BM-MSCs alleviate diabetic nephropathy in male rats by regulating ER stress, oxidative stress, inflammation, and apoptotic pathways

Introduction: Diabetic nephropathy (DN), a chronic kidney disease, is a major cause of end-stage kidney disease worldwide. Mesenchymal stem cells (MSCs) have become a promising option to mitigate several diabetic complications. Methods: In this study, we evaluated the therapeutic potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) in a rat model of STZ-induced DN. After the confirmation of diabetes, rats were treated with BM-MSCs and sacrificed at week 12 after treatment. Results: Our results showed that STZ-induced DN rats had extensive histopathological changes, significant upregulation in mRNA expression of renal apoptotic markers, ER stress markers, inflammatory markers, fibronectin, and intermediate filament proteins, and reduction of positive immunostaining of PCNA and elevated P53 in kidney tissue compared to the control group. BM-MSC therapy significantly improved renal histopathological changes, reduced renal apoptosis, ER stress, inflammation, and intermediate filament proteins, as well as increased positive immunostaining of PCNA and reduced P53 in renal tissue compared to the STZ-induced DN group. Conclusion: In conclusion, our study indicates that BM-MSCs may have therapeutic potential for the treatment of DN and provide important insights into their potential use as a novel therapeutic approach for DN.

Sialyl LewisX/A and Cytokeratin Crosstalk in Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) encompasses multiple entities and is generally highly aggressive and metastatic. We aimed to determine the clinical and biological relevance of Sialyl-Lewis X and A (sLe^X/A)-a fucosylated glycan involved in metastasis-in TNBC. Here, we studied tissues from 50 TNBC patients, transcripts from a TNBC dataset from The Cancer Genome Atlas (TCGA) database, and a primary breast cancer cell line. All 50 TNBC tissue samples analysed expressed sLe^X/A. Patients with high expression of sLe^X/A had 3 years less disease-free survival than patients with lower expression. In tissue, sLe^X/A negatively correlated with cytokeratins 5/6 (CK5/6, which was corroborated by the inverse correlation between fucosyltransferases and CK5/6 genes. Our observations were confirmed in vitro when inhibition of sLe^X/A remarkably increased expression of CK5/6, followed by a decreased proliferation and invasion capacity. Among the reported glycoproteins bearing sLe^X/A and based on the STRING tool, α6 integrin showed the highest interaction score with CK5/6. This is the first report on the sLe^X/A expression in TNBC, highlighting its association with lower disease-free survival and its inverse crosstalk with CK5/6 with α6 integrin as a mediator. All in all, sLe^X/A is critical for TNBC malignancy and a potential prognosis biomarker and therapeutic target.

Neurofilament Light Chain (NfL) in Blood-A Biomarker Predicting Unfavourable Outcome in the Acute Phase and Improvement in the Late Phase after Stroke

Increased sensitivity of methods assessing the levels of neurofilament light chain (NfL), a neuron-specific intermediate filament protein, in human plasma or serum, has in recent years led to a number of studies addressing the utility of monitoring NfL in the blood of stroke patients. In this review, we discuss that elevated blood NfL levels after stroke may reflect several different neurobiological processes. In the acute and post-acute phase after stroke, high blood levels of NfL are associated with poor clinical outcome, and later on, the blood levels of NfL positively correlate with secondary neurodegeneration as assessed by MRI. Interestingly, increased blood levels of NfL in individuals who survived stroke for more than 10 months were shown to predict functional improvement in the late phase after stroke. Whereas in the acute phase after stroke the injured axons are assumed to be the main source of blood NfL, synaptic turnover and secondary neurodegeneration could be major contributors to blood NfL levels in the late phase after stroke. Elevated blood NfL levels after stroke should therefore be interpreted with caution. More studies addressing the clinical utility of blood NfL assessment in stroke patients are needed before the inclusion of NfL in the clinical workout as a useful biomarker in both the acute and the chronic phase after stroke.

Tramadol aggravates cardiovascular toxicity in a rat model of alcoholism: Involvement of intermediate microfilament proteins and immune-expressed osteopontin

Tramadol and alcohol are among commonly abused drugs. Although there are potential dangers reported upon their mixing, there are no previous reports describing this mixture's effects on the cardiovascular system (CVS). The aim was to study the effects of mixed alcohol and tramadol on the CVS of adult male rats. Fifty rats were divided into four groups: control, tramadol-treated group, alcohol-treated, and coadministration groups. Tramadol caused a significant increases in creatine kinase-MB, troponin I, malondialdehyde, protein carbonyl, 8-hydroxy-2'-deoxyguanosine, and a significant decrease in total antioxidant capacity with histological alterations in sections of the heart and aorta and a significant increase in the area% of collagen fibers while there was a nonsignificant difference in body weight, heart weight, heart weight/body weight ratio, lipid profile, tissue tumor necrosis factor-α and interferon-γ, intermediate microfilament proteins (IFPs) {desmin, vimentin, connexin43} gene expression, mean area% of elastic fibers in aortic tissue and osteopontin expression in cardiac and aortic tissue. Alcohol treatment caused a significant change in all the measured parameters and more damage in histological sections. The changes were highest in the coadministration group. There was a strong positive correlation between the area% of collagen fibers and vimentin gene expression, and the area% of osteopontin expression was positively correlated to connexin43 in cardiac and vascular tissue. Tramadol causes CVS injury mainly through oxidative stresses, while the alcohol effect is multifactorial; mixing both aggravates CVS injury. The study also highlights the role of IFPs and osteopontin-expression in inducing injury.

Filaments and phenotypes: cellular roles and orphan effects associated with mutations in cytoplasmic intermediate filament proteins

Cytoplasmic intermediate filaments (IFs) surround the nucleus and are often anchored at membrane sites to form effectively transcellular networks. Mutations in IF proteins (IFps) have revealed mechanical roles in epidermis, muscle, liver, and neurons. At the same time, there have been phenotypic surprises, illustrated by the ability to generate viable and fertile mice null for a number of IFp-encoding genes, including vimentin. Yet in humans, the vimentin ( VIM) gene displays a high probability of intolerance to loss-of-function mutations, indicating an essential role. A number of subtle and not so subtle IF-associated phenotypes have been identified, often linked to mechanical or metabolic stresses, some of which have been found to be ameliorated by the over-expression of molecular chaperones, suggesting that such phenotypes arise from what might be termed "orphan" effects as opposed to the absence of the IF network per se, an idea originally suggested by Toivola et al. and Pekny and Lane.

A novel desmin (DES) indel mutation causes severe atypical cardiomyopathy in combination with atrioventricular block and skeletal myopathy

Background

DES mutations cause different cardiac and skeletal myopathies. Most of them are missense mutations.

Methods

Using a next‐generation sequencing cardiac 174 gene panel, we identified a novel heterozygous in‐frame indel mutation (DES‐c.493_520del28insGCGT, p.Q165_A174delinsAS) in a Caucasian patient with cardiomyopathy in combination with atrioventricular block and skeletal myopathy. This indel mutation is located in the coding region of the first exon. Family anamnesis revealed a history of sudden cardiac death. We performed cell transfection experiments and in vitro assembly experiments to prove the pathogenicity of this novel DES indel mutation.

Results

These experiments revealed a severe filament formation defect of mutant desmin supporting the pathogenicity. In addition, we labeled a skeletal muscle biopsy from the mutation carrier revealing cytoplasmic desmin positive protein aggregates. In summary, we identified and functionally characterized a pathogenic DES indel mutation causing cardiac and skeletal myopathy.

Conclusion

Our study has relevance for the clinical and genetic interpretation of further DES indel mutations causing cardiac or skeletal myopathies and might be helpful for risk stratification.

The Cytoskeleton of Parabasalian Parasites Comprises Proteins that Share Properties Common to Intermediate Filament Proteins

Certain protist lineages bear cytoskeletal structures that are germane to them and define their individual group. Trichomonadida are excavate parasites united by a unique cytoskeletal framework, which includes tubulin-based structures such as the pelta and axostyle, but also other filaments such as the striated costa whose protein composition remains unknown. We determined the proteome of the detergent-resistant cytoskeleton of Tetratrichomonas gallinarum. 203 proteins with homology to Trichomonas vaginalis were identified, which contain significantly more long coiled-coil regions than control protein sets. Five candidates were shown to associate with previously described cytoskeletal structures including the costa and the expression of a single T. vaginalis protein in T. gallinarum induced the formation of accumulated, striated filaments. Our data suggests that filament-forming proteins of protists other than actin and tubulin share common structural properties with metazoan intermediate filament proteins, while not being homologous. These filament-forming proteins might have evolved many times independently in eukaryotes, or simultaneously in a common ancestor but with different evolutionary trajectories downstream in different phyla. The broad variety of filament-forming proteins uncovered, and with no homologs outside of the Trichomonadida, once more highlights the diverse nature of eukaryotic proteins with the ability to form unique cytoskeletal filaments.

Biomechanical characterization of myofibrillar myopathies

Myofibrillar myopathies (MFMs) are a group of sporadic and hereditary skeletal muscle diseases, which lead to severe physical disability and premature death. Most MFMs are caused by mutations in genes encoding desmin, plectin, VCP, filamin C, BAG3, FHL-1, αB-crystallin, DNAJB6, myotilin, and ZASP. Biomechanical studies on primary human myoblasts carrying desmin and plectin mutations showed increased stiffness and reduced mechanical stress tolerance i.e., higher mechanical vulnerability compared to control cells. Higher stiffness of mutant cells may lead to higher intracellular stress at physiologic stretch and shear deformation, which in turn could trigger muscle fiber degeneration.

Characterization of the chicken vimentin gene: single copy gene producing multiple mRNAs

Genomic clones and cDNA plasmids were isolated for the intermediate filament protein vimentin from chicken. The identity of the various clones was determined both by mRNA selection [Paterson, B. M. & Roberts, B. E. (1981) in Gene Amplification and Analysis, Structural Analysis or Nucleic Acids, eds. Chirikjian, J. G. & Papas, T. S. (Elsevier, North Holland), Vol. 2, pp. 418-435] and nucleotide sequence analysis. Restriction analysis, hybridization data, and heteroduplex studies confirmed that all of the genomic isolates contained overlapping fragments of an identical vimentin gene. No evidence for the existence of a second vimentin gene could be found by a Southern analysis either by using coding fragments from the purified vimentin gene or by using cDNA plasmids as probe. Likewise, copy-number experiments verified that the vimentin gene was present only once in the haploid chicken genome. However, in a RNA blot analysis, at least two equally abundant vimentin mRNA species of approximately 2,200 and 2,500 nucleotides in length were detected in all RNAs tested. Sequence analysis revealed that the vimentin gene contained two sets of tandem polyadenylylation sites, 249 and 532 nucleotides downstream from the stop codon for protein synthesis. It is proposed that the larger mRNA species arise because of complete transcription of the 3'-end of the vimentin gene (560 nucleotides of 3' nontranslated sequence), whereas the smaller mRNA species terminate after the first set of polyadenylylation sites.