Bovine follicular fluid and serum share a unique isoform of matrix metalloproteinase-2 that is degraded by the oviductal fluid

Hydrogel degradation promotes angiogenic and regenerative potential of cell spheroids for wound healing

Chronic nonhealing wounds are debilitating and diminish one's quality of life, necessitating the development of improved strategies for effective treatment. Biomaterial- and cell-based therapies offer an alternative treatment compared to conventional wound care for regenerating damaged tissues. Cell-based approaches frequently utilize endothelial cells (ECs) to promote vascularization and mesenchymal stromal cells (MSCs) for their potent secretome that promotes host cell recruitment. Spheroids have improved therapeutic potential over monodisperse cells, while degradable scaffolds can influence cellular processes conducive to long-term tissue regeneration. However, the role of biomaterial degradation on the therapeutic potential of heterotypic EC-MSC spheroids for wound healing is largely unknown. We formed poly(ethylene) glycol (PEG) hydrogels with varying ratios of matrix metalloproteinase (MMP)-degradable and non-degradable crosslinkers to develop three distinct constructs - fully degradable, partially degradable, and non-degradable - and interrogate the influence of degradation rate on engineered cell carriers for wound healing. We found that the vulnerability to degradation was critical for cellular proliferation, while inhibition of degradation impaired spheroid metabolic activity. Higher concentrations of degradable crosslinker promoted robust cell spreading, outgrowth, and secretion of proangiogenic cytokines (i.e., VEGF, HGF) that are critical in wound healing. The degree of degradation dictated the unique secretory profile of spheroids. When applied to a clinically relevant full-thickness ex vivo skin model, degradable spheroid-loaded hydrogels restored stratification of the epidermal layer, confirming the efficacy of scaffolds to promote wound healing. These results highlight the importance of matrix remodeling and its essential role in the therapeutic potential of heterotypic spheroids.

Hematochemical Patterns in Follicular Fluid and Blood Stream in Cycling Mares: A Comparative Note

The aim of this study was to verify the existence of possible cross-talk between biochemical contents of follicular fluid (FF) and systemic concentrations according to the follicular development of the metabolites: glucose (GLU), lactate (LACT), cholesterol (CHOL), triglycerides (TG), total bilirubin (T BIL), blood urea nitrogen (BUN), and creatinine (CREAT); enzymatic activities: gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and aspartate aminotransferase (AST); electrolytes: calcium (Ca), phosphorus (P), sodium (Na), chloride (Cl), potassium (K), magnesium (Mg), and iron (Fe); total proteins (TP) and their fractions: albumin (ALB), α1-, α2-, β-, and γ-globulins (GLOB) of FF and blood strain and their correlations with follicular size in cycling mares. Systemic concentrations of GLU, T BIL, BUN, Fe, TP, ALB, α-1, and α-2 and δ-GLOB and of ALP, GGT, and AST activities were higher than in the FF (P < .05); LACT, CHOL, and TG were higher in FF than systemic ones (P < .05). Glucose, CHOL, TG, LACT, and T BIL were higher in large follicles than in medium and small follicles (P < .05); however, BUN, Fe, ALP, and AST were lower in large follicles than in medium or small follicles (P < .05). Alkaline phosphatase, GGT, and AST activities decreased in medium and large follicles compared with small follicles (P < .05). These results suggest that the metabolic, enzymatic, electrolytic, and protein composition of FF of growing follicles could occur according to the bloodstream changes; hence, it is possible to presume that the nutritional environment of oocyte and follicular cells could improve the clinical diagnoses of infertility in the mare.

Dynamic in vivo changes in the activities of gelatinases, matrix metalloproteinases (MMPs), and tissue inhibitor of metalloproteinases (TIMPs) in buffalo (Bubalus bubalis) uterine luminal fluid during estrous cycle and early pregnancy

In ruminants, the phenomenon of endometrial tissue remodeling during the estrous cycle and early pregnancy is not fully understood. In this report, the occurrence of tissue remodeling, if any, in buffalo endometrium was studied by detecting gelatinases, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs); the key regulators of tissue remodeling, in uterine luminal fluids (ULF) of cycling and early pregnant (approx. 43-65 days) buffaloes. Each stage of the estrous cycle and pregnant ULF demonstrated a unique profile of gelatinase activities compared to serum/follicular fluid, with a major gelatinase band of 60 kDa with highest activity in early-luteal stage. In addition to a 32 kDa uterus-specific gelatinase band detected in both non-pregnant and pregnant ULFs, the pregnant ULF displayed three new gelatinase bands of 86, 78, and 57 kDa. Western blot technique confirmed the presence of MMP-2 (54 kDa), MMP-9 (76/73 kDa), TIMP-1 (32 kDa), TIMP-2(20 kDa), and two molecular weight forms (31 and 22 kDa) of TIMP-3 in buffalo ULF with varying band intensities. Highest MMP-2 and MMP-9 activities were observed in follicular and early-luteal stage ULFs, respectively. Highest TIMP-1 activity was observed in early-luteal ULF. Interestingly, TIMP-2 activity was only detected in mid-luteal, late-luteal, and follicular stage ULFs with significantly increasing intensities. Highest activities of 31 and 22 kDa TIMP-3 were associated with late-luteal and early-luteal stage ULFs, respectively. The varied activities of MMPs and TIMPs in buffalo ULF during the estrous cycle and early pregnancy might be a reflection of dynamic structural remodeling of the endometrium and/or developing conceptus.

Selective processing of a follicular matrix metalloproteinase-2 isoform by human oviducal fluid

The present study demonstrates that a unique isoform of matrix metalloproteinase (MMP)-2 present in human follicular fluid (FF) can be processed selectively by human oviducal fluid (OF). A gelatin zymogram of untreated FF showed distinct 88-, 84- and 62-kDa gelatinases. Treatment of FF with EDTA resulted in the appearance of 110-kDa gelatinase (GA110). Most gelatinases, except for the 88- and 84-kDa gelatinases, were abolished by pretreatment with EDTA or phenanthroline, but not by pretreatment with a serine/threonine protease inhibitor. When EDTA-pretreated FF was mixed with OF, the GA110 of the FF was specifically reduced. The reduction in GA110 was dependent upon the amount of OF protein and the incubation period after mixing. Treatment of FF with aminophenylmercuric acetate reduced GA110 activity, but this reduction was accompanied by a concomitant increase of 62-kDa gelatinase activity. Anti-human MMP-2 antibody strongly reacted with both GA110 and 62-kDa gelatinases of FF, but only GA110 immunoreactivity was abolished when FF was mixed with OF. The results suggest that the GA110 of FF is an MMP-2 isoform that can be processed selectively by OF.

Protein kinase C stimulates release of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 by human decidual cells

OBJECTIVE

Increased concentrations of amniotic fluid matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 have been observed in the context of premature rupture of membranes (PROM) and microbial invasion of the amniotic cavity. However, the source of the stimuli that contribute to the accumulation of these proteins in amniotic fluid remains to be identified. The present study was conducted to investigate MMP-2, MMP-9 and TIMP-1 secretion by decidual cells in response to activated protein kinase C (PKC).

METHODS

Decidual cells were isolated from term placentae, grown to confluence and incubated with control media or 10(-11) to 10(-8) mol/l concentrations of phorbol 12-myristate 13-acetate (PMA). Concentrations of MMP-2, MMP-9 and TIMP-1 in the culture supernatant were determined using sensitive and specific immunoassays. Substrate zymography was conducted to confirm MMP-9 assays.

RESULTS

PMA induced a concentration-dependent stimulation of release of MMP-9 (control vs. PMA l0(-9) and 10(-8) mol/l; p < 0.01) and TIMP-1 (control vs. PMA 10(-9) and 10(-8) mol/l; p < 0.001), but not MMP-2. A direct positive correlation was observed between MMP-9 and TIMP-1 release (r = 0.645; p < 0.001). Substrate zymography confirmed increased release of MMP-9 in response to PMA (control vs. PMA 10(-8) and PMA 10(-7) mol/l; p < 0.01).

CONCLUSIONS

Activation of PKC within the decidua will result in enhanced MMP-9 release, which upon activation could contribute to degradation of matrices within fetal membranes leading to PROM.

Prostaglandin E1 Inhibits Abnormal Follicle Rupture and Restores Ovulation in Indomethacin-Treated Rats1

In the presence of indomethacin, an inhibitor of prostaglandin (PG) synthesis, the gonadotropin surge induces abnormal follicle rupture at the basolateral follicle sides, thus preventing effective ovulation in rats. This study was undertaken to analyze whether exogenous prostaglandin administration can overcome the antiovulatory action of indomethacin. Cycling rats were treated with vehicle (olive oil) or indomethacin (1 mg/rat) on the morning of proestrus. Rats treated with indomethacin were injected with different doses (50, 250, or 500 micro g/rat) of PGE(1), PGE(2), PGF(2alpha), or vehicle (saline) at 1900 h in proestrus. The ovulatory response was analyzed on the morning of estrus by evaluating follicle rupture and the location of the oocytes in serially sectioned ovaries. The number of oocytes in the oviducts was also counted in rats treated with the highest prostaglandin doses. In indomethacin-treated rats, most newly formed corpora lutea showed abnormal follicle rupture at the basolateral sides. In addition, invasion of the ovarian stroma and blood and lymphatic vessels by granulosa cells and follicular fluid was observed. Prostaglandins of the E series, and especially PGE(1), inhibited abnormal follicle rupture and restored ovulation, although the number of oocytes in the oviducts were significantly decreased. PGF(2alpha) was only partially effective in inhibiting abnormal follicle rupture and restoring ovulation. These data suggest that prostaglandins of the E series, and particularly PGE(1), play a crucial role in ovulation by determining the targeting of follicle rupture at the apex, thus allowing release of oocytes to the periovarian space.