cADPR induced calcium influx mediates axonal degeneration caused by paclitaxel

Activation of the NAD hydrolase domain of Sarm1 mediates axonal degeneration caused by chemotherapy drugs, but the downstream events are unknown. In this issue, Li and colleagues (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202106080) demonstrate that cADPR, a breakdown product of NAD, mediates paclitaxel-induced axonal degeneration by promoting influx of calcium into the axons.

Evaluation of pesticide residues in commercial Swiss beeswax collected in 2019 using ultra-high performance liquid chromatographic analysis

The aim of this study was to determine residue levels of pesticides in Swiss commercial beeswax. Foundation samples were collected in 2019 from nine commercial manufacturers for analysis of 21 pesticides using ultra-high performance liquid chromatography. Individual samples showed the variability and residue ranges and pooled samples represented the average annual residue values of the Swiss production. In total, 17 pesticides were identified and 13 pesticides were quantified. They included 13 acaricides and/or insecticides, two fungicides as well as a synergist and a repellent. The means calculated from individual samples were similar to the average annual residue values for most tested pesticides. Mean values of 401, 236, 106 and 3 μg·kg−1 were obtained for the beekeeping-associated contaminants coumaphos, tau-fluvalinate, bromopropylate and N-(2,4-Dimethylphenyl)-formamide (DMF; breakdown product of amitraz), respectively. For the other pesticides, the mean values were 203 μg·kg−1 (synergist piperonyl butoxide), 120 μg·kg−1 (repellent N,N-Diethyl-3-methylbenzamide, DEET), 19 μg·kg−1 (chlorfenvinphos) and 4 μg·kg−1 ((E)-fenpyroximate), while the means for acrinathrin, azoxystrobin, bendiocarb, boscalid, chlorpyrifos, flumethrin, permethrin, propoxur and thiacloprid were below the limit of quantification (< LOQ). Individual samples contained from seven to 14 pesticides. The ranges of values for coumaphos and piperonyl butoxide (from 14 to 4270 μg·kg−1; from 6 to 1555 μg·kg−1, respectively) were larger as compared to the ranges of values for DEET and tau-fluvalinate (from < LOQ to 585 μg·kg−1; from 16 to 572 μg·kg−1, respectively). In conclusion, the most prominent contaminants were the pesticides coumaphos and tau-fluvalinate, which are both acaricides with previous authorization for beekeeping in Switzerland, followed by piperonyl butoxide, a synergist to enhance the effect of insecticides. Graphical abstract

Physicochemical Stability of a Novel Tacrolimus Ophthalmic Formulation for the Treatment of Ophthalmic Inflammatory Diseases

Tacrolimus is an immunosuppressant used to treat a large variety of inflammatory or immunity-mediated ophthalmic diseases. However, there are currently no commercial industrial forms available that can provide relief to patients. Various ophthalmic formulations have been reported in the literature, but their stability has only been tested over short periods. The objective of this study was to evaluate the physicochemical stability of a preservative-free tacrolimus formulation (0.2 and 1 mg/mL) at three storage temperatures (5 °C, 25 °C and 35 °C) for up to nine months in a multidose eyedropper. Analyses performed were the following: visual inspection and chromaticity, turbidity, viscosity, size of micelles, osmolality and pH measurements, tacrolimus quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. In an in-use study, tacrolimus quantification was also performed on the drops emitted from the eyedroppers. All tested parameters remained stable during the nine month period when the eyedrops were stored at 5 °C. However, during storage at 25 °C and 35 °C, several signs of chemical instability were detected. Furthermore, a leachable compound originating from a silicone part of the eyedropper was detected during the in-use assay. Overall, the 0.2 mg/mL and 1 mg/mL tacrolimus ophthalmic solutions were physicochemically stable for up to nine months when stored at 5 °C.

Evaluation of PET Degradation Using Artificial Microbial Consortia

Polyethylene terephthalate (PET) biodegradation is regarded as an environmentally friendly degradation method. In this study, an artificial microbial consortium composed of Rhodococcus jostii, Pseudomonas putida and two metabolically engineered Bacillus subtilis was constructed to degrade PET. First, a two-species microbial consortium was constructed with two engineered B. subtilis that could secrete PET hydrolase (PETase) and monohydroxyethyl terephthalate hydrolase (MHETase), respectively; it could degrade 13.6% (weight loss) of the PET film within 7 days. A three-species microbial consortium was further obtained by adding R. jostii to reduce the inhibition caused by terephthalic acid (TPA), a breakdown product of PET. The weight of PET film was reduced by 31.2% within 3 days, achieving about 17.6% improvement compared with the two-species microbial consortium. Finally, P. putida was introduced to reduce the inhibition caused by ethylene glycol (EG), another breakdown product of PET, obtaining a four-species microbial consortium. With the four-species consortium, the weight loss of PET film reached 23.2% under ambient temperature. This study constructed and evaluated the artificial microbial consortia in PET degradation, which demonstrated the great potential of artificial microbial consortia in the utilization of complex substrates, providing new insights for biodegradation of complex polymers.

Transmission of the effect of Mercurius corrosivus 30 CH on -amylase in cell free medium through water.

Background Mercurius corrosivus 30CH promoted -amylase activity in a cell free medium invitro. -amylase causes hydrolysis of starch. The activity of the enzyme is measured in terms of the amount of maltose liberated due to breakdown of starch. In a number of experimental studies it has been demonstrated that the effect of homeopathic potency would be transmitted from one plant to another through water. Here one leaf of a pair of plants was dipped in water in a beaker. The two beakers were connected by a water filled polythene tube. The effect of treatment of one plant with homeopathic potency would be observed in the directly treated plant as well as the connected plant. Two groups of toads were kept in water in two different containers. The two containers were connected by a water filled polythene tube. The effect of treatment of one group of toads with homeopathic potency would be observed in both the directly treated group as well as the connected group. Objectives The purpose of the present study is to see whether the effect of Mercurius corrosivus 30 CH on -amylase in one test tube would be transmitted to another test tube connected with the former by water filled capillary tube. Methods Mercurius corrosivus 30 CH was diluted with distilled water (1:100). Two hard glass test tubes each containing -amylase were connected with a water filled capillary tube while one test tube received Mercurius corrosivus 30CH solution, the other only the control solution. The control solution consisted of equal amount of 90% ethanol diluted with water (1:100).There were two more test tubes, one containing same amount of distilled water instead of Mercurius corrosivus 30 CH solution and the other test tube the same amount of 90% ethanol (1:100) as in the control set. After 10 mins starch solution in Sodium acetate buffer was added to each test tube. The enzyme in each test tube was allowed to react with starch for 15 mins and then it was stopped by DNSA (Dinitro salicylic acid) solution .The activity of -amylase was measured by standard biochemical process. The breakdown product maltose in each test tube was quantified by a standard curve prepared by measuring the optical density of the maltose solution at 560 nm in a UV-VIS Spectrophotometer. This experiment was repeated 20 times. Results Activity of -amylase was expressed in terms of the amount of maltose liberated from breakdown of starch with standard errors in 15mins at a fixed temperature. The data were analyzed statistically using t-test. Mercurius corrosivus 30 CH enhanced the enzyme activity significantly in the directly treated test tube as well as the connected one (p

Deficiency in Androgen Receptor Aggravates Traumatic Brain Injury-Induced Pathophysiology and Motor Deficits in Mice

Androgens have been shown to have a beneficial effect on brain injury and lower reactive astrocyte expression after TBI. Androgen receptors (ARs) are known to mediate the neuroprotective effects of androgens. However, whether ARs play a crucial role in TBI remains unknown. In this study, we investigated the role of ARs in TBI pathophysiology, using AR knockout (ARKO) mice. We used the controlled cortical impact model to produce primary and mechanical brain injuries and assessed motor function and brain-lesion volume. In addition, the AR knockout effects on necrosis and autophagy were evaluated after TBI. AR knockout significantly increased TBI-induced expression of the necrosis marker alpha-II-spectrin breakdown product 150 and astrogliosis marker glial fibrillary acidic protein. In addition, the TBI-induced astrogliosis increase in ARKO mice lasted for three weeks after a TBI. The autophagy marker Beclin-1 was also enhanced in ARKO mice compared with wild-type mice after TBI. Our results also indicated that ARKO mice showed a more unsatisfactory performance than wild-type mice in a motor function test following TBI. Further, they were observed to have more severe lesions than wild-type mice after injury. These findings strongly suggest that ARs play a role in TBI.

MMP-2 gene silencing attenuates age-dependent carotid stiffness via reduction of elastin degradation and increased eNOS activation

Background and aims Arterial stiffness is a hallmark of vascular aging. Being characterized by a loss of elasticity of large arterial walls, arterial stiffness is associated with an increased risk of cardiovascular disease (CVD). The age-dependent arterial stiffness is primarily attributed to alterations in the elastic and collagen deposition that is regulated by a number of enzymes, including matrix metalloproteinase-2 (MMP-2). Nevertheless, the mechanistic link between age-dependent arterial stiffness and MMP-2 remains unclear. In this study, we investigated the effect and efficacy of therapeutic MMP-2 knockdown using small interfering RNA (siRNA) on age-dependent arterial stiffness. Methods Pulse wave velocity (PWV) was assessed in the right carotid artery of wild-type (WT) mice of different age groups. MMP-2 levels and activity in the carotid artery and plasma of young (3 months) and aged (20–25 months) WT mice were determined. Old WT mice (18–21 months) were treated for 4 weeks with either MMP-2 or scrambled siRNA, in which carotid PWV was assessed at baseline, 2 and 4 weeks after the start of the treatment. Elastin to collagen ratio, desmosin (DES) level, and endothelial nitric oxide synthase (eNOS) pathways were also evaluated and compared. Lastly, levels of circulating MMP-2 and DES, the breakdown product of elastin, were measured in a human cohort (23–86 years old), in whom carotid-femoral PWV was assessed. Results Carotid PWV, as well as both vascular and circulating MMP-2 levels, were elevated with increasing age in WT mice (Figure 1). Therapeutic MMP-2 knockdown in aged WT mice reduced the vascular MMP-2 expression and attenuated age-dependent carotid stiffness. Increased elastin to collagen ratio and a lower plasma DES level were observed on MMP-2 silenced treated animals (Figure 2). Moreover, siMMP-2 treated mice showed enhanced eNOS phosphorylation on Ser1177. A direct interaction between MMP-2 and eNOS was also observed, which, interestingly, is augmented with age. Finally, collected human data showed a higher level of circulating MMP-2 levels on the elderly subjects. In addition, plasma DES level is positively correlated with age and aortic PWV, indicating the involvement of vascular elastin catabolism on arterial stiffness. Conclusions Therapeutic MMP-2 gene silencing, specifically targeting vascular MMP-2, attenuates age-dependent carotid stiffness. This effect is mediated by augmenting eNOS activation and reducing elastin degradation. Thus, our findings indicate MMP-2 as a potential therapeutic target to mitigate age-dependent arterial stiffness and CVD. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation,Foundation for Cardiovascular Research–Zurich Heart House Figure 1

Airway Thiol-NO Adducts as Determinants of Exhaled NO

Thiol-NO adducts such as S-nitrosoglutathione (GSNO) are endogenous bronchodilators in human airways. Decreased airway S-nitrosothiol concentrations are associated with asthma. Nitric oxide (NO), a breakdown product of GSNO, is measured in exhaled breath as a biomarker in asthma; an elevated fraction of expired NO (FENO) is associated with asthmatic airway inflammation. We hypothesized that FENO could reflect airway S-nitrosothiol concentrations. To test this hypothesis, we first studied the relationship between mixed expired NO and airway S-nitrosothiols in patients endotracheally intubated for respiratory failure. The inverse (Lineweaver-Burke type) relationship suggested that expired NO could reflect the rate of pulmonary S-nitrosothiol breakdown. We thus studied NO evolution from the lungs of mice (GSNO reductase −/−) unable reductively to catabolize GSNO. More NO was produced from GSNO in the −/− compared to wild type lungs. Finally, we formally tested the hypothesis that airway GSNO increases FENO using an inhalational challenge model in normal human subjects. FENO increased in all subjects tested, with a median t1/2 of 32.0 min. Taken together, these data demonstrate that FENO reports, at least in part, GSNO breakdown in the lungs. Unlike GSNO, NO is not present in the lungs in physiologically relevant concentrations. However, FENO following a GSNO challenge could be a non-invasive test for airway GSNO catabolism.

A Panel of CSF and Serum Biomarkers Reflecting Injury Severity and Outcome in a Human Spinal Cord Injury Study

Acute spinal cord injury (SCI) results in catastrophic neurological impairment. We aimed to examine the temporal profile and severity correlation of biomarkers, and their relationship with the American Spinal Injury Association Scale (AIS) improvement in human SCI. 15 SCI and 10 non-SCI healthy subjects were classified according to the initial and discharge AIS grade. Serial cerebrospinal fluid (CSF) and serum samples were collected. Spectrin breakdown products (SBDP) 150, SBDP145, glial fibrillary acidic protein (GFAP), and GFAP breakdown product (GBDP) 38/44K were found to be elevated in the acute phase CSF samples in SCI patients on immunoblotting. SBDP150, ubiquitin C-terminal hydrolase-L1 (UCH-L1), GFAP, S100B, neurofilament light chain protein (NF-L), Tau & interleukin (IL) -6 were elevated in the acute phase CSF and serum samples on ELISA. CSF SBDP150, UCH-L1, GFAP, S100B and Tau were seen to peak on day 1 after injury, while CSF IL-6 and NF-L peaked on day 5. Serum SBDP150, IL-6, S100B, GFAP, UCHL-1 and Tau peaked on day 1, while serum NF-L peaked on day 5 post-injury. CSF alpha II-spectrin, SBDP150/145, and GBDP 44-38K levels (by immunoblots), CSF SBDP150, S100B, GFAP, UCHL-1 and Tau (ELISA) and serum UCHL-1 and Tau (ELISA) at specific time points showed SCI severity-correlation. CSF SBDP150, GFAP, and Tau and serum UCHL-1 and Tau (ELISA) were seen to have the best correlation with the severity at discharge. Receiver Operating Characteristic Curve analysis showed that CSF and serum biomarkers (SBDP150, IL-6, S100B, GFAP, NF-L, UCHL-1 and Tau) were associated with the severity of SCI.