The protective effect of recombinant globular adiponectin on testis by modulating autophagy, endoplasmic reticulum stress and oxidative stress in streptozotocin-induced diabetic mice

Human umbilical cord mesenchymal stem cells improve bone marrow hematopoiesis through regulation of bone marrow adipose tissue

Bone marrow adipose tissue (BMAT) exhibits a multitude of biological functionalities and influences hematopoiesis. The adiposity status of the bone marrow may play a role in the decline of hematopoietic function. Mesenchymal stem cells (MSCs) constitute crucial regulators within the bone marrow microenvironment; however, their precise role in modulating BMAT and the subsequent implications for hematopoiesis remain poorly understood. We conducted in vivo studies to observe the effects of human umbilical cord mesenchymal stem cells (hucMSCs) on BMAT accumulation and restoration of hematopoietic function in mice with drug-induced hematopoietic impairment. Concurrently, in vitro co-culture experiments were used to investigate the impact of hucMSCs on preadipocytes and mature adipocytes, and the potential subsequent consequences for hematopoietic cells. Moreover, we explored the potential mechanisms underlying these interactions. Our findings reveal that hucMSCs concomitantly mitigate BMAT accumulation and facilitate the recovery of hematopoietic function in mouse models with drug-induced hematopoietic impairment. In vitro, hucMSCs potentially impede adipogenic differentiation of 3T3-L1 preadipocytes through interference with the JAK2/STAT3 signaling pathway and affect the functionality of mature adipocytes, thus mitigating the detrimental effects of adipocytes on hematopoietic stem cells (HSCs). Furthermore, we demonstrate that hucMSCs may protect hematopoietic cells from adipocyte-induced damage by protecting antioxidative mechanisms. These results suggest that hucMSCs exhibit an inhibitory effect on the excessive expansion of adipose tissue and modulate adipose tissue function, which may potentially contribute to the regulation of the bone marrow microenvironment and favorably influence hematopoietic function improvement.

Decreased AdipoR1 signaling and its implications for obesity-induced male infertility

Obesity is among the risk factors for male infertility. Although several mechanisms underlying obesity-induced male subfertility have been reported, the entire mechanism of obesity-induced male infertility still remains unclear. Here, we show that sperm count, sperm motility and sperm fertilizing ability were decreased in male mice fed a high-fat diet and that the expression of the AdipoR1 gene and protein was decreased, and the expression of pro-apoptotic genes and protein increased, in the testis from mice fed a high-fat diet. Moreover, we demonstrate that testes weight, sperm count, sperm motility and sperm fertilizing ability were significantly decreased in AdipoR1 knockout mice compared to those in wild-type mice; furthermore, the phosphorylation of AMPK was decreased, and the expression of pro-apoptotic genes and proteins, caspase-6 activity and pathologically apoptotic seminiferous tubules were increased, in the testis from AdipoR1 knockout mice. Furthermore, study findings show that orally administrated AdipoRon decreased caspase-6 activity and apoptotic seminiferous tubules in the testis, thus ameliorating sperm motility in male mice fed a high-fat diet. This was the first study to demonstrate that decreased AdipoR1/AMPK signaling led to increased caspase-6 activity/increased apoptosis in the testis thus likely accounting for male infertility.

Diabetes-Induced Autophagy Dysregulation Engenders Testicular Impairment via Oxidative Stress

Testes produce sperms, and gamete generation relies on a proper niche environment. The disruption of hierarchical regulatory homeostasis in Leydig or Sertoli cells may evoke a sterile phenotype in humans. In this study, we recapitulated type 2 diabetes mellitus by using a high-fat diet- (HFD-) fed mouse model to identify the phenotype and potential mechanism of diabetes-induced testicular impairment. At the end of the study, blood glucose levels, testosterone structure, testicular antioxidant capacity, and testosterone level and the expression of hypoxia-inducible factor- (HIF-) 1α, apoptosis-related protein cleaved-caspase3, and autophagy-related proteins such as LC3I/II, p62, and Beclin1 were evaluated. We found that long-term HFD treatment causes the development of diabetes mellitus, implicating increased serum glucose level, cell apoptosis, and testicular atrophy (P < 0.05 vs. Ctrl). Mechanistically, the results showed enhanced expression of HIF-1α in both Sertoli and Leydig cells (P < 0.05 vs. Ctrl). Advanced glycation end products (AGEs) were demonstrated to be a potential factor leading to HIF-1α upregulation in both cell types. In Sertoli cells, high glucose treatment had minor effects on Sertoli cell autophagy. However, AGE treatment stagnated the autophagy flux and escalated cell apoptosis (P < 0.05 vs. Ctrl+Ctrl). In Leydig cells, high glucose treatment was adequate to encumber autophagy induction and enhance oxidative stress. Similarly, AGE treatment facilitated HIF-1α expression and hampered testosterone production (P < 0.05 vs. Ctrl+Ctrl). Overall, these findings highlight the dual effects of diabetes on autophagy regulation in Sertoli and Leydig cells while imposing oxidative stress in both cell types. Furthermore, the upregulation of HIF-1α, which could be triggered by AGE treatment, may negatively affect both cell types. Together, these findings will help us further understand the molecular mechanism of diabetes-induced autophagy dysregulation and testicular impairment, enriching the content of male reproductive biology in diabetic patients.

Adipose tissue alleviates the stress response by releasing adiponectin during laparoscopic surgery in patients with colorectal cancer

Background and objectives

Laparoscopic colorectal surgery causes a lower stress response than open surgery. Adiponectin is mainly derived from adipocytes and has antidiabetic, antioxidative, and anti-inflammatory capabilities. The objective of the present study was to investigate the protein expression of adiponectin in adipose tissue, and the serum levels of adiponectin, oxidative stress markers and proinflammatory factors during laparoscopic colorectal surgery and open surgery periods.

Methods

Forty patients aged 60 to 80, with American Society of Anesthesiologists (ASA) I ~ II who underwent radical resection of colorectal cancer were recruited to the study. Laparoscopic group and open group included 20 patients each. Mesenteric adipose tissue and venous blood before (T1) and at the end (T2) of surgery were collected to examine adiponectin levels, and venous blood was collected to examine serum levels of oxidative stress related markers (superoxide dismutase (SOD), glutathione (GSH), lipid peroxide (LPO), malondialdehyde (MDA)), and inflammation-related factors (interleukin (IL)-1β, interleukin (IL)-6, tumor necrosis factor-α (TNF-α)).

Results

Protein and serum levels of adiponectin were analyzed, and adiponectin levels were significantly increased at T2 than T1 in the laparoscopic surgery, while adiponectin levels were significantly higher in the laparoscopic surgery than in the open surgery at T2. In addition, the serum levels of SOD and GSH were significantly higher in the laparoscopic surgery than in open surgery at T2. However, the serum levels of LPO, TNF-α, IL-1β, and IL-6 were significantly lower in the laparoscopic group than in open group at T2.

Conclusion

Laparoscopic surgery induced higher levels of adiponectin in both adipose tissue and the bloodstream. Oxidative stress and the inflammatory response were lower during laparoscopic colorectal surgery than during conventional open surgery. These data suggest that adipose tissue may alleviate the stress response during laparoscopic surgery by releasing adiponectin in patients with colorectal cancer.

Adiponectin Synthesis, Secretion and Extravasation from Circulation to Interstitial Space

Adiponectin, an adipokine that circulates as multiple multimeric complexes at high levels in serum, has antidiabetic, anti-inflammatory, antiatherogenic, and cardioprotective properties. Understanding the mechanisms regulating adiponectin's physiological effects is likely to provide critical insight into the development of adiponectin-based therapeutics to treat various metabolic-related diseases. In this review, we summarize our current understanding on adiponectin action in its various target tissues and in cellular models. We also focus on recent advances in two particular regulatory aspects; namely, the regulation of adiponectin gene expression, multimerization, and secretion, as well as extravasation of circulating adiponectin to the interstitial space and its degradation. Finally, we discuss some potential therapeutic approaches using adiponectin as a target and the current challenges facing adiponectin-based therapeutic interventions.

Comparative Study of the Steroidogenic Effects of Human Chorionic Gonadotropin and Thieno[2,3-D]pyrimidine-Based Allosteric Agonist of Luteinizing Hormone Receptor in Young Adult, Aging and Diabetic Male Rats

Low-molecular-weight agonists of luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor (LHCGR), which interact with LHCGR transmembrane allosteric site and, in comparison with gonadotropins, more selectively activate intracellular effectors, are currently being developed. Meanwhile, their effects on testicular steroidogenesis have not been studied. The purpose of this work is to perform a comparative study of the effects of 5-amino-N-tert-butyl-4-(3-(1-methylpyrazole-4-carboxamido)phenyl)-2-(methylthio)thieno[2,3-d] pyrimidine-6-carboxamide (TP4/2), a LHCGR allosteric agonist developed by us, and hCG on adenylyl cyclase activity in rat testicular membranes, testosterone levels, testicular steroidogenesis and spermatogenesis in young (four-month-old), aging (18-month-old) and diabetic male Wistar rats. Type 1 diabetes was caused by a single streptozotocin (50 mg/kg) injection. TP4/2 (20 mg/kg/day) and hCG (20 IU/rat/day) were administered for 5 days. TP4/2 was less effective in adenylyl cyclase stimulation and ability to activate steroidogenesis when administered once into rats. On the 3rd–5th day, TP4/2 and hCG steroidogenic effects in young adult, aging and diabetic rats were comparable. Unlike hCG, TP4/2 did not inhibit LHCGR gene expression and did not hyperstimulate the testicular steroidogenesis system, moderately increasing steroidogenic proteins gene expression and testosterone production. In aging and diabetic testes, TP4/2 improved spermatogenesis. Thus, during five-day administration, TP4/2 steadily stimulates testicular steroidogenesis, and can be used to prevent androgen deficiency in aging and diabetes.

The Effects of Naringin on Cigarette Smoke-Induced Dynamic Changes in Oxidation/Antioxidant System in Lung of Mice

Naringin possesses strong antioxidative activity and can protect against some respiratory diseases. Oxidative stress is thought to be a major factor in the development of many tobacco-caused diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a critical role in the regulation of oxidative stress. The dynamic changes in the antioxidant system in the lung that are induced by cigarette smoke (CS) are not well investigated, and how naringin affects these changes remains unknown. This study aimed to investigate the dynamic changes between the oxidation and antioxidant systems resulting from CS exposure and the effects of naringin on these changes in mice. Mice were chronically exposed to CS for 30 days. The levels of malondialdehyde (MDA), glutathione (GSH), interleukin (IL)-6, and tumor necrosis factor-alpha (TNF-α); the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px); and the expressions of Nrf2, heme oxygenase-1 (HO-1), and nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1) in lung tissue were measured on days 2, 7, and 30. The levels of MDA, GSH, IL-6, and TNF-α in the lung were found to increase throughout the exposure. SOD and GSH-Px activities showed an increase on day 2 and a decrease on days 7 and 30. The messenger ribonucleic acid expressions of Nrf2, HO-1, and NQO1 were elevated on day 2 and decreased on day 7; Nrf2 and HO-1 expressions were continually decreased, but NQO1 expression was increased again, on day 30. Naringin restored the levels of these biochemical indices to normal throughout the experiment, suggesting that naringin protected against the CS-induced oxidative damage by suppressing the increase of antioxidants resulting from the early stage of CS exposure, as well as inhibiting the depletion of antioxidants due to long-term oxidative stress. Naringin also suppressed lung inflammation by inhibiting IL-6 and TNF-α. These results indicate that naringin possesses a powerful ability to maintain the balance of the oxidation/antioxidant system in the lung when subjected to CS exposure, probably by regulating the Nrf2 signaling pathway.