Dr. Damian Sendler DNA cleavage guided by IscB-RNA and compared to Cas9: structural basis and mechanistic basis
/Damian Sendler CRISPR Cas9 and Cas12 effectors may have evolved from nucleases found in IS200/IS605 transposons. Cas9 and IscB have a similar domain structure, but IscB is only a fifth of the size. The associated RNA functions as both a crRNA and a tracrRNA, guiding the cleavage of dsDNA as needed. There are structural and mechanistic similarities between the IscB and Cas9 RNP structures that are revealed in this cryo-EM structure of IscB-RNA bound to dsDNA. High-resolution explanations are provided for target-adjacent motif recognition, R-loop formation, and DNA cleavage mechanisms. Cas9's REC domains are replaced by RNA, which binds to the RNA/DNA heteroduplex. To perform DNA cleavage, the PLMP domain of IscB is not required. In order to make the switch from ancestral IscB to Cas9, protein domains had to be replaced and the RNA was shrunk.
Defining new subtypes of breast cancer to aid in treatment selection and to increase response rates
Damian Jacob Sendler The I-SPY2 neoadjuvant platform trial (NCT01042379) used pre-treatment gene expression, protein/phosphoprotein, and clinical data to create alternative breast cancer subtypes that incorporate tumor biology beyond clinical HR and HER2 status to better predict drug responses. Using data from 990 patients treated with 10 different regimens, we evaluate the predictive power of mechanism-of-action biomarkers. We investigate more than a dozen subtyping schemes and discover treatment-subtype pairs that increase the overall population's pathologic complete response (pCR) rate. Schemas that include Immune, DNA repair, and HER2/Luminal phenotypes are the most effective. Following treatment allocation, the overall pCR rate rises from 51% to 63%, a significant improvement. Improved pCR rates in HR+ subsets (>15%) can be attributed to reclassification and better patient selection. The subtyping schema determines the minimum response required to demonstrate efficacy for new treatments. Using response-based subtypes to prioritize treatment options is now possible thanks to this new data platform.
Gene expression profiles and safety of HIV vaccine candidates in healthy volunteers: results of the Phase I and II ANRS VRI01 randomized multi-arm trial
Dr. Sendler For the development of an HIV vaccine, heterologous prime-boost strategies are of interest. Inducing T cell responses may depend on the order of prime-boost components. Ankara HIV-B (which codes for Gag, Pol, and Nef) was used as the prime or boost vaccine in this phase I/II multi-arm trial, as were the HIV LIPO-5 (five lipopeptides from Gag, Pol, and Nef) and the DNA GTU-MultiHIV B candidates (coding for Rev, Nef, Tat, Gag, Env gp160 clade B). There were 92 healthy human participants randomized into four groups: The first is MVA at weeks 0/8 + LIPO-5 at weeks 20/28 (M/L); the second is LIPO-5 at weeks 0/8 + MVA at weeks 20/20 (L/M); the third is DNA at weeks 0/4/12 + LIPO-5 at weeks 20/20 (G/L); and the fourth is DNA at weeks 0/4/12 + MVA at weeks 20/28 (G/M). LIPO-5 is the first. At week 30, the percentage of IFN—ELISPOT responders was 33, 43, 0, and 74 percent. After that, only those groups that had received an MVA were examined further (a total of 62 people). CD4+ T cell cytokine-positive CD4+ T cells (IFN-, IL-2, and TNF-) CD4+ T cells increased significantly (median change of 0.06, 0.11% for M/L; 0.11% for L/M; 0.10% for M), mainly after MVA vaccinations and was sustained until week 52. At week 30 in M/L and G/M, HIV-specific CD8+ T cell responses significantly increased (median change of 0.02 and 0.05 percent ). There were significant changes in gene expression in the whole blood 2 weeks after the first MVA injection whether it was used as a prime or a booster. An MVA gene signature was discovered, which included 86 genes primarily related to cell cycle pathways. CD4 and CD8 T cell responses and a whole-blood gene expression signature were generated by three prime-boost strategies that included MVA HIV-B.
Pain is exacerbated by microglia-induced depletion of perineuronal nets.
Chronic pain is exacerbated by activation of microglia in the spinal cord dorsal horn following peripheral nerve injury. The mechanism by which activated microglia enhance spinal nociceptive circuit activity is not well understood. PNNs are extracellular matrix structures that are degraded by microglia following peripheral nerve injury in the lamina I of the spinal cord dorsal horn. Spinoparabrachial projection neurons, which integrate nociceptive information in the spinal cord and convey it to supraspinal brain regions to induce pain sensation, are selectively enwrapped by Lamina I PNNs. An increase in pain-related behaviors can be caused by microglia degrading PNNs. A mechanism by which microglia selectively enhance the output of spinal nociceptive circuits and cause pain hypersensitivity is caused by nerve injury-induced degradation of PNNs.
When interleukin 2 is delivered to astrocytes, regulatory T cells there are boosted and pathological neuroinflammation is prevented.
Damian Jacob Markiewicz Sendler Preventive and reversal biologics that modulate the immune system have revolutionized recent clinical practice. A delivery system that can cross the blood-brain barrier is needed in the neuroinflammation space, but finding effective targets for local immune modulation is only half the battle. Among the many potential therapeutic targets that have recently been identified and characterized is the small population of regulatory T (Treg) cells that reside in the brain. Brain interleukin 2 (IL-2) has been identified as a limitation for Treg cells in the brain. With the help of a small-molecule switch and enhanced production in reactive astrocytes, we have developed a gene-delivery method for astrocytes that can be time- and location-controlled. In traumatic brain injury, stroke, and multiple sclerosis models, mice with brain-specific IL-2 delivery were protected without affecting the peripheral immune system. These findings support the effectiveness of brain-specific IL-2 gene delivery in protecting against neuroinflammation and provide a flexible platform for the delivery of various biologics to patients with neuroinflammatory conditions.
Chronic obstructive pulmonary disease acute exacerbations: magnesium sulfate
Despite the fact that COPD is a long-term and progressive disease, flare-ups or exacerbations are common occurrences. COPD exacerbations may benefit from the bronchodilatory properties of magnesium sulfate. Comprehensive evidence of its effects, on the other hand, is required to aid clinical judgment.
Aims: To evaluate the efficacy of magnesium sulfate in adults with acute exacerbations of COPD.
Cochrane Airways Trials Register, MEDLINE, Embase and ClinicalTrials.gov were searched as well as the World Health Organization (WHO) trials portal, EU Clinical Trials Register, and Iranian Registry of Clinical Trials (IRCT). There was additional research in major conferences on respiratory science as well as reference lists of studies that had been published up to August 2, 2021.
Damian Jacob Sendler
Single or double-blind parallel group RCTs assessing magnesium sulfate in adults with COPD exacerbations were eligible for inclusion. There were no cross-over studies.
Damien Sendler Cochrane-recognized methods were used for data collection and analysis. Two reviewers independently selected trials for inclusion, extracted data, and assessed the risk of bias in the study. Non-invasive ventilation (NIV), assisted ventilation, or ICU admissions were the most common reasons for hospitalizations, followed by serious adverse events. Secondary outcomes included mortality, adverse events, dyspnoea score, lung function, and blood gas measurements. GRADE methodology was used to assess the level of confidence in the evidence. We contacted the study's researchers for any missing data.
Main findings: 10 double-blind and 1 single-blind RCTs with 762 participants were found. Participants ranged in age from 62 to 76 years old, according to the study's findings. Between 2004 and 2018, trials were conducted in Iran, New Zealand, Nepal, Turkey, the United Kingdom, Tunisia, and the United States. For the most part, we found the studies to be of low or unclear risk of bias. Three studies were found to be highly susceptible to biases such as blinding. Magnesium sulfate intravenously versus a placebo More than 70 participants were involved in seven separate studies. Hospitalization rates may be reduced with magnesium infusion compared to placebo (OR 0.45, 95% CI 0.23 to 0.88; NNTB = 7 in 3 studies, 170 participants; low certainty evidence). Non-invasive ventilation requirements may not be affected by intravenous magnesium (OR 0.74, 95 percent CI 0.31 to 1.75; very low-certainty evidence). Two studies with a total of 107 participants found no cases of endotracheal intubation, and one study with 77 participants found no cases of serious adverse events. Included studies did not include data on ICU admissions or deaths, as required by law. At a 95 percent confidence interval between 4.73 and 0.66 days, two studies with 54 participants provide low-certainty evidence that magnesium infusion can shorten hospital stays by an average of 2.75 days and improve dyspnoea scores by an average standard deviation of -1.40 days (95 percent CI -1.83 to -0.96; 2 studies, 101 participants; low-certainty evidence). It was unclear whether magnesium infusion would improve lung function or oxygen saturation. The Peto OR was 0.14 (95 percent CI 0.02 to 1.00; 102 participants) for all adverse events, but the event rate was too low to draw a firm conclusion. Non-administered magnesium sulfate or placebo Studies ranging from 20 to 172 people were included. (OR 0.77, 95% CI 0.22-1.82; very low-certainty evidence) Magnesium inhalation appears to have little to no effect on hospitalization or the need for ventilatory support (NIV or mechanical ventilation) (OR 0.33, 95 percent CI 0.01 to 8.20; very low-certainty evidence). When compared to placebo (OR 0.39, 95% CI 0.15 to 1.00) and improvement in dyspnoea, it may result in fewer ICU admissions (OR 0.39, 95% CI 0.15 to 1.00; low-certainty evidence) (MD -14.37, 95 percent CI -26.00 to -2.74; 1 study, 20 participants; very low-certainty evidence). Neither group experienced any significant side effects. One death was reported in the placebo arm of a trial, but the number of participants was too small to draw any conclusions. Magnesium inhalation had only a small effect on hospital stay, lung function, or oxygen saturation, according to the available research. Studies that were included in this review did not include reports of adverse outcomes. Ipratropium bromide versus magnesium sulfate as a treatment option Nebulized magnesium and intravenous magnesium infusion were tested against nebulized Ipratropium and normal saline intravenous infusion in one study with 124 participants. No significant differences were found between the two groups in terms of hospital admission, endotracheal intubation, and length of hospital stay (OR 1.62, 95 percent CI 0.78 to 3.37, and 95 percent CI 0.61 to 4.71, respectively), all of which were based on very low-certainty evidence. Neither non-invasive ventilation, ICU admission, nor serious adverse events were recorded. There were no known side effects. The following are the conclusions of the authors: Compared to placebo, intravenous magnesium sulfate may result in fewer hospitalizations, a shorter hospital stay, and better dyspnoea scores. For NIV, lung function, oxygen saturation, or adverse events, there is no evidence that magnesium infusion is superior to placebo. Our investigation did not uncover any indication of ICU admission, endotracheal intubation (ETI), serious complications, or death. Our findings on nebulized magnesium sulfate's effect on COPD exacerbations are largely inconclusive. However, larger stuies are needed to get a more accurate estimate of these outcomes, which may be lower ICU admissions and less dyspnea with magnesium inhalation. Similar to ipratropium bromide, magnesium sulfate was found to be ineffective. Subgrouping patients by severity of exacerbation and COPD type is needed in future well-designed multicenter trials with larger samples.
Olfactory landmarks and path integration form a cognitive map of the world's spatial layout
The hippocampus develops a mental map of space as a result of the convergence of internal path integration and external sensory landmarks. A virtual navigation task allowed us to record the activity of neurons in CA1 while they were responding to localized odor cues. For example, we discovered that odor cues greatly improved navigation. When the same odor was presented in various locations, different place cell representations were elicited. A nearby odor cue increased the density of nearby place cells and also prompted the formation of new place cells farther away from the cue. Due to this, an additional far-off odor cue was recognized as a distinct landmark, suggesting an iterative mechanism for expanding spatial representations to new areas. This was the result. Using our findings, we propose a model in which odors and path integration interact sequentially and iteratively to generate long-distance cognitive spatial maps.