Publications by authors named "Jean Francois Desaphy"

The integrity of esophageal epithelial cells in patients with gastroesophageal reflux disease (GERD) or GERD-like symptoms is the first mechanism of protection to decrease the sensitivity to gastric reflux and heartburn symptoms. We investigated the protective effects of Poliprotect (PPRO), a CE-marked medical device, on esophageal epithelial integrity using in vitro and ex vivo models. In vitro, the protective effects of PPRO were tested on Caco-2 cells.

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Mexiletine (NaMuscla™) is indicated for the symptomatic treatment of myotonia in adults with non-dystrophic myotonia. A cardiac assessment is required as mexiletine may have a pro-arrhythmic effect. Long-term safety data supporting the use of mexiletine in patients with non-dystrophic myotonia combined with the extensive clinical experience of an expert group resulted in creation of an algorithm for cardiac monitoring of patients treated with mexiletine.

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Immunoglobulin (Ig) replacement therapy (IgRT) consists of the administration of low-dose human polyclonal Igs for the treatment of primary and secondary hypogammaglobulinemia that are associated with recurrent infections and immune dysfunction. IgRT restores physiological antibody levels and induces an immunomodulatory effect by strengthening immune effector cells, thus reducing infections. Here, we describe the pharmacology of different Ig formulations with a particular focus on their mechanism of action as low-dose IgRT, including the direct anti-microbial effect and the immunomodulatory function.

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Mexiletine is the first choice drug in the treatment of non-dystrophic myotonias. However, 30% of patients experience little benefit from mexiletine due to poor tolerability, contraindications and limited efficacy likely based on pharmacogenetic profile. Safinamide inhibits neuronal voltage-gated sodium and calcium channels and shows anticonvulsant activity, in addition to a reversible monoamine oxidase-B inhibition.

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Arrhythmic risk stratification in patients with Lamin A/C gene (LMNA)-related cardiomyopathy influences clinical decisions. An implantable cardioverter defibrillator (ICD) should be considered in patients with an estimated 5-year risk of malignant ventricular arrhythmia (MVA) of ≥10%. The risk prediction score for MVA includes non-missense LMNA mutations, despite their role as an established risk factor for sudden cardiac death (SCD) has been questioned in several studies.

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Article Synopsis
  • Multiple myeloma (MM) progression is influenced by the bone marrow microenvironment, particularly fibroblasts and immune cells, enabling immune evasion and drug resistance.
  • The study introduces a bi-specific DARPin (α-FAPx4-1BB) that targets activated fibroblasts and immune cells, enhancing the immune response against MM by improving NK cell adhesion and activation.
  • This treatment strategy may help overcome the immunosuppressive environment in bone marrow, potentially leading to better elimination of dormant MM cells and achieving minimal residual disease negativity in patients.
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  • The European Space Agency (ESA) regularly updates its science plans by talking to scientists about what they need to know.
  • The SSCWP 9 document focuses on "Biology in Space" and discusses important questions that scientists want to answer about how living things adapt to space.
  • One big question is how different organisms change at the molecular level when they are in microgravity, which could help both space missions and new technologies on Earth.
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In France, mexiletine - a class I antiarrhythmic drug - can be prescribed for the symptomatic treatment of myotonia of the skeletal muscles in adult patients with myotonic dystrophy under a compassionate use programme. Mexiletine is used according to its summary of product characteristics, which describes its use for myotonia treatment in adult patients with non-dystrophic myotonia, a different neuromuscular condition without cardiac involvement. A cardiac assessment is required prior to initiation and throughout treatment due to potential proarrhythmic effects.

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Background: The nondystrophic myotonias are rare muscle hyperexcitability disorders caused by gain-of-function mutations in the SCN4A gene or loss-of-function mutations in the CLCN1 gene. Clinically, they are characterized by myotonia, defined as delayed muscle relaxation after voluntary contraction, which leads to symptoms of muscle stiffness, pain, fatigue, and weakness. Diagnosis is based on history and examination findings, the presence of electrical myotonia on electromyography, and genetic confirmation.

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Progress in mechanobiology allowed us to better understand the important role of mechanical forces in the regulation of biological processes. Space research in the field of life sciences clearly showed that gravity plays a crucial role in biological processes. The space environment offers the unique opportunity to carry out experiments without gravity, helping us not only to understand the effects of gravitational alterations on biological systems but also the mechanisms underlying mechanoperception and cell/tissue response to mechanical and gravitational stresses.

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Article Synopsis
  • The white paper discusses the need for research on how changes in gravity impact animal and human cellular and tissue systems, which is vital for understanding health in space.
  • Current knowledge gaps hinder the development of accurate models to predict long-term health impacts for astronauts during extended missions beyond low Earth orbit.
  • Researchers recommend a more integrated approach to connect biological and physiological effects to better address space adaptation challenges and promote astronaut health during deep space missions.
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Several commercially available and newly synthesized riluzole analogs were evaluated in vitro as voltage-gated skeletal muscle sodium-channel blockers. Data obtained from the patch-clamp technique demonstrated that potency is well correlated with lipophilicity and the introduction of a protonatable amino function in the benzothiazole 2-position enhances the use-dependent behavior. The most interesting compound, the 2-piperazine analog of riluzole (), although slightly less potent than the parent compound in the patch-clamp assay as well as in an in vitro model of myotonia, showed greater use-dependent Nav1.

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Intracellular pH (pHi) regulation is a challenge for the exocrine pancreas, where the luminal secretion of bicarbonate-rich fluid is accompanied by interstitial flows of acid. This acid-base transport requires a plethora of ion transporters, including bicarbonate transporters and the Na/H exchanger isoform 1 (NHE1), which are dysregulated in Pancreatic Ductal Adenocarcinoma (PDAC). PDAC progression is favored by a Collagen-I rich extracellular matrix (ECM) which exacerbates the physiological interstitial acidosis.

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Extracellular vesicles (EVs) have emerged as important players in cell-to-cell communication within the bone marrow (BM) of multiple myeloma (MM) patients, where they mediate several tumor-associated processes. Here, we investigate the contribution of fibroblasts-derived EVs (FBEVs) in supporting BM angiogenesis. We demonstrate that FBEVs' cargo contains several angiogenic cytokines (i.

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Angiogenesis represents a pivotal hallmark of multiple myeloma (MM) that correlates to patients' prognosis, overall survival, and drug resistance. Hence, several anti-angiogenic drugs that directly target angiogenic cytokines (i.e.

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Invasive and painful procedures, which often induce feelings of anxiety, are necessary components of pediatric cancer treatment, and adequate pain and anxiety management during these treatments is of pivotal importance. In this context, it is widely recognized that a holistic approach, including pharmacological and non-pharmacological modalities, such as distraction techniques, should be the standard of care. Recent evidence suggested the use of virtual reality (VR) as an effective non-pharmacological intervention in pediatrics.

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Article Synopsis
  • Non-dystrophic myotonias consist of different conditions, including myotonia congenita and other forms caused by gene mutations in CLCN1 and SCN4A.
  • A study analyzed five affected family members and discovered two novel gene mutations, p.K1302R in SCN4A and p.H838P in CLCN1, which were shown to co-segregate with the disorder.
  • Experiments revealed that while the mutations led to mild functional changes in ion channels, these changes could explain the mixed myotonic symptoms and suggested that medications like mexiletine and lamotrigine could be beneficial for those carrying the K1302R mutation.
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Skeletal muscle ion channelopathies are rare genetic diseases mainly characterized by myotonia (muscle stiffness) or periodic paralysis (muscle weakness). Here, we reviewed the available therapeutic options in non-dystrophic myotonias (NDM) and periodic paralyses (PP), which consists essentially in drug repositioning to address stiffness or weakness attacks. Empirical use followed by successful randomized clinical trials eventually led to the orphan drug designation and marketing authorization granting of mexiletine for NDM and dichlorphenamide for PP.

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Article Synopsis
  • Myotonia congenita (MC) is a rare inherited condition that involves muscle stiffness due to mutations in the ClC-1 chloride channel, which is essential for muscle relaxation after contraction.
  • These mutations can be categorized as "gating-defective" or "expression-defective," with no direct treatment available, making current options mainly palliative.
  • A study evaluated the potential of niflumic acid (NFA), a common anti-inflammatory drug, to enhance chloride currents in cells with trafficking-defective ClC-1 mutations, finding that NFA effectively restored channel function and protein expression without affecting its overall operation.
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Ion channels are pore-forming proteins that allow ions to flow across plasma membranes and intracellular organelles in both excitable and non-excitable cells. They are involved in the regulation of several biological processes (i.e.

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Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides that are not translated into proteins. Nowadays, lncRNAs are gaining importance as key regulators of gene expression and, consequently, of several biological functions in physiological and pathological conditions, including cancer. Here, we point out the role of lncRNAs in the pathogenesis of multiple myeloma (MM).

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Over 90% of deaths in cancer patients are attributed to tumor drug resistance. Resistance to therapeutic agents can be due to an innate property of cancer cells or can be acquired during chemotherapy. In recent years, it has become increasingly clear that regulation of membrane ion channels is an important mechanism in the development of chemoresistance.

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Three analogues of To042, a tocainide-related lead compound recently reported for the treatment of myotonia, were synthesized and evaluated in vitro as skeletal muscle sodium channel blockers possibly endowed with enhanced use-dependent behavior. Patch-clamp experiments on hNav1.4 expressed in HEK293 cells showed that N-[(naphthalen-1-yl)methyl]-4-[(2,6-dimethyl)phenoxy]butan-2-amine, the aryloxyalkyl bioisostere of To042, exerted a higher use-dependent block than To042 thus being able to preferentially block the channels in over-excited membranes while preserving healthy tissue function.

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