In vitro Exposure to Inflammatory Mediators Affects the Differentiation of Mesenchymal Progenitors.

The increasing prevalence of joint disease, and in particular osteoarthritis (OA), calls for novel treatment strategies to prevent disease progression in addition to existing approaches focusing mainly on the relief of pain symptoms. The inherent properties of mesenchymal stem cells (MSCs) make them an attractive candidate for novel tissue repair strategies, as these progenitors have the potential to differentiate into chondrocytes needed to replace degraded cartilage and can exert a modulating effect on the inflammatory environment of the diseased joint. However, the inflammatory environment of the joint may affect the ability of these cells to functionally integrate into the host tissue and exert beneficial effects, as hinted by a lack of success seen in clinical trials. Identification of factors and cell signalling pathways that influence MSC function is therefore critical for ensuring their success in the clinic, and here the effects of inflammatory mediators on bone marrow-derived MSCs were evaluated. Human MSCs were cultured in the presence of inflammatory mediators typically associated with OA pathology (IL-1ß, IL-8, IL-10). While exposure to these factors did not produce marked effects on MSC proliferation, changes were observed when the mediators were added under differentiating conditions. Results collected over 21 days showed that exposure to IL-1ß significantly affected the differentiation response of these cells exposed to chondrogenic and osteogenic conditions, with gene expression analysis indicating changes in MAPK, Wnt and TLR signalling pathways, alongside an increased expression of pro-inflammatory cytokines and cartilage degrading enzymes. These results highlight the value of MSCs as a preclinical model to study OA and provide a basis to define the impact of factors driving OA pathology on the therapeutic potential of MSCs for novel OA treatments.

Opioid-like adverse effects of tianeptine in male rats and mice.

RATIONALE: Tianeptine is a mu-opioid receptor (MOR) agonist with increasing reports of abuse in human populations. Preclinical data regarding the abuse potential and other opioid-like adverse effects of tianeptine at supratherapeutic doses are sparse. OBJECTIVES: The present study evaluated tianeptine in a rat model of abuse potential assessment and in mouse models of motor, gastrointestinal, and respiratory adverse effects. METHODS: Abuse potential was assessed in adult male Sprague-Dawley rats using an intracranial self-stimulation (ICSS) procedure to determine effects of acute and repeated tianeptine on responding for electrical brain stimulation. Male ICR mice were used to determine the effects of tianeptine in assays of locomotor behavior and gastrointestinal motility. Male Swiss-Webster mice were monitored for respiratory changes using whole-body plethysmography. RESULTS: In rats, acute tianeptine produced weak and delayed evidence for abuse-related ICSS facilitation at an intermediate dose (10 mg/kg, IP) and pronounced, naltrexone-preventable ICSS depression at a higher dose (32 mg/kg, IP). Repeated 7-day tianeptine (10 and 32 mg/kg/day, IP) produced no increase in abuse-related ICSS facilitation, only modest tolerance to ICSS depression, and no evidence of physical dependence. In mice, tianeptine produced dose-dependent, naltrexone-preventable locomotor activation. Tianeptine (100 mg/kg, SC) also significantly inhibited gastrointestinal motility and produced naloxone-reversible respiratory depression. CONCLUSIONS: Tianeptine presents as a MOR agonist with resistance to tolerance and dependence in our ICSS assay in rats, and it has lower abuse potential by this metric than many commonly abused opioids. Nonetheless, tianeptine produces MOR agonist-like acute adverse effects that include motor impairment, constipation, and respiratory depression.

Acute pain-related depression of operant responding maintained by social interaction or food in male and female rats.

RATIONALE: Clinically relevant pain is often associated with functional impairment and behavioral depression, including depression of social behavior. Moreover, recovery of function is a major goal in pain treatment. We used a recently developed model of operant responding for social interaction in rats to evaluate the vulnerability of social behavior to an experimental pain manipulation and the sensitivity of pain-depressed social behavior to treatment with clinically effective analgesics. METHODS: Sprague-Dawley male and female rats were trained to lever press for social access to another rat, and responding was evaluated after treatment with (a) intraperitoneal injection of dilute lactic acid (IP acid; 0.18-5.6%) administered alone as a visceral noxious stimulus, (b) the mu-opioid receptor (MOR) agonist morphine (0.32-10 mg/kg) or nonsteroidal anti-inflammatory drug (NSAID) ketoprofen (10 mg/kg) administered alone, or (c) morphine or ketoprofen administered before IP acid. For comparison, the same treatments were evaluated in separate rats trained to lever press for food delivery. RESULTS: Both IP acid alone and morphine alone more potently decreased responding maintained by social interaction than by food, whereas ketoprofen did not affect responding for either reinforcer. In general, analgesics were most effective to rescue operant responding when relatively low IP acid concentrations produced significant but submaximal behavioral depression; however, morphine was not effective to rescue responding for social interaction. CONCLUSIONS: Operant responding maintained by social interaction was more sensitive to pain-related disruption and less responsive to opioid analgesic rescue than food-maintained operant responding. Social behavior may be especially vulnerable to depression by pain states.

Tazemetostat for the treatment of multiple types of hematological malignancies and solid tumors.

Epigenetic alterations contributing to malignancy have become a more prominent field of investigation over the past several years, as several hallmarks of cancer are substantially altered by changes in the epigenome. Enhancer of zeste homologue 2 (EZH2), an enzyme involved in silencing the transcription of various genes, is overexpressed or mutated in multiple cancers and can lead to proliferation of dedifferentiated cells. Both gain-of-function and loss-of-function mutations have been noted in hematologic cancers, with gain-of-function mutations prevalent among non-Hodgkin lymphomas. Tazemetostat is a first-in-class EZH2 inhibitor developed to target this overexpression. Phase I trials have shown it is generally well tolerated and efficacious in solid tumors as well as hematological malignancies. Tazemetostat was approved by the U.S. Food and Drug Administration (FDA) for use in epithelioid sarcoma in January 2020 on the basis of the results of a recent phase II trial, but with several clinical trials ongoing, the use of tazemetostat for hematological malignancies is a promising avenue for treatment.

Resistance of Food-Maintained Operant Responding to Mechanical Punishment in Rats: Further Evidence for Weak "Affective/Motivational Pain" in Rat Models of Inflammatory and Neuropathic Pain.

Clinically relevant chronic pain is often associated with functional impairment and behavioral depression as an "affective/motivational" sign of pain; however preclinical animal models of inflammatory and neuropathic pain often produce weak evidence of impaired function. We hypothesized that hindpaw mechanical stimulation produced by a requirement to rear on a textured "NOX" plate would punish operant responding in rats treated with intraplantar complete Freund's adjuvant (CFA, a model of inflammatory pain) or the chemotherapeutic paclitaxel (PTX, a model of neuropathic pain) and produce sustained pain-related depression of operant behavior. Male Sprague-Dawley rats were trained under a progressive-ratio (PR) schedule of food-maintained operant responding, then treated with CFA (100 µL in left hindpaw), PTX (2.0 mg/kg IP on alternate days for four total injections; 6.6 mg/kg IV on alternate days for three total injections), or saline vehicle. PR break points and mechanical thresholds for paw withdrawal from von Frey filaments were then tracked for 28 days. Subsequently, rats were tested with the opioid receptor antagonist naltrexone to assess latent sensitization and with the kappa opioid receptor (KOR) agonist U69593 to assess KOR function. CFA produced significant mechanical hypersensitivity for 3 weeks but decreased PR breakpoints for only 1 day. Both IP and IV PTX produced mechanical hypersensitivity for at least three weeks; however, only IV PTX decreased PR breakpoints, and this decrease was not alleviated by morphine. After recovery, naltrexone reinstated mechanical hypersensitivity in CFA- but not PTX-treated rats, and it did not reinstate depression of breakpoints in any group. U69593 dose-dependently decreased PR breakpoints in all groups with no difference between control vs. CFA/PTX groups. These results suggest that rearing on a textured NOX plate was not sufficient to punish operant responding in CFA- and PTX-treated rats despite the presence of sustained mechanical hypersensitivity. The rapid recovery of operant responding could not be attributed to latent sensitization, KOR downregulation, or behavioral tolerance. These results extend the range of conditions under which putative chronic pain manipulations produce weak evidence for depression of operant responding as a sign of the "affective/motivational" component of pain in rats.

Six novel HLA-B, -DRB1, and -DQB1 alleles identified in Brazilian individuals.

The novel HLA alleles B*40:331, B*40:343, B*42:24, DRB1*01:74, DQB1*03:243, and DQB1*03:02:20 were identified in Brazilian individuals.

High-resolution HLA allele and haplotype frequencies in majority and minority populations of Costa Rica and Nicaragua: Differential admixture proportions in neighboring countries.

The HLA system shows the most extensive polymorphism in the human genome. Allelic and haplotypic frequencies of HLA genes vary dramatically across human populations. Due to a complex history of migration, populations in Latin America show a broad variety of admixture proportions, usually varying not only between countries, but also within countries. Knowledge of HLA allele and haplotype frequencies is essential for medical fields such as transplantation, but also serves as a means to assess genetic diversity and ancestry in human populations. Here, we have determined high-resolution HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies in a sample of 713 healthy subjects from three Mestizo populations, one population of African descent, and Amerindians of five different groups from Costa Rica and Nicaragua and compared their profiles to a large set of indigenous populations from Iberia, Sub-Saharan Africa, and the Americas. Our results show a great degree of allelic and haplotypic diversity within and across these populations, with most extended haplotypes being private. Mestizo populations show alleles and haplotypes of putative European, Amerindian, and Sub-Saharan African origin, albeit with differential proportions. Despite some degree of gene flow, Amerindians and Afro-descendants show great similarity to other Amerindian and West African populations, respectively. This is the first comprehensive study reporting high-resolution HLA diversity in Central America, and its results will shed light into the genetic history of this region while also supporting the development of medical programs for organ and stem cell transplantation.

KIR2DL1 allele sequence extensions and discovery of 2DL1*0010102 and 2DL1*0010103 alleles by DNA sequencing.

Full-length KIR2DL1 allele sequence extensions characterised by single molecule real-time (SMRT) DNA sequencing.

The novel KIR2DL1 allele, KIR2DL1*037, defined in the cell line SPO010 (IHW9036).

The novel KIR2DL1*037 allele discovered and characterised by single molecule real-time (SMRT) DNA sequencing.