RESUMEN
BACKGROUND: The substances present in cigarette smoke have a negative impact on cellular integrity and metabolism, can reduce blood flow to tissues, and can disrupt collagen synthesis. Ultimately this can lead to cell death, which clinically may result in impaired tendon healing and the onset of chronic tendinopathy. Within the shoulder, the exact association between the extent of apoptosis in the long head of the biceps (LHB) tendon and harmful factors like cigarette smoke remains unclear. OBJECTIVES: The purpose of this study was to investigate the connection between smoking, the degree of apoptosis in LHB tendinopathy, and the long-term outcomes of surgical treatment. DESIGN: Observational, retrospective study. METHODS: This study included 22 consecutive patients who had undergone arthroscopic biceps tenodesis or tenotomy for symptomatic LHB tendinopathy with or without concomitant rotator cuff tears (RCT). The intra-articular LHB tendon remnants were histologically examined by measuring the level of expression of apoptotic cell markers such as BCL2, cleaved caspase 3, and p53. Pre- and postoperative clinical outcomes were analyzed by collecting patient report outcome measures such as the American Shoulder and Elbow Surgeons (ASES) score and the Visual Analogue Scale (VAS) for pain. RESULTS: The smokers group had a mean pack-year history of 13.12 (SD = 9.94), mean number of cigarettes per day of 14.77 (SD = 4.64), and a mean smoking duration of 16.38 (SD = 10.1) years. Among the smoking indexes, the number of cigarettes per day showed a positive correlation with Snyder classification (p = 0.0459, rho = 0.3682). Non-smokers and smokers did not show a statistically significant difference in the expression indexes of BCL2, cleaved caspase 3, or p53 (p = 0.4216, p = 0.5449, p = 0.5613, respectively). However, the cleaved caspase 3 expression index showed a negative correlation with the severity of rotator cuff lesions in the total population (p = 0.0193, rho = -0.4651). CONCLUSIONS: While apoptotic processes in the LHB tendon were observed, no significant association was found between tobacco smoking, the extent of apoptosis, and clinical outcomes. However, the expression of the apoptotic marker cleaved caspase 3 correlated with the severity of rotator cuff pathology. Furthermore, active smoker status was associated with worse clinical outcomes in terms of pain following LHB tenodesis or tenotomy.
RESUMEN
The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor ß (TGF-ß) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-ß known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-ß signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-ß-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.
