A global perspective: characteristics of infertility-related randomized clinical trials.

BACKGROUND: Infertility is a prevalent global condition, and emerging reproductive technologies may enhance its evaluation and treatment. Understanding the current features of randomized clinical trials in infertility is crucial for improving study design and ensuring the translation of results for patient benefits. OBJECTIVES: To investigate the primary characteristics of randomized clinical trials related to infertility and areas where require improvement. MATERIALS AND METHODS: We conducted a search on the International Clinical Trials Registry platform for eligible infertility trials between 2003 and 2022. The distribution ratio of various characteristics uploaded by infertility-related studies on the platform was analyzed and compared according to sex and registration year. RESULTS: Out of the total trials, 85.3% (1,906) included only women, 8.6% (192) included only men, and 6.1% (136) included couples. The majority of retrieved trials followed a parallel arm design (91.0%) and were non-industry-funded (92.2%), with a median planned sample size of 131 patients (interquartile range 75-270). Among these trials, 54.5% (1,217) were conducted in Asia. The most common primary purpose of infertility-related trials was treatment (88.8%), with over half of the investigated interventions focusing on medication (57.9%). DISCUSSION: Asia is the leading region for research, and the drug therapy is still widely used and updated. However, support care for infertile couples has also received some preference. Areas that require improvement and promotion include addressing male infertility and focusing on underserved regions like Africa. The results also highlight deficiencies in trial registration and masking methods, emphasizing the need for better regulation and facilitation of infertility trials in the post-COVID-19 era. CONCLUSION: Based on the current status of infertility RCT studies, greater attention should be paid to infertile men and populations in underdeveloped regions like Africa in future studies, together with a standardized registration and implementation procedures.

The protective effects and underlying mechanisms of dapagliflozin on diabetes-induced testicular dysfunction.

Male diabetic individuals present a marked impairment in fertility; however, knowledge regarding the pathogenic mechanisms and therapeutic strategies is unsatisfactory. The new hypoglycemic drug dapagliflozin has shown certain benefits, such as decreasing the risk of cardiovascular and renal events in patients with diabetes. Even so, until now, the effects and underlying mechanisms of dapagliflozin on diabetic male infertility have awaited clarification. Here, we found that dapagliflozin lowered blood glucose levels, alleviated seminiferous tubule destruction, and increased sperm concentrations and motility in leptin receptor-deficient diabetic db/db mice. Moreover, the glucagon-like peptide-1 receptor (GLP-1R) antagonist exendin (9-39) had no effect on glucose levels but reversed the protective effects of dapagliflozin on testicular structure and sperm quality in db/db mice. We also found that dapagliflozin inhibited the testicular apoptotic process by upregulating the expression of the antiapoptotic protein B-cell lymphoma 2 (BCL2) and X-linked inhibitor of apoptosis protein (XIAP) and inhibiting oxidative stress by enhancing the antioxidant status, including total antioxidant capacity, total superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity, as well as decreasing the level of 4-hydroxynonenal (4-HNE). Exendin (9-39) administration partially reversed these effects. Furthermore, dapagliflozin upregulated the glucagon-like peptide-1 (GLP-1) level in plasma and GLP-1R expression by promoting AKT8 virus oncogene cellular homolog (Akt) phosphorylation in testicular tissue. Exendin (9-39) partially inhibited Akt phosphorylation. These results suggest that dapagliflozin protects against diabetes-induced spermatogenic dysfunction via activation of the GLP-1R/phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Our results indicate the potential effects of dapagliflozin against diabetes-induced spermatogenic dysfunction.

Therapeutic Effects of Xianlu Oral Solution on Rats with Oligoasthenozoospermia through Alleviating Apoptosis and Oxidative Stress.

Idiopathic oligoasthenozoospermia (iOAZS) is one of the major causes of male infertility, and the ideal therapies for iOAZS have not been established yet. Traditional Chinese medicine (TCM), including Xianlu oral solution (XL), has been widely used as an adjunct treatment for male infertility in the clinic. However, the underlying mechanisms of XL treatment on iOAZS are still not known. Here, we found that XL treatment has therapeutic effects on ornidazole (ORN)-induced OAZS model rats through the amelioration of testis tissues spermatogenesis and the improvement of sperm concentration and motility. Moreover, XL treatment ameliorated the serum hormone levels, mitochondrial membrane potential, apoptosis status, and oxidative stress status in the testis tissues of iOAZS model rats. These findings identify a potential mechanism underlying the therapeutic effects of Xianlu oral solution on iOAZS, and Xianlu oral solution may be used as a traditional Chinese medicine (TCM) therapy for male infertility caused by iOAZS in clinical practice.

Contribution of TRESK two-pore domain potassium channel to bone cancer-induced spontaneous pain and evoked cutaneous pain in rats.

Cancer-associated pain is debilitating. However, the mechanism underlying cancer-induced spontaneous pain and evoked pain remains unclear. Here, using behavioral tests with immunofluorescent staining, overexpression, and knockdown of TRESK methods, we found an extensive distribution of TRESK potassium channel on both CGRP+ and IB4+ nerve fibers in the hindpaw skin, on CGRP+ nerve fibers in the tibial periosteum which lacks IB4+ fibers innervation, and on CGRP+ and IB4+ dorsal root ganglion (DRG) neurons in rats. Moreover, we found a decreased expression of TRESK in the corresponding nerve fibers within the hindpaw skin, the tibial periosteum and the DRG neurons in bone cancer rats. Overexpression of TRESK in DRG neurons attenuated both cancer-induced spontaneous pain (partly reflect skeletal pain) and evoked pain (reflect cutaneous pain) in tumor-bearing rats, in which the relief of evoked pain is time delayed than spontaneous pain. In contrast, knockdown of TRESK in DRG neurons produced both spontaneous pain and evoked pain in naïve rats. These results suggested that the differential distribution and decreased expression of TRESK in the periosteum and skin, which is attributed to the lack of IB4+ fibers innervation within the periosteum of the tibia, probably contribute to the behavioral divergence of cancer-induced spontaneous pain and evoked pain in bone cancer rats. Thus, the assessment of spontaneous pain and evoked pain should be accomplished simultaneously when evaluating the effect of some novel analgesics in animal models. Also, this study provides solid evidence for the role of peripheral TRESK in both cancer-induced spontaneous pain and evoked cutaneous pain.

Roles of CatSper channels in the pathogenesis of asthenozoospermia and the therapeutic effects of acupuncture-like treatment on asthenozoospermia.

Rationale: Idiopathic asthenozoospermia (iAZS) is one of the major causes of male infertility and has no effective therapeutic treatment. Understanding the potential mechanisms that cause it may be helpful in seeking novel targets and treatment strategies for overcoming the problem of low sperm motility in iAZS individuals. Methods: Computer-assisted semen analysis (CASA) was utilized to assess the sperm motility. RT-qPCR, Western blot, immunofluorescence staining, and calcium imaging analysis were performed to examine the expression and function of CatSper channels. Hyperactivation and acrosome reaction were used to evaluate the functional characteristics of epididymal sperm. In vivo fertility assay was applied to determine the fertility of rats. CatSper1 knockdown and overexpression experiments were performed to confirm the roles of CatSper channels in the pathogenesis of iAZS and the therapeutic effects of electroacupuncture (EA) treatment on AZS model rats. Results: Here, we reported a functional down-regulation of CatSper channel from CatSper1 to CatSper 4 in the sperm of both iAZS patients and ornidazole (ORN)-induced AZS model rats, and an impaired sperm function characterized by a reduction of protein tyrosine phosphorylation, hyperactivation, and acrosome reaction in the epididymal sperm of AZS rats. Knockdown of CatSper1 in the testis tissues is sufficient to induce AZS in normal rats, and this action was validated by the reversal effects of CatSper1 overexpression. Transcutaneous electrical acupoint stimulation (TEAS) and electroacupuncture (EA) at 2 Hz frequency improve the sperm motility via enhancing the functional expression of CatSper channels in the sperm. Gene silencing CatSper1 in the sperm abolishes the therapeutic effects of 2 Hz-EA treatment on AZS rats. Conclusions: We conclude that a functional down-regulation of CatSper channel in the sperm may be a contributor or a downstream indicator for a portion of AZS, especially iAZS, while 2 Hz-TEAS or EA treatment has a therapeutic effect on iAZS through inducing the functional up-regulation of CatSper channels in the sperm. This study provides a novel mechanism for the pathogenesis of some AZS especially iAZS, and presents a potential therapeutic target of CatSper for iAZS treatment. Acupuncture treatment like TEAS may be used as a promising complementary and alternative medicine (CAM) therapy for male infertility caused by iAZS in clinical practice.

Contribution of microglial reaction to increased nociceptive responses in high-fat-diet (HFD)-induced obesity in male mice.

The progressive increase in the prevalence of obesity in the population can result in increased healthcare costs and demands. Recent studies have revealed a positive correlation between pain and obesity, although the underlying mechanisms still remain unknown. Here, we aimed to clarify the role of microglia in altered pain behaviors induced by high-fat diet (HFD) in male mice. We found that C57BL/6CR mice on HFD exhibited enhanced spinal microglial reaction (increased cell number and up-regulated expression of p-p38 and CD16/32), increased tumor necrosis factor-α (TNF-α) mRNA and brain-derived neurotrophic factor (BDNF) protein expression as well as a polarization of spinal microglial toward a pro-inflammatory phenotype. Moreover, we found that using PLX3397 (a selective colony-stimulating factor-1 receptor (CSF1R) kinase inhibitor) to eliminate microglia in HFD-induced obesity mice, inflammation in the spinal cord was rescued, as was abnormal pain hypersensitivity. Intrathecal injection of Mac-1-saporin (a saporin-conjugated anti-mac1 antibody) resulted in a decreased number of microglia and attenuated both mechanical allodynia and thermal hyperalgesia in HFD-fed mice. These results indicate that the pro-inflammatory functions of spinal microglia have a special relevance to abnormal pain hypersensitivity in HFD-induced obesity mice. In conclusion, our data suggest that HFD induces a classical reaction of microglia, characterized by an enhanced phosphorylation of p-38 and increased CD16/32 expression, which may in part contribute to increased nociceptive responses in HFD-induced obesity mice.

Decreased abundance of TRESK two-pore domain potassium channels in sensory neurons underlies the pain associated with bone metastasis.

Cancer-associated pain is debilitating. Understanding the mechanisms that cause it can inform drug development that may improve quality of life in patients. Here, we found that the reduced abundance of potassium channels called TRESK in dorsal root ganglion (DRG) neurons sensitized nociceptive sensory neurons and cancer-associated pain. Overexpressing TRESK in DRG neurons suppressed tumor-induced neuronal hyperexcitability and pain hypersensitivity in bone metastasis model rats, whereas knocking down TRESK increased neuronal hyperexcitability and pain hypersensitivity in normal rats. Mechanistically, tumor-associated production of vascular endothelial growth factor (VEGF) activated the receptor VEGFR2 on DRGs, which increased the abundance of the calcineurin inhibitor DSCR1, which, in turn, decreased calcineurin-mediated activation of the transcription factor NFAT, thereby reducing the transcription of the gene encoding TRESK. Intrathecal application of exogenous calcineurin to tumor-bearing rats rescued TRESK abundance and abrogated both DRG hyperexcitability and pain hypersensitivity, whereas either inhibition or knockdown of calcineurin in normal rats reduced TRESK abundance and increased DRG excitability and pain sensitivity. These findings identify a potentially targetable mechanism that may cause bone metastasis-associated pain in cancer patients.

Activation of CRF/CRFR1 signaling in the basolateral nucleus of the amygdala contributes to chronic forced swim-induced depressive-like behaviors in rats.

The basolateral nucleus of the amygdala (BLA) plays a key role in processing stressful events and affective disorders. Previously we have documented that exposure of chronic forced swim (FS) to rats produces a depressive-like behavior and that sensitization of BLA neurons is involved in this process. In the present study, we demonstrated that chronic FS stress (CFSS) could activate corticotropin-releasing factor (CRF)/CRF receptor type 1 (CRFR1) signaling in the BLA, and blockade of CRF/CRFR1 signaling by intra-BLA injection of NBI27914 (NBI), a selective CRFR1 antagonist, could prevent the CFSS-induced depressive-like behaviors in rats, indicating that activation of CRF/CRFR1 signaling in the BLA is required for CFSS-induced depression. Furthermore, we discovered that exposure of chronic FS to rats could reinforce long-term potentiation (LTP) at the external capsule (EC)-BLA synapse and increase BLA neuronal excitability, and that all these alterations were inhibited by CRFR1 antagonist NBI. Moreover, we found that application of exogenous CRF also may facilitate LTP at the EC-BLA synapse and sensitize BLA neuronal excitability in normal rats via the activation of CRFR1. We conclude that activation of CRF/CRFR1 signaling in the BLA contributes to chronic FS-induced depressive-like behaviors in rats through potentiating synaptic efficiency at the EC-BLA pathway and sensitizing BLA neuronal excitability.

[Experimental Study for the Treatment of Asthenozoospermia by Electroacupuncture in Rats].

OBJECTIVE: To investigate the effects of different electroacupuncture (EA) parameters for the treatment of asthenozoospermia in rats. METHODS: One hundred and five male Sprague-Dawley rats were randomly divided into 2 Hz-EA treatment daily in 3 d group (n=9), sham-EA group (n=10), model group (n=10); 2 Hz-EA treatment every other day in 5 d group, sham-EA group, model group (8 rats in each group); 2 Hz-EA treatment every other day in 9 d group, sham-EA group, model group (10 rats in each group); 100 Hz-EA treatment every other day in 9 d group (n=7), sham-EA group (n=8), model group (n=7). Asthenozoospermia model was established by intragastric administration of ornidazole (ORN,400 mg·kg-1·d-1) once daily till the end of treatment. EA treatments (2 Hz or 100 Hz) were applied to "Shenshu" (BL 23,bilateral), "Zusanli" (ST 36, bilateral) for 30 min, intensity of 1-2-3 mA (increasing 1 mA per 10 min), once a day or once every other day for 3 times or 5 times. Sham-EA groups were treated with similar procedure except that the output leads of the stimulator were disconnected. The sperm density, viability, motility, the number of grade A sperm, and grade A+B sperm were examined by computer-assisted sperm analysis. RESULTS: (1) 2 Hz-EA treatment daily in 3 d:compared with the model group and the sham-EA group, 2 Hz-EA treatment once daily had no significant effect on all of the sperm motility indexes in the asthenozoospermic rats (P>0.05). (2) 2 Hz-EA treatment every other day in 5 d:compared with the model group, EA treatment could increase the sperm motility (P<0.05), the number of grade A sperm (P<0.05), and the number of grade A+B sperm (P<0.05) in the asthenozoospermic rats. However, compared with the sham-EA group, EA treatment could only improve the number of grade A+B sperm (P<0.05). (3) 2 Hz-EA treatment every other day in 9 d:compared with both the model group and the sham-EA group, EA treatment could markedly improve the sperm viability (P<0.001), the sperm motility (P<0.001), the number of grade A sperm (P<0.001), and the number of grade A+B sperm (P<0.001) in the asthenozoospermic rats. (4) 100 Hz-EA treatment every other day in 9 days:compared with both the model group and the sham-EA group, all of the sperm indexes in the asthenozoospermic rats including the sperm viability (P<0.001 vs. the model group, P<0.05 vs. the sham-EA group), the sperm motility (P<0.001 vs. the model group, P<0.01 vs. the sham-EA group), the number of grade A sperm (P<0.01) and the number of grade A+B sperm (P<0.01) also could be improved after EA treatment. Unexpectedly,none of the EA treatment had significant influence on the sperm density in the asthenozoospermic rats. CONCLUSIONS: Both 2 Hz-EA and 100 Hz-EA treatment once every other day for 5 times in 9 d had a therapeutic effect on asthenozoospermia by improving the sperm viability and the sperm motility in the rats.

BDNF Contributes to Spinal Long-Term Potentiation and Mechanical Hypersensitivity Via Fyn-Mediated Phosphorylation of NMDA Receptor GluN2B Subunit at Tyrosine 1472 in Rats Following Spinal Nerve Ligation.

Previously we have demonstrated that brain-derived neurotrophic factor (BDNF) contributes to spinal long-term potentiation (LTP) and pain hypersensitivity through activation of GluN2B-containing N-methyl-D-aspartate (GluN2B-NMDA) receptors in rats following spinal nerve ligation (SNL). However, the molecular mechanisms by which BDNF impacts upon GluN2B-NMDA receptors and spinal LTP still remain unclear. In this study, we first documented that Fyn kinase-mediated phosphorylation of GluN2B subunit at tyrosine 1472 (pGluN2BY1472) was involved in BDNF-induced spinal LTP and pain hypersensitivity in intact rats. Second, we revealed a co-localization of Fyn and GluN2B-NMDA receptor in cultured dorsal horn neurons, implying that Fyn is a possible intermediate kinase linking BDNF/TrkB signaling with GluN2B-NMDA receptors in the spinal dorsal horn. Furthermore, we discovered that both SNL surgery and intrathecal active Fyn could induce an increased expression of dorsal horn pGluN2BY1472, as well as pain hypersensitivity in response to von Frey filaments stimuli; and more importantly, all these actions were effectively abrogated by pre-treatment with either PP2 or ifenprodil to respectively inhibit Fyn kinase and GluN2B-NMDA receptors activity. Moreover, we found that intrathecal administration of BDNF scavenger TrkB-Fc prior to SNL surgery, could prevent the nerve injury-induced increase of both pFynY420 and pGluN2BY1472 expression, and also inhibit the mechanical allodynia in neuropathic rats. Collectively, these results suggest that Fyn kinase-mediated pGluN2BY1472 is critical for BDNF-induced spinal LTP and pain hypersensitivity in SNL rats. Therefore, the BDNF-Fyn-GluN2B signaling cascade in the spinal dorsal horn may constitute a key mechanism underlying central sensitization and neuropathic pain development after peripheral nerve injury.

[Transcutaneous electrical acupoint stimulation for asthenozoospermia].

OBJECTIVE: To study the effect of transcutaneous electrical acupoint stimulation (TEAS) in the treatment of asthenozoospermia. METHODS: We randomly divided 72 asthenozoospermia patients into a 2 Hz TEAS (n = 29), a 100 Hz TEAS (n = 20), and a blank control group (n = 23), those in the former two groups treated by 30 minutes of TEAS at 2 Hz and 100 Hz respectively, applied to the acupoints of bilateral Shenshu, left Zusanli, and Guanyuan, once a day for 60 days, while those in the blank control group left untreated. Using computer-assisted sperm analysis (CASA), we examined sperm concentration and motility as well as the percentages of grade a and grade a+b sperm in different groups of the patients. RESULTS: Compared with the baseline, 2 Hz TEAS significantly increased sperm motility (ï¼»12.76 ± 1.39ï¼½ vs ï¼»18.89 ± 2.46ï¼½%, P<0.05) and the percentage of grade a+b sperm ( ï¼»10.68 ± 1.22ï¼½ vs ï¼»16.32 ± 2.10ï¼½%, P<0.05) in the asthenozoospermic patients, while 100 Hz TEAS improved not only sperm motility (ï¼»12.32 ± 2.21ï¼½ vs ï¼»23.81 ± 3.42ï¼½%, P<0.01) and the percentage of grade a+b sperm (ï¼»10.45 ± 1.98ï¼½ vs ï¼»20.25 ± 2.82 ï¼½%, P<0.01), but also the percentage of grade a sperm (ï¼»6.44 ± 1.16ï¼½ vs ï¼»13.31 ± 2.30ï¼½%, P<0.05). Moreover, in comparison with the blank control group, 2 Hz TEAS also remarkably increased sperm motility (ï¼»9.57 ± 1.60ï¼½ vs ï¼»18.89 ± 2.46ï¼½%, P<0.05) and the percentage of grade a+b sperm (ï¼»7.81 ± 1.31ï¼½ vs ï¼»16.32 ± 2.10ï¼½%, P<0.05) in the asthenozoosperma patients, while 100 Hz TEAS improved not only sperm motility (ï¼»9.57 ± 1.60ï¼½ vs ï¼»23.81 ± 3.42ï¼½%, P<0.01) and the percentage of grade a+b sperm (ï¼»7.81 ± 1.31ï¼½ vs ï¼»20.25 ± 2.82ï¼½%, P<0.01) but also the percentage of grade a sperm (ï¼»4.87 ± 1.01ï¼½ vs ï¼»13.31 ± 2.30ï¼½%, P<0.01). Meanwhile, the rate of clinical effectiveness was significantly higher in the 100 Hz TEASthan in the blank control group either in intention-to-treat (ITT) analysis (100% vs 18.18%) orper-protocol (PP) analysis (90% vs 0%), and so was it than in the 2 Hz TEAS group based on the data of ITT (100% vs 33.33%). CONCLUSIONS: Both 2 Hz and 100 Hz TEAS are effective for the treatment of asthenozoospermia by improving sperm motility and vitality.

Sensitization of neurons in the central nucleus of the amygdala via the decreased GABAergic inhibition contributes to the development of neuropathic pain-related anxiety-like behaviors in rats.

BACKGROUND: Despite high prevalence of anxiety accompanying with chronic pain, the mechanisms underlying pain-related anxiety are largely unknown. With its well-documented role in pain and emotion processing, the amygdala may act as a key player in pathogenesis of neuropathic pain-related anxiety. Pain-related plasticity and sensitization of CeA (central nucleus of the amygdala) neurons have been shown in several models of chronic pain. In addition, firing pattern of neurons with spike output can powerfully affect functional output of the brain nucleus, and GABAergic neurons are crucial in the modulation of neuronal excitability. In this study, we first investigated whether pain-related plasticity (e.g. alteration of neuronal firing patterns) and sensitization of CeA neurons contribute to nerve injury-evoked anxiety in neuropathic rats. Furthermore, we explored whether GABAergic disinhibition is responsible for regulating firing patterns and intrinsic excitabilities of CeA neurons as well as for pain-related anxiety in neuropathic rats. RESULTS: We discovered that spinal nerve ligation (SNL) produced neuropathic pain-related anxiety-like behaviors in rats, which could be specifically inhibited by intra-CeA administration of anti-anxiety drug diazepam. Moreover, we found potentiated plasticity and sensitization of CeA neurons in SNL-induced anxiety rats, of which including: 1) increased burst firing pattern and early-adapting firing pattern; 2) increased spike frequency and intrinsic excitability; 3) increased amplitude of both after-depolarized-potential (ADP) and sub-threshold membrane potential oscillation. In addition, we observed a remarkable reduction of GABAergic inhibition in CeA neurons in SNL-induced anxiety rats, which was proved to be important for altered firing patterns and hyperexcitability of CeA neurons, thereby greatly contributing to the development of neuropathic pain-related anxiety. Accordantly, activation of GABAergic inhibition by intra-CeA administration of muscimol, a selective GABAA receptors agonist, could inhibit SNL-induced anxiety-like behaviors in neuropathic rats. By contrast, suppression of GABAergic inhibition by intra-CeA administration of bicuculline, a selective GABAA receptors antagonist, produced anxiety-like behavior in normal rats. CONCLUSIONS: This study suggests that reduction of GABAergic inhibition may be responsible for potentiated plasticity and sensitization of CeA neurons, which likely underlie the enhanced output of amygdala and neuropathic pain-related anxiety in SNL rats.