Blockage of the adenosine A2B receptor prevents cardiac fibroblasts overgrowth in rats with pulmonary arterial hypertension

Sustained pressure overload and fibrosis of the right ventricle (RV) are the leading causes of mortality in pulmonary arterial hypertension (PAH). Although the role of adenosine in PAH has been attributed to the control of pulmonary vascular tone, cardiac reserve, and inflammatory processes, the involvement of the nucleoside in RV remodelling remains poorly understood. Conflicting results exist on targeting the low-affinity adenosine A2B receptor (A2BAR) for the treatment of PAH mostly because it displays dual roles in acute vs. chronic lung diseases. Herein, we investigated the role of the A2BAR in the viability/proliferation and collagen production by cardiac fibroblasts (CFs) isolated from RVs of rats with monocrotaline (MCT)-induced PAH. CFs from MCT-treated rats display higher cell viability/proliferation capacity and overexpress A2BAR compared to the cells from healthy littermates. The enzymatically stable adenosine analogue, 5'-N-ethylcarboxamidoadenosine (NECA, 1-30 μM), concentration-dependently increased growth, and type I collagen production by CFs originated from control and PAH rats, but its effects were more prominent in cells from rats with PAH. Blockage of the A2BAR with PSB603 (100 nM), but not of the A2AAR with SCH442416 (100 nM), attenuated the proliferative effect of NECA in CFs from PAH rats. The A2AAR agonist, CGS21680 (3 and 10 nM), was virtually devoid of effect. Overall, data suggest that adenosine signalling via A2BAR may contribute to RV overgrowth secondary to PAH. Therefore, blockage of the A2AAR may be a valuable therapeutic alternative to mitigate cardiac remodelling and prevent right heart failure in PAH patients.

The collagen market and knowledge, attitudes, and practices of Brazilian consumers regarding collagen ingestion

Collagen is considered a nutraceutical, and its consumption has been expanding due to the increased life expectancy, rising per capita income, and increased consumer awareness of health care. This study aimed to evaluate consumers' perceptions, knowledge, attitudes, and practices about the consumption of collagen-based products by using an online questionnaire and to correlate them with socio-economic data. A market survey (pharmacy stores and online) was also conducted to evaluate the available products. In total, 275 participants answered the survey, 73.3% from the Southeast region, mostly female (84.0%). Most participants reported three months as the period of collagen intake (31.6%), and the consumption period was associated with the perception of the health benefits (p < 0.001). Furthermore, the participants' knowledge and perceptions regarding collagen intake are frequently associated with dermatological and orthopedic changes. Collagen-based products supplementation is a growing market with a broad target audience (genders, age groups, and socio-economic levels). The commercial presentation of collagen has been diversified over the years, and powder collagen is the most consumed (52.7%) and cheapest compared with capsules, pills, or gummies. The results of the present study demonstrate that most consumers of this type of supplement associate its benefits with aesthetic care such as skin, hair, and nails, although the scientific literature has shown its effects in treating osteoarticular diseases, for example. Undoubtedly, the correct dose prescription, treatment time, and choice of product presentation must be analyzed carefully, as they significantly impact treatment results.

Upregulation of HSP72 attenuates tendon adhesion by regulating fibroblast proliferation and collagen production via blockade of the STAT3 signaling pathway

The proliferation of fibroblasts creates an environment favoring post-operative tendon adhesion, but targeted therapy of this pathology remains in its infancy. In this study, we explored the effect of heat shock protein 72 (HSP72), a major inducible member of the heat shock protein family that can protect cells against many cellular stresses including heat shock, on fibroblast proliferation in tendon adhesion, with its underlying mechanisms investigated. HSP72 expression was examined in an established rat model of tendon injury using RT-qPCR and immunoblot analysis. After conducting ectopic expression and depletion experiments in fibroblast NIH3T3 cells, we determined the effects of HSP72 on the expression of α-SMA and STAT3 signaling pathway-related genes, fibroblast proliferation, as well as collagen production. The mRNA (65.46%) and protein (63.65%) expression of HSP72 was downregulated in the rat model of tendon injury. The in vitro experiments revealed that overexpression of HSP72 inhibited fibroblast proliferation (42.57%) and collagen production (45.60%), as well as reducing α-SMA expression (42.49%) and the extent of STAT3 phosphorylation (55.46%). Moreover, we observed that HSP72 overexpression reduced inflammation as well as the number of inflammatory cell infiltration and fibroblasts in vivo. Furthermore, the inhibited extent of STAT3 phosphorylation contributed to the impaired fibroblast proliferation and collagen production evoked by upregulated HSP72. In summary, the present study unveils an inhibitory role of HSP72 in tendon adhesion via inactivation of the STAT3 signaling pathway. This finding may enable the development of new therapeutic strategies for the prevention against tendon adhesion.

Biocide triclosan impairs byssus formation in marine mussels Mytilus galloprovincialis

The effects of the biocide Triclosan, used in personal care products and known as a common environmental contaminant, on byssal apparatus were studied in the marine mussel Mytilus galloprovincialis. Experimental evidences indicated that an exposure for 7 days at a concentration of 10 μg/L induced marked alterations in the byssus gland resulting in a significant delay in byssus regrowth and in a decrease in threads resistance to traction. Such alterations in animals exposed to tidal and waves action would cause a significant loss in ecological fitness and severely impact on mussel survival. Triclosan release in coastal environments therefore should be more carefully monitored to prevent drastic consequences.

Impact of retort process on characteristics and bioactivities of herbal soup based on hydrolyzed collagen from seabass skin

Impact of retort processing on the characteristics and bioactivity of herbal soup, based on hydrolyzed collagen from seabass fish skins, as sterilized health drink in glass bottles, was investigated. Retort processing was conducted at either 115 °C or 121 °C for 5, 7, 9 or 11 min (F0 values) and compared to no retort processing. All retort processing conditions yielded sterile soups, but some differences in moisture content, pH, viscosity, UV-absorbance, browning index, fluorescence intensity, color, α-amino group and total reducing compound contents were observed, compared to those without retort processing. Retort processing enhanced antioxidative activity of herbal hydrolyzed collagen (HHC) soups, regardless of conditions. HHC soups with F0 value of 7 at 115 °C (115/7) and 121 °C (121/7) showed significantly higher ABTS and DPPH radical scavenging activities, ferric reducing antioxidant power and H2O2 scavenging activity, compared to others. Retort processing had no significant (p > 0.05) effect on the appearance, color, odor, viscosity, flavor, taste and overall perception of HHC soups. The 115/7 and 121/7 samples stimulated cell proliferation and enhance collagen production of L929 mouse fibroblast cells. It was therefore concluded that retort processing could be used for preparing sterilized HHC soup as a ready-to-serve functional drink that is both healthy and safe.

Effects of formaldehyde exposure on the development of pulmonary fibrosis induced by bleomycin in mice

Environmental and Occupational pollution has been extensively studied because of its serious implications on the human health. Formaldehyde (FA) is a pollutant widely employed in several industries and also in anatomy, pathology and histology laboratories. Studies have shown the correlation between FA exposure and development or worsening of asthma. However, the effect of FA exposure on the pulmonary fibrosis (PF) is unknown. PF is a progressive and chronic lung disease with high incidence and considerable morbidity and mortality. Few studies have shown a worsening of PF after pollutants exposure such as ozone and nitrogen dioxide. Therefore, our objective was to assess the effects of FA on the PF. Male mice C57BL6 were treated or not with bleomycin (1,5 U/kg) and exposed or not to FA inhalation (0.92 mg/m3, 1 h/day, 5 days/week during 2 weeks). Non-manipulated mice were used as control. Our data showed that FA exposure in fibrotic mice increased the number of granulocytes in the bronchoalveolar lavage followed by elevated levels of interleukin 1 beta and interleukin 17. In addition, FA exposure in fibrotic mice enhanced the gene expression of C-X-C motif chemokine ligand 1 (CXCL1) and tumor necrosis factor alpha (TNF-α) in the lung. We also showed an increase in the collagen production, while lung elastance was reduced. No differences were found in the mucus production, oedema and interstitial thickening in the lung tissue of fibrotic mice after FA exposure. In conclusion our study showed that FA exposure aggravates the lung neutrophils influx and collagen production, but did not alter the lung elastance, mucus production, oedema and interstitial tickening. This work contributes to understand the effects of pollution in the development of PF.

Photobiomodulation therapy improves both inflammatory and fibrotic parameters in experimental model of lung fibrosis in mice

Lung fibrosis (LF) is a chronic and progressive lung disease characterized by pulmonary parenchyma progressive lesion, inflammatory infiltration, and interstitial fibrosis. It is developed by excessive collagen deposition and other cellular matrix components, resulting in severe changes in the alveolar architecture. Considering the absence of effective treatment, the aim of this study was to investigate the effect of photobiomodulation therapy (PBMT) on the development of PF. For this purpose, we used C57BL6 mice subjected to induction of LF by bleomycin administration (1.5 U/kg) by orotracheal route and, after 14 days of the induction, mice were treated with PBMT applied to the thorax 1×/day for 8 days (wavelength 660 ± 20 nm, power 100 mW, radiant exposure 5 J/cm², irradiance 33.3 mW/cm², spot size 2.8cm², total energy 15 J, time of irradiation: 150 s) and inflammatory and fibrotic parameters were evaluated with or without PBMT. Our results showed that PBMT significantly reduced the number of inflammatory cells in the alveolar space, collagen production, interstitial thickening, and static and dynamic pulmonary elastance. In addition, we observed reduced levels of IL-6 e CXCL1/KC released by pneumocytes in culture as well as reduced level of CXCL1/KC released by fibroblasts in culture. We can conclude that the PBMT improves both inflammatory and fibrotic parameters showing a promising therapy which is economical and has no side effects.

Low-level laser therapy (904nm) can increase collagen and reduce oxidative and nitrosative stress in diabetic wounded mouse skin

BACKGROUND AND OBJECTIVE

Over the last decade we have seen an increased interest in the use of Low-Level Laser Therapy (LLLT) in diseases that involve increased oxidative stress. It is well established that hyperglycemia in diabetes elicits a rise in reactive oxygen species (ROS) production but the effect of LLLT remains unclear. This study aimed to investigate whether LLLT was able to improve oxidative/nitrosative stress parameters in the wound healing process in diabetic mice.

STUDY DESIGN/MATERIALS AND METHODS

Twenty male mice were divided into four groups: non-irradiated control (NIC), irradiated control (IC), non-irradiated and diabetic (NID), irradiated and diabetic (ID). Diabetes was induced by administration of streptozotocin. Wounds were created 120days after the induction of diabetes in groups IC and ID and these groups were irradiated daily for 5days (superpulsed 904nm laser, average power 40mW, 60s). All animals were sacrificed 1day after the last irradiation and histology, collagen amount, catalase activity, nitrite and thiobarbituric acid reactive substances (TBARS) were measured.

RESULTS

Histology showed that collagen fibers were more organized in IC and ID when compared to NID group, and significant differences in collagen content were found in group ID versus NID. Catalase activity was higher in IC group compared to other groups (p<0.001). TBARS levels were higher in IC versus NIC, but were lower in ID versus NID (p<0.001). Nitrite was lower in both irradiated groups versus the respective non-irradiated groups (p<0.001).

CONCLUSIONS

Delayed wound healing in diabetes is still a challenge in clinical practice with high social costs. The increased production of collagen and decreased oxidative and nitrosative stress suggests that LLLT may be a viable therapeutic alternative in diabetic wound healing.