Hyaluronic acid reagent suppressed endometriotic lesion formation in a mouse model

The pro-inflammatory and anti-inflammatory role of hyaluronic acid in endometriosis

OBJECTIVE

Endometriosis is a bothersome disease affected women worldwide, the mechanism of disease development is still under investigation. Several inflammatory responses after clinical hyaluronic acid (HA) use were reported. Cyclooxygenase (COX)-2 mediated inflammation pathway is involved in the pathogenesis of endometriosis. Thus, we tried to investigate the inflammatory role of hyaluronic acid in endometriosis.

MATERIALS AND METHODS

Peritoneal fluid was collected in endometriosis and disease-free patients for the measurement of HA. Endometriotic stromal cells were treated with IL-1β and HA and expression of COX-2 was evaluated. Mice model of endometriosis was established and treated with fluid or gel form of HA. Endometriotic lesion size and weight were recorded and level of COX-2 was evaluated by immunohistochemistry staining.

RESULTS

The level of HA in the peritoneal fluid had no statistically significant difference between normal, early and advanced stage endometriosis patients. The overexpression of COX-2 protein was detected when treating endometriotic stromal cell with HA in the presence of IL-1β (P < 0.001). The endometriotic lesion size was reduced in mice model when treated with higher concentration gel form HA. It further showed less proportion of strong COX-2 expression compare of gel form HA to fluid form treatment in COX-2 expression score of endometriosis lesion.

CONCLUSION

Both proinflammatory evidence, elevated COX-2 expression, and anti-inflammatory result, reduced endometriosis lesion size and COX-2 expression score, were noted in our study after treating HA in in vivo and in vitro models. We hypothesized it is possible that HA may induce an acute proinflammatory response followed by chronic anti-inflammatory reaction in the formation of endometriosis.

The Hyaluronic Acid System is Intact in Menstrual Endometrial Cells in Women With and Without Endometriosis

OBJECTIVE

To characterize the production and degradation of hyaluronic acid (HA) in menstrual endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs) in women with and without endometriosis. To identify the presence of CD44, the primary receptor of HA, in menstrual EECs and ESCs in women with and without endometriosis.

DESIGN

In vitro study.

SETTING

Academic center.

PATIENT(S)

Deidentified patient samples from women with and without endometriosis.

INTERVENTIONS

EECs and ESCs were isolated from menstrual endometrial biopsies performed on women with (N = 9) and without (N = 11) endometriosis confirmed by laparoscopy.

MAIN OUTCOME MEASURE

Real-time polymerase chain reaction, Western blot, and immunohistochemistry were used to assess hyaluronic acid synthase (HAS) isoforms 1, 2, and 3; hyaluronidase (HYAL) isoforms 1 and 2; and standard CD44. Student t test was used to analyze the results.

RESULTS

There was no significant difference in messenger RNA (mRNA) or protein expression of HAS2, HAS3, HYAL1, or HYAL2 in EECs or ESCs from women with or without endometriosis. HAS1 mRNA was variably detected, whereas HAS1 protein was similarly expressed in EECs and ESCs from women with and without endometriosis. Standard CD44 was expressed in both cell types, and expression did not differ in cells from women with or without endometriosis.

CONCLUSIONS

The HA system is expressed in eutopic menstrual ESCs and EECs from women with and without endometriosis. There are no differences in expression in HA production or degradation enzymes in EECs or ESCs from women with and without endometriosis. Standard CD44 expression does not differ in eutopic menstrual endometrial cells from women with and without endometriosis.

Hyaluronic acid reagent functional chitosan-PEI conjugate with AQP2-siRNA suppressed endometriotic lesion formation

To identify a new drug candidate for treating endometriosis which has fewer side effects, a new polymeric nanoparticle gene delivery system consisting of polyethylenimine-grafted chitosan oligosaccharide (CSO-PEI) with hyaluronic acid (HA) and small interfering RNA (siRNA) was designed. There was no obvious difference in sizes observed between (CSO-PEI/siRNA)HA and CSO-PEI/siRNA, but the fluorescence accumulation in the endometriotic lesion was more significant for (CSO-PEI/siRNA)HA compared with CSO-PEI/siRNA due to the specific binding of HA to CD44. In addition, the (CSO-PEI/siRNA)HA nanoparticle gene therapy significantly decreased the endometriotic lesion sizes with atrophy and degeneration of the ectopic endometrium. The epithelial cells of ectopic endometrium from rat models of endometriosis showed a significantly lower CD44 expression than control after treatment with (CSO-PEI/siRNA)HA. Furthermore, observation under an electron microscope showed no obvious toxic effect on the reproductive organs. Therefore, (CSO-PEI/siRNA)HA gene delivery system can be used as an effective method for the treatment of endometriosis.

Inhibition of Hyaluronic Acid Synthesis Suppresses Angiogenesis in Developing Endometriotic Lesions

Background

The development and long-term survival of endometriotic lesions is crucially dependent on an adequate vascularization. Hyaluronic acid (HA) through its receptor CD44 has been described to be involved in the process of angiogenesis.

Objective

To study the effect of HA synthesis inhibition using non-toxic doses of 4-methylumbelliferone (4-MU) on endometriosis-related angiogenesis.

Materials and Methods

The cytotoxicity of different in vitro doses of 4-MU on endothelial cells was firstly tested by means of a lactate dehydrogenase assay. The anti-angiogenic action of non-cytotoxic doses of 4-MU was then assessed by a rat aortic ring assay. In addition, endometriotic lesions were induced in dorsal skinfold chambers of female BALB/c mice, which were daily treated with an intraperitoneal injection of 0.9% NaCl (vehicle group; n = 6), 20mg/kg 4-MU (n = 8) or 80mg/kg 4-MU (n = 7) throughout an observation period of 14 days. The effect of 4-MU on their vascularization, survival and growth were studied by intravital fluorescence microscopy, histology and immunohistochemistry.

Main Results

Non-cytotoxic doses of 4-MU effectively inhibited vascular sprout formation in the rat aortic ring assay. Endometriotic lesions in dorsal skinfold chambers of 4-MU-treated mice dose-dependently exhibited a significantly smaller vascularized area and lower functional microvessel density when compared to vehicle-treated controls. Histological analyses revealed a downregulation of HA expression in 4-MU-treated lesions. This was associated with a reduced density of CD31-positive microvessels within the lesions. In contrast, numbers of PCNA-positive proliferating and cleaved caspase-3-positive apoptotic cells did not differ between 4-MU-treated and control lesions.

Conclusions

The present study demonstrates for the first time that targeting the synthesis of HA suppresses angiogenesis in developing endometriotic lesions. Further studies have to clarify now whether in the future this anti-angiogenic effect can be used beneficially for the treatment of endometriosis.

Transcription, translation, and function of lubricin, a boundary lubricant, at the ocular surface

IMPORTANCE

Lubricin may be an important barrier to the development of corneal and conjunctival epitheliopathies that may occur in dry eye disease and contact lens wear.

OBJECTIVE

To test the hypotheses that lubricin (ie, proteoglycan 4 [PRG4 ]), a boundary lubricant, is produced by ocular surface epithelia and acts to protect the cornea and conjunctiva against significant shear forces generated during an eyelid blink and that lubricin deficiency increases shear stress on the ocular surface and promotes corneal damage.

DESIGN, SETTING, AND PARTICIPANTS

Human, porcine, and mouse tissues and cells were processed for molecular biological, immunohistochemical, and tribological studies, and wild-type and PRG4 knockout mice were evaluated for corneal damage.

RESULTS

Our findings demonstrate that lubricin is transcribed and translated by corneal and conjunctival epithelial cells. Lubricin messenger RNA is also present in lacrimal and meibomian glands, as well as in a number of other tissues. Absence of lubricin in PRG4 knockout mice is associated with a significant increase in corneal fluorescein staining. Our studies also show that lubricin functions as an effective friction-lowering boundary lubricant at the human cornea-eyelid interface. This effect is specific and cannot be duplicated by the use of hyaluronate or bovine serum albumin solutions.

CONCLUSIONS AND RELEVANCE

Our results show that lubricin is transcribed, translated, and expressed by ocular surface epithelia. Moreover, our findings demonstrate that lubricin presence significantly reduces friction between the cornea and conjunctiva and that lubricin deficiency may play a role in promoting corneal damage.

Is abnormal eutopic endometrium the cause of endometriosis? The role of eutopic endometrium in pathogenesis of endometriosis

Endometriosis (EM) is one of the most common diseases which severely affect the health and reproductive function of women of childbearing age. There are fundamental abnormal changes within the eutopic endometrium of women with endometriosis compared to normal endometrium of women without endometriosis. Eutopic endometrium shows enhanced ability of proliferation, implantation and angiogenesis, and greater probability of escaping the unfavorable conditions of the ectopic environment. Therefore, the character of eutopic endometrium determines the fate of the backward-flowing endometrial tissue – to live or to die. The abnormal endometrial tissue in EM patients flows backward to the pelvic cavity, completing a 3-step procedure of pathogenesis (attachment-aggression-angiogenesis), and ultimately develops into EM. Abnormal eutopic endometrium may also play important roles in endometriosis-associated infertility. This recognition regarding the pathogenesis of endometriosis ultimately will help to discover new methods for diagnosis and treatment. Endometrial markers for micro-invasive diagnosis and direct treatment of eutopic endometrium as the origin of the disease should be further investigated.