Skeletal muscle desmin alterations following revascularization in peripheral artery disease claudicants.

Peripheral artery disease (PAD) is characterized by varying severity of arterial stenosis, exercise induced claudication, malperfused tissue precluding normal healing and skeletal muscle dysfunction. Revascularization interventions improve circulation, but post-reperfusion changes within the skeletal muscle are not well characterized. This study investigates if revascularization enhanced hemodynamics increases walking performance with concurrent improvement of mitochondrial function and reverses abnormal skeletal muscle morphological features that develop with PAD. Fifty-eight patients completed walking performance testing and muscle biopsy before and 6 months after revascularization procedures. Muscle fiber morphology, desmin structure, and mitochondria respiration assessments before and after the revascularization were evaluated. Revascularization improved limb hemodynamics, walking function, and muscle morphology. Qualitatively not all participants recovered normal structural architecture of desmin in the myopathic myofibers after revascularization. Heterogenous responses in the recovery of desmin structure following revascularization may be caused by other underlying factors not reversed with hemodynamic improvements. Revascularization interventions clinically improve patient walking ability and can reverse the multiple subcellular functional and structural abnormalities in muscle cells. Further study is needed to characterize desmin structural remodeling with improvements in skeletal muscle morphology and function.

Phenotype and Clinical Outcomes in Desmin-Related Arrhythmogenic Cardiomyopathy.

BACKGROUND: Desmin (DES) pathogenic variants cause a small proportion of arrhythmogenic cardiomyopathy (ACM). Outcomes data on DES-related ACM are scarce. OBJECTIVES: This study sought to provide information on the clinical phenotype and outcomes of patients with ACM caused by pathogenic variants of the DES gene in a multicenter cohort. METHODS: We collected phenotypic and outcomes data from 16 families with DES-related ACM from 10 European centers. We assessed in vitro DES aggregates. Major cardiac events were compared to historical controls with lamin A/C truncating variant (LMNA-tv) and filament C truncating variant (FLNC-tv) ACM. RESULTS: Of 82 patients (54% males, median age: 36 years), 11 experienced sudden cardiac death (SCD) (n = 7) or heart failure death (HFd)/heart transplantation (HTx) (n = 4) before clinical evaluation. Among 68 survivors, 59 (86%) presented signs of cardiomyopathy, with left ventricular (LV) dominant (50%) or biventricular (34%) disease. Mean LV ejection fraction was 51% ± 13%; 36 of 53 had late gadolinium enhancement (ring-like pattern in 49%). During a median of 6.73 years (Q1-Q3: 3.55-9.52 years), the composite endpoint (sustained ventricular tachycardia, aborted SCD, implantable cardioverter-defibrillator therapy, SCD, HFd, and HTx) was achieved in 15 additional patients with HFd/HTx (n = 5) and SCD/aborted SCD/implantable cardioverter-defibrillator therapy/sustained ventricular tachycardia (n = 10). Male sex (P = 0.004), nonsustained ventricular tachycardia (P = 0.017) and LV ejection fraction ≤50% (P = 0.012) were associated with the composite endpoint. Males with DES variants had similar outcomes to historical FLNC-tv and LMNA-tv controls. However, females showed better outcomes than those with LMNA-tv. In vitro experiments showed the characteristic finding of DES aggregates in 7 of 12 variants. CONCLUSIONS: DES ACM is associated with poor outcomes which can be predicted with potentially successful treatments, underscoring the importance of familial evaluation and genetic studies to identify at risk individuals.

Partial loss of desmin expression due to a leaky splice site variant in the human DES gene is associated with neuromuscular transmission defects.

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.

Primary Pulmonary Myxoid Sarcoma and Thoracic Angiomatoid Fibrous Histiocytoma: Two Sides of the Same Coin?

Primary pulmonary myxoid sarcoma (PPMS) and thoracic angiomatoid fibrous histiocytoma (AFH) are rare neoplasms with EWSR1 fusions and overlapping morphology. Both tumor types often show epithelial membrane antigen expression, but AFH characteristically co-expresses desmin. We encountered a case of PPMS with the unexpected finding of patchy, strong anaplastic lymphoma kinase (ALK) (previously reported in AFH) and synaptophysin expression. We evaluated a cohort of PPMS and thoracic AFH with systematic morphologic comparison and surveyed for aberrant expression of ALK and synaptophysin. Medical records and slides were reviewed for 16 molecularly confirmed cases of PPMS (n=5) and thoracic AFH (n=11). Each case was scored for morphologic characteristics typical of PPMS and/or AFH. ALK, synaptophysin, chromogranin, desmin, and epithelial membrane antigen immunostains were performed on cases with available tissue. AFH and PPMS cases showed similar age at presentation and long-term tumor behavior. Almost all cases of PPMS and AFH had a fibrous pseudocapsule and lymphoid rim. All PPMS had myxoid stroma and reticular growth pattern, but these features were also present in a subset of AFH. Synaptophysin expression was present in 6 of 11 AFH and 1 of 5 PPMS; all tested cases were negative for chromogranin (n=15). One case of AFH and 1 case of PPMS showed focally strong coexpression of synaptophysin and ALK. AFH and PPMS show considerable clinicopathologic overlap. When supportive, the immunohistochemical findings described may aid in diagnosis before molecular confirmation. PPMS and AFH may be morphologic variants of the same clinicopathologic entity, which can show more immunophenotypic variability than previously reported.

[Clinical and genetic analysis of a patient with Desminopathy manifesting initially with myalgia after lower limb activity].

OBJECTIVE: To explore the clinical characteristics and genetic variant of a patient with desminopathy manifesting with atypical symptoms. METHODS: A patient who was admitted to the Department of Neurology of Jing'an District Central Hospital on February 24, 2021 was selected as the study subject. Clinical data, laboratory tests, muscle pathology, muscle magnetic resonance imaging (MRI) and genetic testing of the patient were retrospectively analyzed. RESULTS: The patient had developed myalgia after lower limb activity, and gradually developed asymmetrical muscle weakness and atrophy of the lower limbs. Cardiac examination revealed atrioventricular block and decreased left ventricular diastolic function. Muscle MRI showed that semitendinosus, sartorius, gracilis, fibula, gastronemius and supinator muscles were selectively involved at the early stage. Muscle biopsy confirmed pathological changes of desmin positive myofibrils. Genetic testing revealed that the patient has harbored a c.1024A>G (p.n342d) missense variant in exon 6 of the DES gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic (PS4_moderate+PM2_supporting+PP3_moderate+PP1). CONCLUSION: Desmin disease has a great clinical heterogeneity. Postexercise myalgia of lower limbs is a rare clinical phenotype. For patients harboring the c.1024A>G (p.n342d) variant of the DES gene, in addition to semitendinosus and fibula, Cardiac involvement is relatively insidious and easy to be ignored in clinic. Timely muscle MRI, muscle biopsy and gene detection will help the early diagnosis of the disease.

EWSR1::WT1 Fusions in Neoplasms Other Than Conventional Desmoplastic Small Round Cell Tumor: Three Tumors Occurring Outside the Female Genital Tract.

Desmoplastic small round cell tumor (DSRCT) is a high-grade, primitive round cell sarcoma classically associated with prominent desmoplastic stroma, coexpression of keratin and desmin, and a characteristic EWSR1::WT1 gene fusion. DSRCT typically arises in the abdominopelvic cavity of young males with diffuse peritoneal spread and poor overall survival. Although originally considered to be pathognomonic for DSRCT, EWSR1::WT1 gene fusions have recently been detected in rare tumors lacking the characteristic morphologic and immunohistochemical features of DSRCT. Here, we report 3 additional cases of neoplasms other than conventional DSCRCT with EWSR1::WT1 gene fusions that occurred outside the female genital tract. Two occurred in the abdominopelvic cavities of a 27-year-old man and a 12-year-old girl, whereas the third arose in the axillary soft tissue of an 85-year-old man. All cases lacked prominent desmoplastic stroma and were instead solid and cystic with peripheral fibrous pseudocapsules and occasional intervening fibrous septa. Necrosis was either absent (1/3) or rare (2/3), and mitotic activity was low (<1 to 3 per 10 hpf). In immunohistochemical studies, there was expression of smooth muscle actin (3/3) and desmin (3/3), rare to focal reactivity for EMA (2/3), and variable expression of CK AE1/AE3 (1/3). Myogenin and MyoD1 were negative, and C-terminus-specific WT1 was positive in both cases tested (2/2). All 3 tumors followed a more indolent clinical course with 2 cases demonstrating no evidence of disease at 20 and 44 months after resection. The patient from case 3 died of other causes at 14 months with no evidence of recurrence. DNA methylation profiling showed that the 3 cases clustered with DSRCT; however, they demonstrated fewer copy number variations with 2 cases having a flat profile (0% copy number variation). Differential methylation analysis with hierarchical clustering further showed variation between the 3 cases and conventional DSRCT. Although further study is needed, our results, in addition to previous reports, suggest that EWSR1::WT1 gene fusions occur in rare and seemingly distinctive tumors other than conventional DSRCT with indolent behavior. Proper classification of these unusual soft tissue tumors with EWSR1::WT1 gene fusions requires direct correlation with tumor morphology and clinical behavior, which is essential to avoid overtreatment with aggressive chemotherapy.

Direct observation of oriented behavior of actin filaments interacting with desmin intermediate filaments.

BACKGROUND: Associations between actin filaments (AFs) and intermediate filaments (IFs) are frequently observed in living cells. The crosstalk between these cytoskeletal components underpins cellular organization and dynamics; however, the molecular basis of filamentous interactions is not fully understood. Here, we describe the mode of interaction between AFs and desmin IFs (DIFs) in a reconstituted in vitro system. METHODS: AFs (rabbit skeletal muscle) and DIFs (chicken gizzard) were labeled with fluorescent dyes. DIFs were immobilized on a heavy meromyosin (HMM)-coated collodion surface. HMM-driven AFs with ATP hydrolysis was assessed in the presence of DIFs. Images of single filaments were obtained using fluorescence microscopy. Vector changes in the trajectories of single AFs were calculated from microscopy images. RESULTS: AF speed transiently decreased upon contact with DIF. The difference between the incoming and outgoing angles of a moving AF broadened upon contact with a DIF. A smaller incoming angle tended to result in a smaller outgoing angle in a nematic manner. The percentage of moving AFs decreased with an increasing DIF density, but the speed of the moving AFs was similar to that in the no-desmin control. An abundance of DIFs tended to exclude AFs from the HMM-coated surfaces. CONCLUSIONS: DIFs agitate the movement of AFs with the orientation. DIFs can bind to HMMs and weaken actin-myosin interactions. GENERAL SIGNIFICANCE: The study indicates that apart from the binding strength, the accumulation of weak interactions characteristic of filamentous structures may affect the dynamic organization of cell architecture.

Woven bone formation and mineralization by rat mesenchymal stromal cells imply increased expression of the intermediate filament desmin.

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.

Desmin immunostaining is effective for improving interobserver variability in the depth assessment of the submucosal invasion of colorectal cancers.

Tumor depth evaluation is essential for pathological tumor staging because it affects clinical management as an independent risk factor for lymph node metastasis in colorectal cancers. However, poor interobserver variability of invasion depth has been reported. This study aimed to clarify the effectiveness of desmin immunostaining in the histological diagnosis of colorectal cancer. Overall, 63 sets of slides of colorectal cancer stained with hematoxylin and eosin (H&E) and desmin were prepared and independently reviewed by four examiners. After reviewing the desmin-stained slides, the interobserver variability of H&E slides alone was significantly improved for all examiners. For the assessment of Tis vs. T1, the sensitivity and accuracy were significantly improved for all examiners by combining H&E and desmin immunostaining. For the diagnosis of T1b vs. Tis or T1a, specificity and accuracy were significantly improved by adding desmin immunostaining. Ancillary desmin staining to assess submucosal invasion in colorectal cancers significantly improved interobserver agreement, led to efficient screening of T1 cancers, and reduced excessive T1b diagnoses. The combination of desmin immunostaining and H&E staining is highly recommended for diagnosing invasive colorectal cancer.

[Fibrocartilaginous lipoma: a clinicopathological analysis of six cases].

Objective: To investigate the clinicopathological characteristics, immunophenotype, molecular genetics and differential diagnoses of fibrocartilaginous lipomas which consist of adipose tissue, fibrocartilage and fibrous elements. Methods: The clinicopathological features, immunohistochemical profiles and molecular profiles in six cases of fibrocartilaginous lipomas diagnosed at Foshan Traditional Chinese Medicine Hospital, Fudan University Shanghai Cancer Center, the Fifth Affiliated Hospital of Zhengzhou University and the Fourth Affiliated Hospital of Harbin Medical University from January 2017 to February 2022 were included. The follow-up information, diagnosis and differential diagnoses were evaluated. Results: There were three males and three females with a median age of 53 years (range 36-69 years) at presentation. Tumors were located in the extremities, the head and neck region and trunk; and presented as painless masses that were located in the subcutaneous tissue or deep soft tissue. Grossly, three cases were well defined with thin capsule, one case was well circumscribed without capsule, two cases were surrounded by some skeletal muscle. The tumors were composed of fatty tissue with intermingled gray-white area. The tumors ranged from 1.50-5.50 cm (mean 2.92 cm). Microscopically, the hallmark of these lesions was the complex admixture of mature adipocytes, fibrocartilage and fibrous element in varying proportions; the fibrocartilage arranged in a nodular, sheet pattern with some adipocytes inside. Tumor cells had a bland appearance without mitotic activity. Immunohistochemical analysis using antibodies to SMA, desmin, S-100, SOX9, HMGA2, RB1, CD34, adipopholin was performed in six cases; the fibrocartilage was positive for S-100 and SOX9, adipocytes were positive for S-100, adipopholin and HMGA2; CD34 was expressed in the fibroblastic cells, while desmin and SMA were negative. Loss of nuclear RB1 expression was not observed. Other genetic abnormalities had not been found yet in four cases. Follow-up information was available in six cases; there was no recurrence in five, and one patient only underwent biopsy of the mass. Conclusions: Fibrocartilaginous lipoma is a benign lipomatous tumor with mature adipocytes, fibrocartilage and fibrous elements. By immunohistochemistry, they show the expression of fat and cartilage markers. No specific molecular genetics changes have been identified so far. Familiarity with its clinicopathological features helps the distinction from its morphologic mimics.

A primary multiple pleomorphic rhabdomyosarcoma of the heart in an adult dog.

BACKGROUND: Heart tumors are rare in dogs. They can be benign or malignant. Clinical signs depend primarily on the location of the tumor and its effect on blood flow. CASE PRESENTATION: An eleven-year-old crossbreed male dog lethargic and anorectic for previous 3 days was presented to the veterinary clinic. The focused ultrasound assessment with sonograms in trauma (FAST) revealed multiple tumors in the heart which were then confirmed in echocardiographic examination performed by a veterinary cardiologist. Due to the poor general condition and grave prognosis, the dog was humanely euthanized. The autopsy revealed numerous intracardiac tumors in all four heart chambers. No proliferative changes were found in other organs either in thoracic or abdominal cavity. Immunohistochemical examination was performed using formalin-fixed, paraffin-embedded tissue from heart masses. The antibodies against myoglobin, desmin, smooth muscle actin, vimentin, CD34, S100, and pan-cytokeratin (AE1/AE3) were used. Microscopically, the tumor was composed of fascicles of spindle-shaped cells with pale eosinophilic cytoplasm with round, oval, and focally elongated nuclei and one or two prominent nucleoli. The tumor cells showed strong diffuse cytoplasmic immunopositivity for myoglobin and vimentin and focal staining for desmin. Immunostainings for smooth muscle actin-SMA, CD34, pan-cytokeratin, S-100 protein were negative. The immunohistochemical staining pattern confirmed rhabdomyosarcoma. CONCLUSIONS: This is the first description of the primary multiple heart rhabdomyosarcoma in a dog.

Clinicopathological and immunohistochemical analysis of maxillofacial granular cell tumor.

OBJECTIVES: To analyze the clinicopathological features of maxillofacial granular cell tumors (GCT) with the aid of immunohistochemical staining. METHODS: Seven cases of maxillofacial GCT were retrospectively collated, and the microscopic morphology of maxillofacial GCT was analyzed. The expression of S-100, neuron-specific enolase (NSE), SOX-10, CD68, actin, desmin, and Ki-67 in GCT was detected by immunohistochemical staining. The cases were observed in the follow-ups after clinical treatment. RESULTS: All seven GCT tumors lacked envelopes and were poorly defined. Microscopically, the sizes of the tumor cells were large and appeared with inconspicuous cell membranes, forming a syncytium-like appearance. The cytoplasm was filled with characteristic eosinophilic granules. The immunohistochemical results showed that six cases were NSE-positive, five cases were S-100-positive, seven cases were CD68-positive, five cases were SOX-10-positive, one case was actin-positive, and seven cases were desmin-negative. The Ki-67 index did not exceed 5% in all cases. In the follow-up sessions, none of the six cases presented a recurrence. CONCLUSIONS: Maxillofacial GCT has a characteristic histological structure. Immunohistochemical S-100, CD68, and other indicators can assist in diagnosis, and the prognosis is good after clinical resection.

First report of primary testicular leiomyosarcoma in two dogs.

BACKGROUND: Testicular tumours are common in dogs and, among them, interstitial cell tumours, seminomas and sustentacular cell tumours are the most reported. Mesenchymal testicular tumours are rarely reported in humans as in veterinary medicine where only three cases of sarcomas (leiomyomas and leomyosarcomas) have been described in two stallions and in a ram. CASE PRESENTATION: The present cases regarded a 12-year-old mixed-breed dog and a 10-year-old American Staffordshire Terrier that underwent bilateral orchiectomy. Formalin fixed testes were referred for histopathological diagnosis. At gross examination, in one of the testes of both dogs, a white, firm and variably cystic testicular mass, effacing and replacing the testicular parenchyma was detected. Samples were collected from both neoplastic and contralateral testes, routinely processed for histology and serial sections were also examined immunohistochemically with primary antibodies against cytokeratins, vimentin, Von Willebrand factor, inhibin-α, α-smooth muscle actin, smooth muscle myosin and desmin. Histopathological features as well as the immunohistochemical results, positive for vimentin, actin, myosin and desmin, confirmed the mesenchymal origin and the myoid phenotype of both testicular tumours supporting the diagnoses of leiomyosarcoma. CONCLUSIONS: To the authors knowledge these are the first cases of primary testicular sarcoma reported in the canine species. However, even rare, these tumours deserve to be considered in routine diagnosis when a testicular spindle cell tumour is observed. The immunohistochemical panel applied was useful to distinguish the present tumours from undifferentiated Sertoli cell tumours confirming the diagnosis of leiomyosarcoma.

Pericardial malignant mesothelioma diagnosed in a dog by immunocytochemistry of the pericardial fluid: a case report.

BACKGROUND: Pericardial effusions are one of the most common cardiac diseases in dogs. Common causes of haemorrhagic pericardial effusions include neoplasia, such as hemangiosarcoma, mesothelioma, chemodectoma, and ectopic thyroid tumours, and benign idiopathic pericardial effusion. Distinguishing among reactive mesothelial cells, malignant mesothelioma, and adenocarcinoma in body effusions is a diagnostic challenge. Therefore, the author aimed to discover whether the observed cells were reactive mesothelial, mesothelioma, or adenocarcinoma cells through immunocytochemistry using five markers (cytokeratin, vimentin, desmin, E-cadherin, and calretinin) in a canine patient. CASE PRESENTATION: A 2.1 kg, spayed female, 10-year-old Yorkshire Terrier dog presented to a local hospital with dyspnoea and was evaluated for pericardial effusion. The presence of pericardial fluid was confirmed, and she was referred to our hospital for further evaluation. In cytological evaluation, cells shed individually or in clusters were observed, along with numerous non-degenerative neutrophils and macrophages. The cells showed binucleation, anisocytosis, anisokaryosis, abnormal nucleoli, abundant basophilic cytoplasm, high nuclear-cytoplasmic ratio, and coarse chromatin. Large atypical multinucleate cells were also observed. Erythrophagia was observed, indicating chronic haemorrhage. Immunocytochemistry using pericardial fluid was positive for cytokeratin, vimentin, desmin, E-cadherin, and calretinin. Therefore, malignant mesothelioma was diagnosed. CONCLUSIONS: Immunocytochemistry is a very useful diagnostic technique because it can determine whether several fluorescent markers are simultaneously expressed in the same cell. Further, E-cadherin and calretinin can be used for the differential diagnosis of reactive mesothelial cells, malignant mesothelioma, and adenocarcinoma in dogs.

Upregulated desmin/integrin ß1/MAPK axis promotes elastic cartilage regeneration with increased ECM mechanical strength.

Elastic cartilage tissue engineering is promising for providing available scaffolds for plastic reconstructive surgery. The insufficient mechanical strength of regenerative tissue and scarce resources of reparative cells are two obstacles for the preparation of tissue-engineered elastic cartilage scaffolds. Auricular chondrocytes are important reparative cells for elastic cartilage tissue engineering, but resources are scarce. Identifying auricular chondrocytes with enhanced capability of elastic cartilage formation is conducive to reducing the damage to donor sites by decreasing the demand on native tissue isolation. Based on the biochemical and biomechanical differences in native auricular cartilage, we found that auricular chondrocytes with upregulated desmin expressed more integrin ß1, forming a stronger interaction with the substrate. Meanwhile, activated MAPK pathway was found in auricular chondrocytes highly expressing desmin. When desmin was knocked down, the chondrogenesis and mechanical sensitivity of chondrocytes were both impaired, and the MAPK pathway was downregulated. Finally, auricular chondrocytes highly expressing desmin regenerated more elastic cartilage with increased ECM mechanical strength. Therefore, desmin/integrin ß1/MAPK signaling can not only serve as a selection standard but also a manipulation target of auricular chondrocytes to promote elastic cartilage regeneration.

Development of Scaffold-Free Three-Dimensional Cholangiocyte Organoids to Study the Progression of Primary Sclerosing Cholangitis.

Organoids are novel in vitro models to study intercellular cross talk between the different types of cells in disease pathophysiology. To better understand the underlying mechanisms driving the progression of primary sclerosing cholangitis (PSC), scaffold-free multicellular three-dimensional cholangiocyte organoids (3D-CHOs) were developed using primary liver cells derived from normal subjects and patients with PSC. Human liver samples from healthy donors and patients with PSC were used to isolate primary cholangiocytes [epithelial cell adhesion molecule (EpCam)+/ cytokeratin-19+], liver endothelial cells (CD31+), and hepatic stellate cells (HSCs; CD31-/CD68-/desmin+/vitamin A+). 3D-CHOs were formed using cholangiocytes, HSCs, and liver endothelial cells, and kept viable for up to 1 month. Isolated primary cell lines and 3D-CHOs were further characterized by immunofluorescence, quantitative RT-PCR, and transmission electron microscopy. Transcription profiles for cholangiocytes (SOX9, CFTR, EpCAM, AE, SCT, and SCTR), fibrosis (ACTA2, COL1A1, DESMIN, and TGFß1), angiogenesis (PECAM, VEGF, CDH5, and vWF), and inflammation (IL-6 and TNF-α) confirmed PSC phenotypes of 3D-CHOs. Because cholangiocytes develop a neuroendocrine phenotype and express neuromodulators, confocal immunofluorescence was used to demonstrate localization of the neurokinin-1 receptor within cytokeratin-19+ cholangiocytes and desmin+ HSCs. Moreover, 3D-CHOs from patients with PSC confirmed PSC phenotypes with up-regulated neurokinin-1 receptor, tachykinin precursor 1, and down-regulated membrane metalloendopeptidase. Scaffold-free multicellular 3D-CHOs showed superiority as an in vitro model in mimicking PSC in vivo phenotypes compared with two-dimensional cell culture, which can be used in PSC disease-related research.

Clinicopathologic and genetic characterization of angiofibroma of soft tissue: a study of 12 cases including two cases with AHRR::NCOA3 gene fusion.

AIMS: Angiofibroma of soft tissue (AFST) is a benign tumour characterised by prominent arborizing blood vessels throughout the lesion. Approximately two-thirds of AFST cases were reported to have AHRR::NCOA2 fusion, and only two cases have been reported to have other gene fusions: GTF2I::NCOA2 or GAB1::ABL1. Although AFST is included in fibroblastic and myofibroblastic tumours in the World Health Organization's 2020 classification, histiocytic markers, especially CD163, have been reported to be positive in almost all examined cases, and it still remains the possibility of a fibrohistiocytic nature of the tumour. Therefore, we aimed to clarify the genetic and pathological spectrum of AFST and identify whether histiocytic marker-positive cells were true neoplastic cells. METHODS AND RESULTS: We evaluated 12 AFST cases, which included 10 cases with AHRR::NCOA2 and two with AHRR::NCOA3 fusions. Pathologically, nuclear palisading, which has not been reported in AFST, was detected in two cases. Furthermore, one tumour resected by additional wide resection revealed severe infiltrative growth. Immunohistochemical analysis indicated varying levels of desmin-positive cells in nine cases, whereas CD163- and CD68-positive cells were diffusely distributed in all 12 cases. We also performed double immunofluorescence staining and immunofluorescence in situ hybridisation in four resected cases with >10% desmin-positive tumour cells. The results suggested that the CD163-positive cells differed from desmin-positive cells with AHRR::NCOA2 fusion in all four cases. CONCLUSION: Our findings suggested that AHRR::NCOA3 could be the second most frequent fusion gene, and histiocytic marker-positive cells are not genuine neoplastic cells in AFST.

Astragalus polysaccharide alleviates angiotensin II-induced glomerular podocyte dysfunction by inhibiting the expression of RARRES1 and LCN2.

Podocyte loss is a predictor of kidney disease development, including diabetic nephropathy. Astragalus polysaccharide (APS) was considered a renoprotective drug, whereas the mechanisms operated by APS on podocyte dysfunction are rarely mentioned. This study aims at the mechanistic underlying of APS on angiotensin II (Ang II)-induced podocyte dysfunction. Mouse glomerular podocytes MPC5 were induced with Ang II, the morphologic changes were observed and nephrin, desmin and Wilms' tumour protein-1 (WT-1) levels were determined. The MPC5 cells were treated with APS (50, 100 and 200 µg/mL) and transduced with retinoic acid receptor responder protein 1 (RARRES1) overexpression vectors. The expression of RARRES1, lipocalin-2 (LCN2), nephrin and desmin was tested, MPC5 cell viability and apoptosis were evaluated, and the levels of an endocytotic receptor megalin, Bcl-2, Bax, interleukin (IL)-6, IL-1ß and tumour necrosis factor (TNF)-α were assessed. The binding of RARRES1 to LCN2 was predicted and verified. Mice were infused with Ang II to evaluate histopathological alterations and 24-h urinary albumin content. Ang II induction suppressed MPC5 cell viability, reduced the expression of nephrin, WT-1, megalin and Bcl-2, and augmented the expression of desmin, Bax, IL-6, IL-1ß and TNF-α, which were significantly nullified by APS treatment. RARRES1 interacted with LCN2, and APS treatment inhibited RARRES1 and LCN2 expression in a dose-dependent manner, thereby alleviating Ang II-induced podocyte dysfunction. Ang II infusion in mice facilitated pathological alterations in renal tissues and increased urinary albumin content, which were attenuated after APS treatment. Overall, APS treatment alleviated Ang II-induced podocyte dysfunction by inhibiting RARRES1/LCN2 expression and blocked kidney injury development in vivo.

Mapping the Immune Cell Microenvironment with Spatial Profiling in Muscle Tissue Injected with the Venom of Daboia russelii.

Pathological and inflammatory events in muscle after the injection of snake venoms vary in different regions of the affected tissue and at different time intervals. In order to study such heterogeneity in the immune cell microenvironment, a murine model of muscle necrosis based on the injection of the venom of Daboia russelii was used. Histological and immunohistochemical methods were utilized to identify areas in muscle tissue with a different extent of muscle cell damage, based on the presence of hypercontracted muscle cells, a landmark of necrosis, and on the immunostaining for desmin. A gradient of inflammatory cells (neutrophils and macrophages) was observed from heavily necrotic areas to less damaged and non-necrotic areas. GeoMx® Digital Spatial Profiler (NanoString, Seattle, WA, USA) was used for assessing the presence of markers of various immune cells by comparing high-desmin (nondamaged) and low-desmin (damaged) regions of muscle. Markers of monocytes, macrophages, M2 macrophages, dendritic cells, neutrophils, leukocyte adhesion and migration markers, and hematopoietic precursor cells showed higher levels in low-desmin regions, especially in samples collected 24 hr after venom injection, whereas several markers of lymphocytes did not. Moreover, apoptosis (BAD) and extracellular matrix (fibronectin) markers were also increased in low-desmin regions. Our findings reveal a hitherto-unknown picture of immune cell microheterogeneity in venom-injected muscle which greatly depends on the extent of muscle cell damage and the time lapse after venom injection.

[MicroRNA-22-3p Regulates the Expression of Kruppel-like Factor 6 to Affect the Cardiomyocyte-like Differentiation of Bone Marrow Mesenchymal Stem Cell].

Objective To explore the effect of microRNA-22-3p (miR-22-3p) regulating the expression of Kruppel-like factor 6 (KLF6) on the cardiomyocyte-like differentiation of bone marrow mesenchymal stem cell (BMSC). Methods Rat BMSC was isolated and cultured,and the third-generation BMSC was divided into a control group,a 5-azacytidine(5-AZA)group,a mimics-NC group,a miR-22-3p mimics group,a miR-22-3p mimics+pcDNA group,and a miR-22-3p mimics+pcDNA-KLF6 group.Real-time fluorescent quantitative PCR (qRT-PCR) was carried out to determine the expression of miR-22-3p and KLF6 in cells.Immunofluorescence staining was employed to detect the expression of Desmin,cardiac troponin T (cTnT),and connexin 43 (Cx43).Western blotting was employed to determine the protein levels of cTnT,Cx43,Desmin,and KLF6,and flow cytometry to detect the apoptosis of BMSC.The targeting relationship between miR-22-3p and KLF6 was analyzed by dual luciferase reporter gene assay. Results Compared with the control group,5-AZA up-regulated the expression of miR-22-3p (q=7.971,P<0.001),Desmin (q=7.876,P<0.001),cTnT (q=10.272,P<0.001),and Cx43 (q=6.256,P<0.001),increased the apoptosis rate of BMSC (q=12.708,P<0.001),and down-regulated the mRNA (q=20.850,P<0.001) and protein (q=11.080,P<0.001) levels of KLF6.Compared with the 5-AZA group and the mimics-NC group,miR-22-3p mimics up-regulated the expression of miR-22-3p (q=3.591,P<0.001;q=11.650,P<0.001),Desmin (q=5.975,P<0.001;q=13.579,P<0.001),cTnT (q=7.133,P<0.001;q=17.548,P<0.001),and Cx43 (q=4.571,P=0.037;q=11.068,P<0.001),and down-regulated the mRNA (q=7.384,P<0.001;q=28.234,P<0.001) and protein (q=4.594,P=0.036;q=15.945,P<0.001) levels of KLF6.The apoptosis rate of miR-22-3p mimics group was lower than that of 5-AZA group (q=8.216,P<0.001).Compared with the miR-22-3p mimics+pcDNA group,miR-22-3p mimics+pcDNA-KLF6 up-regulated the mRNA(q=23.891,P<0.001) and protein(q=13.378,P<0.001)levels of KLF6,down-regulated the expression of Desmin (q=9.505,P<0.001),cTnT (q=10.985,P<0.001),and Cx43 (q=8.301,P<0.001),and increased the apoptosis rate (q=4.713,P=0.029).The dual luciferase reporter gene experiment demonstrated that KLF6 was a potential target gene of miR-22-3p. Conclusion MiR-22-3p promotes cardiomyocyte-like differentiation of BMSC by inhibiting the expression of KLF6.