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Small Heat Shock Proteins are considered as the first line of defense when proteostasis fails. Among them, αB-crystallin is expressed in striated muscles in which it interacts with desmin intermediate filaments to stabilize them, maintaining cytoskeleton's integrity and muscular functionalities. Desmin is a key actor for muscle health; its targeting by αB-crystallin is thus crucial, especially in stress conditions. αB-crystallin is phosphorylated and O-GlcNAcylated. Its phosphorylation increases consecutively to various stresses, correlated with its recruitment for cytoskeleton's safeguarding. However, phosphorylation as unique signal for cytoskeleton translocation remains controversial; indeed, O-GlcNAcylation was also proposed to be involved. Thus, there are still some gaps for a deeper comprehension of how αB-crystallin functions are finely regulated by post-translational modifications. Furthermore, desmin also bears both post-translational modifications; while desmin phosphorylation is closely linked to desmin intermediates filaments turnover, it is unclear whereas its O-GlcNAcylation could impact its proper function. In the herein paper, we aim at identifying whether phosphorylation and/or O-GlcNAcylation are involved in αB-crystallin targeting towards cytoskeleton in proteotoxic stress induced by proteasome inhibition in C2C12 myotubes. We demonstrated that proteotoxicity led to αB-crystallin's phosphorylation and O-GlcNAcylation patterns changes, both presenting a dynamic interplay depending on protein subfraction. Importantly, both post-translational modifications showed a spatio-temporal variation correlated with αB-crystallin translocation towards cytoskeleton. In contrast, we did not detect any change of desmin phosphorylation and O-GlcNAcylation. All together, these data strongly support that αB-crystallin phosphorylation/O-GlcNAcylation interplay rather than changes on desmin is a key regulator for its cytoskeleton translocation, preserving it towards stress. [Display omitted] • Small Heat Shock Proteins (sHSPs) are the first line of defense when proteostasis failed in stressful conditions. • The MG132-induced proteotoxicity modifies O-GlcNAcylation/phosphorylation patterns of αB-crystallin. • The MG132-induced proteotoxicity does not modify the O-GlcNAcylation/phosphorylation patterns of desmin. • Phosphorylation/O-GlcNAcylation of αB-crystallin spatio-temporally varies along proteotoxic stress. • Phosphorylation/O-GlcNAcylation interplay is a key regulator of αB-crystallin cytoskeleton translocation. [ABSTRACT FROM AUTHOR]

The identification of non-hematopoietic cells in effusions is a diagnostic challenge in cytology. Biopsies from mesothelium or primary lesions are infrequently performed in clinical settings and immunochemistry on smears or immunohistochemistry on cell blocks are the most common ancillary test to refine the cytological diagnosis. Cavitary effusions are an ideal matrix for flow cytometry and the availability of a cytometric panel to describe non-hematopoietic cells would represent a useful tool. Here we present the results of the flow cytometric and immunohistochemical determination of cytokeratin (CK), vimentin (VIM) and desmin (DES) in 36 canine effusions. The concordance between the two methods was perfect for CK (100%), substantial for VIM (77.8%), and almost perfect for DES (97.2%). The panel was interpreted to define the epithelial (CK+VIM-DES-), mesothelial (CK+VIM+DES+), or mesenchymal (CK-VIM+DES-) origin of the cells. Unexpected profiles were considered doubtful and observed patterns were individually discussed. The concordance of the panel interpretation between two methods was 75%. The evaluation of discordant and doubtful cases suggests a lower sensitivity of flow cytometry in detecting VIM expression and revealed a high frequency of VIM+ epithelial cells, variable expression of VIM in mesothelial cells, and an important role of DES in excluding an epithelial origin when positive. Multicentric studies based on histopathological diagnoses are necessary to confirm these findings and evaluate the diagnostic utility of the panel to refine cytological diagnosis. Our results show that flow cytometry can be a timesaving alternative to IHC on cell blocks in clinical settings to detect CK, VIM and DES expression. The interpretation of the panel is similar in most cases; however, occasional discordant results, particularly for VIM, may occur. [ABSTRACT FROM AUTHOR]

Abstract Desmin intermediate filaments play a crucial role in stress transmission and mechano-protection. The loss of its integrity triggers myofibril breakdown and muscle atrophy for which desmin phosphorylation (pDes) is a priming factor. We investigated whether eccentric accentuated resistance exercise (RE) influences the regulation of pDes, effecting its susceptibility to cleavage. Ten healthy persons performed 14 RE-sessions (2 per week). Muscle biopsies were collected in both untrained and trained conditions at rest (pre 1, pre 14) and one hour after RE (post 1, post 14). Western blotting and immunohistochemistry were utilized to assess desmin content, phosphorylation at several sites and susceptibility to cleavage. In untrained condition (pre 1, post 1), RE induced dephosphorylation of serin 31 and 60. Trained muscle exhibited more pronounced dephosphorylation at Serin 31 post-RE. Dephosphorylation was accompanied by reduced susceptibility of desmin to cleavage. Additionally, training increased total desmin content, upregulated baseline serine 31 phosphorylation and attenuated pDes at serine 60 and threonine 17. Our findings suggest that acute and repeated RE changes the phosphorylation pattern of desmin and its susceptibility to cleavage, highlighting pDes as an adaptive mechanism in skeletal muscle, contributing to the proteostatic regulation in response to recurring stress.

Abstract Aging enhances numerous processes that compromise homeostasis and pathophysiological processes. Among these, activated HSCs play a pivotal role in advancing liver fibrosis. This research delved into how aging impacts liver fibrosis mechanisms. The study involved 32 albino rats categorized into four groups: Group I (young controls), Group II (young with liver fibrosis), Group III (old controls), and Group IV (old with liver fibrosis). Various parameters including serum ALT, adiponectin, leptin, and cholesterol levels were evaluated. Histopathological analysis was performed, alongside assessments of TGF-β, FOXP3, and CD133 gene expressions. Markers of fibrosis and apoptosis were the highest in group IV. Adiponectin levels significantly decreased in Group IV compared to all other groups except Group II, while cholesterol levels were significantly higher in liver fibrosis groups than their respective control groups. Group III displayed high hepatic expression of desmin, α-SMA, GFAP and TGF- β and in contrast to Group I. Increased TGF-β and FOXP3 gene expressions were observed in Group IV relative to Group II, while CD133 gene expression decreased in Group IV compared to Group II. In conclusion, aging modulates immune responses, impairs regenerative capacities via HSC activation, and influences adipokine and cholesterol levels, elevating the susceptibility to liver fibrosis.

• We report a recurrent intronic homozygous c.1023+5G> A desmin mutation in indian patients. • Second report of recessive desminopathy associated with mixed limb girdle CMS – myofibrillar myopathy. • Partial loss of desmin leading to NMJ dysfunction and CMS phenotype. • Leaky splice site with intron retention leads to partial desmin loss. Recessive desminopathies are rare and often present as severe early-onset myopathy. Here we report a milder phenotype in three unrelated patients from southern India (2 M, 1F) aged 16, 21, and 22 years, who presented with childhood-onset, gradually progressive, fatigable limb-girdle weakness, ptosis, speech and swallowing difficulties, without cardiac involvement. Serum creatine kinase was elevated, and repetitive nerve stimulation showed decrement in all. Clinical improvement was noted with pyridostigmine and salbutamol in two patients. All three patients had a homozygous substitution in intron 5: DES(NM_001927.4):c.1023+5G> A , predicted to cause a donor splice site defect. Muscle biopsy with ultrastructural analysis suggested myopathy with myofibrillar disarray, and immunohistochemistry showed partial loss of desmin with some residual staining, while western blot analysis showed reduced desmin. RT-PCR of patient muscle RNA revealed two transcripts: a reduced normal desmin transcript and a larger abnormal transcript suggesting leaky splicing at the intron 5 donor site. Sequencing of the PCR products confirmed the inclusion of intron 5 in the longer transcript, predicted to cause a premature stop codon. Thus, we provide evidence for a leaky splice site causing partial loss of desmin associated with a unique phenotypic presentation of a milder form of desmin-related recessive myopathy overlapping with congenital myasthenic syndrome. [ABSTRACT FROM AUTHOR]

Cotyledonoid Dissecting Leiomyoma is a rare condition that can be presented as a malignant tumor and may be challenging to diagnose for gynecologists, radiologists and pathologists. We report a case of this tumor in a 40-year-old woman better to understand its clinical, surgical and pathologic features and explore its diagnostic and treatment aspects. The patient presented with chronic suprapubic pain for over two years, while the clinical, radiological and surgical findings were worrisome. In our case, the histopathological examination did not reveal any malignant features, confirming the benign nature of CDL. Positive staining for desmin and caldesmon confirmed the smooth muscle nature of this tumor, and the absence of coagulative tumor cell necrosis, nuclear atypia and absence of increased mitotic activity ruled out leiomyosarcoma. This rare case report provides distinctive patient's clinical presentation, diagnostic workup, surgical intervention and histopathological findings. [ABSTRACT FROM AUTHOR]

Nestin is a unique intermediate filament expressed for a short period in the developing heart. It was also documented in several cell types of the adult myocardium under pathological conditions such as myocardial infarction or fibrosis. However, circumstances of nestin re-occurrence in the diseased or aging heart have not been elucidated yet. In this work we immunohistochemically detected nestin to determine its expression and distribution pattern in the left ventricular myocardium of normotensive Wistar Kyoto (WKY) rats and in the hypertrophic ones of spontaneously hypertensive (SHR) rats, both at the age of 1 and 1.5 year. No nestin+ cells were identified in the intact myocardium of 1-year-old WKY rats, whereas in the aged 1.5-year-old WKY rats nestin+ endothelial cells in some blood vessels were discovered. In the hypertrophic myocardium of all SHR rats, nestin was rarely detected in desmin+ vimentin− cardiomyocytes and in some vimentin+ interstitial cells often accumulated in clusters, varying in intensity of desmin immunoreactivity. Moreover, nestin was infrequently expressed in the endothelial cells of some myocardial blood vessels in 1-year-old SHR rats, but not in 1.5-year-old ones. Quantitative image analysis of nestin expression in the myocardium confirmed significant increase in 1.5-year-old WKY rats and in SHR rats of both ages compared to the intact 1-year-old WKY rats. This study firstly documents nestin re-expression indicating cytoskeletal remodelling in different cell types of the aging intact and chronically pressure over-loaded hypertrophied myocardium. Our findings confirm nestin involvement in complex changes during myocardial hypertrophy and progressive aging. [ABSTRACT FROM AUTHOR]

The identification of non-hematopoietic cells in effusions is a diagnostic challenge in cytology. Biopsies from mesothelium or primary lesions are infrequently performed in clinical settings and immunochemistry on smears or immunohistochemistry on cell blocks are the most common ancillary test to refine the cytological diagnosis. Cavitary effusions are an ideal matrix for flow cytometry and the availability of a cytometric panel to describe non-hematopoietic cells would represent a useful tool. Here we present the results of the flow cytometric and immunohistochemical determination of cytokeratin (CK), vimentin (VIM) and desmin (DES) in 36 canine effusions. The concordance between the two methods was perfect for CK (100%), substantial for VIM (77.8%), and almost perfect for DES (97.2%). The panel was interpreted to define the epithelial (CK+VIM-DES-), mesothelial (CK+VIM+DES+), or mesenchymal (CK-VIM+DES-) origin of the cells. Unexpected profiles were considered doubtful and observed patterns were individually discussed. The concordance of the panel interpretation between two methods was 75%. The evaluation of discordant and doubtful cases suggests a lower sensitivity of flow cytometry in detecting VIM expression and revealed a high frequency of VIM+ epithelial cells, variable expression of VIM in mesothelial cells, and an important role of DES in excluding an epithelial origin when positive. Multicentric studies based on histopathological diagnoses are necessary to confirm these findings and evaluate the diagnostic utility of the panel to refine cytological diagnosis. Our results show that flow cytometry can be a timesaving alternative to IHC on cell blocks in clinical settings to detect CK, VIM and DES expression. The interpretation of the panel is similar in most cases; however, occasional discordant results, particularly for VIM, may occur.

Abstract Background Desmin is a major cytoskeletal protein considered ubiquitous in mature muscle fibers. However, we earlier reported that a subgroup of muscle fibers in the soft palate of healthy subjects and obstructive sleep apnea patients (OSA) lacked immunoexpression for desmin. This raised the question of whether these fibers also lack messenger ribonucleic acid (mRNA) for desmin and can be considered a novel fiber phenotype. Moreover, some fibers in the OSA patients had an abnormal distribution and aggregates of desmin. Thus, the aim of the study was to investigate if these desmin protein abnormalities are also reflected in the expression of desmin mRNA in an upper airway muscle of healthy subjects and OSA patients. Methods Muscle biopsies from the musculus uvulae in the soft palate were obtained from ten healthy male subjects and six male patients with OSA. Overnight sleep apnea registrations were done for all participants. Immunohistochemistry, in-situ hybridization, and reverse transcription–quantitative polymerase chain reaction (RT–qPCR) techniques were used to evaluate the presence of desmin protein and its mRNA. Results Our findings demonstrated that a group of muscle fibers lacked expression for desmin mRNA and desmin protein in healthy individuals and OSA patients (12.0 ± 5.6% vs. 23.1 ± 10.8%, p = 0.03). A subpopulation of these fibers displayed a weak subsarcolemmal rim of desmin accompanied by a few scattered mRNA dots in the cytoplasm. The muscles of OSA patients also differed from healthy subjects by exhibiting muscle fibers with reorganized or accumulated aggregates of desmin protein (14.5 ± 6.5%). In these abnormal fibers, the density of mRNA was generally low or concentrated in specific regions. The overall quantification of desmin mRNA by RT–qPCR was significantly upregulated in OSA patients compared to healthy subjects (p = 0.01). Conclusions Our study shows evidence that muscle fibers in the human soft palate lack both mRNA and protein for desmin. This indicates a novel cytoskeletal structure and challenges the ubiquity of desmin in muscle fibers. Moreover, the observation of reorganized or accumulated aggregates of desmin mRNA and desmin protein in OSA patients suggests a disturbance in the transcription and translation process in the fibers of the patients.

Nucleocytoplasmic transport is one of the key features in regulation of cellular physiology. Developing a better understanding of the molecular mechanism underlying the nucleocytoplasmic shuttling of proteins can broaden our perspective and understanding on the elaborate sorting mechanisms within cells. Desmin is a muscle specific intermediate filament with amphiphilic properties and has interactions with the components of the nuclear pore complex which facilitates the transport between the cytoplasm and nucleus. The study aims to develop a better understanding of the amphiphilic nature of desmin and its relation to nucleocytoplasmic transport.

The ultra-rare DES c.1289-2A>G mutation, resulting in a 48-base pair insertion in the Desmin tail domain, is associated with late-onset MFM1 (myofibrillar myopathy-1; OMIM number; 601419) and exhibits distinctive pathological features. Despite sustained expression and cytoskeletal integrity, muscle biopsies reveal dystrophic characteristics through an unidentified mechanism. A deeper understanding of the molecular mechanisms underlying Desmin-related MFM1 could enhance our perspective and comprehension of the disease’s pathophysiology. In this study, we aimed to investigate the pathological phenotype by assessing the myogenic potency of MyoD-induced patient-derived fibroblasts.

Hamartomas, a focal excess of normal tissue usually presenting as isolated masses, are rarely found in the head and neck region. The purpose of this report is to discuss a rare case of an intra-oral angioleiomyomatous hamartoma in a 14-year-old male who presented with a congenital nodule over the anterior palatal mucosa. The confirmatory diagnosis was done based on histopathology and immunohistochemistry using various markers. A brief review of the literature and clinical differential diagnoses are discussed, along with the clinical significance of hamartomas associated with syndromes. Hence, the identification of such hamartomas may lead to early diagnosis of associated syndromes in pediatric patients. [ABSTRACT FROM AUTHOR]

Background: Spermatogonial stem cells (SSCs) were considered to be stem cells with limited potencies due to their existence in adult organisms. However, the production of spermatogonial stem cell colonies with broader differentiation capabilities in primary germ cell cultures from mice of select genetic backgrounds (C57BL6/Tg14, ddY, FVB and 129/Ola) indicated that SSCs from these strains were pluripotent. Methods: We established primary cultures of SSCs from neonatal and adult Swiss 3T3 Albino mice. Stemness of SSC colonies were evaluated by performing real-time PCR and immunofluorescence analysis for a panel of chosen stemness markers. Differentiation potentials of SSCs were examined by attempting the generation of embryoid bodies and evaluating the expression of ectodermal, mesodermal and endodermal markers using immunofluorescence and real-time PCR analysis. Results: Spermatogonial stem cells from neonatal and mature mice testes colonised in vitro and formed compact spermatogonial stem cell colonies in culture. The presence of stem cell markers ALPL, ITGA6 and CD9 indicated stemness in these colonies. The differentiation potential of these SSC colonies was demonstrated by their transformation into embryoid bodies upon withdrawal of growth factors from the culture medium. SSC colonies and embryoid bodies formed were evaluated using immunofluorescence and real-time PCR analysis. Embryoid body like structures derived from both neonatal and adult mouse testis were quite similar in terms of the expression of germ layer markers. Conclusion: These results strongly suggest that SSC-derived EB-like structures could be used for further differentiation into cells of interest in cell-based therapeutics. [ABSTRACT FROM AUTHOR]

Understanding the structure and function of intermediate filaments (IFs) is necessary in order to explain why more than 70 related IF genes have evolved in vertebrates while maintaining such dramatically tissue-specific expression. Desmin is a member of the large multigene family of IF proteins and is specifically expressed in myocytes. In an effort to elucidate its muscle-specific behavior, we have used a yeast two-hybrid system in order to identify desmin's head binding partners. We described a mitochondrial and a lysosomal protein, NADH ubiquinone oxidoreductase core subunit S2 (NDUFS2), and saposin D, respectively, as direct desmin binding partners. In silico analysis indicated that both interactions at the atomic level occur in a very similar way, by the formation of a three-helix bundle with hydrophobic interactions in the interdomain space and hydrogen bonds at R16 and S32 of the desmin head domain. The interactions, confirmed also by GST pull-down assays, indicating the necessity of the desmin head domain and, furthermore, point out its role in function of mitochondria and lysosomes, organelles which are disrupted in myopathies due to desmin head domain mutations. [ABSTRACT FROM AUTHOR]

Background: Desmin is a major cytoskeletal protein considered ubiquitous in mature muscle fibers. However, we earlier reported that a subgroup of muscle fibers in the soft palate of healthy subjects and obstructive sleep apnea patients (OSA) lacked immunoexpression for desmin. This raised the question of whether these fibers also lack messenger ribonucleic acid (mRNA) for desmin and can be considered a novel fiber phenotype. Moreover, some fibers in the OSA patients had an abnormal distribution and aggregates of desmin. Thus, the aim of the study was to investigate if these desmin protein abnormalities are also reflected in the expression of desmin mRNA in an upper airway muscle of healthy subjects and OSA patients. Methods: Muscle biopsies from the musculus uvulae in the soft palate were obtained from ten healthy male subjects and six male patients with OSA. Overnight sleep apnea registrations were done for all participants. Immunohistochemistry, in-situ hybridization, and reverse transcription–quantitative polymerase chain reaction (RT–qPCR) techniques were used to evaluate the presence of desmin protein and its mRNA. Results: Our findings demonstrated that a group of muscle fibers lacked expression for desmin mRNA and desmin protein in healthy individuals and OSA patients (12.0 ± 5.6% vs. 23.1 ± 10.8%, p = 0.03). A subpopulation of these fibers displayed a weak subsarcolemmal rim of desmin accompanied by a few scattered mRNA dots in the cytoplasm. The muscles of OSA patients also differed from healthy subjects by exhibiting muscle fibers with reorganized or accumulated aggregates of desmin protein (14.5 ± 6.5%). In these abnormal fibers, the density of mRNA was generally low or concentrated in specific regions. The overall quantification of desmin mRNA by RT–qPCR was significantly upregulated in OSA patients compared to healthy subjects (p = 0.01). Conclusions: Our study shows evidence that muscle fibers in the human soft palate lack both mRNA and protein for desmin. This indicates a novel cytoskeletal structure and challenges the ubiquity of desmin in muscle fibers. Moreover, the observation of reorganized or accumulated aggregates of desmin mRNA and desmin protein in OSA patients suggests a disturbance in the transcription and translation process in the fibers of the patients. [ABSTRACT FROM AUTHOR]

Abstract Background Sex cord gonadal stromal tumors compose less than 10% of all testicular neoplasms and consist of a variety of histological subtypes. In 2016, the World Health Organization introduced a novel subtype, the myoid gonadal stromal tumor, that consists of spindle-shaped cells with immunohistologic features of muscle cells. Only few cases have been reported to date. Due to its rarity and owing to its only recent introduction, the current knowledge about myoid gonadal stromal tumor is limited, and particularly, appropriate clinical management is still ill-defined. Case presentation A 47-year-old man of Caucasian descent presented with nonspecific scrotal discomfort. A roundish and well demarcated hypoechoic mass of 8.5 mm in diameter was detected in the cranial region of the left testis. Serum tumor marker levels were within normal ranges. Testis-sparing surgery revealed a 9-mm whitish, hard mass with sharp surgical margin. Histologically, the neoplasm consisted of microfibrillar tissue with spindle-shaped cells harboring elongated nuclei. Immunohistochemical work-up disclosed expression of desmin, small muscle actin, and S100 protein giving evidence for the myogenic nature of the neoplastic cells. There was no indication of malignancy, neither histologically nor clinically. Follow-up of 1 year was uneventful. Conclusion A literature survey revealed 22 previous cases of myoid gonadal stromal tumor. The median age was 37 years, the median size of the neoplasm was 20 mm, and there was no side-preponderance. Myoid gonadal stromal tumor is not much different from other subtypes of gonadal stromal tumors nor from testicular gem cell tumors regarding age and laterality; however, tumor size is smaller in myoid gonadal stromal tumors than in germ cell tumors. Although rarely performed so far, testis-sparing surgery probably constitutes an appropriate treatment of this neoplasm. Myoid gonadal stromal tumor represents an emerging novel entity of benign testicular new growths that caregivers of patients with testicular tumors should be aware of.

Background. Heart transplantation is currently the treatment of choice for patients in terminal stages of chronic heart failure. The critical shortage of donor organs and the growing need for heart transplantation necessitate the expansion of donor selection criteria, including the estimated ischemia time of the donor heart. Despite numerous studies, the issue remains regarding the safe cold ischemia time; no definite limit to the acceptable preservation time is known and no relevant pathomorphological data are available on the state of the donor heart myocardium at different time parameters. Objective. To comparatively assess the features of cardiomyocyte pathomorphology and expression of protein markers (actin and desmin) in the myocardium of a donor heart prior to the main stage of orthotopic heart transplantation. Methods. The work adopted the design of an observational clinical study, which was prospective in nature. The study used intraoperative myocardial biopsy specimens of the left atrial appendage from donors aged up to 60 years, following cold ischemia of the transplant in Bretschneider solution (Dr. Franz Köhler Chemie GmbH, Germany) lasting up to 240 minutes (Group 1, n = 10) and over 240 minutes (Group 2, n = 7). The nature of pathomorphological myocardial transformation in the left atrial appendage of the donor heart was determined at different cold ischemia times. Histological myocardial sections were stained with hematoxylin and eosin according to standard procedures. After that, they were further studied using light and polarization microscopy; the immunohistochemical method was used to analyze the expression of actin and desmin. Morphometry was performed using the ImageJ 1.48v software (USA). In the analysis of actin and desmin amount, the area of DAB(3,3′-diaminobenzidine)-positive products of the immunohistochemical reaction was estimated as a percentage of the image area. The volume density of immunohistochemically detectable actin and desmin was determined using 20 images at a magnification of 40×10. In order to study the intensity of the immune reaction, a semiquantitative method was used, which involved counting the number of cells in 25 randomly selected fields of view. The types of myocardial contracture damage were assessed via polarization microscopy. Results. Patients included in the first and second groups were comparable in terms of mean age and anthropometric indices. The mean age of patients amounted to 50 [44;59] years in Group 1 and 50 [49;50] years in Group 2, р = 0.193. The body mass index was 25 [22;27] in Group1 and 25 [21;31] in Group 2, р = 0.288. Both groups showed male predominance: 8 (80%) in Group 1 and 6 (85.7%) in Group 2, р = 0.256. The comprehensive morphological assessment of ischemic myocardial damage at different cold ischemia times revealed the uniformity and reversibility of changes in cellular structures (in both groups) that take the form of I–II class contractures, lysis changes in individual cardiomyocytes (only in Group 2), preserved immunohistochemical reactions to actin and desmin in both groups at their average intensity and the complete absence of areas showing no reaction to desmin, which gives an idea about the degree of preservation of their macromolecular structure. Conclusion. The obtained study results showed that due to having a balanced elemental composition that determines the metabolic protection of cells and their ionic balance, the Bretschneider solution effectively protects the donor heart during its transportation, with the myocardial cold ischemia lasting up to 240 min and more.

Abstract Background Beyond the observed alterations in cellular structure and mitochondria, the mechanisms linking rare genetic mutations to the development of heart failure in patients affected by desmin mutations remain unclear due in part, to the lack of relevant human cardiomyocyte models. Methods To shed light on the role of mitochondria in these mechanisms, we investigated cardiomyocytes derived from human induced pluripotent stem cells carrying the heterozygous DES E439K mutation that were either isolated from a patient or generated by gene editing. To increase physiological relevance, cardiomyocytes were either cultured on an anisotropic micropatterned surface to obtain elongated and aligned cardiomyocytes, or as a cardiac spheroid to create a micro-tissue. Moreover, when applicable, results from cardiomyocytes were confirmed with heart biopsies of suddenly died patient of the same family harboring DES E439K mutation, and post-mortem heart samples from five control healthy donors. Results The heterozygous DES E439K mutation leads to dramatic changes in the overall cytoarchitecture of cardiomyocytes, including cell size and morphology. Most importantly, mutant cardiomyocytes display altered mitochondrial architecture, mitochondrial respiratory capacity and metabolic activity reminiscent of defects observed in patient’s heart tissue. Finally, to challenge the pathological mechanism, we transferred normal mitochondria inside the mutant cardiomyocytes and demonstrated that this treatment was able to restore mitochondrial and contractile functions of cardiomyocytes. Conclusions This work highlights the deleterious effects of DES E439K mutation, demonstrates the crucial role of mitochondrial abnormalities in the pathophysiology of desmin-related cardiomyopathy, and opens up new potential therapeutic perspectives for this disease.

Equine endometrosis is one of the major causes of equine infertility, often associated with signs of periglandular fibrosis occurring in the endometrium. As the oviduct is a key location of early embryo development, we hypothesized that disturbances in hormonal action may be associated with a loss of contact between mucosal cells in the uterus and oviducts. This study investigates the expression of intermediate filament proteins (vimentin and desmin), oestrogen receptor alpha (ERα), and progesterone receptor A (PRA) in the stroma and epithelia of the endometria and oviducts of healthy mares and mares with endometrosis. Endometrium samples were obtained from 56 mares, culled in a slaughterhouse, and were designated either healthy endometrium (n = 26) or endometrium with signs of moderate to severe endometrosis (n = 20). The phase of the ovarian cycle and the expression of vimentin, desmin, ERα, and PRA were compared between these groups. The expressions of both vimentin and desmin were higher in the endometrial stroma of the endometrosis group than in healthy endometria. The expression of ERα in the healthy endometrial stroma and luminal epithelium during the follicular phase was higher than in the luteal phase, but showed no differences in the endometrium of mares with endometrosis. PRA expression was significantly higher in the stoma oviduct during the follicular phase than in the luteal phase. It seems possible that mucosal cells may support the occurrence of moderate to severe endometrosis through their altered intermediate filament and sex steroid receptor interactions. In addition, the oviduct appears to be less sensitive to hormonal changes than the uterus. Changes in the expression of intermediate filament and steroid hormone proteins may be a leading factor contributing to the functional status of the oviduct in endometrosis.

Background: Sex cord gonadal stromal tumors compose less than 10% of all testicular neoplasms and consist of a variety of histological subtypes. In 2016, the World Health Organization introduced a novel subtype, the myoid gonadal stromal tumor, that consists of spindle-shaped cells with immunohistologic features of muscle cells. Only few cases have been reported to date. Due to its rarity and owing to its only recent introduction, the current knowledge about myoid gonadal stromal tumor is limited, and particularly, appropriate clinical management is still ill-defined. Case presentation: A 47-year-old man of Caucasian descent presented with nonspecific scrotal discomfort. A roundish and well demarcated hypoechoic mass of 8.5 mm in diameter was detected in the cranial region of the left testis. Serum tumor marker levels were within normal ranges. Testis-sparing surgery revealed a 9-mm whitish, hard mass with sharp surgical margin. Histologically, the neoplasm consisted of microfibrillar tissue with spindle-shaped cells harboring elongated nuclei. Immunohistochemical work-up disclosed expression of desmin, small muscle actin, and S100 protein giving evidence for the myogenic nature of the neoplastic cells. There was no indication of malignancy, neither histologically nor clinically. Follow-up of 1 year was uneventful. Conclusion: A literature survey revealed 22 previous cases of myoid gonadal stromal tumor. The median age was 37 years, the median size of the neoplasm was 20 mm, and there was no side-preponderance. Myoid gonadal stromal tumor is not much different from other subtypes of gonadal stromal tumors nor from testicular gem cell tumors regarding age and laterality; however, tumor size is smaller in myoid gonadal stromal tumors than in germ cell tumors. Although rarely performed so far, testis-sparing surgery probably constitutes an appropriate treatment of this neoplasm. Myoid gonadal stromal tumor represents an emerging novel entity of benign testicular new growths that caregivers of patients with testicular tumors should be aware of. [ABSTRACT FROM AUTHOR]

Introduction: LMNA splicing mutations occur in 9.1% of cases with cardiac involvement cases, but the phenotype and severity of disease they cause have not yet been systematically studied. The aim of this study was to understand the clinical and pathogenic characteristics of the LMNA splice-site mutation phenotype in patients with LMNA-related dilated cardiomyopathy (DCM) and sudden cardiac death (SCD). Methods and Results: First, we reported a novel family with LMNA-related DCM and SCD, and the clinical characteristics of all current patients with LMNA splicing mutations were further summarized through the ClinVar database. Seventeen families with a total of 134 individuals, containing a total of 15 LMNA splicing mutation sites, were enrolled. A total of 42 subjects (31.3%) had SCD. Compared without with the non-DCM group (n = 56), the patients within the DCM group (n = 78) presented a lower incidence of atrioventricular block (AVB) (p = 0.015) and a higher incidence rates of non-sustained ventricular tachycardia (p = 0.004),) and implantable cardioverter defibrillator (ICD) implantation (p = 0.005). Kaplan--Meier survival analysis showed that the patients with pacemaker (PM) implantation had a significantly reduced the occurrence of SCD compared to patientswith those without PM implantation (log-rank p < 0.001), while there was no significant difference in ICD implantation between the two groups (log-rank p = 0.73). Second, we identified the family that we reported with a mutation in an LMNA c.513+1 G>A mutation in the reported family, and pathogenic prediction analysis showed that the mutation site was extremely harmful. Next, we conducted gene expression levels and cardiac pathological biopsy studies on the proband of this family. We found that the expression of normal LMNA mRNA from the proband was significantly downregulated in peripheral blood mononuclear cells than incompared with healthy individuals. Finally, we comprehensively summarized the pathological characteristics of LMNA-related DCM, including hypertrophy, atrophy, fibrosis, white blood cell infiltration, intercalated disc remodeling, and downregulation of desmin and connexin 43 (Cx43) expression. Discussion: Above all, Cardiaccardiac involvement in patients with LMNA splicesite mutation presented with a high rate of SCD. Implanting a pacemaker significantly reduced the SCD rate in non-DCM patients with AVB. The pathogenic characterization was not only haveinvolved suppressed the expression of the healthy LMNA allele, but was also associated with abnormal expression and distribution of desmin and Cx43. [ABSTRACT FROM AUTHOR]

In muscle cells subjected to mechanical stimulation, LINC complex and cytoskeletal proteins are basic to preserve cellular architecture and maintain nuclei orientation and positioning. In this context, the role of lamin A/C remains mostly elusive. This study demonstrates that in human myoblasts subjected to mechanical stretching, lamin A/C recruits desmin and plectin to the nuclear periphery, allowing a proper spatial orientation of the nuclei. Interestingly, in Emery-Dreifuss Muscular Dystrophy (EDMD2) myoblasts exposed to mechanical stretching, the recruitment of desmin and plectin to the nucleus and nuclear orientation were impaired, suggesting that a functional lamin A/C is crucial for the response to mechanical strain. While describing a new mechanism of action headed by lamin A/C, these findings show a structural alteration that could be involved in the onset of the muscle defects observed in muscular laminopathies. [ABSTRACT FROM AUTHOR]

Background: Beyond the observed alterations in cellular structure and mitochondria, the mechanisms linking rare genetic mutations to the development of heart failure in patients affected by desmin mutations remain unclear due in part, to the lack of relevant human cardiomyocyte models. Methods: To shed light on the role of mitochondria in these mechanisms, we investigated cardiomyocytes derived from human induced pluripotent stem cells carrying the heterozygous DESE439K mutation that were either isolated from a patient or generated by gene editing. To increase physiological relevance, cardiomyocytes were either cultured on an anisotropic micropatterned surface to obtain elongated and aligned cardiomyocytes, or as a cardiac spheroid to create a micro-tissue. Moreover, when applicable, results from cardiomyocytes were confirmed with heart biopsies of suddenly died patient of the same family harboring DESE439K mutation, and post-mortem heart samples from five control healthy donors. Results: The heterozygous DESE439K mutation leads to dramatic changes in the overall cytoarchitecture of cardiomyocytes, including cell size and morphology. Most importantly, mutant cardiomyocytes display altered mitochondrial architecture, mitochondrial respiratory capacity and metabolic activity reminiscent of defects observed in patient's heart tissue. Finally, to challenge the pathological mechanism, we transferred normal mitochondria inside the mutant cardiomyocytes and demonstrated that this treatment was able to restore mitochondrial and contractile functions of cardiomyocytes. Conclusions: This work highlights the deleterious effects of DESE439K mutation, demonstrates the crucial role of mitochondrial abnormalities in the pathophysiology of desmin-related cardiomyopathy, and opens up new potential therapeutic perspectives for this disease. [ABSTRACT FROM AUTHOR]

Maintenance of the highly organized striated muscle tissue requires a cell-wide dynamic network through protein-protein interactions providing an effective mechanochemical integrator of morphology and function. Through a continuous and complex trans -cytoplasmic network, desmin intermediate filaments ensure this essential role in heart and in skeletal muscle. Besides their role in the maintenance of cell shape and architecture (permitting contractile activity efficiency and conferring resistance towards mechanical stress), desmin intermediate filaments are also key actors of cell and tissue homeostasis. Desmin participates to several cellular processes such as differentiation, apoptosis, intracellular signalisation, mechanotransduction, vesicle trafficking, organelle biogenesis and/or positioning, calcium homeostasis, protein homeostasis, cell adhesion, metabolism and gene expression. Desmin intermediate filaments assembly requires αB-crystallin, a small heat shock protein. Over its chaperone activity, αB-crystallin is involved in several cellular functions such as cell integrity, cytoskeleton stabilization, apoptosis, autophagy, differentiation, mitochondria function or aggresome formation. Importantly, both proteins are known to be strongly associated to the aetiology of several cardiac and skeletal muscles pathologies related to desmin filaments disorganization and a strong disturbance of desmin interactome. Note that these key proteins of cytoskeleton architecture are extensively modified by post-translational modifications that could affect their functional properties. Therefore, we reviewed in the herein paper the impact of post-translational modifications on the modulation of cellular functions of desmin and its molecular chaperone, the αB-crystallin. • Desmin IFs are key actors of muscle homeostasis; αB-crystallin its molecular chaperone, ensures their proper assembly. • Both proteins are strongly linked to the aetiology of numerous cardiac and skeletal muscle diseases. • Both are highly modified by PTMs, in particular phosphorylation and O-GlcNAcylation, regulating their functions. • αB-Crystallin emerges as a new great therapeutic tool against protein aggregation and the resulting proteotoxicity. • Considering PTMs opens a new research field in the world of molecular chaperones and their target proteins. [ABSTRACT FROM AUTHOR]

Myocardial sleeve around human pulmonary veins plays a critical role in the pathomechanism of atrial fibrillation. Besides the well‐known arrhythmogenicity of these veins, there is evidence that myocardial extensions into caval veins and coronary sinus may exhibit similar features. However, studies investigating histologic properties of these structures are limited. We aimed to investigate the immunoreactivity of myocardial sleeves for intermediate filament desmin, which was reported to be more abundant in Purkinje fibers than in ventricular working cardiomyocytes. Sections of 16 human (15 adult and 1 fetal) hearts were investigated. Specimens of atrial and ventricular myocardium, sinoatrial and atrioventricular nodes, pulmonary veins, superior caval vein and coronary sinus were stained with anti‐desmin monoclonal antibody. Intensity of desmin immunoreactivity in different areas was quantified by the ImageJ program. Strong desmin labeling was detected at the pacemaker and conduction system as well as in the myocardial sleeves around pulmonary veins, superior caval vein, and coronary sinus of adult hearts irrespective of sex, age, and medical history. In the fetal heart, prominent desmin labeling was observed at the sinoatrial nodal region and in the myocardial extensions around the superior caval vein. Contrarily, atrial and ventricular working myocardium exhibited low desmin immunoreactivity in both adults and fetuses. These differences were confirmed by immunohistochemical quantitative analysis. In conclusion, this study indicates that desmin is abundant in the conduction system and venous myocardial sleeves of human hearts. [ABSTRACT FROM AUTHOR]

This report describes the cytologic, histopathologic, and immunohistochemical features of adult‐type rhabdomyoma located within the subcutaneous tissue in a 14‐year‐old female Border Collie (thigh) and a 13‐year‐old male Mongrel (flank). In both cases, fine‐needle aspiration biopsy revealed cluster‐forming, epithelial‐like polygonal cells with abundant foamy cytoplasm, and moderate to marked anisocytosis and anisokaryosis; therefore, an epithelial tumor was suspected. After surgical excision, tumors underwent histopathologic examination with additional immunohistochemistry. Both tumors were well‐demarcated and located within the subcutaneous tissue in the vicinity of the cutaneous muscle. The tumor mass consisted of densely packed round or polygonal cells with distinct vacuolation of the cytoplasm. Tumor cells expressed vimentin, desmin, and NSE and were cytokeratin and α‐SMA negative. Based on histologic features and immunophenotyping, adult‐type rhabdomyoma was diagnosed in both cases. This study highlights that the cytologic features of rhabdomyoma can be misleading and may suggest an epithelial tumor. [ABSTRACT FROM AUTHOR]

Summary: Pathogenic variants in the DES gene clinically manifest as progressive skeletal muscle weakness, cardiomyopathy with associated severe arrhythmias, and respiratory insufficiency, and are collectively known as desminopathies. While most DES pathogenic variants act via a dominant mechanism, recessively acting variants have also been reported. Currently, there are no effective therapeutic interventions for desminopathies of any type. Here, we report an affected individual with rapidly progressive dilated cardiomyopathy, requiring heart transplantation at age 13 years, in the setting of childhood-onset skeletal muscle weakness. We identified biallelic DES variants (c.640-13 T>A and c.1288+1 G>A) and show aberrant DES gene splicing in the affected individual’s muscle. Through the generation of an inducible lentiviral system, we transdifferentiated fibroblast cultures derived from the affected individual into myoblasts and validated this system using RNA sequencing. We tested rationally designed, custom antisense oligonucleotides to screen for splice correction in these transdifferentiated cells and a functional minigene splicing assay. However, rather than correctly redirecting splicing, we found them to induce undesired exon skipping. Our results indicate that, while an individual precision-based molecular therapeutic approach to splice-altering pathogenic variants is promising, careful preclinical testing is imperative for each novel variant to test the feasibility of this type of approach for translation.

Visceral leiomyosarcoma is well described in dogs, but information about non-visceral locations and prevalence is lacking. The diagnosis of leiomyosarcoma is challenging without a gold standard, and often includes the use of immunohistochemical (IHC) stains. We used defined histopathologic patterns, histochemical staining, and IHC staining for smooth muscle actin (SMA), desmin, and laminin to characterize suspected non-visceral leiomyosarcoma in dogs at a single academic institution. In a retrospective search, we identified 24 dogs with a definitive or suspected histologic diagnosis of leiomyosarcoma in a non-visceral location. Histopathology results and clinical details were obtained. Biopsy sections were reviewed by a single pathologist using standardized histologic criteria, including light microscopic appearance, immunohistochemistry (more than two-thirds of neoplastic cells labeled with SMA and desmin or laminin), and histochemical staining (minimal-to-mild matrix deposition by Masson trichrome). Of the 24 cases of possible non-visceral leiomyosarcomas, 4 were consistent with a definitive diagnosis of non-visceral leiomyosarcoma (3) or leiomyoma (1) based on the established criteria. Only the leiomyoma had more than two-thirds of neoplastic cells label with all 3 markers; all 3 leiomyosarcomas had more than two-thirds of neoplastic cells label with SMA and laminin. Our data highlight the uncommon nature of non-visceral leiomyosarcoma and the importance of IHC for their diagnosis. A definitive diagnosis could not be made based on SMA alone, and desmin was not useful in this cohort. Further studies are needed to clarify the histopathologic, IHC, and clinical features of canine non-visceral SMA-positive mesenchymal tumors.

Mesenchymal hamartoma of the liver (MHL) is rare. Less than 50 adult cases have been described. Due to their potential degeneration or recurrence, a complete surgical resection must be performed. We describe a case of a 26-year-old with a palpable solid lesion, which displaced abdominal organs. Percutaneous needle biopsies suggested the diagnosis of MHL. A right hemi-hepatectomy without segment 1 was performed; the post-operative course was uneventful. The mesenchymal component of the tumour was reactive to desmin and smooth muscle actin. Low proliferation index was confirmed (MIB1). Genetic counselling: the sequencing analysis of DICER1 and CDKN1C gene was negative, DNA methylation analysis on the chromosome 11p15 region was normal. After 42 months, there was no recurrence. In conclusion, clinicians should consider MHL in the differential diagnosis. The dimension and the need of radicality impose major liver resections or liver transplantations, which should be performed in referral centres. [ABSTRACT FROM AUTHOR]

Desminopathy is the most common intermediate filament disease in humans. The most frequent mutation causing desminopathy in patients is a R350P DES missense mutation. We have developed a rat model with an analogous mutation in R349P Des. To investigate the role of R349P Des in mechanical loading, we stimulated the sciatic nerve of wild-type littermates (WT) (n = 6) and animals carrying the mutation (MUT) (n = 6) causing a lengthening contraction of the dorsi flexor muscles. MUT animals showed signs of ongoing regeneration at baseline as indicated by a higher number of central nuclei (genotype: P

Objective: Myofibrillar myopathies (MFM) are a group of sporadic and inherited progressive skeletal muscle disorders that can lead to physical disability and premature death. To date, pathogenic variants in different genes are associated with MFM. MFM induced by variants in the Desmin (DES) gene is the most common subtype of MFM. Case presentation: A 15-year-old boy with MFM was described, whose symptoms first presented as cardiac symptoms. Enlarged right and left atria, thickened ventricular septal (IVS) and mild mitral (MR) and tricuspid regurgitation (TR) in the echocardiography were found. Atrial fibrillation, intermittent atrioventricular (AV) block, ST-T changes in the dynamic electrocardiogram (ECG) were shown. Mild myopathic changes in the electromyographic exam were detected. Ultrastructural analysis found slight Z-line changes and a few small myolysis lesions, but no abnormal inclusion bodies. Genetic testing detected a heterozygous missense variant (c.1216C > T) of DES, and 2 rare variants: TNNI3K (c.1102C > G) and PRDM16 (c.3074G > A). The patient's parents didn't show skeletal and cardiac muscle disorders. DNA sequencing analysis showed no variant of DES was carried by them. Thus, we detected a case of MFM caused by de novo DES variant c.1216C > T/p.Arg406Trp with predominantly myocardial alterations.

Exon-skipping therapy is a promising treatment strategy for Duchenne muscular dystrophy (DMD), which is caused by loss-of-function mutations in the DMD gene encoding dystrophin, leading to progressive cardiomyopathy. In-frame deletion of exons 3–9 (Δ3–9), manifesting a very mild clinical phenotype, is a potential targeted reading frame for exon-skipping by targeting actin-binding domain 1 (ABD1); however, the efficacy of this approach for DMD cardiomyopathy remains uncertain. In this study, we compared three isogenic human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) expressing Δ3–9, frameshifting Δ3–7, or intact DMD. RNA sequencing revealed a resemblance in the expression patterns of mechano-transduction-related genes between Δ3–9 and wild-type samples. Furthermore, we observed similar electrophysiological properties between Δ3–9 and wild-type hiPSC-CMs; Δ3–7 hiPSC-CMs showed electrophysiological alterations with accelerated CaMKII activation. Consistently, Δ3–9 hiPSC-CMs expressed substantial internally truncated dystrophin protein, resulting in maintaining F-actin binding and desmin retention. Antisense oligonucleotides targeting exon 8 efficiently induced skipping exons 8–9 to restore functional dystrophin and electrophysiological parameters in Δ3–7 hiPSC-CMs, bringing the cell characteristics closer to those of Δ3–9 hiPSC-CMs. Collectively, exon-skipping targeting ABD1 to convert the reading frame to Δ3–9 may become a promising therapy for DMD cardiomyopathy.

Patients with chronic critical illness lose a considerable portion of their muscle mass while hospitalized in an intensive care unit, which can have long-term detrimental effects. Among other factors, this leads to a disintegration of muscle cytoskeleton, and currently there are no comprehensive studies describing the mechanisms behind the development of this pathology. Here, we aimed to investigate the signaling processes that contribute to desmin degradation in patients with critical illness myopathy (CIM). Incisional needle biopsies of the soleus muscle were taken from 6 patients with a chronic (≥ 2 months) disorder of consciousness, undergoing treatment at the Polenov Neurosurgical Institute (Almazov National Medical Research Center, St. Petersburg) and healthy men (control). Muscle tissue samples were frozen in liquid nitrogen for subsequent Western blot and PCR analyses, as well as immunohistochemical examination. The analysis showed that fibers with an altered histological desmin pattern were visually identified in 4 out of 6 patients. A significant decrease in desmin (by 69%) and its mRNA (by 24%) levels was observed in patients with CIM. Desmin degradation is known to occur due to increased calpain activity and activation of the ubiquitin-proteasome system. In this study, calpain-1 content increased in CIM patients at the protein level, while remaining unchanged at the mRNA level. We detected changes in GSK3-β Ser9-phosphorylation, which is a critical step in calpain-1-mediated depolymerization of desmin filaments. A study of ubiquitin ligases revealed a significant 155% increase in Trim32 expression paralleled by a decrease in Atrogin1 and MuRF1 expression. Thus, we observed a decrease in desmin content under CIM conditions. Desmin degradation may result from its increased GSK3β-mediated phosphorylation and subsequent calpain-1-mediated cleavage. Moreover, we found an increase in the expression of the E3 ubiquitin ligase Trim32 whose activity, according to the literature, also rises after desmin phosphorylation. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: Myofiber culture has been employed to investigate muscle physiology in vitro and is well‐established in the rodent hind limb. Thyroarytenoid (TA) myofiber culture has not been described, providing an opportunity to employ this method to investigate distinct TA myofiber functions. The purpose of this study was to assess the feasibility of a TA myofiber culture model. Study Design: In vitro. Methods: TA muscles from five Sprague Dawley rats were independently isolated and digested for 90 min. A smooth‐tip, wide‐bored pipette dissociated TA myofibers from cartilage, and the fibers were distributed on collagen‐coated dishes and incubated at 37°C, 5% CO2 for 2 h. Myofiber specificity was determined via immunolabeling for desmin and myosin heavy chain (MHC). Myofibers viability was assessed over 7 days via esterase assay. Additional myofibers were immunolabeled for satellite cell marker Pax‐7. Glucocorticoid (GC) receptor (GR) was immunolabeled following GC treatment. Results: The harvest technique yielded ~120 myofibers per larynx. By day 7, ~60% of the fibers remained attached and were calcein AM‐positive/ethidium homodimer‐negative, indicating viability. Myofibers were positive for desmin and MHC, indicating muscle specificity. Cells surrounding myofibers were positive for Pax‐7, indicating the presence of myogenic satellite cells. Myofibers also responded to GC treatment as determined by GR nuclear translocation. Conclusion: TA myofibers remained viable in culture for at least 7 days with a predictable response to exogenous stimuli. This technique provides novel investigative opportunities regarding TA structure and function. Level of Evidence: N/A Laryngoscope, 133:3109–3115, 2023 [ABSTRACT FROM AUTHOR]

Employing animal models to study heart failure (HF) has become indispensable to discover and test novel therapies, but their translatability remains challenging. Although cytoskeletal alterations are linked to HF, the tubulin signature of common experimental models has been incompletely defined. Here, we assessed the tubulin signature in a large set of human cardiac samples and myocardium of animal models with cardiac remodeling caused by pressure overload, myocardial infarction or a gene defect. We studied levels of total, acetylated, and detyrosinated α-tubulin and desmin in cardiac tissue from hypertrophic (HCM) and dilated cardiomyopathy (DCM) patients with an idiopathic (n = 7), ischemic (n = 7) or genetic origin (n = 59), and in a pressure-overload concentric hypertrophic pig model (n = 32), pigs with a myocardial infarction (n = 28), mature pigs (n = 6), and mice (n = 15) carrying the HCM-associated MYBPC32373insG mutation. In the human samples, detyrosinated α-tubulin was increased 4-fold in end-stage HCM and 14-fold in pediatric DCM patients. Acetylated α-tubulin was increased twofold in ischemic patients. Across different animal models, the tubulin signature remained mostly unaltered. Only mature pigs were characterized by a 0.5-fold decrease in levels of total, acetylated, and detyrosinated α-tubulin. Moreover, we showed increased desmin levels in biopsies from NYHA class II HCM patients (2.5-fold) and the pressure-overload pig model (0.2–0.3-fold). Together, our data suggest that desmin levels increase early on in concentric hypertrophy and that animal models only partially recapitulate the proliferated and modified tubulin signature observed clinically. Our data warrant careful consideration when studying maladaptive responses to changes in the tubulin content in animal models. [ABSTRACT FROM AUTHOR]

Skeletal muscle myoblastic cell lines can provide a valuable new in vitro model for the exploration of the mechanisms that control skeletal muscle development and its associated molecular regulation. In this study, the skeletal muscle tissues of grass carp were digested with trypsin and collagenase I to obtain the primary myoblast cell culture. Myoblast cells were obtained by differential adherence purification and further analyzed by cryopreservation and resuscitation, chromosome analysis, immunohistochemistry, and immunofluorescence. A continuous grass carp myoblast cell line (named CIM) was established from grass carp (Ctenopharyngodon idellus) muscle and has been subcultured > 100 passages in a year and more. The CIM cells revived at 79.78–95.06% viability after 1–6 months of cryopreservation, and shared a population doubling time of 27.24 h. The number of modal chromosomes of CIM cells was 48, and the mitochondrial 12S rRNA sequence of the CIM cell line shared 99% identity with those of grass carp registered in GenBank. No microorganisms (bacteria, fungi, or mycoplasma) were detected during the whole study. The cell type of CIM cells was proven to be myoblast by immunohistochemistry of specific myogenic protein markers, including CD34, desmin, MyoD, and MyHC, as well as relative expression of key genes. And the myogenic rate and fusion index of this cell line after 10 days of induced differentiation were 8.96 ~ 9.42% and 3–24%, respectively. The telomerase activity and transfection efficiency of CIM cell line were 0.027 IU/mgprot and 23 ~ 24%, respectively. These results suggest that a myoblast cell line named CIM with normal biological function has been successfully established, which may provide a valuable tool for related in vitro studies. [ABSTRACT FROM AUTHOR]

Equine endometrosis is one of the major causes of equine infertility, often associated with signs of periglandular fibrosis occurring in the endometrium. As the oviduct is a key location of early embryo development, we hypothesized that disturbances in hormonal action may be associated with a loss of contact between mucosal cells in the uterus and oviducts. This study investigates the expression of intermediate filament proteins (vimentin and desmin), oestrogen receptor alpha (ERa), and progesterone receptor A (PRA) in the stroma and epithelia of the endometria and oviducts of healthy mares and mares with endometrosis. Endometrium samples were obtained from 56 mares, culled in a slaughterhouse, and were designated either healthy endometrium (n = 26) or endometrium with signs of moderate to severe endometrosis (n = 20). The phase of the ovarian cycle and the expression of vimentin, desmin, ERa, and PRA were compared between these groups. The expressions of both vimentin and desmin were higher in the endometrial stroma of the endometrosis group than in healthy endometria. The expression of ERa in the healthy endometrial stroma and luminal epithelium during the follicular phase was higher than in the luteal phase, but showed no differences in the endometrium of mares with endometrosis. PRA expression was significantly higher in the stoma oviduct during the follicular phase than in the luteal phase. It seems possible that mucosal cells may support the occurrence of moderate to severe endometrosis through their altered intermediate filament and sex steroid receptor interactions. In addition, the oviduct appears to be less sensitive to hormonal changes than the uterus. Changes in the expression of intermediate filament and steroid hormone proteins may be a leading factor contributing to the functional status of the oviduct in endometrosis. [ABSTRACT FROM AUTHOR]

Background: Disordered and hypomineralized woven bone formation by dysfunctional mesenchymal stromal cells (MSCs) characterize delayed fracture healing and endocrine--metabolic bone disorders like fibrous dysplasia and Paget disease of bone. To shed light on molecular players in osteoblast differentiation, woven bone formation, and mineralization by MSCs we looked at the intermediate filament desmin (DES) during the skeletogenic commitment of rat bone marrow MSCs (rBMSCs), where its bone-related action remains elusive. Results: Monolayer cultures of immunophenotypically - and morphologically - characterized, adult male rBMSCs showed co-localization of desmin (DES) with vimentin, F-actin, and runx2 in all cell morphotypes, each contributing to sparse and dense colonies. Proteomic analysis of these cells revealed a topologically-relevant interactome, focused on cytoskeletal and related enzymes//chaperone/signalling molecules linking DES to runx2 and alkaline phosphatase (ALP). Osteogenic differentiation led to mineralized woven bone nodules confined to dense colonies, significantly smaller and more circular with respect to controls. It significantly increased also colony-forming efficiency and the number of DES-immunoreactive dense colonies, and immunostaining of co-localized DES/runx-2 and DES/ALP. These data confirmed pre-osteoblastic and osteoblastic differentiation, woven bone formation, and mineralization, supporting DES as a player in the molecular pathway leading to the osteogenic fate of rBMSCs. Conclusion: Immunocytochemical and morphometric studies coupled with proteomic and bioinformatic analysis support the concept that DES may act as an upstream signal for the skeletogenic commitment of rBMSCs. Thus, we suggest that altered metabolism of osteoblasts, woven bone, and mineralization by dysfunctional BMSCs might early be revealed by changes in DES expression//levels. Non-union fractures and endocrine -- metabolic bone disorders like fibrous dysplasia and Paget disease of bone might take advantage of this molecular evidence for their early diagnosis and follow-up. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, fish research has seen significant advancements, driven by the expansion of aquaculture species production, the ornamental fish industry, and biomedical studies involving aquatic organisms. Immunohistochemistry (IHC) has emerged as a valuable tool in veterinary research for studying fish biology and pathology. However, the need for validated antibodies optimized for fish species remains a challenge, leading to potential false results and misinterpretations. This study systematically assessed the reactivity of commercially available antibodies (CK AE1/AE3, vimentin, S-100, GFAP, and desmin) in IHC assays on four fish species: Sparus aurata, Dicentrarchus labrax, Oncorhynchus mykiss, and Carassius auratus. We employed Western immunoblotting (WB) and IHC techniques to evaluate antibody specificity. The results revealed a good cross-reactivity for anti-cytokeratin AE1/AE3, GFAP, and S-100 antibodies, demonstrating specific staining. Conversely, vimentin and desmin antibodies displayed no reactivity. In conclusion, this research emphasizes the need for validating antibodies specifically for fish species to ensure accurate and reliable results in fish research involving IHC analysis. In recent years, research on fish has seen remarkable advancements, especially in aquaculture, ornamental fish industry, and biomedical studies. Immunohistochemistry has become crucial in fish research, aiding in physiological and pathological investigations. However, the use of antibodies originally developed for mammals has raised concerns about their cross-reactivity and specificity in fish. This study systematically evaluated the reactivity of commonly used antibodies for diagnostic purposes, especially in fish pathology, including pan-cytokeratin, vimentin, S-100, glial fibrillary acidic protein, and desmin in the tissue of Sparus aurata, Dicentrarchus labrax, Oncorhynchus mykiss, and Carassius auratus. Western immunoblotting was employed to assess antibody specificity. The results revealed that the pan-cytokeratin and glial fibrillary acidic protein antibodies cross-react with all tested fish species, while S-100 demonstrated specific staining in sea bream, goldfish, and rainbow trout tissues. Conversely, vimentin and desmin antibodies displayed no reactivity. In conclusion, the anti-cytokeratin clone AE1/AE3 and the polyclonal rabbit anti-glial fibrillary acidic protein antibody, which are extensively used in mammals, were validated for fish immunohistochemical studies. Regrettably, D33 anti-desmin and V9 anti-vimentin clones are unsuitable for immunohistochemistry in the tested fish. These findings underscore the need for species-specific antibodies and proper validation for accurate immunohistochemistry analyses in fish research. [ABSTRACT FROM AUTHOR]

Low complexity (LC) head domains 92 and 108 residues in length are, respectively, required for assembly of neurofilament light (NFL) and desmin intermediate filaments (IFs). As studied in isolation, these IF head domains interconvert between states of conformational disorder and labile, β-strand-enriched polymers. Solid-state NMR (ss-NMR) spectroscopic studies of NFL and desmin head domain polymers reveal spectral patterns consistent with structural order. A combination of intein chemistry and segmental isotope labeling allowed preparation of fully assembled NFL and desmin IFs that could also be studied by ss-NMR. Assembled IFs revealed spectra overlapping with those observed for β-strand-enriched polymers formed from the isolated NFL and desmin head domains. Phosphorylation and disease-causing mutations reciprocally alter NFL and desmin head domain self-association yet commonly impede IF assembly. These observations show how facultative structural assembly of LC domains via labile, β-strand-enriched self-interactions may broadly influence cell morphology.

Understanding the structure and function of intermediate filaments (IFs) is necessary in order to explain why more than 70 related IF genes have evolved in vertebrates while maintaining such dramatically tissue-specific expression. Desmin is a member of the large multigene family of IF proteins and is specifically expressed in myocytes. In an effort to elucidate its muscle-specific behavior, we have used a yeast two-hybrid system in order to identify desmin’s head binding partners. We described a mitochondrial and a lysosomal protein, NADH ubiquinone oxidoreductase core subunit S2 (NDUFS2), and saposin D, respectively, as direct desmin binding partners. In silico analysis indicated that both interactions at the atomic level occur in a very similar way, by the formation of a three-helix bundle with hydrophobic interactions in the interdomain space and hydrogen bonds at R16 and S32 of the desmin head domain. The interactions, confirmed also by GST pull-down assays, indicating the necessity of the desmin head domain and, furthermore, point out its role in function of mitochondria and lysosomes, organelles which are disrupted in myopathies due to desmin head domain mutations.

BackgroundDisordered and hypomineralized woven bone formation by dysfunctional mesenchymal stromal cells (MSCs) characterize delayed fracture healing and endocrine –metabolic bone disorders like fibrous dysplasia and Paget disease of bone. To shed light on molecular players in osteoblast differentiation, woven bone formation, and mineralization by MSCs we looked at the intermediate filament desmin (DES) during the skeletogenic commitment of rat bone marrow MSCs (rBMSCs), where its bone-related action remains elusive.ResultsMonolayer cultures of immunophenotypically- and morphologically - characterized, adult male rBMSCs showed co-localization of desmin (DES) with vimentin, F-actin, and runx2 in all cell morphotypes, each contributing to sparse and dense colonies. Proteomic analysis of these cells revealed a topologically-relevant interactome, focused on cytoskeletal and related enzymes//chaperone/signalling molecules linking DES to runx2 and alkaline phosphatase (ALP). Osteogenic differentiation led to mineralized woven bone nodules confined to dense colonies, significantly smaller and more circular with respect to controls. It significantly increased also colony-forming efficiency and the number of DES-immunoreactive dense colonies, and immunostaining of co-localized DES/runx-2 and DES/ALP. These data confirmed pre-osteoblastic and osteoblastic differentiation, woven bone formation, and mineralization, supporting DES as a player in the molecular pathway leading to the osteogenic fate of rBMSCs.ConclusionImmunocytochemical and morphometric studies coupled with proteomic and bioinformatic analysis support the concept that DES may act as an upstream signal for the skeletogenic commitment of rBMSCs. Thus, we suggest that altered metabolism of osteoblasts, woven bone, and mineralization by dysfunctional BMSCs might early be revealed by changes in DES expression//levels. Non-union fractures and endocrine – metabolic bone disorders like fibrous dysplasia and Paget disease of bone might take advantage of this molecular evidence for their early diagnosis and follow-up.

The objective of the study was to histologically describe the structure of the testis and epididymis, identifying the GAGs in them. Furthermore, the distribution of smooth muscle alpha‐actin, desmin, and vimentin is described of E. bilineatus, E. perditus, and U. vautieri, through immunohistochemical method. Two adult males of each species of the lizards were collected in southeastern Brazil. In the testicular albuginea, the presence of neutral glycoproteins was detected. In E. bilineatus, the epididymal duct epithelium is simple, composed of secretory cells, cylindrical in shape and acidophilic cytoplasm. In the testis of the three lizards there was a positive immunolocation accentuated for α‐SMA in the dense connective tissue of the tunica albuginea. A moderate reaction was observed in the connective tissue albuginous and in the layer of smooth muscle fibers in a circumferential arrangement of the epididymal duct. The immunolocation for desmin was accentuated in the fibers of the testicular albuginea of E. bilineatus, while in U. vautier and E. perditus was moderate. In the epididymis, only in E. perditus and E. bilineatus positive immunoreaction was verified. In the three lizards there were no observations of immunostaining for vimentin with the antibody utilized. [ABSTRACT FROM AUTHOR]

Desmin is a class III intermediate filament protein highly expressed in cardiac, smooth and striated muscle. Autosomal dominant or recessive mutations in the desmin gene (DES) result in a variety of diseases, including cardiomyopathies and myofibrillar myopathy, collectively called desminopathies. Here we describe the clinical, histological and radiological features of a Greek patient with a myofibrillar myopathy and cardiomyopathy linked to the c.734A>G,p.(Glu245Gly) heterozygous variant in the DES gene. Moreover, through ribonucleic acid sequencing analysis in skeletal muscle we show that this variant provokes a defect in exon 3 splicing and thus should be considered clearly pathogenic. [ABSTRACT FROM AUTHOR]

Introduction: Leiomyoma is the most common benign tumor of the uterus which usually presents with menorrhagia, pain in abdomen or both. In extremely rare cases where uterine leiomyoma can be difficult to distinguish from other uterine smooth muscle tumors, immunohistochemistry is used. This study was aimed to study the expression and sensitivity of immunohistochemical markers SMA, Desmin, CD 10 for uterine leiomyomas and to find average number of mitosis in uterine leiomyomas using Ki 67. Materials and methods: The present study was carried out in the Department of Pathology, Dhiraj General Hospital and Smt. Bhikhiben Kanjibhai Shah Medical Institute and Research Centre, Sumandeep Vidyapeeth, Piparia. A total 50 cases of uterine leiomyomas after its histological diagnosis were evaluated with immunohistochemical markers SMA, Desmin, CD 10 and Ki 67. Results: SMA expression was seen in all 50 cases of uterine leiomyomas with strong expression in 44 cases (88%). Strong SMA expression was seen more in usual leiomyomas as compared to leiomyomas with secondary changes. Desmin expression was also seen in all the 50 cases of uterine leiomyomas with moderate expression in 26 cases (52%). Weak CD 10 expression was seen in 15 cases of uterine leiomyomas (30%). Ki 67 was expressed very focally in only 3 cases of leiomyomas with mean value of only 0.3% tumor cells. Conclusions: Leimyomas was most frequently seen in the women in 4th decade. The most common clinical presentation was menorrhagia. SMA and Desmin expression was seen in all the cases with strong and moderate immunoreactivity respectively. SMA expression was found to be more specific than Desmin in uterine leiomyoma. Weak CD 10 and focal Ki 67 were expressed only in few cases and were found to be insignificant. [ABSTRACT FROM AUTHOR]

The aim of the study was to immunolocalize desmin, vimentin and S-100 proteins in the testes and epididymis of African striped ground squirrel (Xerus erythropus) and establish their spatial distribution in the two organs. Formalin fixed-paraffin- embedded sections of the testis and epididymis obtained from ten apparently healthy adult male African striped ground squirrels were processed routinely for immunohistochemistry, using primary antibodies specific to desmin, vimentin and S- 100. S-100The results showed that desmin reacted intensely in the myoid cells of the seminiferous tubules and smooth muscle cells of the epididymal ducts. It showed a moderate positive immunoreaction in the interstitial cells of Leydig, and the epididymal inter-ductal loose connective tissue. However, there was no immunoreaction of desmin in the spermatogonia or any other spermatogenic cell of the seminiferous tubule. Vimentin reacted intensely in the Leydig cells and spermatogonia. It showed moderate positive reaction in the myoid cells and the epididymal inter-ductal loose connective tissue. There was no immunoreaction of vimentin in the other spermatogenic cells (other than the spermatogonia). The S-100 proteins expressed a mild positive immunoreaction at the interstitial cells of Leydig, but negative immunoreaction in all other parts of testis and epididymis. Also, there was intense immunoreaction of desmin and vimentin and moderate immunoreaction of S-100 in the vascular endothelium in the testis and epididymis. In conclusion, the spatial distribution of desmin, vimentin and S-100 proteins in the testes and epididymis in the African striped ground squirrel showed some similarities and contrast with other mammals, giving insight into the functions of the proteins in these organs of the rodent. [ABSTRACT FROM AUTHOR]

BackgroundDesminopathy is a clinically heterogeneous muscle disease caused by over 60 different mutations in desmin. The most common mutation with a clinical phenotype in humans is an exchange of arginine to proline at position 350 of desmin leading to p.R350P. We created the first CRISPR-Cas9 engineered rat model for a muscle disease by mirroring the R350P mutation in humans.MethodsUsing CRISPR-Cas9 technology, Des c.1045-1046 (AGG > CCG) was introduced into exon 6 of the rat genome causing p.R349P. The genotype of each animal was confirmed via quantitative PCR. Six male rats with a mutation in desmin (n = 6) between the age of 120-150 days and an equal number of wild type littermates (n = 6) were used for experiments. Maximal plantar flexion force was measured in vivo and combined with the collection of muscle weights, immunoblotting, and histological analysis. In addition to the baseline phenotyping, we performed a synergist ablation study in the same animals.ResultsWe found a difference in the number of central nuclei between desmin mutants (1 ± 0.4%) and wild type littermates (0.2 ± 0.1%; P

Performing a supplementation intervention with creatine and protein, in conjunction with low-intensity endurance and resistance exercise is safe and has a positive effect on the quality of life in a patient with desminopathy.