The effect of biological mechanisms of melatonin on the proliferation of spermatogonial stem cells: a systematic review

In the last decade, melatonin has gained recognition as a potent scavenger and an effective antioxidant capable of neutralizing free radicals, including reactive oxygen species. Additionally, it exhibits anti-apoptotic properties. In this review, we will examine a compilation of articles that explore the cellular signaling function of melatonin on spermatogonial stem cells (SSCs) and adjacent cells such as Sertoli and Leydig cells. These cells play a crucial role in the proliferation of SSCs both in vitro and in vivo. In this review, we analyze the function of melatonin in the proliferation of SSCs from other aspects. For this purpose, we examine the articles based on the presence of melatonin on SSCs in four groups: As a supplement in SSCs medium culture, SSCs three-dimensional culture system, SSCs freezing medium, and as a therapeutic factor in vivo. Mechanisms of growth and proliferation of SSCs were considered. The purpose of this study is to investigate the potential effects of melatonin as a powerful antioxidant or growth stimulant for SSCs, both in vivo and in vitro.

COVID-19 and cancer risk arising from ionizing radiation exposure through CT scans: a cross-sectional study

BACKGROUND

The surge in the utilization of CT scans for COVID-19 diagnosis and monitoring during the pandemic is undeniable. This increase has brought to the forefront concerns about the potential long-term health consequences, especially radiation-induced cancer risk. This study aimed to quantify the potential cancer risk associated with CT scans performed for COVID-19 detection.

METHODS

In this cross-sectional study data from a total of 561 patients, who were referred to the radiology center at Imam Hossein Hospital in Shahroud, was collected. CT scan reports were categorized into three groups based on the radiologist's interpretation. The BEIR VII model was employed to estimate the risk of radiation-induced cancer.

RESULTS

Among the 561 patients, 299 (53.3%) were males and the average age of the patients was 49.61 ± 18.73 years. Of the CT scans, 408 (72.7%) were reported as normal. The average age of patients with normal, abnormal, and potentially abnormal CT scans was 47.57 ± 19.06, 54.80 ± 16.70, and 58.14 ± 16.60 years, respectively (p-value < 0.001). The average effective dose was 1.89 ± 0.21 mSv, with 1.76 ± 0.11 mSv for males and 2.05 ± 0.29 mSv for females (p-value < 0.001). The average risk of lung cancer was 3.84 ± 1.19 and 9.73 ± 3.27 cases per 100,000 patients for males and females, respectively. The average LAR for all cancer types was 10.30 ± 6.03 cases per 100,000 patients.

CONCLUSIONS

This study highlights the critical issue of increased CT scan usage for COVID-19 diagnosis and the potential long-term consequences, especially the risk of cancer incidence. Healthcare policies should be prepared to address this potential rise in cancer incidence and the utilization of CT scans should be restricted to cases where laboratory tests are not readily available or when clinical symptoms are severe.

Chitosan Scaffold Containing Periostin Enhances Sternum Bone Healing and Decreases Serum Level of TNF-α and IL-6 after Sternotomy in Rat

BACKGROUND

In the aftermath of bone injuries, such as cranium and sternum, bone wax (BW) is used to control bleeding from the bone surfaces during surgery. Made up of artificial substances, however, it is associated with many complications such as inflammation, increased risk for infection, and bone repair delay. We, therefore, in this study set out to design and evaluate a novel BW without the above-mentioned side-effects reported for other therapies.

METHODS

The pastes (new BW(s)) were prepared in the laboratory and examined by MTT, MIC, MBC, and degradability tests. Then, 60 adult male Wistar rats, divided into six equal groups including chitosan (CT), CT-octacalcium phosphate (OCP), CT-periostin (Post), CT-OCP-Post, Control (Ctrl), and BW, underwent sternotomy surgery. Once the surgeries were completed, the bone repair was assessed radiologically and thereafter clinically in vivo and in vitro using CT-scan, H&E, ELISA, and qRT-PCR.

RESULTS

All pastes displayed antibacterial properties and the CT-Post group had the highest cell viability compared to the control group. In contrast to the BW, CT-Post group demonstrated weight changes in the degradability test. In the CT-Post group, more number of osteocyte cells, high trabeculae percentage, and the least fibrous connective tissue were observed compared to other groups. Additionally, in comparison to the CT and Ctrl groups, higher alkaline phosphatase activity, as well as decreased level of serum tumor necrosis factor-α, interleukin-6, and OCN in the CT-Post group was evident. Finally, Runx2, OPG, and RANKL genes' expression was significantly higher in the CT-Post group than in other groups.

CONCLUSION

Our results provide insights into the desirability of pastes in terms of cellular viability, degradability, antibacterial properties, and surgical site restoration compared to the BW group. Besides, Periostin could enhance the osteogenic properties of bone tissue defect site.

Cryoprotective Effect of Pentoxifylline on Spermatogonial Stem Cell During Transplantation into Azoospermic Torsion Mouse Model

Preserving the spermatogonial stem cells (SSCs) in long periods of time during the treatment of male infertility using stem cell banking systems and transplantation is an important issue. Therefore, this study was conducted to develop an optimal cryopreservation protocol for SSCs using 10 mM pentoxifylline (PTX) as an antioxidant in basal freezing medium. Testicular torsion-a mouse model for long-term infertility-was used to transplant fresh SSCs (n = 6), fresh SSCs treated with PTX (n = 6), cryopreserved SSCs with basal freezing medium (n = 6), and cryopreserved SSCs treated with PTX (n = 6). Eight weeks after germ cell transplantation, samples were assessed for proliferation, through evaluation of Ddx4 and Id4 markers, and differentiation via evaluation of C-Kit and Sycp3, Tnp1, Tnp2, and Prm1 markers. According to morphological and flow cytometry results, SSCs are able to form colonies and express Gfra1, Id4, α6-integrin, and β1-integrin markers. We found positive influence from PTX on proliferative and differentiative markers in SSCs transplanted to azoospermic mice. In the recipient testis, donor SSCs formed spermatogenic colonies and sperm. Respecting these data, adding pentoxifylline is a practical way to precisely cryopreserve germ cells enriched for SSCs in cryopreservation, and this procedure could become an efficient method to restore fertility in a clinical setup. However, more studies are needed to ensure its safety in the long term.

The current knowledge concerning solid cancer and therapy

Solid cancers comprise a large number of new cases and deaths from cancer each year globally. There are a number of strategies for addressing tumors raised from solid organs including surgery, chemotherapy, radiotherapy, targeted therapy, immunotherapy, combinational therapy, and stem cell and extracellular vesicle (EV) therapy. Surgery, radiotherapy, and chemotherapy are the dominant cures, but are not always effective, in which even in a localized tumor there is a possibility of tumor relapse after surgical resection. Over half of the cancer patients will receive radiotherapy as a part of their therapeutic schedule. Radiotherapy can cause an abscopal response for boosting the activity of the immune system outside the local field of radiation, but it may also cause an unwanted bystander effect, predisposing nonradiated cells into carcinogenesis. In the context of immunotherapy, immune checkpoint inhibition is known as the standard-of-care, but the major concern is in regard with cold cancers that show low responses to such therapy. Stem-cell therapy can be used to send prodrugs toward the tumor area; this strategy, however, has its own predicaments, such as unwanted attraction toward the other sites including healthy tissues and its instability. A substitute to such therapy and quite a novel strategy is to use EVs, by virtue of their stability and potential to cross biological barriers and long-term storage of contents. Combination therapy is the current focus. Despite advances in the field, there are still unmet concerns in the area of effective cancer therapy, raising challenges and opportunities for future investigations.

Transgenerational influence of parental morphine exposure on pain perception, anxiety-like behavior and passive avoidance memory among male and female offspring of Wistar rats

Accumulating evidence suggests that epigenetic mechanisms play an important role in the formation and maintenance of memory within the brain. Moreover, the effect of parental drug-exposure before gestation on behavioral state of offspring has been little studied. The main objective of the current study is to evaluate the effect of parental morphine exposure on avoidance memory, morphine preference and anxiety-like behavior of offspring. The total of 32 males and 32 females were used for mating. The animals were treated with morphine. The offspring according to their parental morphine treatment was divided into four groups (n=16) including paternally treated, maternally treated, both of parents treated and naïve animals. The pain perception, anxiety-like behavior, and avoidance memory were evaluated in the offspring. In the current study, the total of 256 offspring was used for the experiments (4 tasks × 4 groups of offspring × 8 female offspring × 8 male offspring). The finding revealed that the avoidance memory and visceral pain were reduced significantly in male and female offspring with at least one morphine-treated parent. Moreover, anxiety-like behavior was reduced significantly in the male offspring with at least one morphine-treated parent. While anxiety-like behavior was increased significantly in female offspring that were treated by morphine either maternally or both of parents. The data revealed that the endogenous opioid system may be altered in the offspring of morphine-treated parent(s), and epigenetic role could be important. However, analysis of variance signified the important role of maternal inheritance.

Correlation among the Behavioral Features in the Offspring of Morphine-Abstinent Rats

BACKGROUND

Critical analysis of new evidence in medical sciences relies on statistics in terms of correlation. The aim of the present study was to evaluate the correlation coefficients among the behavioral features in the offspring of morphine-abstinent parent(s).

METHODS

The offspring of rats with various parental morphine-exposure were divided into four groups including offspring with healthy parents (CTL), offspring with paternal morphine-abstinent (PMA) parent, offspring with maternal morphine-abstinent (MMA) parent, and offspring with both morphine-abstinent (BMA) parents. Pain perception, depression-like behavior and avoidance-memory in the offspring were quantified. The association between variables was measured using Pearson correlation analysis.

FINDINGS

A strong correlation was observed between pain and depressive-like behavior in female and male offspring of healthy parents. Moreover, in the male and female offspring of healthy parents and BMA, no significant correlation was observed between avoidance memory and pain behavior or depressive-like behavior. However, in the offspring of MMA, a strong correlation was observed between avoidance memory and depressive-like behavior.

CONCLUSION

The results revealed that in comparison with the offspring with CTL, the correlation among the behavioral futures in the offspring with MMA or PMA parents is significantly different.

Morphine Exposure and Enhanced Depression-like Behaviour Confronting Chronic Stress in Adult Male Offspring Rat

Introduction:

Opioid addiction is an important concern in the World. Reports demonstrate that substance use disorder could influence genetic and environmental factors, and children of addicts have a higher rate of psychopathology. In this study, we investigated depression-like behavior among offspring of morphine-exposed rat parents.

Methods:

Adult male and female Wistar rats received morphine for 21 consecutive days and then let them were free of drugs for ten days. Offspring of these rats were divided into three distinct groups: maternal morphine-exposed, paternal morphine-exposed, and both maternal and paternal morphine-exposed. We used sucrose preference and Forced Swim Test (FST) to measure depression-like behavior. Also, we induced chronic mild stress using repeated corticosterone injection and evaluated depression-like behavior in offspring of morphine-exposed parents compared with offspring of healthy ones.

Results:

Results indicated that depression-like behaviors in the offspring of morphine-exposed rats were higher than those in the offspring of the control group in confronting with chronic mild stress. Additionally, mild chronic stress can produce an exaggerated effect on depression-like behavior in offspring of the morphine-exposed parent(s) compared with those of the control group.

Conclusion:

Our data support the previous hypothesis that the depression rate is higher in the children of addicts. We verified that even when mother or father was clean of opioid in the time of gestation, their children would be susceptible to depression. Dysregulation of hypothalamic-pituitary-adrenal axis and changing in neuronal features in the hippocampus increased depression-like behavior in the offspring of morphine-exposure parents.

Tumor microenvironment: Interactions and therapy

Tumor microenvironment (TME) is a host for a complex network of heterogeneous stromal cells with overlapping or opposing functions depending on the dominant signals within this milieu. Reciprocal paracrine interactions between cancer cells with cells within the tumor stroma often reshape the TME in favor of the promotion of tumor. These complex interactions require more sophisticated approaches for cancer therapy, and, therefore, advancing knowledge about dominant drivers of cancer within the TME is critical for designing therapeutic schemes. This review will provide knowledge about TME architecture, multiple signaling, and cross communications between cells within this milieu, and its targeting for immunotherapy of cancer.

Roles for osteocalcin in proliferation and differentiation of spermatogonial cells cocultured with somatic cells

Spermatogonial cells (SCs) are key cells for spermatogenesis. These cells are affected by paracrine signals originated from nearby somatic cells, among them Leydig cells have receptors for osteocalcin, a hormone known for exerting positive roles in the promotion of spermatogenesis. The aim of this study was to evaluate roles for osteocalcin on SCs proliferative and differentiation features after coculture with Leydig cells. SCs and Leydig cells were isolated from neonate NMRI offspring mice and adult NMRI mice, respectively. SCs population were then enriched in a differential attachment technique and assessed for morphological features and identity. Then, SCs were cocultured with Leydig cells and incubated with osteocalcin for 4 weeks. Evaluation of proliferation and differentiation-related factors were surveyed using immunocytochemistry (ICC), Western blot, and quantitative real-time polymerase chain reaction (PCR). Finally, the rate of testosterone release to the culture media was measured at the end of 4th week. Morphological and flow cytometry results showed that the SCs were the population of cells able to form colonies and to express ID4, α6-, and β1-integrin markers, respectively. Leydig cells were also able to express Gprc6α as a specific marker for the cells. Incubation of SCs/Leydig coculture with osteocalcin has resulted in an increase in the rate of expressions for differentiation-related markers. Levels of testosterone in the culture media of SCs/Leydig was positively influenced by osteocalcin. It could be concluded that osteocalcin acts as a positive inducer of SCs in coculture with Leydig cells probably through stimulation of testosterone release from Leydig cells and associated signaling.

Roles for Kisspeptin in proliferation and differentiation of spermatogonial cells isolated from mice offspring when the cells are cocultured with somatic cells

Kisspeptin (Kp) expression in testis has caused most of the recent research surveying its functional role in this organ. This peptide influences spermatogenesis and sperm capacitation, so it is considered as a regulator of reproduction. Kp roles exert through hypothalamic/pituitary/gonadal axis. We aimed to evaluate direct roles for Kp on proliferation and differentiation of spermatogonial cells (SCs) when the cells are cocultured with somatic cells. Somatic cells and SCs were isolated from adult azoospermic and newborn mice and then enriched using a differential attachment technique. After the evaluation of identity and colonization for SCs, the cells were cocultured with somatic cells, and three doses of Kp (10^-8 -10^-6  M) was assessed on proliferation (through evaluation of MVH and ID4 markers) and differentiation (via evaluation of c-Kit and SCP₃ , TP_1, TP₂ , and, Prm₁ markers) of the coculture system. Investigations were continued for four succeeding weeks. At the end of each level of testosterone in the culture media was also evaluated. We found positive influence from Kp on proliferative and differentiative markers in SCs cocultured with somatic cells. These effects were dose-dependent. There was no effect for Kp on testosterone level. From our findings, we simply conclude that Kp as a neuropeptide for influencing central part of reproductive axis could also positively affect peripheral processes related to spermatogenesis without having an effect on steroidogenesis.

Is the Nociception Mechanism Altered in Offspring of Morphine-Abstinent Rats?

To investigate the effect of parental drug abuse on children, nociception, electrophysiological alteration, mRNA expression of opioid receptors, and expression of certain intracellular proteins in offspring of morphine-abstinent rats were studied. Adult male and female animals received water-soluble morphine for 21 days. Ten days after the last morphine administration, animals were placed for mating in 4 groups as follows: healthy (drug naive) female and male, morphine-abstinent female and healthy male, morphine-abstinent male and healthy female, morphine-abstinent male and morphine-abstinent female. Their adult male offspring were tested for nociception, neuronal discharge in nucleus accumbens (NAC) and prefrontal cortex (PFC). Our results showed that nociception in male offspring of all morphine-abstinent parent(s) groups was significantly reduced, compared with the control group. In the offspring of morphine-abstinent parent(s) groups, sensitivity to the antinociceptive effect of morphine was enhanced in chronic as well as in acute phases of the formalin test. Neuronal electrical activity reduced in the offspring of the morphine-exposed parent(s) in NAC as well as PFC regions. Moreover, our findings show that opioid receptors' expressions (µ, κ, and δ) increased in NAC of the litter of morphine-abstinent parent(s), compared with the control group. In addition, the expression of κ receptors was remarkably increased in the PFC in morphine-abstinent parent group, relative to the control group. The phosphorylated levels of extracellular regulated kinase 1/2 and cyclic adenosine monophosphate responsive element binding protein were significantly higher in the offspring of the morphine-abstinent parent(s) than the control group in the NAC. Our results indicated that endogenous opioid is altered in offspring of the morphine-exposed parent(s) and that heritage has a major role.

PERSPECTIVE

This study showed that nociception was reduced in offspring of morphine-abstinent rat(s) and also these litters had a low level of neuronal firing rate, and enhanced opioid receptors expression, especially in the NAC. Because these offspring are more sensitive to the analgesic effect of morphine, clinicians should consider this issue to manage the dosage of morphine for treating pain in children with an abstinent parent(s).