Areas of Cartilaginous and Osseous Metaplasia After Experimental Myocardial Infarction in Rats

Anatomy, Histology, Aetiology, Development and Functions of Cartilago Cordis: A Systematic Review

INTRODUCTION

The cartilago cordis is a structure present within the cardiac skeleton of some, but not all, vertebrate species. This systematic review compared the presence, structure, and function of the cartilago cordis from published works covering all vertebrate species.

METHODS

Literature searches were conducted to obtain information relating to the anatomical location, morphology, prevalence, number of structures, development, and function.

RESULTS

The cartilago cordis was most commonly composed of hyaline cartilage but its location within the cardiac skeleton, anatomical, and histological structure varied between species. The cartilago cordis has not been documented in every vertebrate species, or every individual within each species, but it is present in 68 vertebrates including an amphibian, and some mammals, reptiles, and birds. The function of the cartilago cordis is unknown, but theories have ranged from an adaptive mechanism to support cardiac tissue through to roles in conduction and contraction, especially in areas of high mechanical stress. Possible links between the presence of a cartilago cordis and cardiac pathologies were also identified.

CONCLUSION

The cartilago cordis varied in prevalence, structure, and location; further research is required to understand the function and development. In addition, it is possible there are more vertebrate species containing cartilago cordis than presently known about given its varying prevalence and sometimes small size.

Skin Telocytes Could Fundament the Cellular Mechanisms of Wound Healing in Platelet-Rich Plasma Administration

For more than 40 years, autologous platelet concentrates have been used in clinical medicine. Since the first formula used, namely platelet-rich plasma (PRP), other platelet concentrates have been experimented with, including platelet-rich fibrin and concentrated growth factor. Platelet concentrates have three standard characteristics: they act as scaffolds, they serve as a source of growth factors and cytokines, and they contain live cells. PRP has become extensively used in regenerative medicine for the successful treatment of a variety of clinical (non-)dermatological conditions like alopecies, acne scars, skin burns, skin ulcers, muscle, cartilage, and bone repair, and as an adjuvant in post-surgery wound healing, with obvious benefits in terms of functionality and aesthetic recovery of affected tissues/organs. These indications were well documented, and a large amount of evidence has already been published supporting the efficacy of this method. The primordial principle behind minimally invasive PRP treatments is the usage of the patient's own platelets. The benefits of the autologous transplantation of thrombocytes are significant, representing a fast and economic method that requires only basic equipment and training, and it is biocompatible, thus being a low risk for the patient (infection and immunological reactions can be virtually disregarded). Usually, the structural benefits of applying PRP are attributed to fibroblasts only, as they are considered the most numerous cell population within the interstitium. However, this apparent simplistic explanation is still eluding those different types of interstitial cells (distinct from fibroblasts) that are residing within stromal tissue, e.g., telocytes (TCs). Moreover, dermal TCs have an already documented potential in angiogenesis (extra-cutaneous, but also within skin), and their implication in skin recovery in a few dermatological conditions was attested and described ultrastructurally and immunophenotypically. Interestingly, PRP biochemically consists of a series of growth factors, cytokines, and other molecules, to which TCs have also proven to have a positive expression. Thus, it is attractive to hypothesize and to document any tissular collaboration between cutaneous administered PRP and local dermal TCs in skin recovery/repair/regeneration. Therefore, TCs could be perceived as the missing link necessary to provide a solid explanation of the good results achieved by administering PRP in skin-repairing processes.

Adverse Health Effects of the Long-Term Simultaneous Exposure to Arsenic and Particulate Matter in a Murine Model

PM2.5 and arsenic are two of the most hazardous substances for humans that coexist worldwide. Independently, they might cause multiple organ damage. However, the combined effect of PM2.5 and arsenic has not been studied. Here, we used an animal model of simultaneous exposure to arsenic and PM2.5. Adult Wistar rats were exposed to PM2.5, As, or PM2.5 + As and their corresponding control groups. After 7, 14, and 28 days of exposure, the animals were euthanized and serum, lungs, kidneys, and hearts were collected. Analysis performed showed high levels of lung inflammation in all experimental groups, with an additive effect in the coexposed group. Besides, we observed cartilaginous metaplasia in the hearts of all exposed animals. The levels of creatine kinase, CK-MB, and lactate dehydrogenase increased in experimental groups. Tissue alterations might be related to oxidative stress through increased GPx and NADPH oxidase activity. The findings of this study suggest that exposure to arsenic, PM2.5, or coexposure induces high levels of oxidative stress, which might be associated with lung inflammation and heart damage. These findings highlight the importance of reducing exposure to these pollutants to protect human health.

Roles of telocytes dominated cell–cell communication in fibroproliferative acute respiratory distress syndrome

Telocytes (TCs) are a new type of interstitial cell identified in multiple tissues of mammals, including the human lung, and mediate homocellular or heterocellular cell‐cell communication. Acute respiratory distress syndrome (ARDS) is characterized by acute hypoxemia respiratory failure and combined with direct and indirect lung injury, which is induced by pneumonia, sepsis, burns, etc. Pulmonary fibrosis is a progressive lung disease that occurs due to increased fibrosis of lung tissue in response to chronic injury of the epithelium and gets more and more attention as a well‐recognized sequela of ARDS or mechanical ventilation. However, the existing intervention measures could not prevent the progression of pulmonary fibrosis. Although the protective effect of TCs in acute lung injury had been demonstrated in both cellular and animal models in previous studies by our or other researchers, the roles of TCs mediated cell‐cell communication in fibroproliferative ARDS is unclear. This review is aimed at integrating our understanding of TC‐mediated cell–cell communication in lung diseases with pulmonary fibrosis after ARDS.

Dynamic Involvement of Telocytes in Modulating Multiple Signaling Pathways in Cardiac Cytoarchitecture

Cardiac interstitium is a complex and dynamic environment, vital for normal cardiac structure and function. Telocytes are active cellular players in regulating main events that feature myocardial homeostasis and orchestrating its involvement in heart pathology. Despite the great amount of data suggesting (microscopically, proteomically, genetically, etc.) the implications of telocytes in the different physiological and reparatory/regenerative processes of the heart, understanding their involvement in realizing the heart's mature cytoarchitecture is still at its dawn. Our scrutiny of the recent literature gave clearer insights into the implications of telocytes in the WNT signaling pathway, but also TGFB and PI3K/AKT pathways that, inter alia, conduct cardiomyocytes differentiation, maturation and final integration into heart adult architecture. These data also strengthen evidence for telocytes as promising candidates for cellular therapies in various heart pathologies.

Myocardial Fibrosis with Cartilaginous Tissue Formation in Right Atrial Auricle of a Dog

A 13-year-old castrated male Miniature Dachshund exhibited oedema of the face and cervical region. Clinical examination, including computed tomography, revealed a mass on the right atrial wall. Histopathological examination of the mass revealed proliferation of spindle cells, which formed intersecting bundles and abundant proteoglycan material. Multiple islands of hyaline cartilage were also observed within foci of proliferated spindle cells. Although the proliferated spindle cells replaced the myocardial parenchyma, there was no evidence of malignancy. The spindle cells were immunopositive for vimentin and α-smooth muscle actin, while chondrocytes were immunopositive for vimentin and S100. Neither the spindle cells nor the chondrocytes were immunolabelled for cytokeratin AE1/AE3, desmin, factor VIII, melan A, p63 or Ki-67. These findings indicate that the lesion represented myocardial fibrosis with cartilaginous tissue formation.

Therapeutic Potentials of Selected Antihypertensive Agents and Their Fixed-Dose Combinations Against Trastuzumab-Mediated Cardiotoxicity

Trastuzumab (TZM) is useful in the clinical management of HER2-positive metastatic breast, gastric, and colorectal carcinoma but has been limited by its off-target cardiotoxicity. This study investigates the therapeutic potentials of 0.25 mg/kg/day amlodipine, 0.035 mg/kg/day lisinopril, 5 mg/kg/day valsartan, and their fixed-dose combinations in TZM-intoxicated Wistar rats that were randomly allotted into 10 groups of 6 rats for each group. Group I rats were treated with 10 ml/kg/day sterile water orally and 1 ml/kg/day sterile water intraperitoneally; Groups II, III, and IV rats were orally gavaged with 5 mg/kg/day valsartan and 1 ml/kg/day sterile water intraperitoneally, 0.25 mg/kg/day amlodipine and 1 ml/kg/day sterile water via the intraperitoneal route, 0.035 mg/kg/day lisinopril and 1 ml/kg/day sterile water administered intraperitoneally, respectively. Group V rats were orally treated with 10 ml/kg/day of sterile water prior to intraperitoneal administration of 2.25 mg/kg/day of TZM. Groups VI–VIII rats were equally pretreated with 5 mg/kg/day valsartan, 0.25 mg/kg/day amlodipine, and 0.035 mg/kg/day lisinopril before intraperitoneal 2.25 mg/kg/day TZM treatment, respectively; Groups IX and X rats were orally pretreated with the fixed-dose combinations of 0.25 mg/kg/day amlodipine +0.035 mg/kg/day lisinopril and 5 mg/kg/day valsartan +0.035 mg/kg/day lisinopril, respectively, before TZM treatment. Cardiac injury and tissue oxidative stress markers, complete lipids profile, histopathological, and immunohistochemical assays were the evaluating endpoints. Results showed that repeated TZM treatments caused profound increases in the serum TG and VLDL-c levels, serum cTnI and LDH levels, and cardiac tissue caspase-3 and -9 levels but decreased BCL-2 expression. TZM also profoundly attenuated CAT, SOD, GST and GPx activities, and increased MDA levels in the treated tissues. In addition, TZM cardiotoxicity was characterized by marked vascular and cardiomyocyte congestion and coronary artery microthrombi formation. However, the altered biochemical, histopathological, and immunohistochemical changes were reversed with amlodipine, lisinopril, valsartan, and fixed-dose combinations, although fixed-dose valsartan/lisinopril combination was further associated with hyperlipidemia and increased AI and CRI values and coronary artery cartilaginous metaplasia. Thus, the promising therapeutic potentials of amlodipine, lisinopril, valsartan and their fixed-dose combinations in the management of TZM cardiotoxicity, majorly mediated via antiapoptotic and oxidative stress inhibition mechanisms were unveiled through this study.

Chondroid and Osseous Metaplasia of the Central Fibrous Body in Adolescent Hearts with Mutations in TNNI3 and TNNT2 genes

The histological spectrum of the central fibrous body (CFB) of the heart, particularly in humans, is not fully characterized. Herein, we describe the presence of cartilage and bone within the CFB of 2 explanted heart specimens from patients with known mutation-driven cardiomyopathy involving the TNNI3 and TNNT2 genes, review the existing literature on the identified variants particularly TNNI3 (p.Asn185Thrfs*14) and TNNT2 (p.Arg141Trp), and provide insights into the plausible nature of such histopathological observation based on animal studies and the few reported cases in humans.