Proteins In Mouse Model Research Articles

Iron-related Genes and Proteins Involved in Iron Homeostasis in Animal Models of Allergic Asthma: A Systematic Review.

The involvement of the immune oxidative stress response in the pathophysiology and pathogenesis of allergic asthma is well documented. However, reports on the role of iron homeostasis in allergic asthma is scarce. Therefore, this study aims to identify iron-related genes and proteins in mouse models of allergic asthma. Related articles were identified from SCOPUS and Web of Science databases. The article search was limited to publications in English, within a 10-year period (2014 - 2023, up to 16 August 2023) and original/research papers. All identified articles were screened for eligibility using the inclusion and exclusion criteria. All eligible articles were quality appraised prior to data extraction. Five studies were selected for data extraction. Based on the extracted data, three themes and seven subthemes related to iron homeostasis were identified. The type of samples and analytical methods used were also identified. In conclusion, our study elucidates that iron-related proteins are regulated in animal models of allergic asthma. However, the currently available data do not allow us to conclude whether the disease model resulted in iron accumulation or depletion. Therefore, further studies with other related markers should be conducted.

Nerve pathology is prevented by linker proteins in mouse models for LAMA2-related muscular dystrophy.

LAMA2-related muscular dystrophy (LAMA2 MD or MDC1A) is a devastating congenital muscular dystrophy that is caused by mutations in the LAMA2 gene encoding laminin-α2, the long chain of several heterotrimeric laminins. Laminins are essential components of the extracellular matrix that interface with underlying cells. The pathology of LAMA2 MD patients is dominated by an early-onset, severe muscular dystrophy that ultimately leads to death by respiratory insufficiency. However, pathology in nonmuscle tissues has been described. Prior work in the dyW /dyW mouse model for LAMA2 MD has shown that two linker proteins, mini-agrin and αLNNd, when expressed in skeletal muscle fibers, greatly increase survival from a few months up to more than 2 years. However, the restoration of skeletal muscle function accentuates the pathology in nonmuscle tissue in dyW /dyW mice, first and foremost in the peripheral nerve resulting in paralysis of the hind limbs. We now show that the expression of the two linker proteins in all tissues ameliorates the muscular dystrophy and prevents the appearance of the hind limb paralysis. Importantly, the same ameliorating effect of the linker proteins was seen in dy3K /dy3K mice, which represent the most severe mouse model of LAMA2 MD. In summary, these data show that the two linker proteins can compensate the loss of laminin-α2 in muscle and peripheral nerve, which are the two organs most affected in LAMA2 MD. These results are of key importance for designing appropriate expression constructs for mini-agrin and αLNNd to develop a gene therapy for LAMA2 MD patients.

Wound healing approach based on excretory-secretory product and lysate of liver flukes

Exogenous bioactive peptides are considered promising for the wound healing therapy in humans. In this regard, parasitic trematodes proteins may potentially become a new perspective agents. Foodborne trematode Opisthorchis felineus is widespread in Europe and has the ability to stimulate proliferation of bile duct epithelium. In this study, we investigated skin wound healing potential of O. felineus proteins in mouse model. C57Bl/6 mice were inflicted with superficial wounds with 8 mm diameter. Experimental groups included several non-specific controls and specific treatment groups (excretory-secretory product and lysate). After 10 days of the experiment, the percentage of wound healing in the specific treatment groups significantly exceeded the control values. We also found that wound treatment with excretory-secretory product and worm lysate resulted in: (i) inflammation reducing, (ii) vascular response modulating, (iii) type 1 collagen deposition promoting dermal ECM remodeling. An additional proteomic analysis of excretory-secretory product and worm lysate samples was revealed 111 common proteins. The obtained data indicate a high wound-healing potential of liver fluke proteins and open prospects for further research as new therapeutic approaches.

Rapid and specific degradation of endogenous proteins in mouse models using auxin-inducible degrons.

Auxin-inducible degrons are a chemical genetic tool for targeted protein degradation and are widely used to study protein function in cultured mammalian cells. Here, we develop CRISPR-engineered mouse lines that enable rapid and highly specific degradation of tagged endogenous proteins in vivo. Most but not all cell types are competent for degradation. By combining ligand titrations with genetic crosses to generate animals with different allelic combinations, we show that degradation kinetics depend upon the dose of the tagged protein, ligand, and the E3 ligase substrate receptor TIR1. Rapid degradation of condensin I and II - two essential regulators of mitotic chromosome structure - revealed that both complexes are individually required for cell division in precursor lymphocytes, but not in their differentiated peripheral lymphocyte derivatives. This generalisable approach provides unprecedented temporal control over the dose of endogenous proteins in mouse models, with implications for studying essential biological pathways and modelling drug activity in mammalian tissues.

Targeted Transcriptomic Screen of Pneumococcal Genes Expressed during Murine and Human Infection.

The advent of pneumococcal conjugate vaccines led to the near disappearance of most of the included serotypes in high-income settings but also the rise of nonvaccine-type colonization and disease. Alternative strategies, using genetically conserved proteins as antigens, have been evaluated preclinically and clinically for years, so far unsuccessfully. One possible explanation for the failure of these efforts is that the choice of antigens may not have been sufficiently guided by an understanding of the gene expression pattern in the context of infection. Here, we present a targeted transcriptomic analysis of 160 pneumococcal genes encoding bacterial surface-exposed proteins in mouse models, human colonization, and human meningitis. We present the overlap of these different transcriptomic profiles. We identify two bacterial genes that are highly expressed in the context of mouse and human infection: SP_0282, an IID component of a mannose phosphotransferase system (PTS), and SP_1739, encoding RNase Y. We show that these two proteins can confer protection against pneumococcal nasopharyngeal colonization and intraperitoneal challenge in a murine model and generate opsonophagocytic antibodies. This study emphasizes and confirms the importance of studies of pneumococcal gene expression of bacterial surface proteins during human infection and colonization and may pave the way for the selection of a protein-based vaccine candidate.

Multidimensional Dynamics of the Proteome in the Neurodegenerative and Aging Mammalian Brain

The amount of any given protein in the brain is determined by the rates of its synthesis and destruction, which are regulated by different cellular mechanisms. Here, we combine metabolic labeling in live mice with global proteomic profiling to simultaneously quantify both the flux and amount of proteins in mouse models of neurodegeneration. In multiple models, protein turnover increases were associated with increasing pathology. This method distinguishes changes in protein expression mediated by synthesis from those mediated by degradation. In the AppNL-F knockin mouse model of Alzheimer’s disease, increased turnover resulted from imbalances in both synthesis and degradation, converging on proteins associated with synaptic vesicle recycling (Dnm1, Cltc, Rims1) and mitochondria (Fis1, Ndufv1). In contrast to disease models, aging in wild-type mice caused a widespread decrease in protein recycling associated with a decrease in autophagic flux. Overall, this simple multidimensional approach enables a comprehensive mapping of proteome dynamics and identifies affected proteins in mouse models of disease and other live animal test settings.

Trefoil Factor Family: A Troika for Lung Repair and Regeneration.

Tissue damage in the upper and lower airways caused by mechanical abrasion, noxious chemicals, or pathogenic organisms must be followed by rapid restorative processes; otherwise, persistent immunopathology and disease may ensue. This review will discuss evidence for the important role served by trefoil factor (TFF) family members in healthy and diseased airways of humans and rodents. Collectively, these peptides serve to both maintain and restore homeostasis through their regulation of the mucous layer and their control of cell motility, cell differentiation, and immune function in the upper and lower airways. We will also discuss important differences in which trefoil member tracks with homeostasis and disease between humans and mice, which poses a challenge for research in this area. Moreover, we discuss new evidence supporting newly identified receptor binding partners in the leucine-rich repeat and immunoglobulin-like domain-containing NoGo (LINGO) family in mediating the biological effects of TFF proteins in mouse models of epithelial repair and infection. Recent advances in our knowledge regarding TFF peptides suggest that they may be reasonable therapeutic targets in the treatment of upper and lower airway diseases of diverse etiologies. Further work understanding their role in airway homeostasis, repair, and inflammation will benefit from these newly uncovered receptor-ligand interactions.

Rutin inhibited the advanced glycation end products-stimulated inflammatory response and extra-cellular matrix degeneration via targeting TRAF-6 and BCL-2 proteins in mouse model of osteoarthritis.

Background: Osteoarthritis (OA) is degenerative joint disorder mainly characterized by long-term pain with limited activity of joints, the disease has no effective preventative therapy. Rutin (RUT) is a flavonoid compound, present naturally. The flavonoid shows range of biological activities such as anti-inflammatory and anti-cancer effect. We screened RUT for its activity against osteoarthritis with in vivo and in vitro models of osteoarthritis.Methods: Animal model of OA was developed using C57BL/6 mice by surgical destabilization of medial meniscus. For in vitro studies the human articular cartilage tissues were used which were collected from osteoarthritis patients and were processed to isolate chondrocytes. The chondrocytes were submitted to advanced glycation end products (AGEs) for inducing osteoarthritis in vitro. Cell viability was done by CCK-8 assay, ELISA analysis for MMP13, collage II, PGE2, IL-6, TNF-α, ADAMTS-5 and MMP-13. Western blot analysis was done for expression of proteins and in silico analysis was done by docking studies.Results: Pretreatment of RT showed no cytotoxic effect and also ameliorated the AGE mediated inflammatory reaction on human chondrocytes in vitro. Treatment of RT inhibited the levels of COX-2 and iNOS in AGE exposed chondrocytes. RT decreased the AGE mediated up-regulation of IL-6, NO, TNF-α and PGE-2 in a dose dependent manner. Pretreatment of RT decreased the extracellular matrix degradation, inhibited expression of TRAF-6 and BCL-2 the NF-κB/MAPK pathway proteins. The treatment of RT in mice prevented the calcification of cartilage tissues, loss of proteoglycans and also halted the narrowing of joint space is mice subjected to osteoarthritis. The in-silico analysis suggested potential binding affinity of RT with TRAF-6 and BCL-2.Conclusion: In brief RT inhibited AGE-induced inflammatory reaction and also degradation of ECM via targeting the NF-κB/MAPK pathway proteins BCL-2 and TRAF-6. RT can be a potential molecule in treating OA.

1272. Efficacy of a Non-Peptide, Small Molecule Mimic of Host Defense Proteins in Mouse Models of Disseminated Candidiasis and Aspergillosis

BackgroundWe are developing a series of small nonpeptide mimics of host defense proteins (smHDPs) for antifungal applications. MICs < 0.1 µg/ ml have been demonstrated against multiple yeast and mold species. Their potential therapeutic utility has been evaluated in animal models of disseminated fungal infections.MethodsSusceptibility testing against clinical isolates of Candida albicans (CA) and Aspergillus fumigatus (AF) was done according to CLSI guidelines. Cytotoxicity (CC50) in mouse 3T3 and human HepG2 cells was determined in an MTS assay (Promega Cell Titer 96). For candidiasis, neutropenic CD-1 mice were infected IV with 3.5 x 104 CFU CA and test agents were administered subcutaneously (SC) once (QD) or twice (BID) daily beginning 2 hrs post-infection (PI). The positive control was fluconazole (20 mg/kg PO QD). Kidney burdens were measured at 24 hrs PI (n = 5/grp) and survival was measured at 2 weeks after 5 days of treatment (n = 8/grp). For aspergillosis, neutropenic CD-1 mice were infected IV with 4.5 log10 spores AF and test agents were administered SC BID for 5 days beginning 24 hrs PI. The positive control was posaconazole (20 mg/kg PO QD). Liver and kidney fungal burdens were measured 24 hrs after the last dose (n = 10/grp).ResultsThe lead smHDP, FC-5096, has MICs of 0.08 and 0.024 ug/ml, respectively, against the CA and AF clinical isolate strains used in the mouse efficacy studies. Selectivity for antifungal vs. mammalian cell cytotoxicity (MIC/CC50) was >1,000 fold. In the disseminated candidiasis model, FC-5096 significantly reduced fungal kidney burdens relative to untreated mice to levels found at treatment onset (P < 0.0001). Full survival over 2 weeks was observed after 5 days of BID treatment with FC-5096. All untreated mice succumbed between days 3 – 6 PI. Efficacy was comparable to fluconazole. In the disseminated aspergillosis model, FC-5096 produced up to 2.5 log10 reductions in fungal liver burdens and efficacy was significantly better than posaconazole (P = 0.0251). In kidney, both FC-5096 and posaconazole caused > 1.6 log10 reductions in fungal burdens that exceeded the limit of detection.ConclusionThe high antifungal potency, low cytotoxicity and robust in vivo efficacy support further study of FC-5096 for clinical development.DisclosuresRichard W. Scott, PhD, Fox Chase Chemical Diversity Center (Employee) Simon DP Baugh, PhD, Fox Chase Chemical Diversity Center (Employee) Mark E Pulse, MS, Fox Chase Chemical Diversity Center (Independent Contractor)

DPP4 inhibitor reinforces cell junction proteins in mouse model of short bowel syndrome.

Bacterial overgrowth commonly occurs and favors bacterial translocation in short bowel syndrome (SBS). Glucagon-like peptide-2 (GLP-2) is effective for treating SBS, but is rapidly inactivated by dipeptidyl peptidase IV (DPP4). DPP4 inhibitor (DPP4I) is known to be effective for treating SBS. Here, we investigated cell junction protein function following DPP4I administration in a mouse model of SBS. Mice were divided into four groups: naïve (n = 5), naïve + DPP4I (n = 6), control (n = 6), and DPP4I (n = 5). All control and DPP4I mice had 50% of their proximal small bowel resected. DPP4I or normal saline was administered orally twice daily from days 1-7 postoperatively. The functions of cell junction proteins were assessed by RT-PCR and immunohistochemistry. Body weights and blood glucose levels were recorded. E-Cadherin was significantly higher in the DPP4I group than in the control group. E-Cadherin, occludin, and claudin-4 were significantly higher in the naïve group than in the control group. Positive staining for E-cadherin and occludin varied widely between the control and DPP4I groups. Up-regulation of E-cadherin and occludin by DPP4I may be correlated with the anti-inflammatory action of DPP4I. Therefore, DPP4I may reduce bacterial translocation in SBS.

Multidimensional Dynamics of the Proteome in the Neurodegenerating and Ageing Mammalian Brain

The amount of any given protein in the brain is determined by the rates of its synthesis and destruction, which are regulated by different cellular mechanisms. Here, we combine metabolic labelling in live mice with global proteomic profiling to simultaneously quantify both the flux and amount of proteins in mouse models of neurodegeneration. In multiple models, protein turnover increases were associated with increasing pathology. This method distinguishes changes in protein expression mediated by synthesis from those mediated by degradation. In the AppNL-F knockin mouse model of Alzheimer’s disease increased turnover resulted from imbalances in both synthesis and degradation, converging on proteins associated with synaptic vesicle recycling (Dnm1, Cltc, Rims1) and mitochondria (Fis1, Ndufv1). In contrast to disease models, ageing in wildtype mice caused a widespread decrease in protein recycling associated with a decrease in autophagic flux. This simple multidimensional approach enables the comprehensive mapping of proteome dynamics and identifies affected proteins in mouse models of disease and other live animal test settings.

The Physiology of Homeoprotein Transduction.

The homeoprotein family comprises ~300 transcription factors and was long seen as primarily involved in developmental programs through cell autonomous regulation. However, recent evidence reveals that many of these factors are also expressed in the adult where they exert physiological functions not yet fully deciphered. Furthermore, the DNA-binding domain of most homeoproteins contains two signal sequences allowing their secretion and internalization, thus intercellular transfer. This review focuses on this new-found signaling in cell migration, axon guidance, and cerebral cortex physiological homeostasis and speculates on how it may play important roles in early arealization of the neuroepithelium. It also describes the use of homeoproteins as therapeutic proteins in mouse models of diseases affecting the central nervous system, in particular Parkinson disease and glaucoma.

Abstract 302: A novel epigenetic pathway in medulloblastoma

Abstract Medulloblastoma is the most common malignant pediatric brain tumor with variable prognosis due to its clinical and genomic heterogeneity. Despite recent treatment advances, approximately 40% of children experience tumour recurrence, and 30% will die from this disease. Therefore there is a need to develop novel therapies for patients. We recently reported that Casein kinase 1δ (CK1δ) may be an attractive therapeutic target for medulloblastoma. CK1δ is a serine/threonine kinase that controls cell cycle progression, signal transduction and neurogenesis. We found high levels of CK1δ protein in mouse models of medulloblastoma and human medulloblastoma samples. Furthermore, CK1δ inhibition dramatically reduced medulloblastoma tumor progression. We demonstrate here that CK1δ phosphorylates the epigenetic reader bromodomain-containing protein 4 (BRD4). BRD4 has been identified as a therapeutic target in several cancers, including medulloblastoma. We demonstrate that CK1δ phosphorylates BRD4 and that CK1δ is required for BRD4 binding to the Gli1 promoter in vitro and in vivo. Furthermore, combined CK1δ/BRD4 inhibition is a novel means of reducing medulloblastoma growth downstream of SUFU and SMO. These studies define a novel therapeutic means of inhibiting SMO inhibitor resistant medulloblastoma. Citation Format: Nagi Ayad, Clara Penas. A novel epigenetic pathway in medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 302. doi:10.1158/1538-7445.AM2017-302

Critical role of c-jun N-terminal protein kinase in promoting mitochondrial dysfunction and acute liver injury

The mechanism by which c-Jun N-terminal protein kinase (JNK) promotes tissue injury is poorly understood. Thus we aimed at studying the roles of JNK and its phospho-target proteins in mouse models of acute liver injury. Young male mice were exposed to a single dose of CCl4 (50mg/kg, IP) and euthanized at different time points. Liver histology, blood alanine aminotransferase, and other enzyme activities were measured in CCl4-exposed mice without or with the highly-specific JNK inhibitors. Phosphoproteins were purified from control or CCl4-exposed mice and analyzed by differential mass-spectrometry followed by further characterizations of immunoprecipitation and activity measurements. JNK was activated within 1h while liver damage was maximal at 24h post-CCl4 injection. Markedly increased phosphorylation of many mitochondrial proteins was observed between 1 and 8h following CCl4 exposure. Pretreatment with the selective JNK inhibitor SU3327 or the mitochondria-targeted antioxidant mito-TEMPO markedly reduced the levels of p-JNK, mitochondrial phosphoproteins and liver damage in CCl4-exposed mice. Differential proteomic analysis identified many phosphorylated mitochondrial proteins involved in anti-oxidant defense, electron transfer, energy supply, fatty acid oxidation, etc. Aldehyde dehydrogenase, NADH-ubiquinone oxidoreductase, and α-ketoglutarate dehydrogenase were phosphorylated in CCl4-exposed mice but dephosphorylated after SU3327 pretreatment. Consistently, the suppressed activities of these enzymes were restored by SU3327 pretreatment in CCl4-exposed mice. These data provide a novel mechanism by which JNK, rapidly activated by CCl4, promotes mitochondrial dysfunction and acute hepatotoxicity through robust phosphorylation of numerous mitochondrial proteins.

Editorial: Targeting MYCN in Pediatric Cancers.

MYCN is the product of a gene frequently deregulated in childhood tumors that belongs to a small but very famous family of transcription factors whose prototype member is c-MYC. The other member of the family is L-MYC, identified as a gene amplified in a subset of lung cancers. c-MYC is widely expressed in normal tissues, is the most deregulated protooncogene in human cancer, and not surprisingly, it is the subject of intensive investigations in many laboratories worldwide. Clearly, decoding its function in tumorigenesis and finding ways of inhibiting its oncogenic activity would have a very large impact in terms of human health. In contrast to the broad significance of c-MYC, the expression of MYCN is temporally and spatially restricted during embryonal development, being detected mostly in cells of the developing nervous system. This more limited function is also reflected in human pathology, with only a few types of tumors presenting alterations of MYCN. These cancers arise in the nervous system, both central and peripheral, manifesting as medulloblastomas, gliomas, and neuroblastomas. Despite the fact that MYCN-positive tumors are relatively rare, their very aggressive nature and the pediatric setting make therapeutic treatments a clinical challenge.

Ventricular L-Type Ca2+ Channels and Expression of RGK Proteins in Mouse Models Associated with Diabetes

Background: In a diabetic mouse model (db/db) we have shown reduced ICaL density with unchanged single-channel activity and reduced expression of the LTCC pore Cav1.2 (Pereira et al., Diabetes 2006;55:608-15). Of note, LTCC expression and function can be decreased by RGK proteins, including the diabetes-associated protein Rad. Aim of the study: In the present study, we investigate the association between cardiac Rad expression with the expression and function of ventricular LTCC in two mouse models with diabetes-related metabolic disturbances (leptin-deficient obese ob/ob mice and insulin receptor substrate 2 deficient IRS2-k.o. mice). Methods: We obtained expression of Rad and Cav1.2 protein (Western-blot) and mRNA (qRT-PCR) in murine ventricles and recorded whole-cell ICaL in freshly isolated ventricular myocytes. Results: The only significant change at the mRNA level was an increased Rad expression in IRS2-k.o. mice at 16 weeks of age (206±17%). In line with this finding ICaL density was significantly decreased (IRS2-k.o.: −7.8±0.8 pA/pF; wildtype: −10.9±0.9 pA/pF). At an age of 28 weeks, we found expression of both Rad and Cav1.2 protein to be significantly increased in ventricles from ob/ob mice compared to age-matched widtypes (273±23% and 159±14%, respectively) while ICaL density was unchanged (ob/ob: −8.4±0.4 pA/pF; wildtype: −8.9±0.5 pA/pF). Summary and discussion: Our data support the idea of Rad being involved in regulation of ICaL in diabetes. Regarding ICaL Rad seems to act either causal (ICaL decrease in IRS2-k.o. at 16 weeks) or compensatory (increased Cav1.2 expression but unchanged ICaL in ob/ob at 28 weeks). Differences observed between the two investigated diabetic mouse models might be explained by differences in the underlying pathomechanisms (lack of IRS2 vs. leptin deficiency, respectively).

Calcium-activated chloride channels anoctamin 1 and 2 promote murine uterine smooth muscle contractility

To determine the presence of calcium activated chloride channels anoctamin 1 (ANO1) and 2 (ANO2) in human and murine uterine smooth muscle (MUSM) and evaluate the physiologic role for these ion channels in murine myometrial contractility. We performed reverse transcription polymerase chain reaction to determine whether ANO1 and 2 are expressed in human and murine uterine tissue to validate the study of this protein in mouse models. Immunohistochemical staining of ANO1 and 2 was then performed to determine protein expression in murine myometrial tissue. The function of ANO1 and 2 in murine uterine tissue was evaluated using electrophysiologic studies, organ bath, and calcium flux experiments. ANO1 and 2 are expressed in human and MUSM cells. Functional studies show that selective antagonism of these channels promotes relaxation of spontaneous MUSM contractions. Blockade of ANO1 and 2 inhibits both agonist-induced and spontaneous transient inward currents and abolishes G-protein coupled receptor (oxytocin) mediated elevations in intracellular calcium. The calcium activated chloride channels ANO1 and 2 are present in human and murine myometrial tissue and may provide novel potential therapeutic targets to achieve effective tocolysis.

Early onset muscle weakness and disruption of muscle proteins in mouse models of spinal muscular atrophy

BackgroundThe childhood neuromuscular disease spinal muscular atrophy (SMA) is caused by mutations or deletions of the survival motor neuron (SMN1) gene. Although SMA has traditionally been considered a motor neuron disease, the muscle-specific requirement for SMN has never been fully defined. Therefore, the purpose of this study was to investigate muscle defects in mouse models of SMA.MethodsWe have taken advantage of two different mouse models of SMA, the severe Smn-/-;SMN2 mice and the less severe Smn2B/- mice. We have measured the maximal force produced from control muscles and those of SMA model mice by direct stimulation using an ex vivo apparatus. Immunofluorescence and immunoblot experiments were performed to uncover muscle defects in mouse models of SMA. Means from control and SMA model mice samples were compared using an analysis of variance test and Student’s t tests.ResultsWe report that tibialis anterior (TA) muscles of phenotype stage Smn-/-;SMN2 mice generate 39% less maximal force than muscles from control mice, independently of aberrant motor neuron signal transmission. In addition, during muscle fatigue, the Smn-/-;SMN2 muscle shows early onset and increased unstimulated force compared with controls. Moreover, we demonstrate a significant decrease in force production in muscles from pre-symptomatic Smn-/-;SMN2 and Smn2B/- mice, indicating that muscle weakness is an early event occurring prior to any overt motor neuron loss and muscle denervation. Muscle weakness in mouse models of SMA was associated with a delay in the transition from neonatal to adult isoforms of proteins important for proper muscle contractions, such as ryanodine receptors and sodium channels. Immunoblot analyses of extracts from hindlimb skeletal muscle revealed aberrant levels of the sarcoplasmic reticulum Ca2+ ATPase.ConclusionsThe findings from this study reveal a delay in the appearance of mature isoforms of proteins important for muscle contractions, as well as muscle weakness early in the disease etiology, thus highlighting the contributions of skeletal muscle defects to the SMA phenotype.

Homeoprotein Signaling in Development, Health, and Disease: A Shaking of Dogmas Offers Challenges and Promises from Bench to Bed

Homeoproteins constitute a major class of transcription factors active throughout development and in adulthood. Their membrane transduction properties were discovered over 20 years ago, opening an original field of research in the domain of vector peptides and signal transduction. In early development, homeoprotein transfer participates in tissue patterning, cell/axon guidance, and migration. In the axon guidance model, homeoproteins exert their non-cell autonomous activity through the regulation of translation, in particular, that of nuclear-transcribed mitochondrial mRNAs. An important aspect of these studies on patterning and migration is that homeoproteins sensitize the cells to the action of other growth factors, thus cooperating with established signaling pathways. The role of homeoprotein signaling at later developmental stages is also of interest. In particular, the transfer of homeoprotein Otx2 into parvalbumin-expressing inhibitory neurons (PV-cells) in the visual cortex regulates cortical plasticity. The molecular deciphering of the interaction of Otx2 with binding sites at the surface of PV-cells has allowed the development of a specific Otx2 antagonist that reopens plasticity in the adult cortex and cures mice from experimental amblyopia, a neurodevelopmental disease. Finally, the use of homeoproteins as therapeutic proteins in mouse models of glaucoma and Parkinson disease is reviewed. In the latter case, engrailed homeoproteins protect mesencephalic dopaminergic neurons by increasing the local translation of complex I mitochondrial mRNAs. In conclusion, this review synthesizes 20 years of work on the fundamental and potentially translational aspects of homeoprotein signaling.

Proteolytic breakdown of cytoskeleton induces neurodegeneration during pathology of murine cerebral malaria

Fatal murine cerebral malaria is known to induce cellular degeneration by altering cellular morphology and integrity of cell. The morphology and integrity of the cell mainly depends on the cytoskeletal network of the cell. Increased proteolysis of cytoskeletal proteins accompanied by aggravated suicidal proteases activation leads to cellular degeneration. In the present study, we investigated the roles of apoptotic and necrotic cell death proteases, caspase-3, calpain-1 and cathepsin-b in the proteolysis of neuronal cytoskeletal proteins in mouse model of fatal cerebral malaria. We found increased levels of calpain-1, cathepsin-b and caspase-3, with extensive cross talks between these suicidal proteases. Increased levels of these proteases correlated with the enhanced proteolysis of several cytoskeletal proteins including neuronal cytoskeleton proteolytic signature fragments. Further, we also observed that increased levels of these proteases correlated with the appearance of neuronal death that exhibited apo-necrotic continuum. Our results confirm that activation of multiple suicidal proteases, their cross talks and breakdown of the cytoskeletal proteins increase neuronal degeneration and lead to exacerbation of cerebral malaria pathology.