Biology and Toxicology of Gametes, Embryos, and Cancer Cells in Reproductive Systems.

Reproduction is the important process of transmitting one's genetic information to the next generation [...].

Double Mutations in a Patient with Early-Onset Alzheimer's Disease in Korea: An APP Val551Met and a PSEN2 His169Asn.

The etiology of early-onset Alzheimer's disease (EOAD) is associated with alterations in the production of amyloid beta (Aß) species caused by mutations in the APP, PSEN1, and PSEN2 genes. Mutations affect intra- or inter-molecular interactions and processes between the γ-secretase complex and amyloid precursor protein (APP), leading to the aberrant sequential cleavage of Aß species. A 64-year-old woman presented with progressive memory decline, mild right hippocampal atrophy, and a family history of Alzheimer's dementia (AD). Whole exome sequencing was performed to evaluate AD-related gene mutations, which were verified by Sanger sequencing. A mutation-caused structural alteration of APP was predicted using in silico prediction programs. Two AD-related mutations, in APP (rs761339914; c.G1651A; p.V551M) and PSEN2 (rs533813519; c.C505A; p.H169N), were identified. The APP Val551Met mutation in the E2 domain may influence APP homodimerization through changes in intramolecular interactions between adjacent amino acids, altering Aß production. The second mutation was PSEN2 His169Asn mutation, which was previously reported in five EOAD patients from Korea and China, with a relatively high frequency in the East Asian population. According to a previous report, the presenilin 2 protein was predicted to result in a major helical torsion by PSEN2 His169Asn mutation. Notably, the co-existence of APP Val551Met and PSEN2 His169Asn may induce a synergistic effect by both mutations. Future functional studies are needed to clarify the pathological effects of these double mutations.

Identification and quantification of sialylated and core-fucosylated N-glycans in human transferrin by UPLC and LC-MS/MS.

Sialylated and core-fucosylated N-glycans in human transferrin (HTF) are used as glycan biomarkers due to their increased or decreased characteristics in certain diseases. However, their absolute quantities remain unclear. In this study, N-glycans of HTF were identified by UPLC and LC-MS/MS using fluorescence tags [2-aminobenzamide (AB) and procainamide (ProA)] and columns [HILIC and anion exchange chromatography-HILIC (AXH)]. The structures of 14 (including five core-fucosylated) N-glycans in total comprising two non-, six mono-, four di-, and two tri-sialylated N-glycans were identified. The quantities (%) of each N-glycan relative to the total N-glycans (100%) were obtained. HILIC and AXH were better for peak identification and separability except for desialylation, respectively. Specifically, sialylated (in ProA-HILIC and ProA-AXH by UPLC or LC-MS/MS) and core-fucosylated (in AB-HILIC and ProA-AXH by UPLC) N-glycans were efficiently identified. Seven neuraminidase-treated (including three core-fucosylated) N-glycans were efficiently identified in ProA-AXH, even their poor separation. Additionally, ProA-AXH was more efficient for the estimation of the absolute quantities of N-glycans from the results of fluorescence intensity (by UPLC) and relative quantity (by LC-MS/MS). These results first demonstrate that ProA is useful for identifying and quantifying sialylated, core-fucosylated, and neuraminidase-treated desialylated N-glycans in HTF using AXH by UPLC and LC/MS.

A Possible Pathogenic PSEN2 Gly56Ser Mutation in a Korean Patient with Early-Onset Alzheimer's Disease.

Early-onset Alzheimer's disease (EOAD) is characterized by the presence of neurological symptoms in patients with Alzheimer's disease (AD) before 65 years of age. Mutations in pathological genes, including amyloid protein precursor (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2), were associated with EOAD. Seventy-six mutations in PSEN2 have been found around the world, which could affect the activity of γ-secretase in amyloid beta processing. Here, a heterozygous PSEN2 point mutation from G to A nucleotide change at position 166 (codon 56; c.166G>A, Gly56Ser) was identified in a 64-year-old Korean female with AD with progressive cognitive memory impairment for the 4 years prior to the hospital visit. Hippocampal atrophy was observed from magnetic resonance imaging-based neuroimaging analyses. Temporal and parietal cortex hypometabolisms were identified using fluorodeoxyglucose positron emission tomography. This mutation was at the N-terminal portion of the presenilin 2 protein on the cytosolic side. Therefore, the serine substitution may have promoted AD pathogenesis by perturbing to the mutation region through altered phosphorylation of presenilin. In silico analysis revealed that the mutation altered protein bulkiness with increased hydrophilicity and reduced flexibility of the mutated region of the protein. Structural changes were likely caused by intramolecular interactions between serine and other residues, which may have affected APP processing. The functional study will clarify the pathogenicity of the mutation in the future.

Efficacy of topical steroids for the treatment of olfactory disorders caused by COVID-19: A systematic review and meta-analysis.

OBJECTIVES: The aim of this study was to assess the effect of topical steroids on acute-onset olfactory dysfunction in patients infected with COVID-19. DESIGN AND SETTING: Systematic review and meta-analysis of cohort studies. PARTICIPANTS: Patients infected with COVID-19. MAIN OUTCOME MEASURES: PubMed, Embase, the Web of Science, SCOPUS, Cochrane database and Google Scholar were searched for articles up to September 2021. We analysed studies comparing the improvement of olfactory dysfunction between topical steroid treatment and control groups (placebo or no treatment). In addition, we performed a subgroup analysis by study type. RESULTS: The improvement of olfactory score at 2 (standardised mean difference [SMD] = 0.7272, 95% confidence interval = [0.3851, 1.0692], p < .0001, I2  = 62.1%) and 4 weeks post-treatment (SMD = 1.0440 [0.6777, 1.4102], p < .0001, I2  = 61.2%) was statistically greater in the treatment than control group. However, there was no significant difference (odds ratio [OR] = 1.4345 [0.9525, 2.1604], p = .0842, I2  = 45.4%) in the incidence of fully recovery from anosmia/hyposmia between the treatment and control groups. In subgroup analysis, there were no significant differences in the improvement of olfactory score at 4 weeks post-treatment (OR = 0.6177 [0.1309, 1.1045] vs. 0.1720 [0.8002, 1.5438], p = .0761) or the incidence of full recovery from anosmia/hyposmia (OR = 1.8478 [0.6092, 5.6053] vs. 1.3784 [0.8872, 2.1414], p = .8038) between randomised and non-randomised controlled trials. CONCLUSIONS: Although this meta-analysis found that topical steroids improved the acute-onset olfactory dysfunction caused by COVID-19, there was no difference in the rate of full olfactory recovery between treated and control patients.

PLD1 and PLD2 differentially regulate the balance of macrophage polarization in inflammation and tissue injury.

Phospholipase D (PLD) isoforms PLD1 and PLD2 serve as the primary nodes where diverse signaling pathways converge. However, their isoform-specific functions remain unclear. We showed that PLD1 and PLD2 selectively couple to toll-like receptor 4 (TLR4) and interleukin 4 receptor (IL-4R) and differentially regulate macrophage polarization of M1 and M2 via the LPS-MyD88 axis and the IL-4-JAK3 signaling, respectively. Lipopolysaccharide (LPS) enhanced TLR4 or MyD88 interaction with PLD1; IL-4 induced IL-4R or JAK3 association with PLD2, indicating isozyme-specific signaling events. PLD1 and PLD2 are indispensable for M1 polarization and M2 polarization, respectively. Genetic and pharmacological targeting of PLD1 conferred protection against LPS-induced sepsis, cardiotoxin-induced muscle injury, and skin injury by promoting the shift toward M2; PLD2 ablation intensified disease severity by promoting the shift toward M1. Enhanced Foxp3+ regulatory T cell recruitment also influenced the anti-inflammatory phenotype of Pld1LyzCre macrophages. We reveal a previously uncharacterized role of PLD isoforms in macrophage polarization, signifying potential pharmacological interventions for macrophage modulation.

Cellular and subcellular localization of endogenous phospholipase D6 in seminiferous tubules of mouse testes.

Phospholipase D6 (PLD6) plays pivotal roles in mitochondrial dynamics and spermatogenesis, but the cellular and subcellular localization of endogenous PLD6 in testis germ cells is poorly defined. We examined the distribution and subcellular localization of PLD6 in mouse testes using validated specific anti-PLD6 antibodies. Ectopically expressed PLD6 protein was detected in the mitochondria of PLD6-transfected cells, but endogenous PLD6 expression in mouse testes was localized to the perinuclear region of pachytene spermatocytes, and more prominently, to the round (Golgi and cap phases) and elongating spermatids (acrosomal phase); these results suggest that PLD6 is localized to the Golgi apparatus. The distribution of PLD6 in the round spermatids partially overlapped with that of the cis-Golgi marker GM130, indicating that the PLD6 expression corresponded to the GM130-positive subdomains of the Golgi apparatus. Correlative light and electron microscopy revealed that PLD6 expression in developing spermatids was localized almost exclusively to several flattened cisternae, and these structures might correspond to the medial Golgi subcompartment; neither the trans-Golgi networks nor the developing acrosomal system expressed PLD6. Further, we observed that PLD6 interacted with tesmin, a testis-specific transcript necessary for successful spermatogenesis in mouse testes. To our knowledge, these results provide the first evidence of PLD6 as a Golgi-localized protein of pachytene spermatocytes and developing spermatids and suggest that its subcompartment-specific distribution within the Golgi apparatus may be related to the specific functions of this organelle during spermatogenesis.

Prolonged MEK inhibition leads to acquired resistance and increased invasiveness in KRAS mutant gastric cancer.

Gastric cancer (GC) is one of the most common causes of cancer-associated death. However, traditional therapeutic strategies have failed to significantly improve the survival of patient with advanced GC. While KRAS mutations have been found in some patients with gastric cancer, an effective therapy to treat KRAS-driven gastric cancer has not been established yet. To provide a rationale for clinical application of kinase inhibitors targeting RAS pathways, we first determined the sensitivity of GC cell lines harboring KRAS mutations or amplification to RAS pathway inhibitors. We found that MAPK pathway inhibitors (MEKi and ERKi) were more effective than AKT inhibitor, suggesting that KRAS-driven gastric cancer cells are dependent on MAPK pathway for survival. Further, we established a KRAS mutant GC cell line with acquired resistance to MEK inhibitors in order to mimic clinical situation of kinase inhibitor resistance. A comprehensive analysis of tyrosine phosphorylation in receptor tyrosine kinases in combination with small molecule chemical library screening revealed upregulated c-MET phosphorylation in this resistance cell line with elevated sensitivity to c-MET TKI (crizotinib) and PI3K/mTOR dual inhibitor (BEZ235). We also showed that migration and invasion of resistant cells were promoted, and crizotinib and BEZ235 could inhibit this malignant phenotype. Overall, our results indicate that prolonged MAPK pathway inhibition could result in acquired resistance which is associated with increased malignant phenotype in KRAS mutant GC and pharmacological targeting c-MET and PI3K/mTOR could overcome this problem.

Al-Ti-Containing Lightweight High-Entropy Alloys for Intermediate Temperature Applications.

In this study, new high-entropy alloys (HEAs), which contain lightweight elements, namely Al and Ti, have been designed for intermediate temperature applications. Cr, Mo, and V were selected as the elements for the Al-Ti-containing HEAs by elemental screening using their binary phase diagrams. AlCrMoTi and AlCrMoTiV HEAs are confirmed as solid solutions with minor ordered B2 phases and have superb specific hardness when compared to that of commercial alloys. The present work demonstrates the desirable possibility for substitution of traditional materials that are applied at intermediate temperature to Al-Ti-containing lightweight HEAs.

The Impact of Discrepancy between Measured versus Stated Weight on Hemorrhagic Transformation and Clinical Outcomes after Intravenous Alteplase Thrombolysis.

BACKGROUND: An accurate measurement of patient weight is important in determining the dosage for intravenous alteplase thrombolysis. In most emergency rooms, however, weight is not measured. We investigated the difference between stated and measured weight and its effect on hemorrhagic transformation and clinical outcomes. METHODS: We enrolled 128 consecutive patients who had hyperacute stroke and were treated by alteplase. Alteplase dose was calculated using the weight provided by patient or guardian/caregiver, and the actual weight was measured after administration. Patients were classified into 2 groups: overused group (stated weight >measured weight) and underused group (measured weight ≥stated weight). The prevalence of hemorrhagic transformation on follow-up, determined by gradient-recalled echo MRI or non-enhanced CT, was compared between the 2 groups. The predictors for hemorrhage with progression, defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) by a value of 4 or more accompanied by hemorrhage, were determined using multivariable logistic regression analysis and included the overused or underused alteplase and baseline clinical and laboratory findings. RESULTS: Sixty-six (51.6%) of 128 patients were in the underused group and 62 patients (48.4%) in the overused group. The median difference between the stated and measured weights was 1.5 (interquartile range 0.56-3.81) kg, with the largest difference being 25.6 kg. Although there were no significant difference in baseline clinical and laboratory findings between the 2 groups, the overused group showed a significantly higher prevalence of hemorrhagic transformation (p = 0.012) and hemorrhage with progression (p = 0.025). The multivariable logistic regression analysis demonstrated that overused alteplase (OR 7.26; 95% CI 1.24-42.45; p = 0.028), baseline glucose (>144 mg/dL; OR 5.03; 95% CI 1.00-25.26; p = 0.050), and initial NIHSS (OR 1.13 per 1-point NIHSS increase; 95% CI 1.00-1.27; p = 0.047) in model 1 that use alteplase overdose as a categorical variable and overused alteplase (OR 1.67 1-mg increase; 95% CI 1.05-2.66; p = 0.027) in model 2 that use an overused alteplase dose as numerical variable were significant predictors for hemorrhage with progression. CONCLUSION: More alteplase usage than actual weight led to higher hemorrhagic transformation. As one of the predictors for clinical deterioration, it is important to administrate alteplase based on an accurately measured weight.

XAF1 directs apoptotic switch of p53 signaling through activation of HIPK2 and ZNF313.

X-linked inhibitor of apoptosis (XIAP)-associated factor 1 (XAF1) is a tumor suppressor that is frequently inactivated in many human cancers. However, the molecular mechanism underlying its growth-inhibitory function remains largely unknown. Here, we report that XAF1 forms a positive feedback loop with p53 and acts as a molecular switch in p53-mediated cell-fate decisions favoring apoptosis over cell-cycle arrest. XAF1 binds directly to the N-terminal proline-rich domain of p53 and thus interferes with E3 ubiquitin ligase MDM2 binding and ubiquitination of p53. XAF1 stimulates homeodomain-interacting protein kinase 2 (HIPK2)-mediated Ser-46 phosphorylation of p53 by blocking E3 ubiquitin ligase Siah2 interaction with and ubiquitination of HIPK2. XAF1 also steps up the termination of p53-mediated cell-cycle arrest by activating zinc finger protein 313 (ZNF313), a p21(WAF1)-targeting ubiquitin E3 ligase. XAF1 interacts with p53, Siah2, and ZNF313 through the zinc finger domains 5, 6, and 7, respectively, and truncated XAF1 isoforms preferentially expressed in cancer cells fail to form a feedback loop with p53. Together, this study uncovers a novel role for XAF1 in p53 stress response, adding a new layer of complexity to the mechanisms by which p53 determines cell-fate decisions.

7SL RNA represses p53 translation by competing with HuR.

Noncoding RNAs (ncRNAs) and RNA-binding proteins are potent post-transcriptional regulators of gene expression. The ncRNA 7SL is upregulated in cancer cells, but its impact upon the phenotype of cancer cells is unknown. Here, we present evidence that 7SL forms a partial hybrid with the 3'-untranslated region (UTR) of TP53 mRNA, which encodes the tumor suppressor p53. The interaction of 7SL with TP53 mRNA reduced p53 translation, as determined by analyzing p53 expression levels, nascent p53 translation and TP53 mRNA association with polysomes. Silencing 7SL led to increased binding of HuR to TP53 mRNA, an interaction that led to the promotion of p53 translation and increased p53 abundance. We propose that the competition between 7SL and HuR for binding to TP53 3'UTR contributes to determining the magnitude of p53 translation, in turn affecting p53 levels and the growth-suppressive function of p53. Our findings suggest that targeting 7SL may be effective in the treatment of cancers with reduced p53 levels.

RNA-binding protein AUF1 represses Dicer expression.

MicroRNA (miRNA) biogenesis is tightly regulated by numerous proteins. Among them, Dicer is required for the processing of the precursor (pre-)miRNAs into the mature miRNA. Despite its critical function, the mechanisms that regulate Dicer expression are not well understood. Here we report that the RNA-binding protein (RBP) AUF1 (AU-binding factor 1) associates with the endogenous DICER1 mRNA and can interact with several segments of DICER1 mRNA within the coding region (CR) and the 3'-untranslated region (UTR). Through these interactions, AUF1 lowered DICER1 mRNA stability, since silencing AUF1 lengthened DICER1 mRNA half-life and increased Dicer expression, while overexpressing AUF1 lowered DICER1 mRNA and Dicer protein levels. Given that Dicer is necessary for the synthesis of mature miRNAs, the lowering of Dicer levels by AUF1 diminished the levels of miRNAs tested, but not the levels of the corresponding pre-miRNAs. In summary, AUF1 suppresses miRNA production by reducing Dicer production.

Structural identification and quantification of unreported sialylated N-glycans in bovine testicular hyaluronidase by LC-ESI-HCD-MS/MS.

Bovine testicular hyaluronidase (BTH), which accelerates the absorption and dispersion of drugs by decomposing hyaluronan in subcutaneous tissues, has been used in medical applications, including local anesthesia, ophthalmology, and dermatosurgery. The requirement of N-glycans for the activity of human hyaluronidase has been reported, and BTH has greater activity than human hyaluronidase. However, the N-glycan characteristics of BTH are unclear. From a commercial BTH source containing additional proteins, purified BTH (pBTH) was obtained using size exclusion chromatography, and the structures and quantities of its N-glycans were analyzed using liquid chromatography (LC)-electrospray ionization-higher energy collisional dissociation (HCD)-tandem mass spectrometry (MS/MS). In pBTH, 32 N-glycans were identified, with 12 sialylations (39.0% of total N-glycan content), nine core-fucosylations (31.5%), six terminal galactosylations (14.6%), five high-mannosylations (13.7%), and four bisecting N-acetylglucosamine structures (7.8%). The presence of sialylated glycopeptides in pBTH was confirmed by nano-LC-HCD-MS/MS analysis. The absolute quantity of all N-glycans was calculated as 1.4 pmol (0.6 pmol for sialylation) in pBTH (1.0 pmol). The sialylation level (related to half-life, thermal stability, resistance to proteolysis, and solubility) was 24.4 times higher than that of human hyaluronidase. The hyaluronan degradation activity of de-sialylated pBTH decreased to 41.2 ± 4.2%, showing that sialylated N-glycans were required for pBTH activity as well. This is the first study to identify and quantify 32 N-glycans of pBTH and investigate their structural roles in its activity. The presence of larger amounts of sialylated N-glycans in pBTH than in human hyaluronidase suggests a greater utilization of pBTH.

Development of examination objectives for the Korean paramedic and emergency medical technician examination: a survey study.

PURPOSE: The duties of paramedics and emergency medical technicians (P&EMTs) are continuously changing due to developments in medical systems. This study presents evaluation goals for P&EMTs by analyzing their work, especially the tasks that new P&EMTs (with less than 3 years' experience) find difficult, to foster the training of P&EMTs who could adapt to emergency situations after graduation. METHODS: A questionnaire was created based on prior job analyses of P&EMTs. The survey questions were reviewed through focus group interviews, from which 253 task elements were derived. A survey was conducted from July 10, 2023 to October 13, 2023 on the frequency, importance, and difficulty of the 6 occupations in which P&EMTs were employed. RESULTS: The P&EMTs' most common tasks involved obtaining patients' medical histories and measuring vital signs, whereas the most important task was cardiopulmonary resuscitation (CPR). The task elements that the P&EMTs found most difficult were newborn delivery and infant CPR. New paramedics reported that treating patients with fractures, poisoning, and childhood fever was difficult, while new EMTs reported that they had difficulty keeping diaries, managing ambulances, and controlling infection. CONCLUSION: Communication was the most important item for P&EMTs, whereas CPR was the most important skill. It is important for P&EMTs to have knowledge of all tasks; however, they also need to master frequently performed tasks and those that pose difficulties in the field. By deriving goals for evaluating P&EMTs, changes could be made to their education, thereby making it possible to train more capable P&EMTs.

Enhanced translation by Nucleolin via G-rich elements in coding and non-coding regions of target mRNAs.

RNA-binding proteins (RBPs) regulate gene expression at many post-transcriptional levels, including mRNA stability and translation. The RBP nucleolin, with four RNA-recognition motifs, has been implicated in cell proliferation, carcinogenesis and viral infection. However, the subset of nucleolin target mRNAs and the influence of nucleolin on their expression had not been studied at a transcriptome-wide level. Here, we globally identified nucleolin target transcripts, many of which encoded cell growth- and cancer-related proteins, and used them to find a signature motif on nucleolin target mRNAs. Surprisingly, this motif was very rich in G residues and was not only found in the 3'-untranslated region (UTR), but also in the coding region (CR) and 5'-UTR. Nucleolin enhanced the translation of mRNAs bearing the G-rich motif, since silencing nucleolin did not change target mRNA stability, but decreased the size of polysomes forming on target transcripts and lowered the abundance of the encoded proteins. In summary, nucleolin binds G-rich sequences in the CR and UTRs of target mRNAs, many of which encode cancer proteins, and enhances their translation.

A Case Report of Early-Onset Alzheimer's Disease Using 18F-FDG PET and 18F-FBB PET.

We describe a 40-year-old female patient who presented with sleep disturbance, intermittent headache, and gradual subjective cognitive decline. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed mild FDG hypometabolism in bilateral parietal and temporal lobes. However, 18F-florbetaben (FBB) amyloid PET revealed diffuse amyloid retention in the lateral temporal cortex, frontal cortex, posterior cingulate cortex/precuneus, parietal cortex, and cerebellum. This finding supports the clinical significance of amyloid imaging in diagnostic work-up of early-onset Alzheimer's disease (EOAD).

fNIRS Assessment during Cognitive Tasks in Elderly Patients with Depressive Symptoms.

This study aimed to investigate differences in prefrontal cortex activation between older adults with and without depressive symptoms during cognitive tasks using functional near-infrared spectroscopy (fNIRS). We examined 204 older participants without psychiatric or neurological disorders who completed the Geriatric Depression Scale, digit span, Verbal Fluency Test, and Stroop test. At the same time, prefrontal cortex activation was recorded using fNIRS. During the Stroop test, significantly reduced hemodynamics were observed in the depressive-symptom group. The mean accΔHbO2 of all channel averages was 0.14 µM in the control group and -0.75 µM in the depressive-symptom group (p = 0.03). The right hemisphere average was 0.13 µM and -0.96 µM, respectively (p = 0.02), and the left hemisphere average was 0.14 µM and -0.54 µM, respectively (p = 0.12). There was no significant difference in hemodynamic response (mean accΔHbO2) between the two groups during the digit span backward and VFT. In conclusion, reduced hemodynamics in the frontal cortex of the depressive-symptom group has been observed. The frontal fNIRS signal and the Stroop task may be used to measure depressive symptoms sensitively in the elderly.

Multifunctional Edible Oil-Impregnated Nanoporous Oxide Layer on AISI 304 Stainless Steel.

Slippery liquid-infused porous surface (SLIPS) realized on commercial materials provides various functionalities, such as corrosion resistance, condensation heat transfer, anti-fouling, de/anti-icing, and self-cleaning. In particular, perfluorinated lubricants infused in fluorocarbon-coated porous structures have showed exceptional performances with durability; however, they caused several issues in safety, due to their difficulty in degradation and bio-accumulation. Here, we introduce a new approach to create the multifunctional lubricant-impregnated surface with edible oils and fatty acid, which are also safe to human body and degradable in nature. The edible oil-impregnated anodized nanoporous stainless steel surface shows a significantly low contact angle hysteresis and sliding angle, which is similar with general surface of fluorocarbon lubricant-infused systems. The edible oil impregnated in the hydrophobic nanoporous oxide surface also inhibits the direct contact of external aqueous solution to a solid surface structure. Due to such de-wetting property caused by a lubricating effect of edible oils, the edible oil-impregnated stainless steel surface shows enhanced corrosion resistance, anti-biofouling and condensation heat transfer with reduced ice adhesion.

Sustainable production and degradation of plastics using microbes.

Plastics are indispensable in everyday life and industry, but the environmental impact of plastic waste on ecosystems and human health is a huge concern. Microbial biotechnology offers sustainable routes to plastic production and waste management. Bacteria and fungi can produce plastics, as well as their constituent monomers, from renewable biomass, such as crops, agricultural residues, wood and organic waste. Bacteria and fungi can also degrade plastics. We review state-of-the-art microbial technologies for sustainable production and degradation of bio-based plastics and highlight the potential contributions of microorganisms to a circular economy for plastics.