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Balkan Medical Journal Apr 2017Juvenile idiopathic arthritis is the most common chronic rheumatic disease of unknown aetiology in childhood and predominantly presents with peripheral arthritis. The...
Juvenile idiopathic arthritis is the most common chronic rheumatic disease of unknown aetiology in childhood and predominantly presents with peripheral arthritis. The disease is divided into several subgroups, according to demographic characteristics, clinical features, treatment modalities and disease prognosis. Systemic juvenile idiopathic arthritis, which is one of the most frequent disease subtypes, is characterized by recurrent fever and rash. Oligoarticular juvenile idiopathic arthritis, common among young female patients, is usually accompanied by anti-nuclear antibodie positivity and anterior uveitis. Seropositive polyarticular juvenile idiopathic arthritis, an analogue of adult rheumatoid arthritis, is seen in less than 10% of paediatric patients. Seronegative polyarticular juvenile idiopathic arthritis, an entity more specific for childhood, appears with widespread large- and small-joint involvement. Enthesitis-related arthritis is a separate disease subtype, characterized by enthesitis and asymmetric lower-extremity arthritis. This disease subtype represents the childhood form of adult spondyloarthropathies, with human leukocyte antigen-B27 positivity and uveitis but commonly without axial skeleton involvement. Juvenile psoriatic arthritis is characterized by a psoriatic rash, accompanied by arthritis, nail pitting and dactylitis. Disease complications can vary from growth retardation and osteoporosis secondary to treatment and disease activity, to life-threatening macrophage activation syndrome with multi-organ insufficiency. With the advent of new therapeutics over the past 15 years, there has been a marked improvement in juvenile idiopathic arthritis treatment and long-term outcome, without any sequelae. The treatment of juvenile idiopathic arthritis patients involves teamwork, including an experienced paediatric rheumatologist, an ophthalmologist, an orthopaedist, a paediatric psychiatrist and a physiotherapist. The primary goals of treatment are to eliminate active disease, to normalize joint function, to preserve normal growth and to prevent long-term joint damage. Timely and aggressive treatment is important to provide early disease control. The first-line treatment includes disease-modifying anti-rheumatic drugs (methotrexate, sulphasalazine, leflunomide) in combination with corticosteroids, used in different dosages and routes (oral, intravenous, intra-articular). Intra-articular application of steroids seems to be an effective treatment modality, especially in monoarthritis. Biological agents should be added in the treatment of unresponsive patients. Anti-tumour necrosis factor agents (etanercept, infliximab, adalimumab), anti-interleukin-1 agents (anakinra, canakinumab), anti- interleukin-6 agents (tocilizumab) and T-cell regulatory agents (abatacept) have been shown to be safe and effective in childhood patients. Recent studies reported sustained reduction in joint damage with even complete clinical improvement in paediatric patients, compared to previous data.
Topics: Adolescent; Adrenal Cortex Hormones; Anti-Inflammatory Agents, Non-Steroidal; Antirheumatic Agents; Arthritis, Juvenile; Benzimidazoles; Biological Factors; Biological Therapy; Calcium; Child; Child, Preschool; Female; Fever; Hempa; Humans; Indomethacin; Infant; Injections, Intra-Articular; Male; Vitamin D
PubMed: 28418334
DOI: 10.4274/balkanmedj.2017.0111 -
Current Biology : CB Dec 2019The evolution of insect metamorphosis is one of the most important sagas in animal history, transforming small, obscure soil arthropods into a dominant terrestrial group... (Review)
Review
The evolution of insect metamorphosis is one of the most important sagas in animal history, transforming small, obscure soil arthropods into a dominant terrestrial group that has profoundly shaped the evolution of terrestrial life. The evolution of flight initiated the trajectory towards metamorphosis, favoring enhanced differences between juvenile and adult stages. The initial step modified postembryonic development, resulting in the nymph-adult differences characteristic of hemimetabolous species. The second step was to complete metamorphosis, holometaboly, and occurred by profoundly altering embryogenesis to produce a larval stage, the nymph becoming the pupa to accommodate the deferred development needed to make the adult. These changing life history patterns were intimately linked to two hormonal systems, the ecdysteroids and the juvenile hormones (JH), which function in both embryonic and postembryonic domains and control the stage-specifying genes Krüppel homolog 1 (Kr-h1), broad and E93. The ecdysteroids induce and direct molting through the ecdysone receptor (EcR), a nuclear hormone receptor with numerous targets including a conserved transcription factor network, the 'Ashburner cascade', which translates features of the ecdysteroid peak into the different phases of the molt. With the evolution of metamorphosis, ecdysteroids acquired a metamorphic function that exploited the repressor capacity of the unliganded EcR, making it a hormone-controlled gateway for the tissue development preceding metamorphosis. JH directs ecdysteroid action, controlling Kr-h1 expression which in turn regulates the other stage-specifying genes. JH appears in basal insect groups as their embryos shift from growth and patterning to differentiation. As a major portion of embryogenesis was deferred to postembryonic life with the evolution of holometaboly, JH also acquired a potent role in regulating postembryonic growth and development. Details of its involvement in broad expression and E93 suppression have been modified as life cycles became more complex and likely underlie some of the changes seen in the shift from incomplete to complete metamorphosis.
Topics: Animals; Biological Evolution; Insecta; Life History Traits; Metamorphosis, Biological
PubMed: 31794762
DOI: 10.1016/j.cub.2019.10.009 -
EMBO Reports Oct 2023Sexuality is generally prevented in newborns and arises with organizational rewiring of neural circuitry and optimization of fitness for reproduction competition. Recent...
Sexuality is generally prevented in newborns and arises with organizational rewiring of neural circuitry and optimization of fitness for reproduction competition. Recent studies reported that sex circuitry in Drosophila melanogaster is developed in juvenile males but functionally inhibited by juvenile hormone (JH). Here, we find that the fly sex circuitry, mainly expressing the male-specific fruitless (fru ) and/or doublesex (dsx), is organizationally undeveloped and functionally inoperative in juvenile males. Artificially activating all fru neurons induces substantial courtship in solitary adult males but not in juvenile males. Synaptic transmissions between major courtship regulators and all dsx neurons are strong in adult males but either weak or undetectable in juvenile males. We further find that JH does not inhibit male courtship in juvenile males but instead promotes courtship robustness in adult males. Our results indicate that the transition to sexuality from juvenile to adult flies requires organizational rewiring of neural circuitry.
Topics: Animals; Male; Drosophila; Drosophila melanogaster; Transcription Factors; Drosophila Proteins; Juvenile Hormones; Sexual Behavior, Animal; Nerve Tissue Proteins
PubMed: 37530648
DOI: 10.15252/embr.202356898 -
The FEBS Journal Jul 2021Organisms have constant contact with potentially harmful agents that can compromise their fitness. However, most of the times these agents fail to cause serious disease... (Review)
Review
Organisms have constant contact with potentially harmful agents that can compromise their fitness. However, most of the times these agents fail to cause serious disease by virtue of the rapid and efficient immune responses elicited in the host that can range from behavioural adaptations to immune system triggering. The immune system of insects does not comprise the adaptive arm, making it less complex than that of vertebrates, but key aspects of the activation and regulation of innate immunity are conserved across different phyla. This is the case for the hormonal regulation of immunity as a part of the broad organismal responses to external conditions under different internal states. In insects, depending on the physiological circumstances, distinct hormones either enhance or suppress the immune response integrating individual (and often collective) responses physiologically and behaviourally. In this review, we provide an overview of our current knowledge on the endocrine regulation of immunity in insects, its mechanisms and implications on metabolic adaptation and behaviour. We highlight the importance of this multilayered regulation of immunity in survival and reproduction (fitness) and its dependence on the hormonal integration with other mechanisms and life-history traits.
Topics: Adaptation, Physiological; Animals; Endocrine Cells; Fat Body; Hemocytes; Immunity, Cellular; Immunity, Innate; Insecta; Juvenile Hormones; Pore Forming Cytotoxic Proteins
PubMed: 33021015
DOI: 10.1111/febs.15581 -
Frontiers in Cell and Developmental... 2020Polyploidy cells undergo the endocycle to generate DNA amplification without cell division and have important biological functions in growth, development, reproduction,... (Review)
Review
Polyploidy cells undergo the endocycle to generate DNA amplification without cell division and have important biological functions in growth, development, reproduction, immune response, nutrient support, and conferring resistance to DNA damage in animals. In this paper, we have specially summarized current research progresses in the regulatory mechanisms of cell polyploidy in insects. First, insect hormones including juvenile hormone and 20-hydroxyecdysone regulate the endocycle of variant cells in diverse insect species. Second, cells skip mitotic division in response to developmental programming and conditional stimuli such as wound healing, regeneration, and aging. Third, the reported regulatory pathways of mitotic to endocycle switch (MES), including Notch, Hippo, and JNK signaling pathways, are summarized and constructed into genetic network. Thus, we think that the studies in crosstalk of hormones and their effects on canonical pathways will shed light on the mechanism of cell polyploidy and elucidate the evolutionary adaptions of MES through diverse insect species.
PubMed: 32548115
DOI: 10.3389/fcell.2020.00361 -
Cellular and Molecular Life Sciences :... May 2020Metamorphic transformation from larvae to adults along with the high fecundity is key to insect success. Insect metamorphosis and reproduction are governed by two... (Review)
Review
Metamorphic transformation from larvae to adults along with the high fecundity is key to insect success. Insect metamorphosis and reproduction are governed by two critical endocrines, juvenile hormone (JH), and 20-hydroxyecdysone (20E). Recent studies have established a crucial role of microRNA (miRNA) in insect metamorphosis and oogenesis. While miRNAs target genes involved in JH and 20E-signaling pathways, these two hormones reciprocally regulate miRNA expression, forming regulatory loops of miRNA with JH and 20E-signaling cascades. Insect metamorphosis and oogenesis rely on the coordination of hormones, cognate genes, and miRNAs for precise regulation. In addition, the alternative splicing of genes in JH and 20E-signaling pathways has distinct functions in insect metamorphosis and oogenesis. We, therefore, focus in this review on recent advances in post-transcriptional regulation, with the emphasis on the regulatory role of miRNA and alternative splicing, in insect metamorphosis and oogenesis. We will highlight important new findings of miRNA interactions with hormonal signaling and alternative splicing of JH receptor heterodimer gene Taiman.
Topics: Animals; Drosophila melanogaster; Ecdysterone; Gene Expression Regulation, Developmental; Insecta; Juvenile Hormones; Larva; Metamorphosis, Biological; MicroRNAs; Oogenesis; Signal Transduction
PubMed: 31724082
DOI: 10.1007/s00018-019-03361-5 -
Frontiers in Physiology 2022Insect life cycle is coordinated by hormones and their downstream effectors. Krüppel homolog1 (Kr-h1) is one of the crucial effectors which mediates the actions of the... (Review)
Review
Insect life cycle is coordinated by hormones and their downstream effectors. Krüppel homolog1 (Kr-h1) is one of the crucial effectors which mediates the actions of the two critical hormones of insects, the juvenile hormone (JH) and 20-hydroxyecdysone (20E). It is a transcription factor with a DNA-binding motif of eight CH zinc fingers which is found to be conserved among insect orders. The expression of is fluctuant during insect development with high abundance in juvenile instars and lower levels in the final instar and pupal stage, and reappearance in adults, which is governed by the coordination of JH, 20E, and miRNAs. The dynamic expression pattern of is closely linked to its function in the entire life of insects. Over the past several years, accumulating studies have advanced our understanding of the role of during insect development. It acts as a universal antimetamorphic factor in both hemimetabolous and holometabolous species by directly inhibiting the transcription of 20E signaling genes () and (), and steroidogenic enzyme genes involved in ecdysone biosynthesis. Meanwhile, it promotes vitellogenesis and ovarian development in the majority of studied insects. In addition, Kr-h1 regulates insect behavioral plasticity and caste identity, neuronal morphogenesis, maturation of sexual behavior, as well as embryogenesis and metabolic homeostasis. Hence, Kr-h1 acts as a cornerstone regulator in insect life.
PubMed: 35574485
DOI: 10.3389/fphys.2022.905441 -
ELife Dec 2023Experiments exploring the role of juvenile hormone during the life cycle of firebrat insects provide clues about the evolution of metamorphosis.
Experiments exploring the role of juvenile hormone during the life cycle of firebrat insects provide clues about the evolution of metamorphosis.
Topics: Animals; Metamorphosis, Biological; Insecta; Life Cycle Stages; Juvenile Hormones
PubMed: 38126357
DOI: 10.7554/eLife.94410 -
Physiological Research Dec 2023Insect vitellogenins are an intriguing class of complex proteins. They primarily serve as a source of energy for the developing embryo in insect eggs. Vitellogenesis is... (Review)
Review
Insect vitellogenins are an intriguing class of complex proteins. They primarily serve as a source of energy for the developing embryo in insect eggs. Vitellogenesis is a complex hormonally and neurally controlled process that command synthesis of vitellogenin molecules and ensures their transport from the female fat bodies or ovarial cells into eggs. The representatives of all insect hormones such as juvenile hormones, ecdysteroids, and neurohormones participate in vitellogenesis, but juvenile hormones (most insect species) and ecdysteroids (mostly Diptera) play the most important roles in the process. Strikingly, not only insect females, but also males have been reported to synthesize vitellogenins indicating their further utility in the insect body. Indeed, it has recently been found that vitellogenins perform a variety of biological functions in the insect body. They participate in defense reactions against entomopathogens such as nematodes, fungi, and bacteria, as well as against venoms such as the honeybee Apis mellifera venom. Interestingly, vitellogenins are also present in the venom of the honeybee itself, albeit their exact role is unknown; they most likely increase the efficacy of the venom in the victim's body. Within the bee's body vitellogenins contribute to the lifespan regulation as anti-aging factor acting under tight social interactions and hormonal control. The current minireview covers all of these functions of vitellogenins and portrays them as biologically active substances that play a variety of significant roles in both insect females and males, and not only acting as passive energy sources for developing embryo.
Topics: Male; Female; Animals; Vitellogenins; Ecdysteroids; Juvenile Hormones; Ovary; Insecta
PubMed: 38165752
DOI: 10.33549/physiolres.935221 -
Medicina 2018Autoimmune diseases of the peripheral nervous system are common in pediatrics. Guillain-Barré syndrome, juvenile myasthenia gravis, and juvenile dermatomyositis are the... (Review)
Review
Autoimmune diseases of the peripheral nervous system are common in pediatrics. Guillain-Barré syndrome, juvenile myasthenia gravis, and juvenile dermatomyositis are the most important. Their common pathogenesis involves the action of specific autoantibodies which are frequently triggered by viral or bacterial infection. Acute inflammatory demyelinating polyneuropathy is the most frequent pathological feature. There is also a motor axonal form. Both have a progressive ascending clinical course. The specific treatment is immunoglobulin 2 g/kg. Juvenile myasthenia gravis is expressed by ocular signs and generalized and fluctuating fatigability. It can involve respiratory functions triggering a myasthenic crisis. It is treated with anticholinesterase agents, corticosteroids, immunoglobulins, and immunosuppressants. Thymectomy has recently shown effectiveness. Juvenile dermatomyositis is expressed by skin and muscle signs. Elevated muscle enzymes, muscle biopsy, and magnetic resonance imaging contribute to the diagnosis. It is treated with corticosteroids, immunoglobulins, and immunosuppressants. All three disorders, Guillain-Barré, juvenile myasthenia gravis, and juvenile dermatomyositis have a good prognosis.
Topics: Adrenal Cortex Hormones; Cholinesterase Inhibitors; Dermatomyositis; Guillain-Barre Syndrome; Humans; Immunoglobulins; Myasthenia Gravis; Prednisone; Prognosis
PubMed: 30199371
DOI: No ID Found