The cAMP analogue 8-Br-cAMP-AM (8-Br) confers marked protection against global ischaemia/reperfusion of isolated perfused heart. We tested the hypothesis that 8-Br is also protective under clinically relevant conditions (regional ischaemia) when applied either before ischemia or at the beginning of reperfusion, and this effect is associated with the mitochondrial permeability transition pore (MPTP). 8-Br (10 $μ$M) was administered to Langendorff-perfused rat hearts for 5 min either before or at the end of 30 min regional ischaemia. Ca(2+)-induced mitochondria swelling (a measure of MPTP opening) and binding of hexokinase II (HKII) to mitochondria were assessed following the drug treatment at preischaemia. Haemodynamic function and ventricular arrhythmias were monitored during ischaemia and 2 h reperfusion. Infarct size was evaluated at the end of reperfusion. 8-Br administered before ischaemia attenuated ventricular arrhythmias, improved haemodynamic function, and reduced infarct size during ischaemia/reperfusion. Application of 8-Br at the end of ischaemia protected the heart during reperfusion. 8-Br promoted binding of HKII to the mitochondria and reduced Ca(2+)-induced mitochondria swelling. Thus, 8-Br protects the heart when administered before regional ischaemia or at the beginning of reperfusion. This effect is associated with inhibition of MPTP via binding of HKII to mitochondria, which may underlie the protective mechanism.
Bruria Hirsh Raccah PharmD PhD, Yevgeni Erlichman, Arthur Pollak, Ilan Matok, and Mordechai Muszkat. 2021. “Prescribing Errors With Direct Oral Anticoagulants and Their Impact on the Risk of Bleeding in Patients With Atrial Fibrillation.” Journal of cardiovascular pharmacology and therapeutics, Pp. 10742484211019657. Abstract
INTRODUCTION: Anticoagulants are associated with significant harm when used in error, but there are limited data on potential harm of inappropriate treatment with direct oral anticoagulants (DOACs). We conducted a matched case-control study among atrial fibrillation (AF) patients admitting the hospital with a chronic treatment with DOACs, in order to assess factors associated with the risk of major bleeding. METHODS: Patient data were documented using hospital's computerized provider order entry system. Patients identified with major bleeding were defined as cases and were matched with controls based on the duration of treatment with DOACs and number of chronic medications. Appropriateness of prescribing was assessed based on the relevant clinical guidelines. Conditional logistic regression was used to evaluate the potential impact of safety-relevant prescribing errors with DOACs on major bleeding. RESULTS: A total number of 509 eligible admissions were detected during the study period, including 64 cases of major bleeding and 445 controls. The prevalence of prescribing errors with DOACs was 33%. Most prevalent prescribing errors with DOACs were "drug dose too low" (16%) and "non-recommended combination of drugs" (11%). Safety-relevant prescribing errors with DOACs were associated with major bleeding [adjusted odds ratio (aOR) 2.17, 95% confidence interval (CI) 1.14-4.12]. CONCLUSION: Prescribers should be aware of the potential negative impact of prescribing errors with DOACs and understand the importance of proper prescribing and regular follow-up.
Constantin Itin, Rinat Komargodski, Dinorah Barasch, Abraham J. Domb, and Amnon Hoffman. 2021. “Prolonged Delivery of Apomorphine Through the Buccal Mucosa, Towards a Noninvasive Sustained Administration Method in Parkinson's Disease: In Vivo Investigations in Pigs.” Journal of Pharmaceutical Sciences, 110, 4, Pp. 1824–1833. Abstract
In the current work, prolonged systemic delivery of apomorphine via buccal mucosa was shown to be a promising treatment for Parkinson's disease as a substitute for clinically utilized subcutaneous infusions. Due to extensive ‘first-pass' metabolism, apomorphine is administered parenterally to bypass liver metabolism. Drawbacks of parenteral administration cause low patient compliance and adherence to treatment. On the other hand, while also bypassing the liver, delivery through buccal mucosa has a superior safety profile, is less costly, lacks pain and discomfort, and possesses excellent accessibility, overall augmenting patient compliance. Current in vivo study in pigs showed: (1) steady plateau levels of apomorphine in plasma were obtained 30 min following administration and remained constant for 8 h until a delivery device was removed, (2) bioavailability of apomorphine was 55%–80% as opposed to <2% peroral and (3) simulation of the pharmacokinetic profile obtained in pigs predicted therapeutically relevant levels of apomorphine in human. Furthermore, antipyrine was incorporated as a permeation marker to enable mechanistic investigation of apomorphine release from the delivery device and its permeation through the buccal mucosa. In addition, limitations of an Ussing diffusion chamber as an ex vivo research tool were also discussed.
Madison N Myers, Maya Zachut, Joseph Tam, and Andres G Contreras. 2021. “A proposed modulatory role of the endocannabinoid system on adipose tissue metabolism and appetite in periparturient dairy cows.” Journal of animal science and biotechnology, 12, 1, Pp. 21. Abstract
To sustain the nutrient demands of rapid fetal growth, parturition, and milk synthesis, periparturient dairy cows mobilize adipose tissue fatty acid stores through lipolysis. This process induces an inflammatory response within AT that is resolved as lactation progresses; however, excessive and protracted lipolysis compounds the risk for metabolic and inflammatory diseases. The suppression of lipolytic action and inflammation, along with amplification of adipogenesis and lipogenesis, serve as prospective therapeutic targets for improving the health of periparturient dairy cows. Generally, the activation of cannabinoid receptors by endocannabinoids enhances adipogenesis and lipogenesis, suppresses lipolysis, and increases appetite in mammals. These biological effects of activating the endocannabinoid system open the possibility of harnessing the endocannabinoid system through nutritional intervention in dairy herds as a potential tool to improve dairy cows' health, although much is still to be revealed in this context. This review summarizes the current knowledge surrounding the components of the endocannabinoid system, elaborates on the metabolic effects of its activation, and explores the potential to modulate its activity in periparturient dairy cows.
Bruria Hirsh Raccah, Alona Yanovsky, Nir Treves, Victoria Rotshild, Christel Renoux, Haim Danenberg, Ran Eliaz, and Ilan Matok. 2021. “Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) inhibitors and the risk for neurocognitive adverse events: A systematic review, meta-analysis and meta-regression.” International journal of cardiology, 335, Pp. 7–14. Abstract
{BACKGROUND: It has been suggested that lipid lowering therapy causes impaired cognitive changes. The association between the use of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) inhibitors and the risk of neurocognitive adverse events remains unclear. This meta-analysis aims to assess neurocognitive safety of PCSK9 inhibitors in randomized controlled trials (RCTs). METHODS AND RESULTS: The research was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed (MEDLINE), Embase and Cochrane library were searched through September 2019. Selection criteria included RCTs that addressed to neurocognitive adverse events of participants using Alirocumab, Evolocumab or Bococizumab, with a follow up duration of at least 6 months. The search results were screened by two independent reviewers. Safety data from included papers were extracted. Random effects meta-analysis was used to pool results, and meta-regression was utilized when applicable. Twenty-one studies were included. Among 59,733 patients, 31,611 were treated with PCSK9 inhibitors. The follow-up period ranged from 24 weeks to 48 months. No significant difference in the incidence of neurocognitive adverse effects between the groups was identified (RR = 1.01, 95% CI: 0.86-1.19, I(2) = 3%). Similar results were seen in subgroup analysis for each of the medications (alirocumab- RR = 0.88, 95% CI: 0.72-1.08, I(2) = 0%, evolocumab- RR = 1.42, 95% CI: 0.74-2.73, I(2) = 55%). A meta-regression analysis for evolocumab revealed that prolonged study duration was associated with decreased risk for neurocognitive adverse events ($\beta$(week) = -0.0037
Victoria Nahum and Abraham J Domb. 2021. “Recent Developments in Solid Lipid Microparticles for Food Ingredients Delivery.” Foods (Basel, Switzerland), 10, 2. Abstract
Health food has become a prominent force in the market place, influencing many food industries to focus on numerous bioactive compounds to reap benefits from its properties. Use of these compounds in food matrices has several limitations. Most of the food bio-additives are sensitive compounds that may quickly decompose in both food and within the gastrointestinal tract. Since most of these bioactives are highly or partially lipophilic molecules, they possess very low water solubility and insufficient dispersibility, leading to poor bioavailability. Thus, various methods of microencapsulation of large number of food bioactives have been studied. For encapsulation of hydrophobic compounds several lipid carriers and lipid platforms have been studied, including emulsions, microemulsions, micelles, liposomes, and lipid nano- and microparticles. Solid lipid particles (SLP) are a promising delivery system, can both deliver bioactive compounds, reduce their degradation, and permit slow and sustained release. Solid lipid particles have important advantages compared to other polymer carriers in light of their simple production technology, including scale up ability, higher loading capacity, extremely high biocompatibility, and usually low cost. This delivery system provides improved stability, solubility in various matrixes, bioavailability, and targeting properties. This article reviews recent studies on microencapsulation of selected bioactive food ingredients in solid lipid-based carriers from a point of view of production methods, characteristics of obtained particles, loading capability, stability, and release profile.
Wajeha Hamoudi, Felix von Lendenfeld, Maryam Kartawy, Shira Mencer, Huda Suloh, Igor Khaliulin, and Haitham Amal. 2021. “Regional Differences in S-Nitrosylation in the Cortex, Striatum, and Hippocampus of Juvenile Male Mice.” Journal of Molecular Neuroscience. Abstract
Nitric oxide (NO) is a multifunctional neurotransmitter that plays a major role in neuronal and synaptic functions. S-nitrosylation (SNO), the NO-mediated protein posttransitional modification (PTM), is known to regulate physiological and pathological processes in the brain. However, the physiological role in different neuroanatomical brain regions has not been well investigated. To understand the role of SNO in the brain of juvenile WT mice, we used SNOTRAP technology. We mapped the SNO-proteome in three different neuroanatomical regions: cortex, striatum, and hippocampus. By conducting systems biology analysis, we found that the three brain regions share similar biological processes (BP) including biogenesis and developmental processes. Exclusive and different BP and molecular functions were found for each of the regions. Unraveling the BP and signaling mechanisms of SNO in the cortex, striatum, and hippocampus may help to understand the functional differences between the three regions under physiological conditions.
Saja Baraghithy, Yael Soae, Dekel Assaf, Liad Hinden, Shiran Udi, Adi Drori, Yankel Gabet, and Joseph Tam. 2021. “Renal Proximal Tubule Cell Cannabinoid-1 Receptor Regulates Bone Remodeling and Mass via a Kidney-to-Bone Axis.” Cells, 10, 2. Abstract
The renal proximal tubule cells (RPTCs), well-known for maintaining glucose and mineral homeostasis, play a critical role in the regulation of kidney function and bone remodeling. Deterioration in RPTC function may therefore lead to the development of diabetic kidney disease (DKD) and osteoporosis. Previously, we have shown that the cannabinoid-1 receptor (CB(1)R) modulates both kidney function as well as bone remodeling and mass via its direct role in RPTCs and bone cells, respectively. Here we employed genetic and pharmacological approaches that target CB(1)R, and found that its specific nullification in RPTCs preserves bone mass and remodeling both under normo- and hyper-glycemic conditions, and that its chronic blockade prevents the development of diabetes-induced bone loss. These protective effects of negatively targeting CB(1)R specifically in RPTCs were associated with its ability to modulate erythropoietin (EPO) synthesis, a hormone known to affect bone mass and remodeling. Our findings highlight a novel molecular mechanism by which CB(1)R in RPTCs remotely regulates skeletal homeostasis via a kidney-to-bone axis that involves EPO.
Claire Thornton, Etty Grad, and Rami Yaka. 2021. “The role of mitochondria in cocaine addiction.” Biochemical Journal, 478, 4, Pp. 749–764. Abstract
The incidence of cocaine abuse is increasing especially in the U.K. where the rates are among the highest in Europe. In addition to its role as a psychostimulant, cocaine has profound effect on brain metabolism, impacting glycolysis and impairing oxidative phosphorylation. Cocaine exposure alters metabolic gene expression and protein networks in brain regions including the prefrontal cortex, the ventral tegmental area and the nucleus accumbens, the principal nuclei of the brain reward system. Here, we focus on how cocaine impacts mitochondrial function, in particular through alterations in electron transport chain function, reactive oxygen species (ROS) production and oxidative stress (OS), mitochondrial dynamics and mitophagy. Finally, we describe the impact of cocaine on brain energy metabolism in the developing brain following prenatal exposure. The plethora of mitochondrial functions altered following cocaine exposure suggest that therapies maintaining mitochondrial functional integrity may hold promise in mitigating cocaine pathology and addiction.
Regina Leshem, Benjamin Bar-Oz, Orna Diav-Citrin, Siham Gbaly, Jessica Soliman, Christel Renoux, and Ilan Matok. 2021. “Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin Norepinephrine Reuptake Inhibitors (SNRIs) During Pregnancy and the Risk for Autism spectrum disorder (ASD) and Attention deficit hyperactivity disorder (ADHD) in the Offspring: A True Effect o.” Current Neuropharmacology, 19, 6, Pp. 896–906. Abstract
{BACKGROUND AND OBJECTIVE: An inconsistent association between exposure to SSRIs and SNRIs and the risk for ASD and ADHD in the Offspring was observed in observational studies. Some suggest that the reported association might be due to unmeasured confounding. We aimed to study this association and to look for sources of bias by performing a systematic review and meta-analysis. METHODS: Medline, Embase, and the Cochrane Library were searched up to June 2019 for studies reporting on ASD and ADHD in the Offspring following exposure during pregnancy. We followed the PRISMA 2009 guidelines for data selection and extraction. Outcomes were pooled using random- effects models and odds ratios (OR), and 95% confidence intervals (CI) were calculated for each outcome using the adjusted point estimate of each study. RESULTS: Eighteen studies were included in the meta-analysis. We found an association between SSRIs/ SNRIs prenatal use and the risk for ASD and ADHD (OR=1.42, 95% CI: 1.23-1.65, I(2)=58%; OR=1.26, 95% CI: 1.07-1.49
Elka Touitou, Hiba Natsheh, Shatha Boukeileh, and Rania Awad. 2021. “Short Onset and Enhanced Analgesia Following Nasal Administration of Non-Controlled Drugs in Nanovesicular Systems.” Pharmaceutics, 13, 7. Abstract
Nasal nanovesicular delivery systems (NVS) containing the noncontrolled analgesic drugs Ketoprofen, Butorphanol or Tramadol, incorporated in a phospholipid nanovesicular carrier, were designed and investigated. The systems were first characterized for their physicochemical properties. Due to their composition, comprising propylene glycol as a lipid bilayers fluidizer, these systems contain soft vesicles. Pharmacokinetic profiles of Tramadol in plasma and brain and of Ketoprofen in plasma were also assessed. The analgesic effect of each of the three tested drugs was evaluated in the acetic acid mice model for pain. One important result obtained in this work is that the concentration of Tramadol in rats' plasma and brain increased rapidly after administration, reaching a peak value 10 min after administration with a C(max) of 2 to 5 folds greater than that for the oral or nasal non-vesicular treatments, respectively. In the case of Ketoprofen, the peak of the drug level in plasma was measured 10 min post nasal administration in NVS. The C(max) was three-fold higher relative to oral administration of this drug. In the experiment testing analgesia, a rapid and improved analgesia was observed for the tested drugs when delivered nasally in the nanocarrier. On the other hand, a weaker analgesic effect was observed for oral and nasal control systems. This new approach suggests that nasal delivery of non-controlled drugs in soft nanovesicles may open the way for better and noninvasive treatment of severe pain.
Constantin Itin, Abraham J. Domb, and Amnon Hoffman. 2021. “On the Suitability of Porcine Labial Mucosa as a Model for Buccal Mucosal Drug Delivery Research.” Journal of Pharmaceutical Sciences, 110, 4, Pp. 1863–1864. Abstract
Contrary to human, porcine mucosa of the inner side of the lip is parakeratinized. Thus, although desirable due to its large surface area, it does not closely resemble human buccal mucosa to be considered a suitable model for systemic drug delivery research. Nevertheless, it can be utilized for comparative screening of topical or systemic delivery of bioactive agents, mostly lipophilic such as cannabinoids.
Menachem Gross, Fadi Ashqar, Ronit Vogt Sionov, Michael Friedman, Ron Eliashar, Batya Zaks, Irith Gati, Danielle Duanis-Assaf, Mark Feldman, and Doron Steinberg. 2021. “Sustained release varnish containing chlorhexidine for prevention of Streptococcus mutans biofilm formation on voice prosthesis surface: an in vitro study.” International microbiology : the official journal of the Spanish Society for Microbiology. Abstract
OBJECTIVES: In this study, we aimed to develop a novel, sustained release varnish (SRV) for voice prostheses (VP) releasing chlorhexidine (CHX), for the prevention of biofilm formation caused by the common oral bacteria Streptococcus mutans on VP surfaces. METHODS: This study was performed in an in vitro model as a step towards future in vivo trials. VPs were coated with a SRV containing CHX (SRV-CHX) or SRV alone (placebo-SRV) that were daily exposed to S. mutans. The polymeric materials of SRV were composed of ethylcellulose and PEG-400. Biofilm formation was assessed by DNA quantification (qPCR), crystal violet staining, confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and kinetics experiments. RESULTS: The amount of DNA in the biofilms formed by S. mutans on VP surfaces coated once with SRV-CHX (1.024 ± 0.218 ng DNA/piece) was 58.5 ± 8.8% lower than that of placebo-SRV-coated VPs (2.465 ± 0.198 ng DNA/piece) after a 48-h exposure to S. mutans (p = 0.038). Reduced biofilm mass on SRV-CHX-coated VPs was visually confirmed by CLSM and SEM. CV staining of SRV-CHX single-coated VPs that have been exposed to S. mutans nine times showed a 98.1 ± 0.2% reduction in biofilm mass compared to placebo-SRV-coated VPs (p = 0.003). Kinetic experiments revealed that SRV-CHX triple-coated VPs could delay bacterial growth for 23 days. CONCLUSIONS: Coating VPs with SRV-CHX has an inhibitory effect on biofilm formation and prevents bacterial growth in their vicinities. This study is a proof-of-principle that paves the way for developing new clinical means for reducing both VPs' bacterial biofilm formation and device failure.
Reem Odi, David Bibi, Bella Shusterman, Natalia Erenburg, Chanan Shaul, Claudiu T Supuran, Alessio Nocentini, and Meir Bialer. 2021. “Synthesis and Enantioselective Pharmacokinetic/Pharmacodynamic Analysis of New CNS-Active Sulfamoylphenyl Carbamate Derivatives.” International journal of molecular sciences, 22, 7. Abstract
We recently reported a new class of carbamate derivatives as anticonvulsants. Among these, 3-methylpentyl(4-sulfamoylphenyl)carbamate (MSPC) stood out as the most potent compound with ED(50) values of 13 mg/kg (i.p.) and 28 mg/kg (p.o.) in the rat maximal electroshock test (MES). 3-Methylpropyl(4-sulfamoylphenyl)carbamate (MBPC), reported and characterized here, is an MSPC analogous compound with two less aliphatic carbon atoms in its structure. As both MSPC and MBPC are chiral compounds, here, we studied the carbonic anhydrase inhibitory and anticonvulsant action of both MBPC enantiomers in comparison to those of MSPC as well as their pharmacokinetic properties. Racemic-MBPC and its enantiomers showed anticonvulsant activity in the rat maximal electroshock (MES) test with ED(50) values in the range of 19-39 mg/kg. (R)-MBPC had a 65% higher clearance than its enantiomer and, consequently, a lower plasma exposure (AUC) than (S)-MSBC and racemic-MSBC. Nevertheless, (S)-MBPC had a slightly better brain permeability than (R)-MBPC with a brain-to-plasma (AUC) ratio of 1.32 (S-enantiomer), 1.49 (racemate), and 1.27 (R-enantiomer). This may contribute to its better anticonvulsant-ED(50) value. The clearance of MBPC enantiomers was more enantioselective than the brain permeability and MES-ED(50) values, suggesting that their anticonvulsant activity might be due to multiple mechanisms of action.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder manifested in repetitive behavior, abnormalities in social interactions, and communication. The pathogenesis of this disorder is not clear, and no effective treatment is currently available. Protein S-nitrosylation (SNO), the nitric oxide (NO)-mediated posttranslational modification, targets key proteins implicated in synaptic and neuronal functions. Previously, we have shown that NO and SNO are involved in the ASD mouse model based on the Shank3 mutation. The energy supply to the brain mostly relies on oxidative phosphorylation in the mitochondria. Recent studies show that mitochondrial dysfunction and oxidative stress are involved in ASD pathology. In this work, we performed SNO proteomics analysis of cortical tissues of the Shank3 mouse model of ASD with the focus on mitochondrial proteins and processes. The study was based on the SNOTRAP technology followed by systems biology analysis. This work revealed that 63 mitochondrial proteins were S-nitrosylated and that several mitochondria-related processes, including those associated with oxidative phosphorylation, oxidative stress, and apoptosis, were enriched. This study implies that aberrant SNO signaling induced by the Shank3 mutation can target a wide range of mitochondria-related proteins and processes that may contribute to the ASD pathology. It is the first study to investigate the role of NO-dependent mitochondrial functions in ASD.
This review focuses on the improved topical treatment of various medical skin conditions by the use of drugs delivered from carriers containing phospholipid soft vesicles. Topical drug delivery has many advantages over other ways of administration, having increased patient compliance, avoiding the first-pass effect following oral drug administration or not requesting multiple doses administration. However, the skin barrier prevents the access of the applied drug, affecting its therapeutic activity. Carriers containing phospholipid soft vesicles are a new approach to enhance drug delivery into the skin and to improve the treatment outcome. These vesicles contain molecules that have the property to fluidize the phospholipid bilayers generating the soft vesicle and allowing it to penetrate into the deep skin layers. Ethosomes, glycerosomes and transethosomes are soft vesicles containing ethanol, glycerol or a mixture of ethanol and a surfactant, respectively. We review a large number of publications on the research carried out in vitro, in vivo in animal models and in humans in clinical studies, with compositions containing various active molecules for treatment of skin medical conditions including skin infections, skin inflammation, psoriasis, skin cancer, acne vulgaris, hair loss, psoriasis and skin aging.
Leslie Rebibo, Connie Tam, Yan Sun, Eve Shoshani, Amit Badihi, Taher Nassar, and Simon Benita. 2021. “Topical tacrolimus nanocapsules eye drops for therapeutic effect enhancement in both anterior and posterior ocular inflammation models.” Journal of controlled release : official journal of the Controlled Release Society, 333, Pp. 283–297. Abstract
Tacrolimus has shown efficacy in eye inflammatory diseases. However, due to the drug lability, its formulation into a stable ophthalmic product remains a challenge. Tacrolimus-loaded nanocapsules (NCs) were designed for ocular instillation. Further, the stability and effects of the formulation were analyzed under different experimental conditions. Physicochemical characterization of the NCs revealed suitable homogeneous size and high encapsulation efficiency. Moreover, the lyophilized formulation was stable at ICH long term and accelerated storage conditions, for at least 18 and 3 months, respectively. The tacrolimus NCs did not elicit any eye irritation in rabbits after single- and multiple-dose applications. Additionally, ex vivo penetration assays on isolated porcine cornea and pharmacokinetics analyses in various rabbit eye compartments demonstrated the superiority of the NCs in retention and permeation into the anterior chamber of the eye compared to the free drug dissolved in oil. Moreover, multiple dose ocular instillation of the NCs in rats allowed high tacrolimus levels in the eye with very low plasma concentrations. Finally, the developed delivery system achieved a significant decrease in four typical inflammatory markers in a murine model of keratitis, an anterior chamber inflammation. Furthermore, these NCs, applied as eye drops, displayed clinical and histological efficacy in the mainly posterior chamber inflammation model of murine, experimental auto-immune uveitis.
Yuval Ramot, Michal Steiner, Netanel Amouyal, Yossi Lavie, Guy Klaiman, Abraham J. Domb, Abraham Nyska, and Tal Hagigit. 2021. “Treatment of contaminated radial fracture in sprague-dawley rats by application of a degradable polymer releasing gentamicin.” Journal of Toxicologic Pathology, 34, 1, Pp. 11–22. Abstract
Fracture-related infections remain a leading cause of morbidity and mortality. We aimed to establish a simple contaminated radial osteotomy model to assess the efficacy of a biodegradable polymer poly(sebacic-co-ricinoleic acid) [p(SA-RA)] containing 20% w/w gentamicin. A unilateral transverse osteotomy was induced in Sprague-Dawley (SD) rats, followed by application of Staphylococcus aureus suspension over the fracture. After successfully establishing the contaminated open fracture model, we treated the rats either systemically (intraperitoneal cefuroxime), locally with p(SA-RA) containing gentamicin, or both. Control groups included non-contaminated group and contaminated groups that were either untreated or treated with the polymer alone. After 4 weeks, the bones were subjected to micro-CT scanning and microbiological and histopathology evaluations. Micro-CT analysis revealed similar changes in the group subjected to both local and systemic treatment as in the non-contaminated control group. Lack of detectable bacterial growth was noted in most animals of the group subjected to both local and systemic treatment, and all samples were negative for S. aureus. Histopathological evaluation revealed that all treatment modalities containing antibiotics were highly effective in reducing infection and promoting callus repair, resulting in early bone healing. While p(SA-RA) containing gentamicin treatment showed better results than cefuroxime, the combination of local and systemic treatment displayed the highest therapeutic potential in this model.
Aparna Anand, Abhinay Sharma, Miriam Ravins, Debabrata Biswas, Poornima Ambalavanan, Kimberly Xuan Zhen Lim, Rachel Ying Min Tan, Atul Kumar Johri, Boaz Tirosh, and Emanuel Hanski. 2021. “Unfolded protein response inhibitors cure group A streptococcal necrotizing fasciitis by modulating host asparagine.” Science Translational Medicine, 13, 605, Pp. eabd7465. Abstract
Group A streptococcus (GAS) is among the top 10 causes of mortality from an infectious disease, producing mild to invasive life-threatening manifestations. Necrotizing fasciitis (NF) is characterized by a rapid GAS spread into fascial planes followed by extensive tissue destruction. Despite prompt treatments of antibiotic administration and tissue debridement, mortality from NF is still high. Moreover, there is no effective vaccine against GAS, and early diagnosis of NF is problematic because its clinical presentations are not specific. Thus, there is a genuine need for effective treatments against GAS NF. Previously, we reported that GAS induces endoplasmic reticulum (ER) stress to gain asparagine from the host. Here, we demonstrate that GAS-mediated asparagine induction and release occur through the PERK-eIF2$\alpha$-ATF4 branch of the unfolded protein response. Inhibitors of PERK or integrated stress response (ISR) blocked the formation and release of asparagine by infected mammalian cells, and exogenously added asparagine overcame this inhibition. Moreover, in a murine model of NF, we show that the inhibitors minimized mortality when mice were challenged with a lethal dose of GAS and reduced bacterial counts and lesion size when mice were challenged with a sublethal dose. Immunohistopathology studies demonstrated that PERK/ISR inhibitors protected mice by enabling neutrophil infiltration into GAS-infected fascia and reducing the pro-inflammatory response that causes tissue damage. Inhibitor treatment was also effective in mice when started at 12 hours after infection. We conclude that host metabolic alteration induced by PERK or ISR inhibitors is a promising therapeutic strategy to treat highly invasive GAS infections.
Roopesh Singh Gangwar, Hadas Pahima, Pier Giorgio Puzzovio, and Francesca Levi-Schaffer. 2021. “Update on Eosinophil Interaction with Mast Cells: The Allergic Effector Unit.” Methods in Molecular Biology, 2241, Pp. 221–242. Abstract
Mast cells and eosinophils are the key effector cells of allergy [1]. In general, allergic reactions are composed of two phases, namely an early phase and a late phase, and after that resolution occurs. If the allergic reactions fail to resolve after the late phase, allergic inflammation (AI) can evolve into a chronic phase mainly involving mast cells and eosinophils that abundantly coexist in the inflamed tissue in the late and chronic phases and cross-talk in a bidirectional manner. We defined these bidirectional interactions between MCs and Eos, as the “allergic effector unit.” This cross talk is mediated by both physical cell-cell contacts through cell surface receptors such as CD48, 2B4, and respective ligands and through released mediators such as various specific granular mediators, arachidonic acid metabolites, cytokines, and chemokines [2, 3]. The allergic effector unit can be studied in vitro in a customized co-culture system using mast cells and eosinophils derived from either mouse or human sources.