In-vitro study on type I collagen synthesis in low-level laser therapy on the early ligament fibroblasts' healing process.

BACKGROUND: Low-level Laser Therapy (LLLT) has demonstrated its potential in promoting fiber matrix maturation, collagen synthesis, and fibroblast proliferation, contributing to tissue regeneration. Our study aimed to investigate the impact of LLLT on collagen type I synthesis, cell proliferation, and viability in human ligament fibroblasts derived from the Anterior Cruciate Ligament (ACL). METHODS: Tissue samples were obtained from individuals undergoing arthroscopic ACL reconstruction surgery. Primary human fibroblasts were isolated, and immunohistochemical assays confirmed their characteristics. LLLT at 850 nm was administered in three groups: Low dose (1.0 J/cm²), High dose (5.0 J/cm²), and Control (0.0 J/cm²). Cell viability was calculated using a membrane integrity assay, proliferation was determined by automated counting, and collagen type I concentration in cell culture was measured using an immunoassay. RESULTS: Fibroblasts showed decreased viability after low and high doses of LLLT, increased proliferation at the low dose, and increased collagen synthesis at the high dose on day 10 for both sexes after treatment. CONCLUSION: Our study demonstrated that LLLT may improve the early ligament healing process by increasing cell proliferation at the low dose and enhancing collagen type I synthesis at the high dose in human ligament fibroblasts.

Multiparametric study of atresia in ewe antral follicles: histology, flow cytometry, internucleosomal DNA fragmentation, and lysosomal enzyme activities in granulosa cells and follicular fluid.

The differential quantitative participation of apoptosis and necrosis in ewe antral follicles of two different sizes, separated in four stages of atresia using macroscopic, histologic, and esteroid quantification methods was assessed. Annexin V binding and propidium iodide (PI) uptake was used to detect healthy live cells (Annexin V negative/PI negative), early apoptotic cells (Annexin V+/PI-), and necrotic or late apoptotic cells (PI+). Additionally we used internucleosomal DNA fragmentation as a quantitative estimate of apoptosis. Presence and distribution of lysosomal enzymes in follicular fluid and granulosa cells was used as a measure of necrotic cell death. DNA flow cytometry and gel electrophoresis were positively correlated with the progression of atresia, small atretic follicles tend to have higher percentages of internucleosomal cleaved DNA than follicles >6 mm. Annexin/PI binding also indicates that apoptosis and necrosis increase with atresia progression, generally apoptosis outweighs necrosis in small follicles. Acid phosphatase and glucosaminidase in follicular fluid of 3-6 mm follicles showed no significant modifications between healthy and initially atretic follicles, and only a small, but significant increase in activity in advancedly atretic follicles. On the contrary, lysosomal enzyme activity in follicles >6 mm showed positive correlation between atresia stages and the activities of acid phosphatase and glucosaminidase in follicular fluid. A similar size-differential behavior was found in free or membrane-bound lysosomal enzyme activity of granulosa cells. Necrosis, but principally apoptosis, were present during all stages of follicular maturation indicating that growth and maturation of ovarian follicles involves a continuous renewal of granulosa cells, regulated by apoptosis. Mechanisms regulating this equilibrium may participate in the final destiny, whether ovulation or atresia of ovarian follicles.

Metalloproteinase activity during growth, maturation and atresia in the ovarian follicles of the goat.

Metalloproteinases are an important group of hydrolytic enzymes which participate in interstitial matrix degradation during tissue remodelling processes and therefore may be required during follicular growth and maturation. The activity of metalloproteinases (collagenases, gelatinase, and Pz-peptidase), was measured during growth, maturation and atresia of goat antral follicles. These follicles (n = 67) were separated by size and also classified into four groups: non-atretic (Group I); early atretic (Stage I) (Group II); moderately atretic (Stage II) (Group IIIa); and, late atretic (Stage III) (Group IIIb). Pz-peptidase was greater in granulosa than in thecal cells, and almost absent in follicular fluid. In non-atretic follicles, activity in granulosa cells increased with increasing follicle size, whereas activity peaked in 3-6 mm follicles in thecal cells. Atresia was associated with declining activity in thecal cells from follicles in the 3-6 mm range and in granulosa cells from the > 6 mm range. Interstitial collagenase activity was significant and similar in granulosa and thecal cell extracts and low in follicular fluid from non-atretic follicles. Activity increased significantly in thecal cells, but decreased significantly in granulosa cells from large (> 6 mm) non-atretic follicles. Atresia was associated with declining activity in both types cells and increasing activity in follicular fluid. Gelatinase activity was some times associated with five regions corresponding to molecular weights of 22.1, 30.7, 39.6, 63.8 and 71.4 kDa, and rarely at 91.3 and 81.2 kDa. Overall activity declined with atresia in thecal cells from follicles in the 3-6 mm range, but not in those > 6 mm. In granulosa cells from follicles 3-6 mm, activity varied widely with stage of atresia, while in cells from follicles > 6 mm, activity was greatly increased in atretic follicles.

[Galanin, a new neuropeptide. Review]. / Galanina, un nuevo neuropéptido. Revisión.

Galanin is a 29 amino-acid peptide originally isolated from porcine intestine. It is synthesized as part of a large precursor peptide the preprogalanin. Immunological studies has showed that there is interspecies conservation of the N terminal portion although the C-terminal portions has a little of immunoreactivity. Galanin has a number of pharmacological properties in whole animals and isolated tissues. Galanin contracts isolated preparation from rat fundus, ileum, colon and urinary bladder. Direct administration of galanin (pGal) into the rat third ventricule stimulates food intake, increases plasma growth hormone and prolactin levels and decrease dopamine levels in the median eminence. Intravenous infusion in dog and humans induce a hyperglycemia and glucose intolerance and inhibits the insulin, somatostatin and pancreatic polipeptide secretion from pancreas. Galanin is a estrogen-stimulated peptide. Estrogens increase dramatically the synthesis of their mRNA and the peptide in the rat pituitary. Galanin-like immunoreactivity is widely distributed in several mamalian species including humans. In the central nervous system it was found in medium emminence, hypothalamus, arcuate nucleus etc. Its localization in neurosecretory granules suggest that galanin functions as a neurotransmitter. The detection of a Gal-immunorectivity in the plasma after 17 beta estradiol stimulation suggests that galanin has a distal target and therefore, may be an additional anterior pituitary hormone. Galanin has been localized in reproductive tissues and this suggests that it may play an estrogen mediated role in the hypothalamic and pituitary function. However, the molecular mechanisms involved in their function remain to be studied.