryloyl-modified small intestine submucosa (SIS) dECM (SISMA), chitosan methacrylate (ChiMA), and GO-polyethylene glycol (GO-PEG) in a 3D in vitro culture within a hypoxic environment of umbilical cord blood cells (UCBCs). Results not only demonstrate significant cell proliferation within 3D constructs exposed to microcurrents and early growth factors but also highlight the hybrid hydrogel's physiochemical prowess through comprehensive rheological, morphological, and conductivity analyses. Further experiments will focus on identifying the regulatory pathways of cells subjected to electrical stimulation.

Cell Proliferation and Apoptosis-Key Players in the Lung Aging Process.

Currently, the global lifespan has increased, resulting in a higher proportion of the population over 65 years. Changes that occur in the lung during aging increase the risk of developing acute and chronic lung diseases, such as acute respiratory distress syndrome, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and lung cancer. During normal tissue homeostasis, cell proliferation and apoptosis create a dynamic balance that constitutes the physiological cell turnover. In basal conditions, the lungs have a low rate of cell turnover compared to other organs. During aging, changes in the rate of cell turnover in the lung are observed. In this work, we review the literature that evaluates the role of molecules involved in cell proliferation and apoptosis in lung aging and in the development of age-related lung diseases. The list of molecules that regulate cell proliferation, apoptosis, or both processes in lung aging includes TNC, FOXM1, DNA-PKcs, MicroRNAs, BCL-W, BCL-XL, TCF21, p16, NOX4, NRF2, MDM4, RPIA, DHEA, and MMP28. However, despite the studies carried out to date, the complete signaling pathways that regulate cell turnover in lung aging are still unknown. More research is needed to understand the changes that lead to the development of age-related lung diseases.

Cell Cycle Kinetics and Sister Chromatid Exchange in Mosaic Turner Syndrome.

Turner syndrome (TS) is caused by a complete or partial absence of an X or Y chromosome, including chromosomal mosaicism, affecting 1 in 2500 female live births. Sister chromatid exchange (SCE) is used as a sensitive indicator of spontaneous chromosome instability. Cells from mosaic patients constitute useful material for SCE evaluations as they grow under the influence of the same genetic background and endogenous and exogenous factors. We evaluated the proliferation dynamics and SCE frequencies of 45,X and 46,XN cells of 17 mosaic TS patients. In two participants, the 45,X cells exhibited a proliferative disadvantage in relation to 46,XN cells after 72 h of cultivation. The analysis of the mean proliferation index (PI) showed a trend for a significant difference between the 45,X and 46,X+der(X)/der(Y) cell lineages; however, there were no intra-individual differences. On the other hand, mean SCE frequencies showed that 46,X+der(X) had the highest mean value and 46,XX the lowest, with 45,X occupying an intermediate position among the lineages found in at least three participants; moreover, there were intra-individual differences in five patients. Although 46,X+der(X)/der(Y) cell lineages, found in more than 70% of participants, were the most unstable, they had a slightly higher mean PI than the 45,X cell lineages in younger (≤17 years) mosaic TS participants. This suggests that cells with a karyotype distinct from 45,X may increase with time in mosaic TS children and adolescents.

Melittin inactivates YAP/HIF-1α pathway via up-regulation of LATS2 to inhibit hypoxia-induced proliferation, glycolysis and angiogenesis in NSCLC.

BACKGROUND: NSCLC is one of the most common causes of death. The hypoxia microenvironment contributes to cancer progression. The purpose was to explore the effects and mechanism of melittin on NSCLC cells in the hypoxic microenvironment. METHODS: NSCLC cell lines (A549 and H1299) were cultured in normoxia or hypoxia conditions with or without melittin treatment. The viability of the cells was detected via MTT assay and the proliferation ability was evaluated by EdU assay. QRT-PCR was performed to evaluate GLUT1, LDHA, HK2, VEGF and LATS2 mRNA levels. Glucose transport was assessed by the 2-NBDG uptake assay. The angiogenesis was determined by the tubule formation assay. The protein expressions of GLUT1, LDHA, HK2, VEGF, LATS2, YAP, p-YAP and HIF-1α were detected via western blotting assay. The tumor formation assay was conducted to examine the roles of melittin and LATS2 in vivo. RESULTS: Melittin inhibited hypoxia-induced cell viability, proliferation, glycolysis and angiogenesis as well as suppressed YAP binding to HIF-1α in NSCLC. Melittin inactivated the YAP/HIF-1α pathway via up-regulation of LATS2, ultimately inhibiting cancer progression of NSCLC. Moreover, melittin suppressed tumor growth via up-regulation of LATS2 in vivo. CONCLUSION: Melittin inactivated the YAP/HIF-1α pathway via up-regulation of LATS2 to contribute to the development of NSCLC. Therefore, melittin is expected to become a potential prognostic drug for the therapy of NSCLC.

Clinical Correlation of Transcription Factor SOX3 in Cancer: Unveiling Its Role in Tumorigenesis.

Members of the SOX (SRY-related HMG box) family of transcription factors are crucial for embryonic development and cell fate determination. This review investigates the role of SOX3 in cancer, as aberrations in SOX3 expression have been implicated in several cancers, including osteosarcoma, breast, esophageal, endometrial, ovarian, gastric, hepatocellular carcinomas, glioblastoma, and leukemia. These dysregulations modulate key cancer outcomes such as apoptosis, epithelial-mesenchymal transition (EMT), invasion, migration, cell cycle, and proliferation, contributing to cancer development. SOX3 exhibits varied expression patterns correlated with clinicopathological parameters in diverse tumor types. This review aims to elucidate the nuanced role of SOX3 in tumorigenesis, correlating its expression with clinical and pathological characteristics in cancer patients and cellular modelsBy providing a comprehensive exploration of SOX3 involvement in cancer, this review underscores the multifaceted role of SOX3 across distinct tumor types. The complexity uncovered in SOX3 function emphasizes the need for further research to unravel its full potential in cancer therapeutics.

A low dose of curcumin-PDA nanoparticles improves viability and proliferation in endoneurial fibroblasts and Schwann cell cultures.

Curcumin is a polyphenol extracted from Curcuma longa's roots. Low doses of curcumin are related to anti-inflammatory, antioxidant, and neuroprotective effects, while high doses are used for their lethality. This diversity of behaviors allows us to understand curcumin as a compound with hormetic action. Due to its strongly hydrophobic character, curcumin is often solubilized in organic compounds. In this way, we have recently reported the undesirable and occasionally irreversible effects of alcohol and DMSO on the viability of primary Schwann cell cultures. In this scenario, the use of nanoparticles as delivery systems has become a successful alternative strategy for these compounds. In the present work, we describe the structure of Polydopamine (PDA) nanoparticles, loaded with a low dose of curcumin (Curc-PDA) without the use of additional organic solvents. We analyzed the curcumin released, and we found two different forms of curcumin. Small increased cell viability and proliferation were observed in endoneurial fibroblast and Schwann cell primary cultures when Curc-PDA was steadily supplied for 5 days. The increased bioavailability of this natural compound and the impact on cells in culture not only confirm the properties of curcumin at very low doses but also provide a glimpse of a possible therapeutic alternative for PNS conditions in which SCs are involved.

Down-regulation of long noncoding RNA HOXA11-AS nullifies the impact of microRNA-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis.

OBJECTIVES: This study was directed towards exploring the impacts of lncRNA HOXA11-AS-mediated microRNA (miR)-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis (OA). METHODS: The articular cartilages were provided by OA patients who received total knee arthroplasty, and Human Chondrocyte (HC)-OA (HCOA) was also attained. The miR-506-3p and HOXA11-AS expressions in articular cartilages from OA patients and HCOA cells were analyzed via qPCR. After gain- and loss-of-function assays in HCOA cells, MTT assay and flow cytometry (FC) were used for assessing cell viability and apoptosis, accordingly. The levels of PIK3CA, AKT, and mTOR as well as AKT and mTOR phosphorylation levels assessed using western blotting (WB). The targeting correlation of HOXA11-AS and miR-506-3p as well as miR-506-3p and PIK3CA was assessed through Dual-Luciferase Reporter gene Assay (DLRA). RESULT: The articular cartilages from OA patients and Human Chondrocyte (HC)-OA (HCOA) cells showed increased HOXA11-AS and decreased miR-506-3p. Mechanistically, HOXA11-AS was capable of binding to miR-506-3p to increase PIK3CA, the target gene of miR-506-3p. miR-506-3p suppression facilitated HCOA cell proliferation and reduced their apoptosis, which was nullified by further silencing HOXA11-AS or silencing PIK3CA. The down-regulation of HOXA11-AS disrupted the PI3K/AKT/mTOR pathway, which was counteracted by further miR-506-3p inhibition. CONCLUSION: The silencing of HOXA11-AS might block the PI3K/AKT/mTOR pathway through miR-506-3p up-regulation, thereby restricting HCOA cell proliferation and provoking apoptosis.