Fig 2: Summary of the signaling cascade triggered by cannabinoid receptor activation in endometriosis. A summary of the downstream signal alteration upon cannabinoid receptor activation is outlined in this schematic representation. Protein kinases, such as MAPK (p38) and PI3K/Akt family members, are involved in cell growth, migration, and survival under normal circumstances. Endometrial tissues have been identified to possess higher activity of kinases such as MAPK and Akt, which contribute to increased proliferation. Protein levels assessed in this study show that CB1 and CB2 receptor activation by WIN 55 leads to downstream modulation of important MAPK family proteins, such as Erk 1/2, p38, JNK, c-JUN, p53 and HSP27, as well as PI3K/Akt axis to trigger autophagy and eventually apoptosis through caspase-dependent and/or independent pathway. The use of red and green colors within the labeling represents downregulation and upregulation, respectively.

Fig 3: Chronic exposure of WIN 55 in endometriosis (EM) induced mice attenuates lesion growth and vascularization. Immunocompetent C57Bl/6N mice were induced with EM and treated with 14 doses of WIN 55 (1mg/kg i.p) before euthanasia on day 28. Lesions recovered from vehicle, and WIN 55 treated mice were analyzed for hallmarks of EM, such as proliferation and angiogenesis. Representative IHC images of Ki-67 (A,B) (marker of proliferation), CD31 (D,E) (marker of vasculature), Caspase-3 (G,H) (marker of apoptosis), CB1 (J,K), and CB2 (M,N). Lesions from mice that were subjected to chronic exposure of WIN 55 showed a significant reduction in tissue proliferation (C) and angiogenesis (F), while caspase activity was significantly increased (I), which indicates heightened apoptosis. Cannabinoid receptors CB1 (L) and CB2 (O) also showed reduced expression in these lesions compared with the group treated with vehicle. The black box within the IHC images represents the analysis used in this study, where yellow, orange, and red denotes weak, mild, and strong staining, respectively. Scale bar 100 µm. Non-parametric unpaired student's t-test. *P < 0.05 **P < 0.01 ***P < 0.001.

Fig 4: Electroacupuncture treatment upregulated CB2 receptors on microglia and inhibited NF-?B and p-NF-?B expression in lumbar SDH of LDH rats. (a) Representative western blots. Quantification of (b) NF?B-p65, (c) p-NF?B-p65 and (d) CB2R in lumbar SDH on postoperative day 14 in each group, one-way ANOVA, n = 4, *P < 0.05, LDH versus sham; #P < 0.05, electroacupuncture versus sham-electroacupuncture. (e) Colabeling staining of Iba-1 (red) with CB2R (green) in lumbar SDH on postoperative day 14 in each group. The enlarged images revealed that these two markers were colabeled. Quantitative analyses of the (f) number of Iba-1+ cells, (g) number of CB2R+ cells, (h) number of Iba-1+ and CB2R+ double-positive cells, (i) ratio of CB2R+ and Iba-1+ double-positive cells to Iba-1+ cells. one-way ANOVA, n = 3, *P < 0.05, LDH versus sham; #P < 0.05, electroacupuncture versus sham-electroacupuncture. ANOVA, analysis of variance; CB2R, cannabinoid 2 receptor; LDH, lumbar disc herniation; NF-?B, nuclear factor kappa B; SDH, spinal dorsal horn.