Angioleiomyoma: An Update with a 142-Case Series.

Angioleiomyomas are uncommon, noncancerous, smooth muscle tumors that primarily arise from blood vessels. Previous studies have yielded limited data due to the lack of interdisciplinary approaches or restricted patient pools. This study aims to provide a comprehensive analysis of angioleiomyomas, including the demographic, clinical, radiological, and histopathological features, with a large number of patients. Conducted as a retrospective investigation at a single center from January 2005 to June 2023, this study involved 142 patients. Relevant information was extracted from electronic medical records, covering clinical, radiological, histological, and demographic details. Angioleiomyomas mostly occurred at age 59 (1-87), predominately affect females (53%) and commonly arise in subcutaneous tissue (85%) and the lower limbs (76%). MRI findings revealed characteristic signals, with a high prevalence of the solid histologic type (65%), often displaying a reticular sign. Smooth muscle Actin was universally present (n = 95/95), while Desmin and Caldesmon showed positive expression in 83% (n = 71/85) and 98% (n = 92/94) of cases, respectively. This study presents an updated and comprehensive analysis of angioleiomyomas. Typically appearing as well-defined nodules in the extremities, these tumors can be effectively diagnosed using MRI, though histopathological analysis is generally essential for confirmation. Treatment primarily involves straightforward excision, with notable low complication and recurrence rates.

The gene expression of CALD1, CDH2, and POSTN in fibroblast are related to idiopathic pulmonary fibrosis.

Introduction: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive lung dysfunction due to excessive collagen production and tissue scarring. Despite recent advancements, the molecular mechanisms remain unclear. Methods: RNA sequencing identified 475 differentially expressed genes (DEGs) in the TGF-ß1-induced primary lung fibrosis model. Gene expression chips GSE101286 and GSE110147 from NCBI gene expression omnibus (GEO) database were analyzed using GEO2R, revealing 94 DEGs in IPF lung tissue samples. The gene ontology (GO) and pathway enrichment, Protein-protein interaction (PPI) network construction, and Maximal Clique Centrality (MCC) scoring were performed. Experimental validation included RT-qPCR, Immunohistochemistry (IHC), and Western Blot, with siRNA used for gene knockdown. A co-expression network was constructed by GeneMANIA. Results: GO enrichment highlighted significant enrichment of DEGs in TGF-ß cellular response, connective tissue development, extracellular matrix components, and signaling pathways such as the AGE-RAGE signaling pathway and ECM-receptor interaction. PPI network analysis identified hub genes, including FN1, COL1A1, POSTN, KIF11, and ECT2. CALD1 (Caldesmon 1), CDH2 (Cadherin 2), and POSTN (Periostin) were identified as dysregulated hub genes in both the RNA sequencing and GEO datasets. Validation experiments confirmed the upregulation of CALD1, CDH2, and POSTN in TGF-ß1-treated fibroblasts and IPF lung tissue samples. IHC experiments probed tissue-level expression patterns of these three molecules. Knockdown of CALD1, CDH2, and POSTN attenuated the expression of fibrotic markers (collagen I and α-SMA) in response to TGF-ß1 stimulation in primary fibroblasts. Co-expression analysis revealed interactions between hub genes and predicted genes involved in actin cytoskeleton regulation and cell-cell junction organization. Conclusions: CALD1, CDH2, and POSTN, identified as potential contributors to pulmonary fibrosis, present promising therapeutic targets for IPF patients.

Proximal Tibia Primary Leiomyosarcoma: A Case Report and Review of Literature.

The paper at hand presents a unique case of leiomyosarcoma (LMS) involving the left leg in a 56-year-old patient. This individual experienced pain and the presence of a mass for approximately eight months before seeking medical attention. A diagnostic biopsy revealed the presence of multinucleated pleomorphic cells arranged in intersecting fascicles upon immunohistochemistry (IHC) staining for vimentin, caldesmon, and smooth muscle actin. The rarity of LMS in the extremities highlights the need for further understanding and research to determine the most suitable treatment approaches for such patients. In this specific case, the patient underwent tumor excision followed by reconstruction using a megaprosthesis. This report emphasizes the importance of considering unique treatment strategies when dealing with rare neoplasms like LMS in the extremities. As medical knowledge continues to evolve, gaining insights into the optimal management of such cases will be crucial for improving patient outcomes and overall prognosis.

Effect of caldesmon mutations in the development of zebrafish embryos.

Cancer is a profound medical concern and better treatments are needed for cancer patients. Therefore, new cancer targets are constantly being studied. These targets need not only be relevant for cancer progression, but their modulation needs to be tolerated reasonably well by the host. Caldesmon is one of these proposed novel targets for cancer therapy. Therefore, we analyzed effects of caldesmon mutations in normal development using genetically modified zebrafish embryos. We analyzed mutations in both zebrafish caldesmon genes, cald1a and cald1b and analyzed effects of either mutation alone or as in combination in double homozygous embryos using molecular, morphological and functional analyses. The effects of caldesmon mutations were mild and the gross development of zebrafish embryos was normal. The caldesmon mutant embryos had, however, alterations in response to light-stimulus in behavioural assays. Taken together, the effects of caldesmon mutations in the development of zebrafish embryos were reasonably well tolerated and did not indicate significant concerns for caldesmon being a potential target for cancer therapy.

Dual thick and thin filament linked regulation of stretch- and L-NAME-induced tone in young and senescent murine basilar artery.

Stretch-induced vascular tone is an important element of autoregulatory adaptation of cerebral vasculature to maintain cerebral flow constant despite changes in perfusion pressure. Little is known as to the regulation of tone in senescent basilar arteries. We tested the hypothesis, that thin filament mechanisms in addition to smooth muscle myosin-II regulatory-light-chain-(MLC20)-phosphorylation and non-muscle-myosin-II, contribute to regulation of stretch-induced tone. In young BAs (y-BAs) mechanical stretch does not lead to spontaneous tone generation. Stretch-induced tone in y-BAs appeared only after inhibition of NO-release by L-NAME and was fully prevented by treatment with 3 µmol/L RhoA-kinase (ROK) inhibitor Y27632. L-NAME-induced tone was reduced in y-BAs from heterozygous mice carrying a point mutation of the targeting-subunit of the myosin phosphatase, MYPT1 at threonine696 (MYPT1-T696A/+). In y-BAs, MYPT1-T696A-mutation also blunted the ability of L-NAME to increase MLC20-phosphorylation. In contrast, senescent BAs (s-BAs; >24 months) developed stable spontaneous stretch-induced tone and pharmacological inhibition of NO-release by L-NAME led to an additive effect. In s-BAs the MYPT1-T696A mutation also blunted MLC20-phosphorylation, but did not prevent development of stretch-induced tone. In s-BAs from both lines, Y27632 completely abolished stretch- and L-NAME-induced tone. In s-BAs phosphorylation of non-muscle-myosin-S1943 and PAK1-T423, shown to be down-stream effectors of ROK was also reduced by Y27632 treatment. Stretch- and L-NAME tone were inhibited by inhibition of non-muscle myosin (NM-myosin) by blebbistatin. We also tested whether the substrate of PAK1 the thin-filament associated protein, caldesmon is involved in the regulation of stretch-induced tone in advanced age. BAs obtained from heterozygotes Cald1+/- mice generated stretch-induced tone already at an age of 20-21 months old BAs (o-BA). The magnitude of stretch-induced tone in Cald1+/- o-BAs was similar to that in s-BA. In addition, truncation of caldesmon myosin binding Exon2 (CaD-▵Ex2-/-) did not accelerate stretch-induced tone. Our study indicates that in senescent cerebral vessels, mechanisms distinct from MLC20 phosphorylation contribute to regulation of tone in the absence of a contractile agonist. While in y-and o-BA the canonical pathways, i.e., inhibition of MLCP by ROK and increase in pMLC20, predominate, tone regulation in senescence involves ROK regulated mechanisms, involving non-muscle-myosin and thin filament linked mechanisms involving caldesmon.

[Caldesmon and tumor growth: prospects for optimizing diagnosis and targeted therapy]. / Kal'desmon i opukholevyi rost: perspektivy optimizatsii diagnostiki i targetnoi terapii.

Tumor invasion plays a key role in the progression of tumors. This process is regulated by the interactions of cells and tissues, in which physical, cellular and molecular determinants undergo changes throughout the entire period of progression of tumor growth. Tumor invasion is triggered and maintained by specialized signal cascades that control the dynamic state of the cytoskeleton in tumor cells, the processes of rearrangement of cell-matrix and intercellular connections, followed by cell migration to neighboring tissues. Studying the mechanisms of regulation of cell motor activity and determining its main regulators is an important task for understanding the pathophysiology of tumor growth. Caldesmon is an actin, myosin and calmodulin binding protein. It is involved in the regulation of smooth muscle contraction by inhibiting actin and myosin binding, in the formation of actin stress fibers, and in the transport of intracellular granules. Currently, caldesmon is considered as a potential biomarker of tumor cell invasion, migration, and metastasis. The study of signaling molecules involved in tumor progression, such as caldesmon, is necessary to predict response to chemotherapy and radiotherapy. This review highlights the main functions of caldesmon and analyzes its role in oncological pathology.

Immunohistochemical Expression Analysis of Caldesmon Isoforms in Colorectal Carcinoma Reveals Interesting Correlations with Tumor Characteristics.

Colorectal cancer is a notorious disease, with almost half of the patients succumbing to the disease. The prevalence and incidence rates of colorectal cancer are increasing in many parts of the world, highlighting the need to discover new biomarkers for diagnosis and therapy. Caldesmon (CaD), an actin-binding protein that plays a significant role in controlling cell motility, has emerged as a promising biomarker. The CALD1 gene encodes CaD as multiple transcripts that mainly encode two protein isoforms: High-molecular-weight (h-CaD), expressed in smooth muscle, and low-molecular-weight (l-CaD), expressed in nonsmooth muscle cells. Most studies have suggested an oncogenic role of CaD in colorectal cancer, but the exact subcellular localization of the two CaD isoforms in tumor cells and stroma have not been clarified yet. Here, we analyzed tissue samples from 262 colorectal cancer patients by immunohistochemistry analysis using specific antibodies for l-CaD and h-CaD. The results showed elevated cytoplasmic expression levels of l-Cad in 187/262 (71.4%) cases. l-Cad was expressed at low levels in the normal colon mucosa and was also consistently expressed in the cancer-associated stroma of all cases, suggesting that it could play a role in modulating the tumor microenvironment. l-CaD expression in cancer cells was associated with preinvasive stages of cancer. Survival analysis indicated that patients with high l-CaD expression in tumor cells could respond poorly to selective chemotherapeutic 5FU, but not combination chemotherapy. h-CaD was expressed in colonic and vascular smooth muscle cells as expected and to a lesser extent in the tumor-associated stroma, but it was not expressed in the cancer cells or normal colon mucosal epithelial cells. Collectively, these data clarify how the expression patterns of CaD isoforms in colorectal cancer can have applications in the management of colorectal cancer patients.

Emerging role of caldesmon in cancer: A potential biomarker for colorectal cancer and other cancers.

Colorectal cancer (CRC) is a devastating disease, mainly because of metastasis. As a result, there is a need to better understand the molecular basis of invasion and metastasis and to identify new biomarkers and therapeutic targets to aid in managing these tumors. The actin cytoskeleton and actin-binding proteins are known to play an important role in the process of cancer metastasis because they control and execute essential steps in cell motility and contractility as well as cell division. Caldesmon (CaD) is an actin-binding protein encoded by the CALD1 gene as multiple transcripts that mainly encode two protein isoforms: High-molecular-weight CaD, expressed in smooth muscle, and low-molecular weight CaD (l-CaD), expressed in nonsmooth muscle cells. According to our comprehensive review of the literature, CaD, particularly l-CaD, plays a key role in the development, metastasis, and resistance to chemoradiotherapy in colorectal, breast, and urinary bladder cancers and gliomas, among other malignancies. CaD is involved in many aspects of the carcinogenic hallmarks, including epithelial mesenchymal transition via transforming growth factor-beta signaling, angiogenesis, resistance to hormonal therapy, and immune evasion. Recent data show that CaD is expressed in tumor cells as well as in stromal cells, such as cancer-associated fibroblasts, where it modulates the tumor microenvironment to favor the tumor. Interestingly, CaD undergoes selective tumor-specific splicing, and the resulting isoforms are generally not expressed in normal tissues, making these transcripts ideal targets for drug design. In this review, we will analyze these features of CaD with a focus on CRC and show how the currently available data qualify CaD as a potential candidate for targeted therapy in addition to its role in the diagnosis and prognosis of cancer.

Primary leiomyosarcoma of ovary: A rare malignancy as an incidental finding.

Primary leiomyosarcoma (PLMS) of the ovary is extremely rare tumors comprising 1% of ovarian tumors. About 3% of all ovarian malignancies are primary ovarian sarcomas. Only 72 cases have been reported till date. A 57-year-old postmenopausal female presented with abdominal pain for the last 6 months. Ultrasonography and MRI revealed a heterogeneously enhancing solid lobulated mass in the left adnexa abutting the fundus of the uterus and bowel loops. The endometrial cavity was normal. Ovarian markers CA 125, CEA, CA 19.9, and all hematological parameters were within normal limits. LDH was near normal (284 IU/ml). The specimen was sent for frozen section and a diagnosis of malignant spindle cell lesion of ovary was rendered. Histopathology of the ovarian mass revealed intersecting fascicles of tumor cells consisting of ovoid to spindle-shaped cells having a moderate amount of cytoplasm. Bizarre and atypical cells were seen singly dispersed and in small aggregates along with the brisk mitotic activity. Focal areas of necrosis and hemorrhage were also noted. Immunohistochemistry showed strong positivity for smooth muscle actin and Caldesmon while focal positivity for Desmin and Epithelial Membrane Antigen (EMA) was noted. The lesion was negative for Inhibin, Calretinin, and CD 117 and S100. The final diagnosis of primary ovarian Leiomyosarcoma was given based on histopathology and Immunohistochemistry. PLMS of the ovary are rare incidental findings in postmenopausal women. These are highly malignant tumors and carry a poor prognosis. Hence, early diagnosis and surgical treatment with cytoreduction improve patient survival.

Expression of Matrix Metalloproteinases 7 and 9, Desmin, Alpha-Smooth Muscle Actin and Caldesmon, in Odontogenic Keratocyst Associated with NBCCS, Recurrent and Sporadic Keratocysts.

Nevoid basal cell carcinoma syndrome (NBCCS) associated odontogenic keratocysts (OKCs) show more aggressive behavior and it has a higher frequency of relapse than non-syndromic OKCs. Stromal myofibroblasts (MFs), characterized by α-smooth muscle actin (αSMA), desmin and caldesmon expression, and metalloproteinases (MMPs) have an essential role in the remodeling of the extracellular matrix (ECM). The aim of the study is to analyze the immunohistochemical expression of MMP-7, MMP-9, αSMA and other new markers in the study of OKCs MFs such as desmin and caldesmon in NBCCS-associated OKCs compared to recurrent and sporadic keratocysts. Fourty 40 patients (23 M and 17 F) underwent surgery to remove the OKCs. The histological sections in paraffin were incubated with markers antibodies and a semi-quantitative score was used to evaluate the immunoreactivity. Densitometric analysis showed a very significantly increased expression of αSMA, caldesmon, MMP-7 and MMP-9 in NBCCS-OKCs compared to non-syndromic OKCs (p < 0.001). However, desmin showed a not significant increased expression in non-syndromic OKC compared to NBCCS-OKCs specimens in which desmin was slightly or not at all expressed. NBCSS-OKCs showed a greater distribution of MFs compared to the other OKCs subtypes. Further studies will be needed to evaluate whether the different expressions of these markers can be correlated to a different clinical behavior.

IFITM1, CD10, SMA, and h-caldesmon as a helpful combination in differential diagnosis between endometrial stromal tumor and cellular leiomyoma.

BACKGROUND: The differential diagnosis of endometrial stromal tumor (EST) and uterine cellular leiomyoma (CL) remains a challenge in clinical practice, especially low grade endometrial stromal sarcoma (ESS) and CL, suggesting the need for novel immunomarkers panels for differential diagnosis. Interferon-induced transmembrane protein 1 (IFITM1) is a novel immunomarker for endometrial stromal cells, h-caldesmon is an immunomarker for smooth muscle cells and has a higher specificity than smooth muscle actin (SMA). So this study aimed to evaluate whether IFITM1, cluster of differentiation 10(CD10), SMA, and h-caldesmon are useful biomarker combinations for the differential diagnosis of EST and CL. METHODS: Tissue microarrays were used to detect IFITM1, CD10, SMA, and h-caldesmon immunohistochemical staining in 30 EST and 33 CL cases. RESULTS: The expressions of IFITM1 and CD10 were high in EST (86.7 and 63.3%, respectively) but low in CL (18.2 and 21.2%), whereas those of h-caldesmon and SMA were high in CL (87.9 and 100%) and low in EST (6.9 and 40%). In diagnosing EST, IFITM1 shows better sensitivity and specificity (86.7 and 81.8%, respectively) than CD10 (63.3 and 78.8%). The specificity of h-caldesmon in diagnosing CL was significantly higher (93.1%) than that of SMA (60%). When all four antibodies were combined for the differential diagnosis, the area-under-the-curve (AUC) predictive value was 0.995. The best combination for diagnosing EST was IFITM1 (+) or CD10 (+) and h-caldesmon (-) (sensitivity 86.7%, specificity 93.9%). CONCLUSION: The best combination for diagnosing CL were h-caldesmon (+) and SMA (+) (sensitivity 87.9%, specificity 100%). IFITM1, CD10, SMA, and h-caldesmon are a good combination for the differential diagnosis of EST and CL.

Quantitative Expression of TYR, CD34, and CALD1 Discriminates Between Canine Oral Malignant Melanomas and Soft Tissue Sarcomas.

Canine oral malignant melanomas (OMMs) exhibit a variety of morphologic phenotypes, including a spindloid variant. The microscopic diagnosis of spindloid OMMs is based on junctional activity and/or the presence of melanin pigment. In the absence of these features, spindloid OMMs are difficult to differentiate from soft tissue sarcomas (STS). An antibody cocktail (MDX) that includes Melan-A, PNL2, and tyrosinase-related proteins 1 and 2 (TRP-1 and TRP-2) is the current gold standard for identifying amelanotic OMMs by immunohistochemistry (IHC). However, MDX is less sensitive for diagnosing spindloid amelanotic OMMs. This raises concern for biopsy specimens that lack overlying epithelium, making it potentially difficult to differentiate OMM from STS by IHC. The goal of this study was to identify additional markers to help differentiate between STS and OMMs that lack pigment and junctional activity. SOX-10 has recently been proposed as a sensitive marker for melanocytes in humans but has not been validated in dogs. Similarly, RNA expression for various genes has been analyzed in humans, but not in the context of diagnosing canine melanocytic neoplasms. For this retrospective study, formalin-fixed, paraffin-embedded tissues from 20 OMMs, 20 STS, and 20 oral spindle cell tumors (OSCTs) that lacked junctional activity and pigmentation were selected. IHC for MDX, SOX-10, and laminin, in parallel with RT-qPCR of TYR, SOX10, CALD1, CD34, DES, and LAMA1, was performed in all cases. TYR, CD34, and CALD1 were the most discriminatory genes in differentiating between OMM and STS, all having 100% specificity and 65, 95, and 60% sensitivity, respectively. While all 20 OMMs were immunohistochemically labeled for SOX-10, two STS were also labeled (100% sensitivity and 90% specificity). MDX IHC labeled all 20 OMMs and no STS. Surprisingly, none of the 20 OSCTs expressed TYR RNA above the cutoff, and 14/20 OSCTs expressed CALD1 or CD34 RNA above the cutoff, thereby confirming them as STS. Four OSCT were suspect STS, and no OSCTs were confirmed as OMMs based on IHC and RNA expression patterns. In conclusion, the RNA levels of TYR, CD34, and CALD1 should be evaluated in suspected amelanotic OMMs that are negative for MDX to accurately differentiate between OMM and STS.

Caldesmon: Biochemical and Clinical Implications in Cancer.

Caldesmon, an actin-binding protein, can inhibit myosin binding to actin and regulate smooth muscle contraction and relaxation. However, caldesmon has recently attracted attention due to its importance in cancer. The upregulation of caldesmon in several solid cancer tissues has been reported. Caldesmon, as well as its two isoforms, is considered as a biomarker for cancer and a potent suppressor of cancer cell invasion by regulating podosome/invadopodium formation. Therefore, caldesmon may be a promising therapeutic target for diseases such as cancer. Here, we review new studies on the gene transcription, isoform structure, expression, and phosphorylation regulation of caldesmon and discuss its clinical implications in cancer.

Primary Histiocytic Sarcoma in Adult Polycystic Kidney Disease: Case Report and Review of Literature.

Genetically driven tissue destruction followed by remodeling in adult polycystic kidney disease (APKD) raises the possibility of malignant transformation. Renal cell carcinoma (RCC) associated with APKD has been frequently reported in the literature; however, only a few cases of nonepithelial neoplasms arising in APKD have been described so far. Histiocytic sarcoma (HS) is a lymphohematopoietic malignant neoplasm that accounts for less than 1% of hematologic malignancies. In this article, we describe a case of primary HS occurring in a 61-year-old man with end-stage renal disease secondary to APKD. This is the first reported case of primary HS in the setting of APKD. The aberrant h-caldesmon expression seen in this case is another novel finding that has previously not been described. This case highlights the importance of morphology in guiding diagnostic workup and reiterates the necessity of maintaining a high index of suspicion for neoplastic entities in APKD.

Decreased smooth muscle function, peristaltic activity, and gastrointestinal transit in dystrophic (mdx) mice.

BACKGROUND: Duchenne muscular dystrophy (DMD) is characterized by the lack of dystrophin in skeletal, cardiac, and smooth muscle. Slow colonic transit and constipation are common in DMD patients and animal models of DMD. However, the cause of this hypocontractility and the expression of contractile proteins in smooth muscle are unknown. The aim of the study was to investigate the expression of contractile proteins in the colonic smooth muscle and the function of the colon in control and mdx mice. METHODS: Muscle contraction was measured in muscle strips and isolated muscle cells. Peristaltic activity was measured in ex vivo preparations by spatiotemporal mapping, and gastrointestinal (GI) transit in vivo was measured by the distribution of fluorescent marker along the intestine and colon. mRNA expression of contractile proteins smoothelin, caldesmon, calponin, and tropomyosin was measured by qRT-PCR. RESULTS: Expression of mRNA for contractile proteins was decreased in colonic smooth muscle of mdx mice compared with control. Contraction in response to acetylcholine and KCl was decreased in colonic muscle strips and in isolated muscle cells of mdx mice. Distension of ex vivo colons with Krebs buffer induced peristalsis in both control and mdx mice; however, significantly fewer full peristaltic waves were recorded in the colons of mdx mice. GI transit was also inhibited in mdx mice. CONCLUSION AND INFERENCES: The data indicate that the lack of dystrophin causes decrease in colonic smooth muscle contractility, peristalsis, and GI transit and provides the basis for analysis of mechanisms involved in smooth muscle dysfunction in DMD.

Significance of stromal markers in atypical polypoid adenomyoma.

Atypical polypoid adenomyoma (APA) may progress to endometrioid carcinoma and may mimic myoinvasive carcinoma on biopsy specimens. Here, we present a case of an APA of the uterine cervix hysteroscopically treated, which recurred two years after and progressed to endometrioid carcinoma. In all biopsy specimens and in the hysterectomy specimen, the benign APA component showed an unusual immunohistochemical stromal pattern (periglandular fringe-like CD10 pattern, diffuse h-caldesmon positivity, p16 negativity), which is typical of myoinvasive carcinoma. Interestingly, the other three cases of cancerized APA assessed for h-caldesmon in the literature showed diffuse stromal positivity also in the benign APA component. Our case shows that the stromal markers used for differentiating between APA and myoinvasive carcinoma may be misleading even when their pattern seems unequivocal. Furthermore, our case suggests that h-caldesmon positivity might be a prognostic marker for progression of APA to carcinoma. Further studies are encouraged in this regard.

Adding myofibroblasts to the lacrimal pump.

The lacrimal sac (LS) empties in the nasolacrimal duct to drain the tears in the inferior nasal meatus. Different studies indicated the role of the lacrimal pump in the lacrimal drainage. Although controversial, the lacrimal pump mechanism is an extrinsic one, either active, or passive. An intrinsic contractile potential of the LS was not documented previously. We thus aimed a retrospective immunohistochemical study to test the alpha-smooth muscle actin (α-SMA) and h-caldesmon expression in the LS wall. We used archived paraffin-embedded samples of LS from ten adult patients. The α-SMA + phenotype was detected in basal epithelial cells, in subepithelial ribbons of stromal cells, in vascular smooth muscle cells, as well as in pericytes. H-caldesmon was exclusively expressed in pericytes, vascular smooth muscle cells and myoepithelial cells of the subepithelial glands. The most striking feature we found in all samples was a consistent stromal network of α-SMA+/h-caldesmon- myofibroblasts. This finding supports an intrinsic scaffold useful for the lacrimal pump.

L-caldesmon alters cell spreading and adhesion force in RANKL-induced osteoclasts.

BACKGROUND: Osteoclasts (OCs) are motile multinucleated cells derived from differentiation and fusion of hematopoietic progenitors of the monocyte-macrophage lineage that undergo a multistep process called osteoclastogenesis. The biological function of OCs is to resorb bone matrix for controlling bone strength and integrity, which is essential for bone development. The bone resorption function is based on the remodelling of the actin cytoskeleton into an F-actin-rich structure known as the sealing zone for bone anchoring and matrix degradation. Non-muscle caldesmon (l-CaD) is known to participate in the regulation of actin cytoskeletal remodeling, but its function in osteoclastogenesis remains unclear. METHODS/RESULTS: In this study, gain and loss of the l-CaD level in RAW264.7 murine macrophages followed by RANKL induction was used as an experimental approach to examine the involvement of l-CaD in the control of cell fusion into multinucleated OCs in osteoclastogenesis. In comparison with controls, l-CaD overexpression significantly increased TRAP activity, actin ring structure and mineral substrate resorption in RANKL-induced cells. In contrast, gene silencing against l-CaD decreased the potential for RANKL-induced osteoclastogenesis and mineral substrate resorption. In addition, OC precursor cells with l-CaD overexpression and gene silencing followed by RANKL induction caused 13% increase and 24% decrease, respectively, in cell fusion index. To further understand the mechanistic action of l-CaD in the modulation of OC fusion, atomic force microscopy was used to resolve the mechanical changes of cell spreading and adhesion force in RANKL-induced cells with and without l-CaD overexpression or gene silencing. CONCLUSIONS: l-CaD plays a key role in the regulation of actin cytoskeletal remodeling for the formation of actin ring structure at the cell periphery, which may in turn alter the mechanical property of cell-spreading and cell surface adhesion force, thereby facilitating cell-cell fusion into multinucleated OCs during osteoclastogenesis.

Expression of von Willebrand factor and caldesmon in the placental tissues of pregnancies complicated with intrauterine growth restriction.

PURPOSE: The decreased placental perfusion is the underlying reason for intrauterine growth restriction that in turn leads to reduced placental perfusion and ischemia. However, there are several issues to be understood in the pathophysiology of intrauterine growth restriction. We aimed to study whether any compensatory response in placental vascular bed occur in pregnancies complicated with intrauterine growth restriction by the immunohistochemical staining of von Willebrand factor and caldesmon in placental tissues. MATERIALS AND METHODS: A total of 103 pregnant women was enrolled in the study including 50 patients who were complicated with IUGR and 50 uncomplicated control patients. The study was designed in a prospective manner. All placentas were also stained with von Willebrand factor and caldesmon monoclonal kits. RESULTS: The immunohistochemical staining of von Willebrand factor and caldesmon expressions in placental tissues were different between normal and intrauterine growth restriction group. The percentages of 2+ and 3+ von Willebrand factor expression were higher in the intrauterine growth restriction group comparing with the normal group, although the difference was not statistically significant. The intensity of caldesmon expression was significantly lower in the intrauterine growth restriction group in comparison with the normal group (p < .001). CONCLUSION: Angiogenesis occurs as a placental response to intrauterine growth restriction which is a hypoxic condition. But newly formed vessels are immature and not strong enough. Our study is important to clarify the pathophysiology and placental compensatory responses in intrauterine growth restriction.

Expression and clinical significance of H-caldesmon in gastrointestinal stromal tumor: is it a specific marker for myogenic differentiation?

OBJECTS: To investigate the expression and clinical significance of H-caldesmon which is considered a myogenic marker in GIST. METHODS: The clinical information of 105 patients diagnosed with GIST was obtained from Yantai Yuhuangding Hospital and Rambam Health Care Campus. Morphology, the results of immunohistochemical staining and available molecular detection were reviewed. The expression of H-caldesmon was detected for each specimen by immunohistochemical staining. Comparative analysis was carried out between H-caldesmon expression and clinicopathologic parameters. RESULTS: H-caldesmon was expressed in all patients with GIST including tumors outside the gastrointestinal tract and with CD117-negative expression. Although the pattern of expression was different, the positive rate in our study group was 100%. There was no statistically difference between H-caldesmon expression and parameters such as gender, age, location, morphology, risk, immunologic markers, and molecular mutation. CONCLUSIONS: H-caldesmon is expressed positively in GIST and might not be a specific marker for smooth muscle and associated tumors. GIST outside the gastrointestinal tract or with CD117-negative expression should not be misdiagnosed assmooth muscle tumor because of the positive expression of H-caldesmon in the differential diagnosis. Comprehensive analysis combined with other immunological markers and molecular detection is needed.