Paracrine potential of fibroblasts exposed to cigarette smoke extract with vascular growth factor induction

Reinke's Edema and Risk Factors, A Case-Control Study

Reinke's edema (RE) is a benign pathological non-inflammatory disorder of the vocal folds with a wide range of clinical manifestations. We aim to investigate the relationship between Reinke's edema and some common inhalant abuse. In this case-control study, subjective consisted of 23 patients with RE (the cases), and 50 patients with sinusitis (control) who underwent surgery in the Department of Otolaryngology, between 2015 and 2020. Demographic characteristics, history of some related disease, methods, and the duration of cigarette, and opium consumption were collected through the patients' files. The chi-square (χ²) test was run to analyze the differences in the categorical and, and the Independent Sample T-test was used to compare two sample means from unrelated groups. A significant level (p-value) was considered less than 0.05. The mean age was 54 ± 12 years, and 42 ± 11 years, respectively for Reinke's edema and sinusitis. More women had been recorded in the RE group, compared to men. Allergy, unprincipled use of voice and talkativeness, history of laryngeal surgery, and type of disease were correlated to RE (p < 0.05). Also, cigarette smoking was significantly correlated with Reinke's edema. The average number of cigarettes per day, the duration of smoking, and opium consumption were more frequent in RE (P < 0.05). 90% of the RE and 4% of sinusitis patients were opium consumers. There was a statistically significant difference in the methods of substance use in the two groups of cases and control (p < 0.0001). Among the different methods, the poker and stone method was the most common (69.6%), and the opium smoking pipe was the second most common method. This study also confirmed the hazardous effects of smoking and inhaling opiates in the formation of lesions of the pharynx and larynx. In particular, longer use of these substances will be associated with more serious side effects. Therefore, it seems that people who are addicted to opiates should undergo periodic visits and counseling to reduce and stop their use.

Effects of Electronic (E)-cigarette Vapor and Cigarette Smoke in Cultured Vocal Fold Fibroblasts

OBJECTIVE

The public use of electronic-cigarettes (e-cigs) is rapidly growing. When heated, e-cigs produce a vapor that is inhaled. The vocal folds are among the first tissues exposed to this insult. However, the impact of e-cigs on vocal fold health is almost entirely unknown. Our objective was to evaluate the effects of e-cig vapor on cultured human vocal fold fibroblasts (hVFFs), the primary cell type of the lamina propria. We compared the cellular effects of e-cig vapor without and with nicotine and conventional cigarette smoke.

STUDY DESIGN

In vitro.

METHODS

E-cig vapor extract (EVE) and cigarette smoke extract (CSE) were created by bubbling vapor and smoke, respectively, into the cell culture medium. hVFFs were exposed to EVE without or with nicotine or CSE for 24 hours. Untreated cells were used as a control group. Cells were harvested, and cytotoxicity, extracellular matrix and inflammatory gene expression, and DNA damage were assessed.

RESULTS

Undiluted EVE without and with nicotine reduced the viability of hVFFs to a cytotoxic level. CSE reduced hVFFs viability to a greater extent than EVE and induced DNA damage as measured by DNA double-strand breaks. No changes in gene expression were observed following EVE or CSE exposure.

CONCLUSION

EVE induces cytotoxicity in hVFFs. However, cellular responses were greater following exposure to CSE, suggesting cigarette smoke may induce more harm, at least in the short term. Findings from this investigation improve our understanding of responses of hVFFs to e-cigs and form the basis for an in vitro methodology to study the vocal fold responses to these products.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:139-146, 2023.

The role of cancer stromal fibroblasts in mediating the effects of tobacco-induced cancer cell growth

Tobacco products cause a variety of cancers, nicotine and carcinogens are two major factors to link the tobacco products and various cancers. The mechanism of tobacco inducing carcinogenesis and promoting cancer progression have been studied for a long time. However, mainstream studies just focus on the mutagenic characteristics of tobacco product and its properties to induce carcinogenesis of epithelial cells. In the past decades, people began to aware of the significant role of tumor stroma in cancer development and progression. Fibroblasts, which is associated with various cancer in all stage of disease progression, are the dominant cell type in the tumor microenvironment. While only a few studies explore the crosstalk between tobacco-induced fibroblasts and surrounding epithelial cells. Our purpose is to systematically review the effects of tobacco products on fibroblasts and further discuss how these effects affect the development of cancer cells.

Exploring the Pathophysiology of Reinke's Edema: The Cellular Impact of Cigarette Smoke and Vibration

Objectives

To explore the isolated or combined effects of cigarette smoke extract (CSE) and vibration on human vocal fold fibroblasts (hVFF) in an in vitro setting in order to elucidate their influence in the pathophysiology of Reinke's edema (RE).

Study design

Immortalized hVFF were exposed to CSE or control medium under static or vibrational conditions. A phonomimetic bioreactor was used to deliver vibrational patterns to hVFF over a period of 5 days.

Methods

Cytotoxicity was quantified using a lactate dehydrogenase assay. We employed reverse transcription–quantitative polymerase chain reaction, enzyme‐linked immunosorbent assay, and Magnetic Luminex^(R) assays (R&D Systems, Minneapolis, MN) to assess the influence on extracellular matrix production, fibrogenesis, inflammation, and angiogenesis.

Results

We observed significant changes induced by CSE alone (hyaluronic acid, matrix metalloproteinase 1, Interleukin‐8, cyclooxygenase [COX]1, COX2, vascular endothelial growth factor [VEGF]D), as well as settings in which only the combination of CSE and vibration led to significant changes (transforming growth factor beta 1, VEGFA, VEGFC). Also, CSE‐induced levels of COX2 were only significantly reduced when vibration was applied.

Conclusion

We were able to explore the cellular effects of CSE and vibration on hVFF by employing a phonomimetic bioreactor. Whereas cigarette smoke is generally accepted as a risk factor for RE, the role of vibration remained unclear as it is difficult to study in humans. Our data showed that some genes and proteins in the pathophysiological context of RE were only affected when CSE in combination with vibration was applied.

Level of Evidence

NA Laryngoscope, 131:E547–E554, 2021

Cigarette Smoke Exposure to Pig Larynx in an Inhalation Chamber

OBJECTIVES

This study investigated the effects of cigarette smoke exposure on the pig larynx using an inhalation chamber. Specifically, we compared the effects of cigarette smoke exposure from either 3 cigarettes per day (3cd) or 15 cigarettes per day (15cd) for 20 days.

STUDY DESIGN

In vivo prospective design.

METHODS

Female pigs were exposed via an inhalation chamber to cigarette smoke (3R4F research cigarettes) from 3cd (n = 6) or 15cd (n = 6) for 20 days. Outcomes included histopathology of vocal fold and airway tissues; gene expression of interleukins, TNF-α, and VEGF; protein levels of TNF-α and IL-6; and number of coughs recorded in the chamber.

RESULTS

Pigs exposed to cigarette smoke from 15cd exhibited mild vocal fold edema as compared to the 3cd group on histopathological evaluation. There was also minimal inflammation of nasal and tracheal tissue characterized by presence of more granulocytes in the 15cd group compared to the 3cd group. Cough frequency was significantly greater for the 15cd group compared to the 3cd group.

CONCLUSIONS

A custom-designed large animal inhalation chamber successfully challenged pigs repeatedly, to varying levels of cigarette smoke. Future studies will combine such low levels of smoke exposure with other common challenges such as acid reflux to understand the multifactorial causation of laryngeal pathologies.

Proteomic Analysis of Vocal Fold Fibroblasts Exposed to Cigarette Smoke Extract: Exploring the Pathophysiology of Reinke's Edema

Reinke's edema is a smoking-associated, benign, mostly bilateral lesion of the vocal folds leading to difficulties in breathing and voice problems. Pronounced histological changes such as damaged microvessels or immune cell infiltration have been described in the vocal fold connective tissue, the lamina propria Thus, vocal fold fibroblasts, the main cell type of the lamina propria, have been postulated to play a critical role in disease mediation. Yet information about the pathophysiology is still scarce and treatment is only surgical, i.e. symptomatic. To explore the pathophysiology of Reinke's edema, we exposed near-primary human vocal fold fibroblasts to medium conditioned with cigarette smoke extract for 24 h as well as 4 days followed by quantitative mass spectrometry.Proteomic analyses after 24 h revealed that cigarette smoke increased proteins previously described to be involved in oxidative stress responses in other contexts. Correspondingly, gene sets linked to metabolism of xenobiotics and reactive oxygen species were significantly enriched among cigarette smoke-induced proteins. Among the proteins most downregulated by cigarette smoke, we identified fibrillar collagens COL1A1 and COL1A2; this reduction was validated by complementary methods. Further, we found a significant increase of UDP-glucose 6-dehydrogenase, generating a building block for biosynthesis of hyaluronan, another crucial component of the vocal fold lamina propria In line with this result, hyaluronan levels were significantly increased because of cigarette smoke exposure. Long term treatment of 4 days did not lead to significant changes.The current findings corroborate previous studies but also reveal new insights in possible disease mechanisms of Reinke's edema. We postulate that changes in the composition of the vocal folds' extracellular matrix -reduction of collagen fibrils, increase of hyaluronan- may lead to the clinical findings. This might ease the identification of better, disease-specific treatment options.

Does Reinke's Edema Grade Determine Premalignant Potential?

OBJECTIVE

Reinke's edema (RE) is a benign disease of the vocal folds with a wide spectrum of clinical severity. We aim to evaluate the clinical impact of RE grade and determine if RE grade correlates with severity of dysplasia and tobacco exposure.

METHODS

Patients with isolated RE who underwent surgical excision between December 2010 and December 2014 were retrospectively reviewed. The RE grade was determined from archived laryngeal videostroboscopy exams. Pathologic severity of dysplasia, categorized by squamous intraepithelial neoplasia (SIN) classification, and tobacco history were extracted from medical records.

RESULTS

Of 95 lesions, 3 (3.16%) were RE grade 1, 33 (34.74%) were RE grade 2, 24 (25.26%) were RE grade 3, and 35 (36.84%) were RE grade 4. Fifty-nine lesions (62.11%) had no dysplasia (SIN0), 19 (20.00%) had mild dysplasia (SIN1), 15 (15.79%) had moderate dysplasia (SIN 2), and 2 (2.11%) had severe dysplasia (SIN3). The 2 patients with severe dysplasia had grade 4 lesions. No statistical correlation was identified between RE grade and the severity of dysplasia. Furthermore, no statistical correlation was seen between tobacco exposure and the severity of dysplasia or the RE grade.

CONCLUSIONS

Size of RE lesion does not reflect premalignancy. The majority of RE lesions, regardless of size, have little to no premalignant potential. Severe dysplasia/carcinoma in situ may be more likely seen in grade 4 lesions; however, the paucity of severe dysplasia published in RE data and in this cohort preclude any formal inference. Further study of grade 4 lesions is warranted.

Medications and Adverse Voice Effects

OBJECTIVES

To identify the medications used by patients with dysphonia, describe the voice symptoms reported on initial speech-language pathology (SLP) examination, evaluate the possible direct and indirect effects of medications on voice production, and determine the association between direct and indirect adverse voice effects and self-reported voice symptoms, hydration and smoking habits, comorbidities, vocal assessment, and type and degree of dysphonia.

STUDY DESIGN

This is a retrospective cross-sectional study.

METHODS

Fifty-five patients were evaluated and the vocal signs and symptoms indicated in the Dysphonia Risk Protocol were considered, as well as data on hydration, smoking and medication use. We analyzed the associations between type of side effect and self-reported vocal signs/symptoms, hydration, smoking, comorbidities, type of dysphonia, and auditory-perceptual and acoustic parameters.

RESULTS

Sixty percent were women, the mean age was 51.8 years, 29 symptoms were reported on the screening, and 73 active ingredients were identified with 8.2% directly and 91.8% indirectly affecting vocal function. There were associations between the use of drugs with direct adverse voice effects, self-reported symptoms, general degree of vocal deviation, and pitch deviation.

CONCLUSIONS

The symptoms of dry throat and shortness of breath were associated with the direct vocal side effect of the medicine, as well as the general degree of vocal deviation and the greater pitch deviation. Shortness of breath when speaking was also associated with the greatest degree of vocal deviation.

Acute exposure to vibration is an apoptosis-inducing stimulus in the vocal fold epithelium

Clinical voice disorders pose significant communication-related challenges to patients. The purpose of this study was to quantify the rate of apoptosis and tumor necrosis factor-alpha (TNF-α) signaling in vocal fold epithelial cells in response to increasing time-doses and cycle-doses of vibration. 20 New Zealand white breeder rabbits were randomized to three groups of time-doses of vibration exposure (30, 60, 120min) or a control group (120min of vocal fold adduction and abduction). Estimated cycle-doses of vocal fold vibration were extrapolated based on mean fundamental frequency. Laryngeal tissue specimens were evaluated for apoptosis and gene transcript and protein levels of TNF-α. Results revealed that terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was significantly higher after 120min of vibration compared to the control. Transmission electron microscopy (TEM) revealed no significant effect of time-dose on the mean area of epithelial cell nuclei. Extrapolated cycle-doses of vibration exposure were closely related to experimental time-dose conditions, although no significant correlations were observed with TUNEL staining or mean area of epithelial cell nuclei. TUNEL staining was positively correlated with TNF-α protein expression. Our findings suggest that apoptosis can be induced in the vocal fold epithelium after 120min of modal intensity phonation. In contrast, shorter durations of vibration exposure do not result in apoptosis signaling. However, morphological features of apoptosis are not observed using TEM. Future studies are necessary to examine the contribution of abnormal apoptosis to vocal fold diseases.

Are Vocal Alterations Caused by Smoking in Reinke's Edema in Women Entirely Reversible After Microsurgery and Smoking Cessation?

BACKGROUND

Reinke's edema is a benign lesion of the vocal folds that affects chronic smokers, especially women. The voice becomes hoarse and virilized, and the treatment is microsurgery. However, even after surgery and smoking cessation, many patients remain with a deep and hoarse voice.

OBJECTIVES

The aim of the present study was to compare pre- and postoperative acoustic and perceptual-auditory vocal analyses of women with Reinke's edema and of women in the control group, who were non-smokers.

METHODS

A total of 20 women with videolaryngoscopy diagnosis of Reinke's edema who underwent laryngeal microsurgery were evaluated pre- and postoperatively (6 months) by videolaryngoscopy, acoustic voice, and perceptual-auditory analyses (General degree of dysphonia, Roughness, Breathiness, Asthenia, Strain, and Instability [GRBASI] scale), and the maximum phonation times were calculated. The pre- and postoperative parameters of the women with Reinke's edema were compared with those of the control group of women with no laryngeal lesions, smoking habit, or vocal symptoms.

RESULTS

Acoustic vocal perceptual-auditory analyses and the maximum phonation time of women with Reinke's edema improved significantly in the postoperative evaluations; nevertheless, 6 months after surgery, their voices became worse than the voices of the women from the control group.

CONCLUSIONS

Abnormalities caused by smoking in Reinke's edema in women are not fully reversible with surgery and smoking cessation. One explanation would be the presence of possible structural alterations in fibroblasts caused by the toxicity of cigarette components, resulting in the uncontrolled production of fibrous matrix in the lamina propria, and preventing complete vocal recovery.

CD34-positive fibroblasts in Reinke's edema

OBJECTIVES/HYPOTHESIS

To elucidate whether and to what extent CD34+ fibroblasts (so-called CD34+ fibrocytes, CD34+ dendritic cells, and CD34+ stromal cells) occur in normal human vocal folds and in Reinke's edema.

STUDY DESIGN

Histological study.

METHODS

Conventional, immunohistochemical, and ultrastructural procedures were performed in histological blocks of 18 selected cases of Reinke's edema (with typical findings including acellular edematous spaces in the subepithelial connective tissue of vocal folds, and disarrangement of elastic, collagen, and reticular fibers). For control purposes, four normal vocal folds were analyzed.

RESULTS

In normal vocal folds, most stromal cells were spindle-shaped CD34+ fibroblasts. In Reinke's edema, increased density and changes in the morphology and size of this subpopulation of fibroblasts were demonstrated in the connective tissue surrounding the edematous spaces, particularly in their borders, where together with some macrophages they formed boundaries, mimicking the walls of distended lymphatic vessels when conventional stains were used. These activated CD34+ fibroblasts acquired a dendritic morphology (with long, moniliform, often bifurcated, overlapping multipolar processes), and their cytoplasmic organelles were increased in number. In addition to CD34, they expressed vimentin, CD10 and CD99, but no α-smooth muscle actin (α-SMA), CD31, CD117, CD68, h-caldesmon, desmin, or S-100 protein.

CONCLUSIONS

CD34+ fibroblasts are a major cell component in the stroma of vocal folds in Reinke's edema, and their activation, with increased density and morphologic changes around the edematous spaces, occurs without immunophenotypic transformation toward myofibroblasts (no expression of α-SMA). The mechanisms by which these cells act in Reinke's edema require further study.