UNASSIGNED: The involvement of ATP and cAMP in sperm function has been extensively documented, but the understanding of the role of adenosine and adenosine receptors remains incomplete. This study aimed to examine the presence of adenosine A2A receptor (A2AR) and study the functional role of A2AR in human sperm.
UNASSIGNED: The presence and localization of A2AR in human sperm were examined by western blotting and immunofluorescence assays. The functional role of A2AR in sperm was assessed by incubating human sperm with an A2AR agonist (regadenoson) and an A2AR antagonist (SCH58261). The sperm level of A2AR was examined by western blotting in normozoospermic and asthenozoospermic men to evaluate the association of A2AR with sperm motility and in vitro fertilization (IVF) outcomes.
UNASSIGNED: A2AR with a molecular weight of 43 kDa was detected in the tail of human sperm. SCH58261 decreased the motility, penetration ability, intracellular Ca2+ concentration, and CatSper current of human sperm. Although regadenoson did not affect these sperm parameters, it alleviated the adverse effects of SCH58261 on these parameters. In addition, the mean level of A2AR in sperm from asthenozoospermic men was lower than that in sperm from normozoospermic men. The sperm level of A2AR was positively correlated with progressive motility. Furthermore, the fertilization rate during IVF was lower in men with decreased sperm level of A2AR than in men with normal sperm level of A2AR.
UNASSIGNED: These results indicate that A2AR is important for human sperm motility and is associated with IVF outcome.

Acute pancreatitis (AP) is characterized by elevated intracellular Ca2+ concentrations, mitochondrial dysfunction, and oxidative stress in pancreatic acinar cells. Algal oil (AO) has demonstrated antioxidant and anti-inflammatory properties. This study aims to explore the effects of algal oil on the microenvironment of AP. Rat pancreatic acinar AR42J cells were pretreated with AO containing 0, 50, 100, or 150 μM of docosahexaenoic acid (DHA) 2 h prior to AP induction using sodium taurocholate (STC). After 1 h of STC treatment, AR42J cells exhibited a significant increase in intracellular Ca2+ concentration and the production of amylase, lipase, reactive oxygen species, and pro-inflammatory mediators, including tumor necrosis factor-α and interleukin-6. These STC-induced increases were markedly reduced in cells pretreated with AO. In comparison to cells without AO, those treated with a high dose of AO before STC exposure demonstrated a significant increase in mitochondrial membrane potential and a decrease in lipid peroxidation. Furthermore, STC-activated nuclear factor kappa-B (NF-κB) was attenuated in AO-pretreated cells, as evidenced by a significant decrease in activated NF-κB. In conclusion, AO may prevent damage to pancreatic acinar cells by alleviating intracellular Ca2+ overload, mitigating mitochondrial dysfunction, reducing oxidative stress, and attenuating NF-κB-targeted inflammation.

Resveratrol oligomers, ranging from dimers to octamers, are formed through regioselective synthesis involving the phenoxy radical coupling of resveratrol building blocks, exhibiting remarkable therapeutic potential, including antidiabetic properties. In this study, we elucidate the mechanistic insights into the insulin secretion potential of a resveratrol dimer, (-)-Ampelopsin F (AmF), isolated from the acetone extract of Vatica chinensis L. stem bark in Pancreatic Beta-TC-6 cell lines. The AmF (50 µM) treated cells exhibited a 3.5-fold increase in insulin secretion potential as compared to unstimulated cells, which was achieved through the enhancement of mitochondrial membrane hyperpolarization, elevation of intracellular calcium concentration, and upregulation of GLUT2 and glucokinase expression in pancreatic Beta-TC-6 cell lines. Furthermore, AmF effectively inhibited the activity of DPP4, showcasing a 2.5-fold decrease compared to the control and a significant 6.5-fold reduction compared to the positive control. These findings emphasize AmF as a potential lead for the management of diabetes mellitus and point to its possible application in the next therapeutic initiatives.

Calcium (Ca2+), a critical secondary messenger, is also known as the molecule of life and death. The cell responds to a minute change in Ca2+ concentration and tightly maintains Ca2+ homeostasis. Therefore, determining the cell Ca2+ level is critical to understand Ca2+ distribution in the cell and various cell processes. Many techniques have been developed to measure Ca2+ in the cell. We review here different methods used to detect and measure Ca2+ in filamentous fungi. Ca2+-sensitive fluorescent chlortetracycline hydrochloride (CTC), Ca2+-selective microelectrode, Ca2+ isotopes, aequorins, and RGECOs are commonly used to measure the Ca2+ level in filamentous fungi. The use of CTC was one of the earliest methods, developed in 1988, to measure the Ca2+ gradient in the filamentous fungus Neurospora crassa. Subsequently, Ca2+-specific microelectrodes were developed later in the 1990s to identify Ca2+ ion flux variations, and to measure Ca2+ concentration. Another method for quantifying Ca2+ is by using radio-labeled Ca2+ as a tracer. The usage of 45Ca to measure Ca2+ in Saccharomyces cerevisiae was reported previously and the same methodology was also used to detect Ca2+ in N. crassa recently. Subsequently, genetically engineered Ca2+ indicators (GECIs) like aequorins and RGECOs have been developed as Ca2+ indicators to detect and visualize Ca2+ inside the cell. In this review, we summarize various methodologies used to detect and measure Ca2+ in filamentous fungi with their advantages and limitations. •Chlortetracycline (CTC) fluorescence assay is used for visualizing Ca2+ level, whereas microelectrodes technique is used to determine Ca2+ flux in the cell.•Radioactive 45Ca is useful for quantification of Ca2+ in the cellular compartments.•Genetically modified calcium indicators (GECIs) are used to study Ca2+ dynamics in the cell.

BACKGROUND: A revision of several experimental results on cells shows that electromagnetic radiation, either produced by biofield therapy (BFT) or laser, induced an increase in intracellular free calcium concentration. An explanation of this phenomenon is proposed.
METHODS: Quantum chemistry calculations were performed on Ca2+ with different degrees of hydration with the DFT/r2SCAN-3c method together with the implicit solvation model SMD.
RESULTS: Ca2+ dehydration energy by quantum calculations, in an aqueous medium, coincides with the experimental results of the energy of the photon emitted in biofield therapies and lasers. This strongly suggests that the increased intracellular free calcium concentration is because of calcium ion dehydration upon the application of radiation. The Ca2+ dehydration increases the membrane potential due to an augment of the net charge on Ca2+ and it moves near the membrane by the attraction of its negative ions. The voltage-dependent channels are also activated by this membrane potential.
CONCLUSIONS: The increased intracellular Ca2+ concentration occurs with biofield therapy (BFT) or laser. A novel explanation is given based on resonance-induced Ca2+ dehydration with applied radiation, supported by experimental data and theoretical calculations.

Exposure to pesticides is associated with an increased risk of developing Parkinson\'s disease (PD). Currently, rodent-based risk assessment studies cannot adequately capture neurodegenerative effects of pesticides due to a lack of human-relevant endpoints targeted at neurodegeneration. Thus, there is a need for improvement of the risk assessment guidelines. Specifically, a mechanistic assessment strategy, based on human physiology and (patho)biology is needed, which can be applied in next generation risk assessment. The Adverse Outcome Pathway (AOP) framework is particularly well-suited to provide the mechanistic basis for such a strategy. Here, we conducted a semi-systematic review in Embase and MEDLINE, focused on neurodegeneration and pesticides, to develop an AOP network for parkinsonian motor symptoms. Articles were labelled and included/excluded using the online platform Sysrev. Only primary articles, written in English, focused on effects of pesticides or PD model compounds in models for the brain were included. A total of 66 articles, out of the 1700 screened, was included. PD symptoms are caused by loss of function and ultimately death of dopaminergic neurons in the substantia nigra (SN). Our literature review highlights that a unique feature of these cells that increases their vulnerability is their reliance on continuous low-level influx of calcium. As such, excess intracellular calcium was identified as a central early Key Event (KE). This KE can lead to death of dopaminergic neurons of the SN, and eventually parkinsonian motor symptoms, via four distinct pathways: 1) activation of calpains, 2) endoplasmic reticulum stress, 3) impairment of protein degradation, and 4) oxidative damage. Several receptors have been identified that may serve as molecular initiating events (MIEs) to trigger one or more of these pathways. The proposed AOP network provides the biological basis that can be used to develop a mechanistic testing strategy that captures neurodegenerative effects of pesticides.

Neuropathic pain is a chronic condition that tends to worsen over time, leading to a significant decline in patients\' quality of life. The elderly population is disproportionately affected by this burden, as evidenced by the high prevalence of this condition in such a demographic. While previous studies have demonstrated the involvement of various signaling pathways critical to neuropathic pain, the relationship between aging and the onset or persistence of this condition has been overlooked. Greater focus was placed on the efficacy and tolerability of medications, as well as new protocols for assessing pain in patients with cognitive impairment, with less regard for reasons underlying the increased susceptibility of elderly individuals to pain. This Review thus aims to summarize the contributions of aging to neuropathic pain, covering weakened repair function, increased intracellular calcium signaling, enhanced oxidative stress, dysfunctional brain function, impaired descending inhibition, alterations in the innate immune cell population, and the effects of comorbidity caused by aging. A better understanding of these aspects could drive new treatment options thereby yielding better outcomes for elderly patients in pain.

Vascular calcification (VC) is associated with a number of cardiovascular diseases, as well as chronic kidney disease. The role of smooth muscle cells (SMC) has already been widely explored in VC, as has the role of intracellular Ca2+ in regulating SMC function. Increased intracellular calcium concentration ([Ca2+]i) in vascular SMC has been proposed to stimulate VC. However, the contribution of the non-selective Piezo1 mechanosensitive cation channels to the elevation of [Ca2+]i, and consequently to the process of VC has never been examined. In this work the essential contribution of Piezo1 channels to arterial medial calcification is demonstrated. The presence of Piezo1 was proved on human aortic smooth muscle samples using immunohistochemistry. Quantitative PCR and Western blot analysis confirmed the expression of the channel on the human aortic smooth muscle cell line (HAoSMC). Functional measurements were done on HAoSMC under control and calcifying condition. Calcification was induced by supplementing the growth medium with inorganic phosphate (1.5 mmol/L, pH 7.4) and calcium (CaCl2, 0.6 mmol/L) for 7 days. Measurement of [Ca2+]i using fluorescent Fura-2 dye upon stimulation of Piezo1 channels (either by hypoosmolarity, or Yoda1) demonstrated significantly higher calcium transients in calcified as compared to control HAoSMCs. The expression of mechanosensitive Piezo1 channel is augmented in calcified arterial SMCs leading to a higher calcium influx upon stimulation. Activation of the channel by Yoda1 (10 μmol/L) enhanced calcification of HAoSMCs, while Dooku1, which antagonizes the effect of Yoda1, reduced this amplification. Application of Dooku1 alone inhibited the calcification. Knockdown of Piezo1 by siRNA suppressed the calcification evoked by Yoda1 under calcifying conditions. Our results demonstrate the pivotal role of Piezo1 channels in arterial medial calcification.

Melanocytes stimulated by ultraviolet radiation (UVR) produce melanin and melanosomes, which causes skin pigmentation and acts as an important physiological defence process for photoprotection. Neutral luminal pH of melanosomes is critical for providing optimal conditions for the rate-limiting, pH-sensitive melanin synthesizing enzyme tyrosinase (TYR). As a major component of extraocular phototransduction pathway, transient receptor potential ankyrin1 (TRPA1) can be activated by ultraviolet B (UVB) and reported to be expressed in melanocytes. However, whether TRPA1 is involved in the regulation of melanogenesis remains unclear. Melanogenic activity of TRPA1 was evaluated in primary normal human epidermal melanocytes (HEMs) and murine B16-F10 cell cultures, and the effects of topical applications of TRPA1 specific agonist and antagonist on UVB-induced skin pigmentation were confirmed on in vivo guinea pig models. Calcium (Ca2+ ) imaging and pH imaging were performed to analyse the effects of TRPA1 on intracellular Ca2+ concentration ([Ca2+ ]ic ) and melanosome luminal pH. TRPA1 regulated melanin synthesis, UVB-induced Ca2+ influx and melanosome luminal pH in HEMs and B16-F10 cells. Topical treatment of TRPA1 specific agonist JT010 increased UVB-induced skin pigmentation in guinea pigs, while topical using of TRPA1 selective antagonist HC-030031 mitigated such pigmentation. Our results indicated that TRPA1 activated by UVB enhanced the skin pigmentation, most likely by regulating the [Ca2+ ]ic and the melanosomal pH, consequently influencing the enzymatic activity of TYR. Therefore, the results suggest TRPA1 as a potential therapeutic target in the treatment of skin pigmented disorders that are at high risk under UVB irradiation.

MicroRNAs (miRNAs) are posttranscriptional regulators that play key roles in meat color regulation. Changes in miRNA expression affect their target mRNAs, leading to multifunctional effects on biological processes and phenotypes. In this study, a G > A mutation site located upstream of the precursor miR-22 sequence in Suhuai pigs was significantly correlated with the meat color parameter a*(redness) of the porcine longissimus dorsi (LD) muscle. AA genotype individuals had the highest average meat color a* value and the lowest miR-22 level. When G > A mutation was performed in the miR-22 overexpression vector, miR-22 expression significantly decreased. Considering that Ca2+ homeostasis is closely related to pig meat color, our results further demonstrated that ELOVL6 is a direct target of miR-22 in pigs. The effects of miR-22 on skeletal muscle intracellular Ca2+ were partially caused by the suppression of ELOVL6 expression.