Biology subjects

Tena-Sempere, M.

Publications and source records attributed to Tena-Sempere, M..

5 recordsLinked to original sources

bioRxiv2026

Microglia Rank signaling regulates GnRH function and the Hypothalamic-Pituitary-Gonadal axis

The hypothalamic-pituitary-gonadal axis (HPG) controls pubertal development, sexual maturation, and fertility. We hereby demonstrate a new role of hypothalamic microglia in controlling the HPG axis through Rank signaling, a pathway known for its role in bone and mammary gland biology. Whole-body and microglia Rank depletion leads to hypogonadotropic hypogonadism (HH) resulting from an alteration in gonadotropin-releasing hormone (GnRH) function. In addition, we identify rare gene variants of RANK in patients with HH. Transcriptional profiling upon pubertal Rank loss reveals defective microglia activation and morphological alterations in the median eminence (ME), decreasing the contacts and engulfment of GnRH terminal projections and impairing GnRH responses to kisspeptin. Overall, our data uncovers the crucial role of microglia in regulating GnRH function through Rank signaling, with implications for reproductive maturation and fertility. One-Sentence SummaryMicroglia regulates GnRH function through RANK signaling

cell biology↗

bioRxiv2022

Dissecting the KNDy hypothesis: KNDy neuron-derived kisspeptins are dispensable for puberty but essential for preserved female fertility and gonadotropin pulsatility

Kiss1 neurons in the hypothalamic arcuate-nucleus (ARC) play key roles in the control of GnRH pulsatility and fertility. A fraction of ARC Kiss1 neurons, termed KNDy, co-express neurokinin B (NKB; encoded by Tac2). Yet, NKB- and Kiss1-only neurons are also found in the ARC, while a second major Kiss1-neuronal population is present in the rostral hypothalamus. The specific contribution of different Kiss1 neuron sub-sets to reproductive control remains unfolded. To tease apart the physiological roles of KNDy-born kisspeptins, conditional ablation of Kiss1 in Tac2-expressing cells was implemented in vivo. Mice with Tac2 cell-specific Kiss1 KO (TaKKO) displayed reduced ARC kisspeptin content and Kiss1 expression, with greater suppression in females, which was detectable at infantile-pubertal age. In contrast, Tac2/NKB levels were fully preserved. Despite the drop of ARC Kiss1/kisspeptin, pubertal timing was normal in TaKKO mice of both sexes. However, young-adult TaKKO females displayed disturbed LH pulsatility and sex steroid levels, with suppressed basal LH and pre-ovulatory LH surges, early-onset subfertility and premature ovarian insufficiency. Conversely, testicular histology and fertility were grossly conserved in TaKKO males. Ablation of Kiss1 in Tac2-cells led also to sex-dependent alterations in body composition, glucose homeostasis and locomotor activity. Our data document that KNDy-born kisspeptins are dispensable/compensable for puberty in both sexes, but required for maintenance of female gonadotropin pulsatility and fertility, as well as adult metabolic homeostasis. Significance StatementNeurons in the hypothalamic arcuate nucleus (ARC) co-expressing kisspeptins and NKB, named KNDy, have been recently suggested to play a key role in pulsatile secretion of gonadotropins, and hence reproduction. However, the relative contribution of this Kiss1 neuronal-subset, vs. ARC Kiss1-only and NKB-only neurons, as well as other Kiss1 neuronal populations, has not been assessed in physiological settings. We report here findings in a novel mouse-model with elimination of KNDy-born kisspeptins, without altering other kisspeptin compartments. Our data highlights the heterogeneity of ARC Kiss1 populations and document that, while dispensable/compensable for puberty, KNDy-born kisspeptins are required for proper gonadotropin pulsatility and fertility, specifically in females. Characterization of this functional diversity is especially relevant, considering the potential of kisspeptin-based therapies for management of human reproductive disorders. Disclosure StatementThe authors have nothing to disclose in relation to the contents of this work.

physiology↗

bioRxiv2020

Δ9-Tetrahydrocannabinolic Acid markedly alleviates liver fibrosis and inflammation in murine models of chemically- and obesity-induced liver injury

BackgroundNon-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the Western world, and it is closely associated to obesity, type 2 diabetes mellitus, and dyslipidemia. Hepatocellular stellate cells (HSCs) activation by oxidative stress and inflammation is the hallmark of liver fibrosis and leads to cirrhosis and liver failure resistant to pharmacological management. Cannabinoids have been suggested as a potential therapy for liver fibrosis, prompting us to explore the antifibrotic and anti-inflammatory effects of {Delta}9-THCA-A, a major non-psychotropic cannabinoid from Cannabis sativa L., in animal models of NAFLD. MethodsNon-alcoholic liver fibrosis was induced in mice by CCl4 treatment or, alternatively, by 23-week high fat diet (HFD) feeding. {Delta}9-THCA was administered daily intraperitoneally during the CCl4 treatment or during the last 3 weeks in HFD-fed mice. Liver fibrosis and inflammation were assessed by immunochemistry and qPCR. Blood glucose and plasma insulin, leptin and triglyceride levels were measured in HFD mice. Results{Delta}9-THCA significantly attenuated CCl4-induced liver fibrosis and inflammation and reduced T cell and macrophage infiltration. Mice fed HFD for 23 weeks developed severe obesity (DIO), fatty liver and marked liver fibrosis, accompanied by immune cell infiltration. {Delta}9-THCA, significantly reduced body weight and adiposity, improved glucose tolerance, and drastically attenuated DIO-induced liver fibrosis and immune cell infiltration. Conclusions{Delta}9-THCA prevents liver fibrogenesis in vivo, providing a rationale for additional studies on the medicinal use of this cannabinoid, as well as cannabis preparations containing it, in the treatment of liver fibrosis and the management of NAFLD.

pharmacology and toxicology↗

bioRxiv2020

Image matters: Development of a novel staining method, the RGB-trichrome, as a reliable tool for the study of the musculoskeletal system

Morphometry and histology are essential approaches for investigation and diagnosis of musculo-skeletal disorders. Despite the advent of revolutionary methods of image analysis and high resolution three-dimensional imaging technology, basic conventional light microscopy still provides an incisive overview of the structure and tissue dynamics of the musculoskeletal system. This is crucial to both preclinical and clinical research, since several clinically relevant processes, such as bone repair, osteoarthritis, and metabolic bone diseases, display distinct, if not pathognomonic, histological features. Due to the particular characteristics of the skeletal tissues (i.e., the existence of mineralized extracellular matrices), a large number of staining methods applicable to either decalcified or undecalcified tissues are available. However, it is usually the case that several staining methods need to be sequentially applied in order to achieve the different endpoints required to fully assess skeletal tissue structure and dynamics, and to allow morphometric quantification. We describe herein a novel staining method, the RGB trichrome, amenable for application to decalcified, paraffin embedded human musculoskeletal tissues. The acronym RGB corresponds to the three primary dyes used: picrosirius Red, fast Green, and alcian Blue. Although these individual pigments are commonly used either isolated, in binary combinations, or as part of more complex polychrome staining methods, when merged in the RGB trichrome staining produce high-quality/high-contrast images, permitting not only clear identification of different tissues (i.e., the different types of cartilage, bone and fibrous connective tissue), but also discrimination between calcified and uncalcified bone and cartilage, as well as an unexpected diversity of shades of color, while displaying singular properties among polychrome staining methods, such as the unveiling of the bone osteocyte dendritic/canalicular network. Hence, we propose the RGB trichrome as simple but highly-reliable tool for the preclinical and clinical study of the musculoskeletal system.

cell biology↗

bioRxiv2019

Tetrahydrocannabinolic Acid A (THCA-A) Reduces Adiposity And Prevents Metabolic Disease Caused By Diet-Induced Obesity

Cannabis has remarkable therapeutic potential, but its clinical use is limited by the psychotropic activity of {Delta}9-tetrahydrocannabinol ({Delta}9-THC). Surprisingly, the biological profile of the non-narcotic native precursor of {Delta}9-THC ({Delta}9-THC acid A, {Delta}9-THCA-A) is still largely unexplored. We present evidence that {Delta}9-THCA-A is a partial and selective PPAR{gamma} modulator, endowed with lower adipogenic activity than the full PPAR{gamma} agonist rosiglitazone (RGZ) and with an enhanced osteoblastogenic activity in human mesenchymal stem cells. Docking and in vitro functional assays indicated that {Delta}9-THCA-A binds to and activates PPAR{gamma} by acting at both the canonical and the alternative sites of the ligand-binding domain. Transcriptomic signatures at inguinal white adipose tissue (iWAT) from mice treated with {Delta}9-THCA-A confirmed its mode of action on PPAR{gamma}. Administration of {Delta}9-THCA-A in a mouse model of high fat diet (HFD)-induced obesity significantly reduced fat mass and body weight gain, markedly ameliorating glucose intolerance and insulin resistance, and largely preventing liver steatosis, adipogenesis and macrophage infiltration in fat tissues. Additionally, immunohistochemistry, transcriptomic, and plasma biomarker analyses showed that treatment with {Delta}9-THCA-A caused browning of iWAT and displayed potent anti-inflammatory actions in HFD mice. Altogether, our data validate the potential of {Delta}9-THCA-A as a low adipogenic PPAR{gamma} agonist, capable of substantially improving the symptoms of obesity-associated metabolic syndrome and inflammation. These findings suggest that {Delta}9-THCA-A, and perhaps non-decarboxylated Cannabis sativa extracts, are worth considering for addition to our inventory of cannabis medicines.\n\nSIGNIFICANCE STATEMENTThe medicinal use of Cannabis is gaining momentum, despite the adverse psychotropic effects of {Delta}9-THC, the decarboxylation product of its naturally occurring and non-psychotropic precursor {Delta}9-THCA-A. We present evidence that {Delta}9-THCA-A is a partial ligand agonist of PPAR{gamma} with lower adipogenic activity compared to the full PPAR{gamma} agonist rosiglitazone (RGZ). Moreover, chronic administration of {Delta}9-THCA-A in a mouse model of high fat diet (HFD)-induced obesity significantly reduced body weight gain and fat mass, improved glucose intolerance and insulin resistance, and prevented liver steatosis and macrophage infiltration in fat tissues, additionally inducing white adipose tissue browning. Collectively, these observations qualify {Delta}9-THCA-A, a compound devoid of psychotropic effects, as an efficacious pharmacological agent to manage metabolic syndrome and obesity-associated inflammation.\n\nHighlights- {Delta}9-THCA-A is a partial PPAR{gamma} ligand agonist with low adipogenic activity\n- {Delta}9-THCA-A enhances osteoblastogenesis in bone marrow derived mesenchymal stem cells.\n- {Delta}9-THCA-A reduces body weight gain, fat mass, and liver steatosis in HFD-fed mice\n- {Delta}9-THCA-A improves glucose tolerance, insulin sensitivity, and insulin profiles in vivo\n- {Delta}9-THCA-A induces browning of iWAT and has a potent anti-inflammatory activity

pharmacology and toxicology↗